Hello Moji, nThe density is only relevant for Explicit Dynamics.nThe following steps work in Static Structural for a body with a uniform cross-section. It may not work so well for a part with large holes in it.nIn CAD, create the flat solid, place the fixed end in the cylindrical gap and let the other end poke out.nIn Static Structural, define the wall contacts, a remote displacement on the moving end face, a pressure load and create a multi-step analysis.nIn Step 1, the contact with the wall is Inactive, the pressure is zero.nThe flat hyperelastic part has the end fixed, which is located in the cylindrical gap. At the other end, a Remote Displacement applies a rotation about Z to that face, leaving the X and Y translation DOFs Free. For a uniform plate, that will curl the object into a circular shape during step 1, and the part would be in the cylindrical gap. You won't get that due to the holes.nIn Step 2, contact with the cylindrical walls is made active. If there is some small penetration of the part through the walls due to the non-uniform nature of the part, the contact might successfully resolve that in step 2.nIn Step 3, the remote displacement constraint is made inactive, the part will uncurl until it touches the wall.nIn Step 4, the pressure increases from 0 to something.n