RBE2 vs RBE3 FEA Guide

RBE2 and RBE3 are Multi-Point Constraint (MPC) elements in NASTRAN (and similar solvers) used to connect a central node to multiple surrounding nodes (often visualized as a “spider”). RBE2 = Kinematic / Rigid → Adds infinite stiffness (nodes move together exactly). RBE3 = Distributing / Interpolation → Adds zero stiffness (forces/moments are smeared; nodes can deform relatively). Key Decision Question: “When loaded, do the connected nodes move together (use RBE2) or independently (use RBE3)?” Content is AI-enhanced using NotebookLM for deeper learning