Paso 4 — Resolver, POST1 y CSV

CMSEL,S,bottom_nodes / D,ALL,ALL,0
CMSEL,S,top_nodes
D,ALL,UY,disp / D,ALL,UX,0 / D,ALL,UZ,0
AUTOTS,OFF / KBC,0 / NSUBST,10 / SOLVE

En POST1 suma RFY en el apoyo inferior. Escribe m11_contact_audit.csv con contact_closed, force_error y n_converged. Referencia medida: rfy_close ≈ 5,65 MN, study_passes = 1.