I recommend using/continue using:

  • Hyperelastic material model

  • 2D Axisymmetric geometry. Axis of rotation is Y axis, surface on + X side of Y axis.

  • Half symmetry at the center of the length

  • Displacement in Y on the end face, with X = 0

  • Linear elements, but not too small. PLANE182

  • Mesh with element shapes that deform to better shapes, not worse shapes. Start as wide rectangles, end up square.

  • uniform reduced integration keyopt, 1, 1

  • mixed u-p formulation keyopt, 6, 1

  • more substeps and cumulative iterations