hermit.fenics.stress

Through-thickness stress recovery for the R-M shell (isotropic).

Port of ShellStressRM from femo dev_coupling. Used only for stress postprocessing; needs the isotropic E, nu (so composite stress recovery is a separate future concern). All gradients are plain ufl.grad.

Classes

ShellStressRM

Build isotropic through-thickness stress recovery.

Module Contents

class hermit.fenics.stress.ShellStressRM(mesh, w, h_th, E, nu, *, strains=None)

Build isotropic through-thickness stress recovery.

strains=(eps_mid, kappa, gamma) lets the shell form supply its own kinematics. The fallback preserves the existing constructor surface while using the same constant-normal definitions.

cauchy(xi2)

eps(xi2)

gamma_2(xi2)

Transverse shear, constant through the thickness for RM kinematics.

When the shell form supplies its strains, use its gamma rather than recomputing: the local form here differentiates u(xi2), which carries a xi2 * grad(E2) term that is non-zero on a warped cell under rigid-body motion – the same defect as issue #7, in the shear slot. The supplied gamma is built from grad(u_mid) and cancels exactly.

inplane_stress(xi2)

u(xi2)

von_mises(xi2)

Dmat

E01

E012

G

mesh