hookeai.miscellaneous.materials.plot_yield_surface.get_stress_invariants

get_stress_invariants(stress)

Compute invariants of stress and deviatoric stress.

Parameters:

stress (torch.Tensor(2d)) – Stress.

Returns:

• i1 (torch.Tensor(0d)) – First (principal) invariant of stress tensor.

• i2 (torch.Tensor(0d)) – Second (principal) invariant of stress tensor.

• i3 (torch.Tensor(0d)) – Third (principal) invariant of stress tensor.

• j1 (torch.Tensor(0d)) – First invariant of deviatoric stress tensor.

• j2 (torch.Tensor(0d)) – Second invariant of deviatoric stress tensor.

• j3 (torch.Tensor(0d)) – Third invariant of deviatoric stress tensor.