I have added here a repository for the excel file with all the equation for spherical shell buckling from the video: github.com/hnrwagner/Sphere_Pressure/blob/main/Shell_Buckling_002.xlsx
sir parabolic space seeing steel framed with glass roof of L=35M with Bow Height of 5.5M can you pleas make a video on above example for bulking analysis.
thank you sir for this innteresting video,sir i have one question about riks method, sir i have modeled hollow sphere under internel pressure uding hyperfoma material, my problem i dont know how plot pressure fonction deformed raduis ,and i need the curve after reache max pressure decrases
@@hnrwagner Thanks a lot Prof for the reply..Can we use this same relation for calculating buckling pressure in case of "elliptical" shells as well (for input in non linear analysis)?
Dr. Wagner, why for GNA model error between the analytical solution and the numerical is almost 20%? But the LBA model works really good. Can we explain it from the theory?
Hello Dr. Wagner, thank you so much for this video. How do you create a GNA model with initial imperfection? Do you use a python script to input it in Abaqus?
Hello Dr Ronald, how would we analyze the exact spherical shell but with varying thickness from the apex starting with 200mm thick at the top and to the base where the thickness is 700mm
The shell has a radius of 90 mm :) do you really mean 200 mm shell thickness ? otherwise, in the case of a varying thickness, the most sensitive part will be the apex with the minimum thickness and it will buckle there first. I will make a video about it, because i think its very interesting and i have never done it. Thanks.
@@hnrwagner my deepest apologies i have internet issues at home and im only seeing your messages, these are the details for my spherical dome: * Plan Diameter: D = 60m * Rise of dome: = 8.04m * Radius of spherical shell: = 60m *Minimum shell thickness (at crest) = 200mm * Radius-to-thickness ratio (at crest) = 300 * Support angle = 30 degrees The loading is hydrostatic pressure because im trying to analyse the buckling loads using eigen-solutions for the dome supporting water above and therefore the pressure at the apex of the dome is 0kpa and at the base of the dome is 10kpa.
I have updated the video with timecodes for better and faster overview:
Timecodes:
0:00 - Intro
0:44 - Analytical Buckling Analysis
5:09 - Create CAE model in ABAQUS
6:57 - Define Material data, Assign Material and Thickness
7:53 - Assembly definition
8:00 - Define Analysis Step (Linear Buckling)
8:20 - Create Boundary Conditions and Loading
9:21 - Mesh
9:53 - Create Job 1 - Linear Buckling
10:10 - Create Nonlinear Analysis (Riks)
10:47 - Modify Pressure Load
11:07 - Create Job 2 - Non-Linear Buckling
11:25 - Modify Output (Pressure)
12:38 - Create Models with dimple Imperfection
16:30 - Create Models with cutout Imperfection
20:47 - Numerical results (linear)
21:50 - Comparison with analytical solution
22:45 - Numerical results (nonlinear)
24:05 - Numerical results (dimple)
25:50 - Numerical results (cutout)
27:00 - Numerical results (real measured imperfections)
I have added here a repository for the excel file with all the equation for spherical shell buckling from the video:
github.com/hnrwagner/Sphere_Pressure/blob/main/Shell_Buckling_002.xlsx
what kind of tutorial with spherical shells you want to see next ? comment below !
sir parabolic space seeing steel framed with glass roof of L=35M with Bow Height of 5.5M can you pleas make a video on above example for bulking analysis.
@@sajidsarabi5748 I need a reference/paper or atleast a figure
@@hnrwagner oky i will share in a pdf file so please send me email or any other means to share the file.
@@sajidsarabi5748 ro.wagner@tu-braunschweig.de
thank you sir for this innteresting video,sir i have one question about riks method,
sir i have modeled hollow sphere under internel pressure uding hyperfoma material, my problem i dont know how plot pressure fonction deformed raduis ,and i need the curve after reache max pressure decrases
Hi Prof, Please let me know why 1 MPa pressure value was inserted for Linear analysis instead of 23.5 MPa?
You usually dont know the load beforehand, that why you use 1 and get the linear load
@@hnrwagner Thanks a lot Prof for the reply..Can we use this same relation for calculating buckling pressure in case of "elliptical" shells as well (for input in non linear analysis)?
Dr. Wagner, why for GNA model error between the analytical solution and the numerical is almost 20%? But the LBA model works really good. Can we explain it from the theory?
Nonlinear geometry reduces buckling pressure by 20 % for this particular shell configuration
Sir, How do we plot the volume of the whole model with respect to arc length
Hello Dr. Wagner, thank you so much for this video. How do you create a GNA model with initial imperfection? Do you use a python script to input it in Abaqus?
no I got this one from a chinese research grp, it was already an input file
a video for artifical imperfections is given here:
th-cam.com/video/-8G1Eh1B0CU/w-d-xo.html
Hello Prof. Wagner, is it possible to have some tutorials about FSI Simulation in Abaqus?
not likely because I have never worked with it, I am a structural engineer first :)
Hello Dr Ronald, how would we analyze the exact spherical shell but with varying thickness from the apex starting with 200mm thick at the top and to the base where the thickness is 700mm
The shell has a radius of 90 mm :) do you really mean 200 mm shell thickness ?
otherwise, in the case of a varying thickness, the most sensitive part will be the apex with the minimum thickness and it will buckle there first. I will make a video about it, because i think its very interesting and i have never done it. Thanks.
the video for it will release 12.02.2021
here it is:
th-cam.com/video/1vD1XwKcXdk/w-d-xo.html
@@hnrwagner my deepest apologies i have internet issues at home and im only seeing your messages, these are the details for my spherical dome:
* Plan Diameter: D = 60m
* Rise of dome: = 8.04m
* Radius of spherical shell: = 60m
*Minimum shell thickness (at crest) = 200mm
* Radius-to-thickness ratio (at crest) = 300
* Support angle = 30 degrees
The loading is hydrostatic pressure because im trying to analyse the buckling loads using eigen-solutions for the dome supporting water above and therefore the pressure at the apex of the dome is 0kpa and at the base of the dome is 10kpa.
@@hnrwagner thank you i will go over it