Generalized finite element formulation for efficient first-order plastic hinge analysis

Dae-Jin Kim,Sung-Gul Hong,Hong-Jun Son,Yousun Yi

doi:10.1177/1687814019836366

Abstract

This article presents generalized finite element formulation for plastic hinge modeling based on lumped plasticity in the classical Euler–Bernoulli beam. In this approach, the plastic hinges are modeled using a special enrichment function, which can describe the weak discontinuity of the solution at the location of the plastic hinge. Furthermore, it is also possible to insert a plastic hinge at an arbitrary location of the element without modifying its connectivity or adding more elements. Instead, the formations of the plastic hinges are achieved by hierarchically adding more degrees of freedom to existing elements. Due to these features, the proposed methodology can efficiently perform the first-order plastic hinge analysis of large-frame structures. A generalized finite element solution technique based on the static condensation scheme is also proposed in order to reduce the computational cost of a series of linear elastic problems, which is in general the most time-consuming portion of the first-order plastic hinge analysis. The effectiveness and accuracy of the proposed method are verified by analyzing several representative numerical examples.

Highlights

It is well known that not a small number of structural collapse accidents have been occurring all over the world, and their main causes are natural and man-made disasters such as earthquakes, tsunamis, hurricanes, and terrorist attacks
This study presents a generalized finite element formulation for plastic hinge modeling based on lumped plasticity in the classical Euler–Bernoulli beam
The plastic hinges are modeled using a special enrichment function, which can describe the weak discontinuity of the solution at the location of the plastic hinge

Summary

Introduction

It is well known that not a small number of structural collapse accidents have been occurring all over the world, and their main causes are natural and man-made disasters such as earthquakes, tsunamis, hurricanes, and terrorist attacks. In order to describe the first plastic hinge, the proposed GFEM enriches the two nodes of the horizontal element with the special plastic hinge enrichment discussed in section ‘‘First-order plastic hinge analysis,’’ instead of modifying the mesh of the frame structure as in the case of the standard FEM (Figure 18(d)).

Results

Conclusion