Hi all,
I am working on my first Simscale project. I am designing a box-like pressure hull with internal support structure for a battery pack for an AUV. The reason I try using Simscale is because I want to have more control over the meshing algorithm and solvers.
This model has 3 symmetric planes, X-Z, Y-Z, and X-Y. Thus, the FEA model includes only one-eighth of the full model.
The constraints I set are 3 symmetric planes on cross-sectioned surfaces of the pressure hull and the internal support structure (which made from POM).
This excepts 3 surfaces of supporting columns of the internal structure which I set them to fixed supports, to keep the calculation stable.
Also, the pressure hull has mounting holes for installing on a rack. I set surfaces of these holes, which are supposed to be supported by bolts, to fixed supports.
The contact surfaces between the lid of the pressure hull and the internal structure are set to physical contact with penalty method to allow for separation, but not intrusion.
For forces, I exert clamping forces on the bolted joints in the first time step and then ramp up pressure on the wetted surfaces of the pressure hull in later time steps.
I tried quite similar setting in Fusion 360 simulation and it works. However, when I ran a simulation on Simscale I got an error message
The solution matrix is singular. This may be caused by an unconstrained rigid body motion, a physical contact definition with open gap in a nonlinear static analysis or incoherent material parameters
which confuses me.
Any advice would be really appreciated!
Here is my project link >> AUV_Battery_Hull_v1 by sitthichats | SimScale
Thank you,
Boris
