forked from 1b-agent/fieldcraft-upstream
jyvikoandClaude Opus 5.5
6ca3233aaa
A return map at the closed secondary nodes on the mortar slip in its rate form (w_A = B_A dx, B_A = [int Phi_A N_i P, -int Phi_A N_j P]): stick within mu p_A, slip back to the cone, static coefficient for a node that stuck in the last increment and kinetic for one that slipped; the friction does the virtual work t . B_A dx, so a slipping interface carries mu N exactly. The tangent is symmetrised (stick and slip stiffness kept, the coupling to the pressure and the change of B left out; the residual is exact). Tractions and slip states are committed with the converged increment. After a chattering cutback, nodes open by less than 1e-3 of their element's thickness keep their penalty in the tangent for the rest of the step. Results carry the shear traction, the slip and stick/slip status. Co-Authored-By: Claude Opus 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo