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Ideas for smoothing solid-flex contacts (PSHELL)?

erik_spe
Attached model drags a simple block across a simple flexible plate's surface. Force is too unsteady to be of any use. Even with flexbody rigid, force is unsteady.
 
I've noticed using SI2 solver dramatically helps, but hoping someone out there has other tricks up their sleeve (other than just softening the contact parameters).
Attached Files (2)
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  • 0
    Can you help me figure out how to get it to converge (better)?
     
    The model is a pretty simple illustration of sliding of a solid on a flex body surface, sharp corners or not. Seems like it'd be useful for anyone encountering the same issue in the future.
     
    The three pictures show the original coarse mesh and another model with a refined mesh, per your feedback. As seen, I've tried ERROR=1e-7, HMAX=1e-6, still not converging. On a rigidized mesh, I used ERROR=1E-8 and HMAX=1e-7 and didn't converge. (Plot shows large deviation from the 50 lbf contact load and large variance in angular acceleration about Z). It does run quite well for a short time, but then large blips in angular acceleration start to show up.
     
    These run times were well beyond expectation for the apparent simplicity of the models, borderline unusable but for sake of solving the problem, which is where the attribution to 'brute force' approaches came to mind--sorry about the use of the term "brute force", again, not to dismiss the need for care in this area, for such problems in general.
     
    Currently, the models I'm applying this generic concept to do use the v1 sphere approximation. Actual geometry, with sharp edges and all, would be preferred, though. My next thought would be to split the box in sub-sections, then apply to the refined mesh version (several grid elements per box segment). So, it'll end up being much like the spheres, but with shapes that better represent true geometry.
     
    Rigid_not_converging
     
    Refined_not_converging
    Original_not_converging
    Attached Files (1)
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  • 0
    Can you help me figure out how to get it to converge (better)?
     
    The model is a pretty simple illustration of sliding of a solid on a flex body surface, sharp corners or not. Seems like it'd be useful for anyone encountering the same issue in the future.
     
    The three pictures show the original coarse mesh and another model with a refined mesh, per your feedback. As seen, I've tried ERROR=1e-7, HMAX=1e-6, still not converging. On a rigidized mesh, I used ERROR=1E-8 and HMAX=1e-7 and didn't converge. (Plot shows large deviation from the 50 lbf contact load and large variance in angular acceleration about Z). It does run quite well for a short time, but then large blips in angular acceleration start to show up.
     
    These run times were well beyond expectation for the apparent simplicity of the models, borderline unusable but for sake of solving the problem, which is where the attribution to 'brute force' approaches came to mind--sorry about the use of the term "brute force", again, not to dismiss the need for care in this area, for such problems in general.
     
    Currently, the models I'm applying this generic concept to do use the v1 sphere approximation. Actual geometry, with sharp edges and all, would be preferred, though. My next thought would be to split the box in sub-sections, then apply to the refined mesh version (several grid elements per box segment). So, it'll end up being much like the spheres, but with shapes that better represent true geometry.
     
    Rigid_not_converging
     
    Refined_not_converging
    Original_not_converging
    Attached Files (1)
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