Plastic pushover performs a nonlinear inelastic analysis on a load case, continuously increasing the loading on the structure until a stopping criterion is met, such as maximum loading displacement at a particular joint in a particular direction. Plastic pushover analysis is a simplified form of progressive collapse.
The progressive collapse analysis simulates structural loss such as cable-snapping. LARSA's nonlinear solver uses arc length auto-stepping to increase loads at critical regions on the post-buckling stress-strain curve. This analysis is performed using LARSA 4D's inelastic element library.
Moment-curvature analysis is used to determine axial force nonlinear moment-curvature behavior of a cross-section which is then assigned to a hysteretic beam element in the LARSA 4D bridge model.
Once defined, a "family" of moment-curvature curves is created to define element behavior over a user-specified range of axial force values.
Moment-curvature analysis determines the inelastic properties of a reinforced concrete cross-section to establish the displacement capacity using pushover or time history analysis.