Comparative Study Between Conventional Pushover Analysis and the Finite Element Method for Capacity Curve Construction

Abstract

Approximate seismic evaluation procedures based on the validity of the capacity curve have been widely accepted in practical engineering due to their straightforward application and the valuable insights they offer to analysts—such as cracking patterns, inelastic deformations within the structure, and their eventual progression towards collapse. Although these procedures have been extensively studied and are generally accepted, a gap in understanding persists—particularly in practical engineering—regarding the true significance of the capacity curve and, more importantly, the reliability of the results derived from it, especially when compared with those obtained through more numerically robust procedures.

Recent research has examined the consistency of results obtained from approximate procedures and those derived from more rigorous numerical approaches in constructing the capacity curve. This study presents the findings of an investigation into the validity of results obtained using so-called approximate procedures for constructing the capacity curve, comparing them with outcomes from more robust and inherently complex procedures, primarily based on the finite element method.

The approximations reviewed in this work are evaluated against results from an experimental study of a full-scale three-dimensional frame tested by another research group, as well as against those obtained from a non-linear analysis using the finite element software ATENA, which models the structure under conditions identical to those of the experimental test. Finally, the study discusses the results, and the challenges analysts may encounter when modelling a structure using both numerically refined and approximate procedures, such as those implemented in commercial software like ATENA.