Elastic modulus reduction method for stable bearing capacity analysis of dumbbell-shaped CFST arches

Abstract

The elastic modulus adjustment procedures (EMAPs) can achieve much higher efficiency than incremental nonlinear finite element method (INFEM), however it could not take into account the stability effect on structures. In this paper, the elastic modulus reduction method (EMRM) was presented to estimate the stable bearing capacity of dumbbell-shaped concrete filled steel tube (CFST) arch. Firstly, the homogeneous generalized yield function (HGYF) was developed for dumbbell-shaped CFST members under combined action of axial force and bending moment by means of the fiber model technique, which was employed to determine the stable bearing capacity of these members. Secondly, the HGYF was adopted to define the element bearing ratio so that the EMRM was proposed for evaluating the stable bearing capacity of the dumbbell-shaped CFST arch by strategically reducing the elastic modulus of the highly stressed elements. Finally, results from the INFEM and test data of 3 dumbbell-shaped CFST arches and 30 dumbbell-shaped CFST members were adopted as examples to validate the proposed EMRM and the HGYF, which shows that the stability has a significant influence on the CFST arches and the proposed EMRM achieves higher accuracy and efficiency than the INFEM.