PERFORM-3D has powerful capabilities for inelastic analysis, but it is not intended for general purpose nonlinear analysis. If you have no idea how your structure will behave when it becomes inelastic in a strong earthquake, PERFORM-3D can probably help you to identify the weak points, and hence can guide you in improving the design. However, PERFORM-3D is not intended for “design by analysis”, where the engineer expects the analysis to determine exactly how a structure will behave. PERFORM-3D is a powerful tool for implementing displacement-based design and capacity design. It will help you to produce better designs, but it will not do the engineering for you.
