{"id":47588,"date":"2020-08-23T20:09:10","date_gmt":"2020-08-23T20:09:10","guid":{"rendered":"\/forum\/forums\/topic\/hollow-body-in-compression-self-intersecting\/"},"modified":"2020-08-23T20:09:10","modified_gmt":"2020-08-23T20:09:10","slug":"hollow-body-in-compression-self-intersecting","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/hollow-body-in-compression-self-intersecting\/","title":{"rendered":"Hollow Body in compression self intersecting"},"content":{"rendered":"
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I am compressing a body with an inner structure of hollow cylinders (axis in the y direction) (tan body) between a steel plate (gray body) and a model of the human heel (green and grey) by applying a load to the bottom of the plate and holding the heel bone fixed. The steel plate is fixed to only displace in the y direction and the top surface and flat side (xy face) of the skin are fixed in the y and z directions respectively.<\/p>\n

In controls (with no hollow body), this model converges well and quickly. <\/p>\n

However when I add in the hollow body, the model fails. At very early time steps 1e-2, the top surface of the hollow body insects with the bottom surface (see second picture). <\/p>\n

The bottom surface of the hollow body is contacting the steel plate with a bonded contact (no Trim), and the top surface of the hollow body is contacting the skin of the heel with a Frictional contact (0.6, no Trim). I have tried different pinball radii (larger and smaller) to see if it was a issue of the top surface contacting the steel plate. I tried with a Bonded contact with the skin. I also tried allowing the hollow body freedom to move in the x and z directions, as well as the y that it already had. <\/p>\n

For material reference (if it helps), the skin is a second order polynomial, nonlinear material, and the hollow body is linearly elastic with E=12 MPa.<\/p>\n

Any help would be greatly appreciated!<\/p>\n

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\n\"Compressing
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