For the truss example of instability, where you assigned partial moments in truss members to remove instability, not only we released moments in truss members but we also let the members take shear in Z-direction, due to which static check is satisfied and instability is removed. Am i correct on this ? So , whenever we assign partial moment release, we not only allow minor moments to develop but we also allow full shear to develop on the truss members.. I hope i got it correctly.
Hi, I have a confusion about the beam/column displacement and deflection. IF the deflection (lateral displacement) check for a column (considering allowable L/400 for example) is pass using (DJ1,2), however at certain node along the column the node displacement (in Z direction in my case) for the same LC exceeds the allowable limit , then what is the use or purpose of the node displacements? What I understood from many Bentley communities discussion that DFF is applicable for beam (deflection) and column (displacement).
Not sure about this specific scenario. In general, local deflection values in three global axis are considered during actual deflection value calculation (dff) and then it is compared with allowable deflection limit (DFF) to find out the deflection ratio. There is no separate checks for beam or column, during steel design, all members are treated as a general member. When you specify DJ parameters, deflection length and local deflections are calculated considering that information and those members specified under this. You can go through this video (th-cam.com/video/hqqMsi1LNp0/w-d-xo.html) for more details about deflection check - though it is for IS800:2007 code, but the concept is same for all other international design code.
@@surojit_ghosh thanks for your reply. Sorry, I believe I was not clear enough, I meant to say the deflection check (dff and DFF) is clear for me in term of implementation in STAAD. But as the code requirements (most of the international codes) the lateral displacement check is required as well, here we have to check the global nodes displacements, my question is if I perform the deflection check for the columns, is this enough or I have to check the NODES displacements as well?
Sir, i am designing a steel truss 22m self supporting , mounted with both end with bolt M10x40. can you help me to design. i have made model. but i m facing error while post analysis
I have discussed about some of these parameters in this video - th-cam.com/video/LJEPFxBEyow/w-d-xo.html. I will post a detail video on these very soon.
Hello Mr. Surojit_ For shear connection in the beams cant we just provide My and Mz and releases and be done to get rid of the instability instead of the partial release? Another question is that if we give a partial release of the moments in either directions then how are we going to make sure that the provided relaxations in the moment are taken care in the connection design? Kindly find the time to revert on this
Yes Sandip, releasing the end moments (My and Mz) for shear connection is a common modelling technique. Complete release of My and Mz does not always cause instability. You can start modelling with full My and Mz release for shear connections, and if there is any instability for this release, then change that to partial release. But don't release Mx, that causes several problems. If you partially release the moments, then you need to ensure that the assigned connection has the capacity to transfer that moment. One solution- we can use the beam/weld group option available in RAM Connection Standalone to cross check the capacity of any connection. There are several other methods also to cross check the capacity of any joint.
MAY I GET YOUR CONTACT DETAIL IM MODELINGINGN A PARKING SHED IN THAT IM FACING INSTABILY IN MODEL STILL CAN YOU HELP ME ITS JUST A SIMPLE CANTILEVER PARKING SHED
You can post your query and upload your model in Bentley Communities (communities.bentley.com/products/ram-staad/f/ram-staad-forum#pifragment-25818=1) for review.
For the truss example of instability, where you assigned partial moments in truss members to remove instability, not only we released moments in truss members but we also let the members take shear in Z-direction, due to which static check is satisfied and instability is removed. Am i correct on this ? So , whenever we assign partial moment release, we not only allow minor moments to develop but we also allow full shear to develop on the truss members.. I hope i got it correctly.
Hi, I have a confusion about the beam/column displacement and deflection. IF the deflection (lateral displacement) check for a column (considering allowable L/400 for example) is pass using (DJ1,2), however at certain node along the column the node displacement (in Z direction in my case) for the same LC exceeds the allowable limit , then what is the use or purpose of the node displacements?
What I understood from many Bentley communities discussion that DFF is applicable for beam (deflection) and column (displacement).
Not sure about this specific scenario. In general, local deflection values in three global axis are considered during actual deflection value calculation (dff) and then it is compared with allowable deflection limit (DFF) to find out the deflection ratio. There is no separate checks for beam or column, during steel design, all members are treated as a general member. When you specify DJ parameters, deflection length and local deflections are calculated considering that information and those members specified under this.
You can go through this video (th-cam.com/video/hqqMsi1LNp0/w-d-xo.html) for more details about deflection check - though it is for IS800:2007 code, but the concept is same for all other international design code.
@@surojit_ghosh thanks for your reply. Sorry, I believe I was not clear enough, I meant to say the deflection check (dff and DFF) is clear for me in term of implementation in STAAD. But as the code requirements (most of the international codes) the lateral displacement check is required as well, here we have to check the global nodes displacements, my question is if I perform the deflection check for the columns, is this enough or I have to check the NODES displacements as well?
Sir, i am designing a steel truss 22m self supporting , mounted with both end with bolt M10x40. can you help me to design. i have made model. but i m facing error while post analysis
What is the error? Is it related to analysis or design?
Kindly make a video on all design parameters lx,ly, lz..etc as per is code and as well as American code...
Your videos are simply superb 👌 👏 👍 😍 🙌
I have discussed about some of these parameters in this video - th-cam.com/video/LJEPFxBEyow/w-d-xo.html. I will post a detail video on these very soon.
Effective length about y direction is called ly
Effective length about z direction but use local axis
Lx and ly is same in mostly lx use in bending strength find out
Hello Mr. Surojit_ For shear connection in the beams cant we just provide My and Mz and releases and be done to get rid of the instability instead of the partial release?
Another question is that if we give a partial release of the moments in either directions then how are we going to make sure that the provided relaxations in the moment are taken care in the connection design?
Kindly find the time to revert on this
Yes Sandip, releasing the end moments (My and Mz) for shear connection is a common modelling technique. Complete release of My and Mz does not always cause instability. You can start modelling with full My and Mz release for shear connections, and if there is any instability for this release, then change that to partial release. But don't release Mx, that causes several problems.
If you partially release the moments, then you need to ensure that the assigned connection has the capacity to transfer that moment. One solution- we can use the beam/weld group option available in RAM Connection Standalone to cross check the capacity of any connection. There are several other methods also to cross check the capacity of any joint.
thank you so much for such a great information
Fantastic explanation sir.thanks
Good presentation
Sir please make a video a double basement building challenges
I support
Thanks sir.
MAY I GET YOUR CONTACT DETAIL IM MODELINGINGN A PARKING SHED IN THAT IM FACING INSTABILY IN MODEL STILL CAN YOU HELP ME ITS JUST A SIMPLE CANTILEVER PARKING SHED
You can post your query and upload your model in Bentley Communities (communities.bentley.com/products/ram-staad/f/ram-staad-forum#pifragment-25818=1) for review.