In the attached model, i have assigned the Rod Bracing as "Tension Member". But it fails in compression. What is the reason & what is the solution, please clarify.2. JB_053_20_B01_Tyre Curing Press Bldg._R00 (Meghna Innova Rubber Co. Ltd.)(Proposed Bracing).zip
The explanation to this issue can be found here: https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/26838/compression-force-developed-in-tension-members
Thanks a lot for your link. But i have not got yet my answer. I have ignored slenderness check in my model, and i have also given the load as Repeat load, in spite of that, it fails in compression. A picture is attached herewith for your review. Staad Model was also attached previously.
I am still waiting for you answer.
If a tension-only member is vertical or sloping, the selfweight of the member will induce a varying axial force which will be zero at the top node and compressive at the bottom node. In combination cases where the selfweight load case is a component, this will cause the axial force to be tensile at the top and compressive at the bottom. In such cases, the nature of the force at the 2 ends cannot be used as a criteria to decide if the member is in tension or in compression. So, the program uses the sign of force at the mid-point of the member.
Member 294 in your model seems to belong to this category. For load case 145, find the force in the middle by taking the average of the forces at the start and at the end. If it is a negative value, then, the member is considered to be in tension.
However, during steel design, the member has to be designed for the forces at the start node as well as the end node. At the end which is in compression, the member is checked against the AISC clauses for compression.
Thanks for your reply. But, as per your comments i toggle the self weight of the tension members, but it fails again in compression. I have also taken the average of the forces at the start and at the end. And it is a negative value. So, the member should be considered as tension members. But why it fails again in compression? When i increase the size of the members then it passes. But why in given size its behaving such like. What is the solution of this? How can i pass this members without increasing size? Staad model is attached again for your kind review.Tyre Curing Press Bldg..std