An analytical methodology for the dynamic amplification factor in progressive collapse evaluation of building structures

The dynamic amplification factor (DAF) estimated from an inelastic single-degree-of-freedom (SDOF) system is favorable for progressive collapse evaluation of building structures. In this paper, analytical expressions are obtained for the DAFs of an inelastic SDOF model subjected to step loadings. The capacity curve is used to derive the force- and displacement-based DAFs. Numerical analyses are carried out to verify the accuracy of the proposed method. An inelastic fixed–fixed beam is used to demonstrate its application to a multi-hinge structure. The study results indicate that the force- and displacement-based DAFs may be estimated by the analytical methodology.