Adaptively Shifted Integration Technique in the Finite Element Collapse Analysis of Framed Structures

Abstract

The present study is concerned with the refinement of the previously proposed 'shifted integration technique' for the plastic collapse analysis of framed structures using the linear Timoshenko beam element or the cubic beam element based on the Bernoulli-Euler hypothesis. In the newly proposed 'adaptively shifted integration technique', numerical integration points are automatically shifted immediately after the occurrence of plastic hinges according to the previously established relations between the locations of numerical integration points and those of plastic hinges. By using the adaptively shifted integration technique, sufficiently accurate solutions can be obtained in the nonlinear frame analysis by two linear element or only one cubic element idealization for each structural member. The present technique can be easily implemented with a minimum effort into the existing finite element codes utilizing the linear and the cubic beam element.