Learning Forum

[jaffarsadaq96]

In ANSYS Mechanical APDL, I have a curved beam188 element and it has 3 springs attached at each end in x, y and z axes.

1) The other end of the springs in x-axis is left free whereas for the rest of the springs, the other end is fixed. In the 1st step I need to pull the beam (by applying displacement to the beam just to make it straight) at the two ends to make it straight.

2) In the next step, the free ends of the springs in x-axis are fixed and the displacement applied to the beam at it's two ends in the 1st step should be deleted so that the beam is still in straight position as we fixed the springs in x-axis.

3) In the next step, I need to apply displacement in the z-axis direction at the center node of the beam and find out the reaction force acting at that center node for the displacement given.

As the boundary conditions are different at different times, I am not sure how to apply those conditions. I got stuck and I am trying hard to solve it. Anyone please help me in this regard. Here I am attaching the code file and image for understanding the model.

Thanks in advance

CODE FILE.txt

[danielshaw]

How MAPDL performs a multi-step analysis is explained in Section 5.6 of the MAPDL Basic Analysis Guide.nYou just define the BCs for each load step. It appears that you have a multi-step solution with 3 load steps (probably at times 1, 2, and 3). You just define the BCs for load step 1 and solve that load step. then define the BCs for load step 2 and solve that load step, and finally define the BCs for load step 3 and solve that load step. The results file will contain the results for all 3 load steps. The key is to doing a multi-step analysis is not leave the /solu module between solves. Leaving the /solu module triggers a new solution. You would need to restart the analysis to continue from the previous solution(s).nHere is the approach:n/solu ! enter /solu modulentime,1n! apply BCsnsolventime,2n! apply BCsnsolventime,3n! apply BCsnsolvenfinish ! exit /solu modulen/post1nset,# ! identify load step to post-processnnNote: in most situations, once a BC is defined it stays defined for subsequent load steps, until you explicitly delete it or override it. It is not automatically deleted or reset to a default value. So, you may need to take this approach.nn/solu ! enter /solu modulentime,1n! apply BCs for load step 1nsolventime,2n! delete BCs from load step 1n! apply BCs for load step 2nsolventime,3n! delete BCs from load step 2n! apply BCs for load step 3nsolvenfinish ! exit /solu modulenset,# ! identify load step to post-processn

[mzhossain2001]

There are examples for time vs loads for Mechanical APDL in the Ansys help file. You may visit ansys help file for transient analysis details. You will need to apply BC in place of loads. That's it.n