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Principal stress 2D vs 3D. Stationary vs time dependent solid mechanics

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Hi,

I have created a 3D model with the same boundary and initial condition as my 2D one in solid mechanics. when I solve the model time dependent, the principal stresses=0 in the 3D model (solid.sp1, 2,& 3), while the values in 2D model are logical. I checked all the steps and it looks exactly the same as my 2D model. This is while when I solve it stationary, the values are correct. However I dont want it to solve it stationary because it just solves for time 0 while I wanna couple it with my hydrology at different time steps and my hydrology condition is time dependent. I would greatly appreciate if someone could help me with this problem.

bests, Shirin


1 Reply Last Post Sep 25, 2017, 10:05 a.m. EDT
Jeff Hiller COMSOL Employee

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Posted: 7 years ago Sep 25, 2017, 10:05 a.m. EDT
Updated: 7 years ago Sep 25, 2017, 10:14 a.m. EDT

Hello Shirin, There must be some small difference between the two files. Without seeing them, the fact that your principal stresses are zero suggests that maybe the loads are not applied to any selection in the 3D model (A mistake I have made many times myself). But this is only a blind guess, so please consider posting the two files here. To keep them small, make sure to clear the solutions before saving.

Best, Jeff

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Jeff Hiller
Hello Shirin, There must be some small difference between the two files. Without seeing them, the fact that your principal stresses are zero suggests that maybe the loads are not applied to any selection in the 3D model (A mistake I have made many times myself). But this is only a blind guess, so please consider posting the two files here. To keep them small, make sure to clear the solutions before saving. Best, Jeff

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