Hello dear Dr. Dalyo, thank you for your great efforts! I have a radial turbine rotor, the geometry is a one file contains the blades and the shaft as a one part, I need to calculate the deformation as a result of the pressure distributed over the blades...will I consider the shaft as a fixed support and have I insert the rotating velocity ? Thanks
+Have a nice time! You mean as inlet conditions? Or you just want to do an unsteady compressible flow problem. Next time please write your fluent comments under my CFD videos.
Hello! Please could you make video about nonlinear upheaval buckling (buried pipe), and show also soil interaction. Or advice to find that information. Thank you!
ney mar Hi, that is actually a very complicated subject and problem to simulate exactly. Here is two articles I found that might help. brage.bibsys.no/xmlui/bitstream/handle/11250/182853/Ommundsen,%20Marius%20Loen.pdf?sequence=1 www.diva-portal.org/smash/get/diva2:648750/FULLTEXT01.pdf If all you need is just a plain buckling problem, say a straight pipe with contact on the ground, gravity load, and a force to buckle the pipe, i could do that. So i guess it depends on the degree of accuracy you want.
Thanks for you wonderful tutorial. Please could you make a video for a static linear and non linear analysis for a mechanical component and compare the result of both also explain how to validate the result weather it fails or passes regarding design point of view.
+DrDaylo Thank you for this informative video. I would like to ask the following queries related to command object which you mentioned in the video; (1) Why do we need to enter the stress-strain values? (2) You said to take few data points from the experimental data, why not take whole data points? (3) Shall we take the points randomly? or should be taken within linear region or non-linear region or both? (4) Are there any limits for the number of data points which can be used or taken from the original experimental data while entering the stress-strain values in the command object ? (5) I have data points from experimental curve but the total number of data points are around 460 for compression test of concrete material. Can I directly import the data points for command object from excel? Hope to hear from you soon thank you
Thank you for watching! Here are some answers: 1-In this case we need to enter the stress strain values to tell ansys what the stress is at certain strain values because the material is non-linear (and different in compression and tension). 2-Few data points because the more points you include the longer it will take to solve. 3-The command object only includes the non-linear region, the linear region is set with the youngs modulus E. And yes you should includes both the youngs modulus and the non-linear region 4-Not sure about the limits, however I think more than 10 would be excessive and take very long to compute. 5-I would strongly suggest to simplify the number of points to below 10, extract key points. Thanks!
Thanks a lot for this informative video sir. Actually I want to know how to give a strain rate in terms of mm/min on one end rather than a force. Can I again draw the stress and strain graph from the solution of this simulation.
Mantra Satpathy Your welcome! So i think what you could do is use the ANSYS Transient Structural module, and in the analysis settings, you could specify a time so say 1min, and then instead of applying a force as a loading condition, you could apply a "displacement" loading condition. So you could enter the displacement to be for example 1mm, and that would be at time 1min. You could also change this up and even change the rate at the next timestep. All this while still using a custom stress-strain curve if you like for the material is possible. You could plot afterwards the stress-strain output from specific nodes or elements. There is a graph functionality in ANSYS, but you could also just ask for strain and stress results individually and copy the values to excel and make the graph if you dont know how. Hope this helps, if not, feel free to ask more questions. Thanks,
excellent example sir, but i am a little confused about material because you are saying it is cast iron model even though at 2:06 the solid material is structural steel. In addition, could you explain more Commands (APDL) and why we need it? and could you please send me the data, sir?
+joe joe Hi, thats actually a very good question. When you add material data in the command object as I did in the video, this overrides the original material input of structural steel. So basically when the solver runs, it ignores the structural steel data and uses whats inside the command object instead. This is because Ansys workbench does not have all the functionality in an easy GUI format when compared to APDL. So some more advanced functions, such as cast iron table data is not easily found in workbench, so command objects must be used. I hope this answers your question! check your inbox for the data.
I'm just starting out with ansys static structural, and your videos are of great help. So thank you for these great videos! What I want to ask is why is the result for maximum principal stress not symmetric (considering that the compression force is perpendicular to the fixed area)? Is the material property varying across any axis or is it something else? Thanks!
I can see from the code that you have given "cast" to represent cast iron. But what would be the matid for Aluminum alloy NT? I am using Aluminum 7075 T6 to do uniaxial tensile tests. I am doing tests to break the object, so plasticity comes in.
thank you for this helpful video. I have two questions: how do you define nonlinear materials in ansys workbench? I didn't catch you very well. and is there any difference between nonlinear behavior and nonlinear materials?
+Abdell Abdell Well nonlinear material properties would give nonlinear behaviour. I would suggest using the ANSYS built in library, under Engineering Data- Engineering Data Source - General Non-linear materials. Here you could select from a general database of non-linear materials and modify from there. If you want to define a custom non-linear material, things get more complicated. You would have to add properties from the toolbox in the engineering data, and for non-linear behaviour, there are many different models. Some of the most common are Bilinear Isotropic Hardening or Multilinear Isotropic Hardening. Hope this helps, might be abit advanced.. Thanks for subscribing!
First of all Hello Dr. DalyO I m mechanical engineering student and I trying to understand some things like initial substep, max substep and large deflection, Convergence.. vs . What does it mean ? in the force convergence graphic , despite of you' ve entired 25 maxsubstep analysis ended up at the 22.step.. and let me ask you finally question.What does the initial substep benefit in our analysis? Thank you so much.
Unfortunately there is no other way. The only other option you could do is merge the solids into one part in designmodeler, then when you open in mechanical you can just use 1 command object for that "part". Hope this helps.
Sir thank you for this tutorial, Taumax is the 9th real constant of ansys, my question is can i put a TB command to define Taumax for a particular contact pair? ? if i can, than can you please tell me the procedure ?
shojib zaman Hi! Sure thing, so what you need to do is in workbench, under contacts, select your contact and right click, insert, and click commands. this will add a APDL command object under your contact you want to modify the taumax. Then click the command object and add the following line: RMODIF,cid,9,1e20 9 is for the 9th constant as you mentioned. cid is for asymmetric contact pair but you could also use tid for symmetric. the value of 1e20 is the default taumax value, so you could change this to whatever you want. I hope this helps! if so please like+subscribe! thanks.
Sir, can u please explain while applying the external load, you have given the input value of load as -2000psi in the y direction, which is transverse to the specimen (which is generally for the fluxural failure) but rather in the tensile testing (stress strain curves)we use the axial loads... And for the experimental stress strain curve for the cast iron, the ASTM stds generally follow the dumbbell shaped specimen,and you used some random model, so how far these results verify?
Hi, thank you for your comment. The purpose of the video was not to simulate a tensile test specimen bar. The model used in the video was arbitrary and was just supposed to show how to implement the cast iron model for any object. You could use the same method as shown in my tutorial and use your own geometry (so if you want, make an astm std test bar). I hope this answers your question. Please let me know if you need any further clarification. Thanks!
+DrDalyO thanks a lot for the reply I have 2 questions 1. You are using the data of the tensile test (axial loads), and applying the bending loads (transverse loads). 2. The specimen you modelled is not matched with original specimen but then also it shown good validation as comparable with the experimental data Thanks
1. Stress-strain data can be used for any type of loading. 2. Again, this is not a specimen test, just an arbitrary example. Also i am not validating any results to experimental data. Just showing that the input curve is being respected by the results.
Hi sir please explain how we can input non-linear properties directly in engineering data module and use it for generating non-linear load displacement curve
Hello Sir, thanks a lot for all the videos, please, l have a specific problem with [ The None Linear Analysis of Steel/Stainless Steel Concrete Filled Tubes under axial compression ], l have tried several times, but failed to get the Strain, Stress and all the Deformation curves, so l will really appreciate any help or any possible videos link, once again, thanks a lot for the good job you are doing
while running analysis it showing "" Solver pivot warnings or errors have been encountered during the solution. This is usually a result of an ill conditioned matrix possibly due to unreasonable material properties, an under constrained model, or contact related issues. Check results carefully.
I had the same problem, probably the problem is in the geometry's size, probably too small for the force apliced in this tutorial (2000 lb). Try putting a smaller force.
Hi, what if the material has transversely isotropic behaviour. How can we then input stress-strain data from the tensile testing on the 2 axises (one1 parallel to fibre direction and another perpendicular to fibre direction) to Ansys?
Максим Анженко appreciate the thanks! I dont think i understand your question however. This is used when trying to study the behavior of a cast iron material. The mechanical properties of this material are not usual (not as simple as steel). If you want to study the failure or safety factor of a cast iron part, you would use the method explained in my video. It is important to note that the results are usually not exact and must be verified with a failure test in a lab.
DrDalyO Thanks. I meant, did you invent the design of this object? Or is this object applied somewhere in real life? (in mechanical engineering or somewhere else)
Yes i just made up the design. Its not an actual component. If you would like I could make another video of an actual cast iron part, provided the geometry is not that complex.
Thanks a lot, that's exactly what I've been looking for, too! :-) So using the command option is the only way to implement the cast iron model? Or are there other ways to activate cast iron? Am I right that the v. Mises cylinder is used for compression and Rankine cube for tension? Is the material model suitable for simulating die-cast aluminum?
ThoralfG in ansys workbench yes, you have to use the command object. in APDL there is a built in menu for the cast iron model. No other way. not exactly sure about v mises and rankine. cast iron follows the modified mohr coulomb theory. I do not know enough about die-cast aluminum to answer your last question. heres an image for the modified mohr coulomb: image.slidesharecdn.com/freevideolecturesformca-141114100914-conversion-gate01/95/free-video-lectures-for-mca-15-638.jpg?cb=1415959909. Cheers! Hope this helps!
+Hari V Santhosh oh well depends. its only use is when you use the safety factor tool. in that case you can choose to use material properties or custom value, if you choose mat. prop. then you must input the ultimate properties in the eng. data section. if you choose custom, you enter the data right there. cast iron does not have a yield limit, so ultimate only applies for this.
thank you sir nice explanation question 1) what is the difference between convergence in 1) solution> (depend what we choose stress or strain) insert> convergence 2) and the convergence you explained. question 2) about which point convergence occur in 1 case? can we change that point ?
Hi. Can you please explain to me how do you determine whether to look at maximal principal stress or equivalent von-mises. If i use material from database Plastic, PA6 do i need to look at maximal principal stress or equivalent von-mises? Same question about strain, equivalent total or equivalent von-mises? And for stress tool which option should i choose for plastic PA6?
Thanks a lot for the details.. really helps.. Will the basic material definition becomes irrelevant after using this command? Where have you specified the "Yield Strength" of the material? When I try to evaluate the Safety Factor, error message comes : "Yield Strength is required but not defined".. can you help?
Thank you for your very helpful video! i'd like to model a functionally graded material but i couldn't manage to model an elasticity depending on the radius of a sphere with a function. Could you please help?
+deus.ex I do not have much experience with composite materials. Did you check all the possible material properties you could use in Engineering Data? if so, then you should look into using command objects and APDL commands to do this. I dont know much more. good luck, thanks for watching!
hi Dr, thank you for your videos. I have a question which I still dont get any answers. plz can you tell me how could I use stress strain curve for compression and tensin using Multilinear isotropic hardening
+SAID ABDI In engineering data, where you define your material, on the left hand side there is a toolbox with a bunch of different material properties you can add, you can right click on multilinear isotropic hardening and add it to your material or drag and drop it. Then you enter your custom curve for the data. Note that this data will be the same for compression and for tension.
good explanation. Can you send that ansys codes , shown in notepad . i would like to perform compressive behavior of metal. I have stress strain curve of compression testing . Is it enough ?
Hi! Thanks a lot for your tutorial. I have some questions. May you give me the material data relative to cast iron do you use in this tutorial? May you give the material you use in all other tutorials? I am traying to learn to use ansys but I don't have books to do this. May you suggest me some books? Thanks a lot Adriano
see the video description for the data file. You can check the online manual for ansys or watch the ansys channel for more info, or search google books for ansys tutorials
Hi, it's good video. I have a query about adaptive mesh region. I want to know that how to apply adaptive mesh region in 3d model. I know there is a option to pick and apply. But when I used to do so , I was getting error like Non linear tetrahedral etc. Also tell me how to change the element type so that I can easily apply it. Thanks
Hello, I want to increase a point load and accordingly want to find the stress strain curve. And also want to generate Moment-Rotation curve. Please can you help me?
+Harsh Naik did you check out my chart plot tutorial? th-cam.com/video/VdWIHfO9-Mc/w-d-xo.html In the solution branch, you could right click--insert--probe--moment reaction, which would give you the moment results. Im not sure exactly what it is your doing, but hopefully these things gives you a start! Thanks.
Great videos ! I'm trying to learn ANSYS as I was trained on ABAQUS, it really helps to see detailed videos like that. By the way, what does the Safety factor provide? Thanks
Hi there i want to know something, for example i have the option of parameter set on and i need to do 5 experiments with the same material but with different multilinear isotropic hardening for each one, is this posible?
+Gerardo Pulgar The only was you can parameterize the multilinear isotropic hardening is with a scale or offset. So you could have one stress-strain curve, and then scale it differently 5 times, and run the analysis that way. Otherwise, you would have to run each case manually without parameters (duplicate it in the project view), and set your different curves.
Hello DrDalyO, I have a question about cast iron model command: it works fine with compression, but when I try the same command file for tension, it captures only linear region and ANSYS gives error above linear region. The error message is: " Cast iron tension local NR algorithm does not converge for material 1" I tied small steps, stabilization=on and the warning message disappears but still no plastic region is simulated. The model is a simple Stress-Strain specimen. Do you have any idea, how to simulate plastic deformation using different tensile and compression Stress-Strain experimental data? (like cast iron) Thanks in advance.
+Zurab Shermadini i believe the code includes table data for different tension and compression commands no? If its not in this video please see my other one then and get back to me
Thanks a lot for the answer. Yes, the code includes data for different tension and compression commands. As I mentioned in the first comment, it works very fine for compression, and for tension ANSYS has a convergence problem. Then I used displacement instead of force and did the tension stimulation. The result is: it works, but for small strains (very near to elastic regions). Plastic tension data are not simulated The question is: Is there other way to input separately compression and tension data?
Would this work for PET material? I've got the stress-strain curve plot which doesn't have any linear region. If you think I can use this code, could you please send it to me? Thanks!
Bernat Mànuel González Hey, please check your inbox. The thing is the table data input method im using is just 5 data points. so the interpolation between them is linear. You dont want to input so many data points also because then the runtime to solve will be a lot longer. not sure if this is clear, but in short it should work. just simplify your stress-strain curve to a few points and input them. just make sure your youngs modulus is the same as the slope of your first data point, or else it will give an error. Good luck!
I have a problem with modeling concrete beam. I want to change element type and material characteristics using apdl commands but I am not familiar with them enough. Can you help me with this? I try to use video Modelling of RC beam with Ansys Workbench (Alaa Elsisi) as example, learn a lot but still have a problem. Where to put commands and something like that.
+Zarko Petrovic Are you doing an impact on concrete? if so you could use the explicit dynamics solver, and there in engineering data, open the materials library and look under explicit materials and choose CONC-35MPA as a starting point, and change the parameters from there. It seems like many people want a concrete beam tutorial, so I will prepare one. Maybe I could do it by next week, I will see. What exactly is your concrete beam problem? a beam on two supports with a press at the center on top? I assume with rebar? Thanks
+DrDalyO I am modeling two equal span concrete beam loaded with two static force in the middle of each span. I easily modeled beam and add rebar as link body as Alaa Elsisi suggested in his instruction. Instead of default element type I want to use Solid 65 for concrete and Link 180 (or 188) for rebar. I have to do that using apdl commands. In such case, changing of material properties is also by using apdl commands. I know what commands to use but when I specify element type inside Geometry branch and material properties inside Static structural branch workbench don't recognize my commands. Meanwhile I realized by watching some other instruction that maybe I need to activate apdl commands somehow.In further investigation my goal is to model concrete beam strengthened with frp material.Thanks for trying to help me.By the way your tutorials are very helpful.
+Zarko Petrovic Hi. Im happy my videos are helpful! If you are able to add a command object in the geometry branch, then ansys should recognize the commands unless there is an error with your input. If you have multiple bodies inside "Geometry" you have to add a command object to EACH one of the bodies (just copy paste the same lines of code). Try a simple scenario, create a block with a fixed support and load, and run with stainless steel and check the results, then add the command object with code and check to see again if its any different. This will save you time to debug your problem. Here is an example code (i believe the same from the person you mentioned above) to try out. This should work: ET,matid,SOLID65 MPDATA, EX,matid,,2e6 MPDATA, PRXY,matid,,0.25 TB,CONC,matid,1,9, TBTEMP,0 TBDATA,,0.2,0.8,3,30,, TBDATA,,,,,,, R,matid, , , , , , , RMORE, , , , , , , RMORE, , Best of luck! Let me know how it goes. Also, you are not the only one who is asking about RC beams. Doing it in static structural is possible more complicated than doing in in LS-DYNA.
Hi, i use almost the same geometry than you, but in my case it doesn't converge, what i have to modify to converge and have the solutions, should i increse the initial substeps, should i decrese the initial substeps, or maybe de maximum substeps, or modify something else? PD: very good videos
I repeated all you that but after made a model an error massage said solver pivot warnings or eror have been encountered during the solution (results of an I'll conditions matrix ) what should I do ? although I made force and fixed support
Hi. what does the tbtemp 71.6 mean? is it the temperature of the specimen during simulation? and what unit is that in? also, if i were to just use tension alone, how will that change any of the code for the commands APDL? thank you.
+ImJuStoOGoOd those are the temperature properties of the material data. the units can be checked in engineering data. if just tension, you should use isotropic bilinear or multilinear hardening rule in engineering data instead of using complicated command objects.
Hi Dr Dalyo, I am working on a Fluid Structure Interaction project which is a combination of Transient and Fluent. In transient, I have solid shell which has dimensions in micrometer scale. In fluent , i have fluid which flows at a velocity. When both the systems are combined, the result should show me a deformation in solid and how flow path of fluid changes. My question is, If I assign structural steel as the material to the solid shell, I have deformation which is visible and there is no distortion. But, solid shell is a viscoelastic material, which has very low Modulii (Bulk and Shear). If i assign this material, I have heavy distortion of cells (negative cell volume detected). Please help me in modelling this type of model when i assign viscoelastic properties to the structure. Thanks
Hello sir, thanks a lot for the good job. I will really appreciate a workbench video of axially loaded concrete-filled stainless steel tubes, I have difficulties finding the deformation curves. Thanks in advance.
Can you please send me the command file? As you mentioned multi-linear isotropic hardening model(MISO) in one of your comment. If I add tensile yield and ultimate separately along with stress strain graph through MISO in custom material, then will it cause me any problem? Or does adding stress strain graph automatically defines the tensile yield and ultimate values !!
hi drdalyo. the line tb,cast,matid,,,isotropic defines a cast iron model. what if i were to change the material to say, stainless steel. how do i change this line to make it into a steel model. please help. Thanks.
+ImJuStoOGoOd for stainless steel, its much simpler. dont use any command objects. just go into engineering data, and use stainless steel from there. if you want to add nonlinearity, just drop in a multilinear isotropic hardening parameter into the stainless steel details, and enter the data from there.
@@drdalyo Hello Drdalyo, I am using a custom material, and I tried with the multilinear isotropic hardening but the solution is much far off from the experimental data. I resorted to your method out of desperation can you help
Hi Dr Dalyo.. Thank you for the very informative video. I am simulating a PDMS finger and required a non-linear stress-strain curve. Can you please send me the data of your case study? Cheers!
why i need to use the commands to get the graph is there any other way i can get stress or energy graph from static structure on ansys? sorry i just learn to use this ansys
+ישראל הופמן matweb.com has a lot of information. just use a default aluminum from the material library and change the values with these from this site: www.matweb.com/search/datasheet.aspx?matguid=c0652f2efeac49b89b50e7e4c6fba759&ckck=1
I would like how to use a command object in Workbench and Cast Iron Table data to simulate the behavior.these data is how to be written by any soft ware and uploaded on commands pls.
Hi DrDalyo! i checked my inbox but the file was saved as jpg. so i cant copy and paste to command. can you please give us the text file? Thank you very much.
+Serdar AKBULUT I think i already deleted the project. you can follow the tutorial and make an archive yourself though! good luck, thanks for watching.
DrDalyO Can you also send me the code? I would really appreciate it. Also, I have a problem you can maybe help me deal with. I have a stress-strain model curve I should implement in ANSYS, that also has a linear descending branch (last part of the curve, from 0.15 to 0.2 strain value). As I know so far, ANSYS doesn't allow negative slope of any of the multilinear stress-strain line parts. Do you have some advise, how to cover that part?
Igor Dzolev I will send the code to your inbox. Im actually not sure how to do that. Most of the time you would convert your engineering stress-strain to the true stress-strain which would normally give a positive slope. And if it would go negative the material would fail anyway. You could maybe look into using different material properties in ansys such as the Mooney-Rivlin constants.
DrDalyO Thanks a lot. I will search for it to see how it works. Maybe it can be implemented by defining some kind of failure criteria. I will definitely need to dig deeper.
heoy shin You can either reduce the number of elements, so change the global mesh size or do not add a mesh refinement (this will reduce the accuracy of your results obviously), or you can also reduce the number of points used for the stress-strain curve, I think i used 5, but you could simplify it to say 3 data points which would also speed up the solution time. Let me know if this helps, if not i could go into more detail. Thanks,
U r d best dr. Of ansys on youtube
GREAT VIDEO....! This is what i have been looking for....
You are my hero !!!! this is amazing, Exactly what i was looking for and explained perfectly ! Thanks
is there any way to enter the stress/strain curve directly in Workbench (i.e. not using a command line like you did in this video)
It's very helpful. what parameters i should change the same cast iron to bear more load without failing? thank you!
You would need to change the stress-strain curve for cast iron
Hi DrDalyO if you could share the geometry again will be awesome because the only link we have is for the CODE, thanks for your videos
Hello dear Dr. Dalyo, thank you for your great efforts! I have a radial turbine rotor, the geometry is a one file contains the blades and the shaft as a one part, I need to calculate the deformation as a result of the pressure distributed over the blades...will I consider the shaft as a fixed support and have I insert the rotating velocity ? Thanks
Dear Dr. Dalyo, if we need to write a command to define unsteady pressure values, how can we do it? Thanks
+Have a nice time! You mean as inlet conditions? Or you just want to do an unsteady compressible flow problem.
Next time please write your fluent comments under my CFD videos.
Hello! Please could you make video about nonlinear upheaval buckling (buried pipe), and show also soil interaction. Or advice to find that information. Thank you!
ney mar
Hi, that is actually a very complicated subject and problem to simulate exactly. Here is two articles I found that might help.
brage.bibsys.no/xmlui/bitstream/handle/11250/182853/Ommundsen,%20Marius%20Loen.pdf?sequence=1
www.diva-portal.org/smash/get/diva2:648750/FULLTEXT01.pdf
If all you need is just a plain buckling problem, say a straight pipe with contact on the ground, gravity load, and a force to buckle the pipe, i could do that. So i guess it depends on the degree of accuracy you want.
DrDalyO yes I would greatly appreciate if you do that tutorial please
Thanks for you wonderful tutorial. Please could you make a video for a static linear and non linear analysis for a mechanical component and compare the result of both also explain how to validate the result weather it fails or passes regarding design point of view.
+SANKAR GUNAM I will add it to my list of videos to make. Thanks!
+DrDaylo Thank you for this informative video.
I would like to ask the following queries related to command object which you mentioned in the video;
(1) Why do we need to enter the stress-strain values?
(2) You said to take few data points from the experimental data, why not take whole data points?
(3) Shall we take the points randomly? or should be taken within linear region or non-linear region or both?
(4) Are there any limits for the number of data points which can be used or taken from the original experimental data while entering the stress-strain values in the command object ?
(5) I have data points from experimental curve but the total number of data points are around 460 for compression test of concrete material. Can I directly import the data points for command object from excel?
Hope to hear from you soon
thank you
Thank you for watching! Here are some answers:
1-In this case we need to enter the stress strain values to tell ansys what the stress is at certain strain values because the material is non-linear (and different in compression and tension).
2-Few data points because the more points you include the longer it will take to solve.
3-The command object only includes the non-linear region, the linear region is set with the youngs modulus E. And yes you should includes both the youngs modulus and the non-linear region
4-Not sure about the limits, however I think more than 10 would be excessive and take very long to compute.
5-I would strongly suggest to simplify the number of points to below 10, extract key points.
Thanks!
Thanks a lot for this informative video sir. Actually I want to know how to give a strain rate in terms of mm/min on one end rather than a force. Can I again draw the stress and strain graph from the solution of this simulation.
Mantra Satpathy Your welcome! So i think what you could do is use the ANSYS Transient Structural module, and in the analysis settings, you could specify a time so say 1min, and then instead of applying a force as a loading condition, you could apply a "displacement" loading condition. So you could enter the displacement to be for example 1mm, and that would be at time 1min. You could also change this up and even change the rate at the next timestep. All this while still using a custom stress-strain curve if you like for the material is possible. You could plot afterwards the stress-strain output from specific nodes or elements. There is a graph functionality in ANSYS, but you could also just ask for strain and stress results individually and copy the values to excel and make the graph if you dont know how.
Hope this helps, if not, feel free to ask more questions.
Thanks,
excellent example sir, but i am a little confused about material because you are saying it is cast iron model even though at 2:06 the solid material is structural steel. In addition, could you explain more Commands (APDL) and why we need it? and could you please send me the data, sir?
+joe joe Hi, thats actually a very good question. When you add material data in the command object as I did in the video, this overrides the original material input of structural steel. So basically when the solver runs, it ignores the structural steel data and uses whats inside the command object instead. This is because Ansys workbench does not have all the functionality in an easy GUI format when compared to APDL. So some more advanced functions, such as cast iron table data is not easily found in workbench, so command objects must be used. I hope this answers your question! check your inbox for the data.
+DrDalyO thanks a lot, i got it, sir...
I'm just starting out with ansys static structural, and your videos are of great help. So thank you for these great videos! What I want to ask is why is the result for maximum principal stress not symmetric (considering that the compression force is perpendicular to the fixed area)? Is the material property varying across any axis or is it something else? Thanks!
Really helpful. Can you please share the ANSYS manual link from there you copied the manual material code and Poisson's ratio code?
Thank you very much Dr.Dalyo. It was informative
Great tutorial on non-linear deformation. Why is the stress distribution non-uniform while the geometry is symmetric with respect to load?
I can see from the code that you have given "cast" to represent cast iron. But what would be the matid for Aluminum alloy NT? I am using Aluminum 7075 T6 to do uniaxial tensile tests. I am doing tests to break the object, so plasticity comes in.
thank you for this helpful video.
I have two questions:
how do you define nonlinear materials in ansys workbench? I didn't catch you very well. and is there any difference between nonlinear behavior and nonlinear materials?
+Abdell Abdell Well nonlinear material properties would give nonlinear behaviour. I would suggest using the ANSYS built in library, under Engineering Data- Engineering Data Source - General Non-linear materials. Here you could select from a general database of non-linear materials and modify from there.
If you want to define a custom non-linear material, things get more complicated. You would have to add properties from the toolbox in the engineering data, and for non-linear behaviour, there are many different models. Some of the most common are Bilinear Isotropic Hardening or Multilinear Isotropic Hardening.
Hope this helps, might be abit advanced..
Thanks for subscribing!
THANKS
@@drdalyo Hi sir, can I define non linearity within the yield point? If so which model is suitable? I wanted to edit in the engineering data itself.
First of all Hello Dr. DalyO
I m mechanical engineering student and I trying to understand some things like initial substep, max substep and large deflection, Convergence.. vs . What does it mean ? in the force convergence graphic , despite of you' ve entired 25 maxsubstep analysis ended up at the 22.step.. and let me ask you finally question.What does the initial substep benefit in our analysis? Thank you so much.
Hi this is a very helpful video. Do you know how to add commands to all solid at a time? Because I have quite a lot of solids.
Unfortunately there is no other way. The only other option you could do is merge the solids into one part in designmodeler, then when you open in mechanical you can just use 1 command object for that "part".
Hope this helps.
Hey! can you make video on Ansys commands and where to find them or how to script in Ansys command window.
Hello Dr.Plz could you model a prestressed concrete slab in a nonlinear case?
Sir thank you for this tutorial,
Taumax is the 9th real constant of ansys, my question is can i put a TB command to define Taumax for a particular contact pair? ? if i can, than can you please tell me the procedure ?
shojib zaman Hi! Sure thing, so what you need to do is in workbench, under contacts, select your contact and right click, insert, and click commands. this will add a APDL command object under your contact you want to modify the taumax. Then click the command object and add the following line: RMODIF,cid,9,1e20
9 is for the 9th constant as you mentioned. cid is for asymmetric contact pair but you could also use tid for symmetric. the value of 1e20 is the default taumax value, so you could change this to whatever you want.
I hope this helps! if so please like+subscribe! thanks.
Sir, can u please explain while applying the external load, you have given the input value of load as -2000psi in the y direction, which is transverse to the specimen (which is generally for the fluxural failure) but rather in the tensile testing (stress strain curves)we use the axial loads... And for the experimental stress strain curve for the cast iron, the ASTM stds generally follow the dumbbell shaped specimen,and you used some random model, so how far these results verify?
Hi, thank you for your comment. The purpose of the video was not to simulate a tensile test specimen bar. The model used in the video was arbitrary and was just supposed to show how to implement the cast iron model for any object. You could use the same method as shown in my tutorial and use your own geometry (so if you want, make an astm std test bar).
I hope this answers your question. Please let me know if you need any further clarification.
Thanks!
+DrDalyO thanks a lot for the reply
I have 2 questions
1. You are using the data of the tensile test (axial loads), and applying the bending loads (transverse loads).
2. The specimen you modelled is not matched with original specimen
but then also it shown good validation as comparable with the experimental data
Thanks
1. Stress-strain data can be used for any type of loading.
2. Again, this is not a specimen test, just an arbitrary example. Also i am not validating any results to experimental data. Just showing that the input curve is being respected by the results.
+DrDalyO thanks again, I got it.
Hi sir please explain how we can input non-linear properties directly in engineering data module and use it for generating non-linear load displacement curve
Hello Sir, thanks a lot for all the videos, please, l have a specific problem with [ The None Linear Analysis of Steel/Stainless Steel Concrete Filled Tubes under axial compression ], l have tried several times, but failed to get the Strain, Stress and all the Deformation curves, so l will really appreciate any help or any possible videos link, once again, thanks a lot for the good job you are doing
sir, should i have to adopt the same method for simulating the fracture of glass subjected to compression.
while running analysis it showing ""
Solver pivot warnings or errors have been encountered during the solution. This is usually a result of an ill conditioned matrix possibly due to unreasonable material properties, an under constrained model, or contact related issues. Check results carefully.
I had the same problem, probably the problem is in the geometry's size, probably too small for the force apliced in this tutorial (2000 lb). Try putting a smaller force.
Hii the video was great. I have a query that how can i find those compression and tension values for aluminium aloy?
How can you apply loads for a limited area given the entire surface of a model in ANSYS?
how do you get the commands? by using mechanical ADSL?
By reading the help documentation
Hi, what if the material has transversely isotropic behaviour. How can we then input stress-strain data from the tensile testing on the 2 axises (one1 parallel to fibre direction and another perpendicular to fibre direction) to Ansys?
Thanks for the video! Could you tell me where this detail can be used?
Максим Анженко appreciate the thanks! I dont think i understand your question however. This is used when trying to study the behavior of a cast iron material. The mechanical properties of this material are not usual (not as simple as steel). If you want to study the failure or safety factor of a cast iron part, you would use the method explained in my video. It is important to note that the results are usually not exact and must be verified with a failure test in a lab.
DrDalyO Thanks. I meant, did you invent the design of this object? Or is this object applied somewhere in real life? (in mechanical engineering or somewhere else)
Yes i just made up the design. Its not an actual component. If you would like I could make another video of an actual cast iron part, provided the geometry is not that complex.
Thanks a lot, that's exactly what I've been looking for, too! :-) So using the command option is the only way to implement the cast iron model? Or are there other ways to activate cast iron? Am I right that the v. Mises cylinder is used for compression and Rankine cube for tension? Is the material model suitable for simulating die-cast aluminum?
ThoralfG in ansys workbench yes, you have to use the command object. in APDL there is a built in menu for the cast iron model. No other way. not exactly sure about v mises and rankine. cast iron follows the modified mohr coulomb theory. I do not know enough about die-cast aluminum to answer your last question. heres an image for the modified mohr coulomb: image.slidesharecdn.com/freevideolecturesformca-141114100914-conversion-gate01/95/free-video-lectures-for-mca-15-638.jpg?cb=1415959909. Cheers! Hope this helps!
very helpful tutorial.
do you think we need to change the tensile yield strength and compressive yield strength values ?
For the rebar?
+DrDalyO you said u have to change the tensile strength & compressive strength values in material props
+Hari V Santhosh oh well depends. its only use is when you use the safety factor tool. in that case you can choose to use material properties or custom value, if you choose mat. prop. then you must input the ultimate properties in the eng. data section. if you choose custom, you enter the data right there. cast iron does not have a yield limit, so ultimate only applies for this.
Ok thankyou
the value entered in safety factor is yield strength of the material?
+Ammad Yousuf well for cast iron there is no yield point, only ultimate strength. So the safety factor is calculated from that
thank you sir nice explanation
question 1) what is the difference between convergence in 1) solution> (depend what we choose stress or strain) insert> convergence
2) and the convergence you explained.
question 2) about which point convergence occur in 1 case? can we change that point ?
Hi. Can you please explain to me how do you determine whether to look at maximal principal stress or equivalent von-mises. If i use material from database Plastic, PA6 do i need to look at maximal principal stress or equivalent von-mises? Same question about strain, equivalent total or equivalent von-mises?
And for stress tool which option should i choose for plastic PA6?
nice video please what different between "tbtemp,71.6 & tbpt,,"
Thanks a lot for the details.. really helps..
Will the basic material definition becomes irrelevant after using this command?
Where have you specified the "Yield Strength" of the material? When I try to evaluate the Safety Factor, error message comes : "Yield Strength is required but not defined".. can you help?
Thank you for your very helpful video! i'd like to model a functionally graded material but i couldn't manage to model an elasticity depending on the radius of a sphere with a function. Could you please help?
+deus.ex I do not have much experience with composite materials. Did you check all the possible material properties you could use in Engineering Data? if so, then you should look into using command objects and APDL commands to do this. I dont know much more. good luck, thanks for watching!
hi Dr, thank you for your videos. I have a question which I still dont get any answers. plz can you tell me how could I use stress strain curve for compression and tensin using Multilinear isotropic hardening
+SAID ABDI In engineering data, where you define your material, on the left hand side there is a toolbox with a bunch of different material properties you can add, you can right click on multilinear isotropic hardening and add it to your material or drag and drop it. Then you enter your custom curve for the data. Note that this data will be the same for compression and for tension.
thank you for wonderfull vidio its really help me can i get cast iron stress strain data
+akash patel Please see the description of the video, the link should be provided
Hello, can you include the geometry file. Thanks
good explanation. Can you send that ansys codes , shown in notepad . i would like to perform compressive behavior of metal. I have stress strain curve of compression testing . Is it enough ?
see the video description for the data file.
Hi! Thanks a lot for your tutorial. I have some questions. May you give me the material data relative to cast iron do you use in this tutorial? May you give the material you use in all other tutorials? I am traying to learn to use ansys but I don't have books to do this. May you suggest me some books? Thanks a lot Adriano
see the video description for the data file. You can check the online manual for ansys or watch the ansys channel for more info, or search google books for ansys tutorials
Hi, it's good video. I have a query about adaptive mesh region. I want to know that how to apply adaptive mesh region in 3d model. I know there is a option to pick and apply. But when I used to do so , I was getting error like Non linear tetrahedral etc. Also tell me how to change the element type so that I can easily apply it.
Thanks
Hello, I want to increase a point load and accordingly want to find the stress strain curve. And also want to generate Moment-Rotation curve. Please can you help me?
+Harsh Naik did you check out my chart plot tutorial? th-cam.com/video/VdWIHfO9-Mc/w-d-xo.html
In the solution branch, you could right click--insert--probe--moment reaction, which would give you the moment results. Im not sure exactly what it is your doing, but hopefully these things gives you a start!
Thanks.
Great videos ! I'm trying to learn ANSYS as I was trained on ABAQUS, it really helps to see detailed videos like that.
By the way, what does the Safety factor provide?
Thanks
please give the link to download ansys manual data
Hi there i want to know something, for example i have the option of parameter set on and i need to do 5 experiments with the same material but with different multilinear isotropic hardening for each one, is this posible?
+Gerardo Pulgar The only was you can parameterize the multilinear isotropic hardening is with a scale or offset. So you could have one stress-strain curve, and then scale it differently 5 times, and run the analysis that way. Otherwise, you would have to run each case manually without parameters (duplicate it in the project view), and set your different curves.
Hello DrDalyO, I have a question about cast iron model command:
it works fine with compression, but when I try the same command file for tension, it captures only linear region and ANSYS gives error above linear region. The error message is: " Cast iron tension local NR algorithm does not converge for material 1"
I tied small steps, stabilization=on and the warning message disappears but still no plastic region is simulated.
The model is a simple Stress-Strain specimen.
Do you have any idea, how to simulate plastic deformation using different tensile and compression Stress-Strain experimental data? (like cast iron)
Thanks in advance.
+Zurab Shermadini i believe the code includes table data for different tension and compression commands no? If its not in this video please see my other one then and get back to me
Thanks a lot for the answer. Yes, the code includes data for different tension and compression commands. As I mentioned in the first comment, it works very fine for compression, and for tension ANSYS has a convergence problem.
Then I used displacement instead of force and did the tension stimulation. The result is: it works, but for small strains (very near to elastic regions). Plastic tension data are not simulated
The question is: Is there other way to input separately compression and tension data?
Hello. If I should check the residual stress/strain in raw cast part, how should I proceed? Should I use fluent too?
thanks.
Excellent tutorial!
hello Dr how can i put a quasi static force , help me .
Hi, can you pleas forward me, resource on how to apply a multi step loading on my structure, for fatigue analysis? Thank you
Would this work for PET material? I've got the stress-strain curve plot which doesn't have any linear region. If you think I can use this code, could you please send it to me? Thanks!
Bernat Mànuel González Hey, please check your inbox. The thing is the table data input method im using is just 5 data points. so the interpolation between them is linear. You dont want to input so many data points also because then the runtime to solve will be a lot longer. not sure if this is clear, but in short it should work. just simplify your stress-strain curve to a few points and input them. just make sure your youngs modulus is the same as the slope of your first data point, or else it will give an error.
Good luck!
Hi Could you please send me the command to define the nonlinear material properties. thanks!!!
see the video description for the data file.
I have a problem with modeling concrete beam. I want to change element type and material characteristics using apdl commands but I am not familiar with them enough. Can you help me with this? I try to use video Modelling of RC beam with Ansys Workbench (Alaa Elsisi) as example, learn a lot but still have a problem. Where to put commands and something like that.
+Zarko Petrovic Are you doing an impact on concrete? if so you could use the explicit dynamics solver, and there in engineering data, open the materials library and look under explicit materials and choose CONC-35MPA as a starting point, and change the parameters from there.
It seems like many people want a concrete beam tutorial, so I will prepare one. Maybe I could do it by next week, I will see.
What exactly is your concrete beam problem? a beam on two supports with a press at the center on top? I assume with rebar?
Thanks
+DrDalyO I am modeling two equal span concrete beam loaded with two static force in the middle of each span. I easily modeled beam and add rebar as link body as Alaa Elsisi suggested in his instruction. Instead of default element type I want to use Solid 65 for concrete and Link 180 (or 188) for rebar. I have to do that using apdl commands. In such case, changing of material properties is also by using apdl commands. I know what commands to use but when I specify element type inside Geometry branch and material properties inside Static structural branch workbench don't recognize my commands. Meanwhile I realized by watching some other instruction that maybe I need to activate apdl commands somehow.In further investigation my goal is to model concrete beam strengthened with frp material.Thanks for trying to help me.By the way your tutorials are very helpful.
+Zarko Petrovic Hi. Im happy my videos are helpful! If you are able to add a command object in the geometry branch, then ansys should recognize the commands unless there is an error with your input. If you have multiple bodies inside "Geometry" you have to add a command object to EACH one of the bodies (just copy paste the same lines of code).
Try a simple scenario, create a block with a fixed support and load, and run with stainless steel and check the results, then add the command object with code and check to see again if its any different. This will save you time to debug your problem. Here is an example code (i believe the same from the person you mentioned above) to try out. This should work:
ET,matid,SOLID65
MPDATA, EX,matid,,2e6
MPDATA, PRXY,matid,,0.25
TB,CONC,matid,1,9,
TBTEMP,0
TBDATA,,0.2,0.8,3,30,,
TBDATA,,,,,,,
R,matid, , , , , , ,
RMORE, , , , , , ,
RMORE, ,
Best of luck! Let me know how it goes.
Also, you are not the only one who is asking about RC beams. Doing it in static structural is possible more complicated than doing in in LS-DYNA.
+Zarko Petrovic I might do a video on RC beams to clarify your question, as well as others.
Hi, i use almost the same geometry than you, but in my case it doesn't converge, what i have to modify to converge and have the solutions, should i increse the initial substeps, should i decrese the initial substeps, or maybe de maximum substeps, or modify something else?
PD: very good videos
I repeated all you that but after made a model an error massage said solver pivot warnings or eror have been encountered during the solution (results of an I'll conditions matrix ) what should I do ?
although I made force and fixed support
Hi. what does the tbtemp 71.6 mean? is it the temperature of the specimen during simulation? and what unit is that in?
also, if i were to just use tension alone, how will that change any of the code for the commands APDL? thank you.
+ImJuStoOGoOd those are the temperature properties of the material data. the units can be checked in engineering data. if just tension, you should use isotropic bilinear or multilinear hardening rule in engineering data instead of using complicated command objects.
Hi, could you possibly make a video on how to better understand and use the ansys manual for different situations.
Excellent !!!
Hi!
do you have any tutorial of how to model a RBS?
hello sir can i get the code for entering the value in si units...?
+Gopalkrishna Kulkarni I dont have them is SI units, but its easy to convert them!
Hi Dr Dalyo,
I am working on a Fluid Structure Interaction project which is a combination of Transient and Fluent.
In transient, I have solid shell which has dimensions in micrometer scale.
In fluent , i have fluid which flows at a velocity.
When both the systems are combined, the result should show me a deformation in solid and how flow path of fluid changes.
My question is,
If I assign structural steel as the material to the solid shell, I have deformation which is visible and there is no distortion.
But, solid shell is a viscoelastic material, which has very low Modulii (Bulk and Shear). If i assign this material, I have heavy distortion of cells (negative cell volume detected).
Please help me in modelling this type of model when i assign viscoelastic properties to the structure.
Thanks
Hi DrDalyO, I'm trying to run a similar test on basalt fibers, may I know how you obtained the strain equation for your simulation?
Hello there can you send me data and if possible which ANSYS manual should I refer for APDL command
see the video description for the data file.
Hello sir, thanks a lot for the good job. I will really appreciate a workbench video of axially loaded concrete-filled stainless steel tubes, I have difficulties finding the deformation curves. Thanks in advance.
Can you please send me the command file? As you mentioned multi-linear isotropic hardening model(MISO) in one of your comment. If I add tensile yield and ultimate separately along with stress strain graph through MISO in custom material, then will it cause me any problem? Or does adding stress strain graph automatically defines the tensile yield and ultimate values !!
The command file should be in the description of the video!
very helpful video ! can you share the table data please?
awesome tutorial, thanks !! :)
+Mike García thank you! please see your inbox.
Dear Dr. Dalyo, great tutorial! I was wondering if you have the curve data for class 30 cast iron. Could you send the data to me, please?
hi drdalyo. the line tb,cast,matid,,,isotropic defines a cast iron model. what if i were to change the material to say, stainless steel. how do i change this line to make it into a steel model. please help. Thanks.
+ImJuStoOGoOd for stainless steel, its much simpler. dont use any command objects. just go into engineering data, and use stainless steel from there. if you want to add nonlinearity, just drop in a multilinear isotropic hardening parameter into the stainless steel details, and enter the data from there.
@@drdalyo Hello Drdalyo, I am using a custom material, and I tried with the multilinear isotropic hardening but the solution is much far off from the experimental data. I resorted to your method out of desperation can you help
Hi Dr Dalyo.. Thank you for the very informative video. I am simulating a PDMS finger and required a non-linear stress-strain curve. Can you please send me the data of your case study? Cheers!
+Macca Ghani see inbox!
why i need to use the commands to get the graph
is there any other way i can get stress or energy graph from static structure on ansys?
sorry i just learn to use this ansys
Hi, where i can get the data about Aluminium 1100?
+ישראל הופמן matweb.com has a lot of information. just use a default aluminum from the material library and change the values with these from this site: www.matweb.com/search/datasheet.aspx?matguid=c0652f2efeac49b89b50e7e4c6fba759&ckck=1
I would like how to use a command object in Workbench and Cast Iron Table data to simulate the behavior.these data is how to be written by any soft ware and uploaded on commands pls.
hi ,I'm working on aeroelastic. thank you so much for this useful video,may i have the data ?
see the video description for the data file.
hi, i need non linear material properties which u hav used here... can u please send it here
ananth .... Please check your youtube inbox, i sent you the file.
Any code for model soil / clay ?
Dont have, please check online
Please, could you send me the code data that have been used in this tutorial
see the video description for the data file.
Hi , Can you please send the data file.
Hi,
i will also need a data cause Im getting an error. Tnx
+Sanjin Dragičević Please see your inbox! Thanks!
Hi DrDalyo! i checked my inbox but the file was saved as jpg. so i cant copy and paste to command. can you please give us the text file? Thank you very much.
+ars descano check your inbox
Hi. Please, could you send me the code data that have been used in this tutorial
see the video description for the data file.
Dr. Dalyo, do you mind sending me the command files for this video? Thanks.
see the video description for the data file.
Hi mate , thanks a lot for the video.. Can you please share the data ??
see the video description for the data file.
hey thanks for it, can i have archive file?
+Serdar AKBULUT I think i already deleted the project. you can follow the tutorial and make an archive yourself though!
good luck, thanks for watching.
good job man
Hi can you send the code please.
please see the description. updated with the code now.
can i get the cad model pls thank u
see the video description for the data file.
This is what I have been looking for, thank you !! Could you post the code please ?? Thanks again dude !!
Dr.Dre Hey no problem! ill send it to you via PM. check your inbox. please subscribe and like :) thanks.
DrDalyO Can you also send me the code? I would really appreciate it.
Also, I have a problem you can maybe help me deal with.
I have a stress-strain model curve I should implement in ANSYS, that also has a linear descending branch (last part of the curve, from 0.15 to 0.2 strain value). As I know so far, ANSYS doesn't allow negative slope of any of the multilinear stress-strain line parts.
Do you have some advise, how to cover that part?
Igor Dzolev I will send the code to your inbox.
Im actually not sure how to do that. Most of the time you would convert your engineering stress-strain to the true stress-strain which would normally give a positive slope. And if it would go negative the material would fail anyway. You could maybe look into using different material properties in ansys such as the Mooney-Rivlin constants.
DrDalyO Thanks a lot. I will search for it to see how it works. Maybe it can be implemented by defining some kind of failure criteria. I will definitely need to dig deeper.
Hey great video. :) Could u pls share the data file?
see the video description for the data file.
thank you very much for your help, it's very helpful video thk u :)))))
hi, can i know how to reduce the time taken when i get the solution?
heoy shin You can either reduce the number of elements, so change the global mesh size or do not add a mesh refinement (this will reduce the accuracy of your results obviously), or you can also reduce the number of points used for the stress-strain curve, I think i used 5, but you could simplify it to say 3 data points which would also speed up the solution time. Let me know if this helps, if not i could go into more detail. Thanks,
Thanks a lot. Very helpful! Could you pls send me the data, too?
see the video description for the data file.
Thanks a lot. Could u share me the data?
see the video description for the data file.
Hey could you send me the data too please? Thanks
see the video description for the data file.
Can u send the data pls ?
see the video description for the data file.