Learning Forum

[shamik062]

Hello Everyone,

I am running a simple analysis of a simply supported beam with load at midpoint. Now I have modeled the beam with line body. The line body has two straight lines and load is applied at their junction. But whenever I am going to solve the model , "Invalid Boundary Condition" is popping up. I have applied two remote displacement to model Pinned and roller support. One is all free but Y displacement=0 and the other is All=0 but Rotation about Z=Free. Could not find out what I am doing wrong. How to solve this problem

I have attached an image of my boundary condition for better understanding.

Thanks in advance.

[peteroznewman]

Did you use Shared Topology in the Geometry Editor to connect the ends of each line to a common node at the center?

If not, you can use Node Merge under the Mesh Controls to merge the coincident nodes.

[shamik062]

Thanks Peter. Shared Topology solution worked. But what is the concept behind this shared topology in Geometry Editor? I mean since I have only single line body why the topology is not shared by default? 

Also I am getting a warning message like this one "Not enough constraints appear to be applied to prevent rigid body motion.  This may lead to solution warnings or errors.  Check results carefully." I am applying the force by component and the applied force has only Y Component and the beam displacement is completely constrained in Y direction. Though it will rotate about Z axis . But that is due to deformation , not rigid body motion. Then why this warning message is displaying? 

[peteroznewman]

You have two line bodies in Geometry. Just because they happen to have the same coordindates at each end, the software doesn't know if you want them connected or separate, so you have to tell it that you want it connected. A different model might need them separate.

ANSYS produces many warning messages and most of them can be safely ignored, as this one can because you know that you have no rigid body motion.