What could be possible reason of singularity warnings shown in Message window?

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Answer: You can see the warning message below after analysis.


If you scroll up the window, You can find details about this warning message. According to the first warning message, something is wrong in the prestress load.



If you see the tendon property dialog, the input data is unreasonable. It might result from the mistake with the unit system.


As for the second warning message, there are singular warning messages, which means that your model is not stable in the 2nd stage. The FEM program like midas Civil checks the singularity regardless of the loading conditions. Thus, the model should be stable in the 3D condition. At the CS2 stage, the individual girder is stable in the 2D (X-Z plane) condition, but not in the 3D condition. Each girder has no resistance of the rotation about the global X axis and the global Z axis. In order to fix this, you should fix the RX dof for the left support and fix the DY dof for the right support of the girder.


After above modifications, the displacement will be normal.