Hybrid Finite Element Formulation for Geometrically Nonlinear Buckling Analysis of Truss System Under Mechanical and Thermal Load

Abstract

This paper introduces a novel approach to establish the nonlinear buckling problem of truss systems under mechanical and thermal load due to constant temperature change based hybrid FEM. In geometrical nonlinear displacement-based finite element analysis, the thermal deformation of truss element is dependent on the incremental element length and requires the implementation of additional thermal deformation constraints. For escaping the implementation process the research proposed to build the hybrid finite model assembling two types of truss finite elements with different numbers of unknowns (common truss element and thermal truss element). Both common truss element and thermal truss element are established based on the large displacement theory. The hybrid global equilibrium equations are developed by assembling constructed common and thermal truss elements. For solving geometrically nonlinear buckling analysis of truss under mechanical and thermal load the incremental-iterative algorithm is established using the arc-length method. The calculation program is written for investigating the effect of thermal load on the buckling behavior of plan truss.KeywordsHybrid formulationGeometrically nonlinear analysis of trussThermal truss elementTruss under thermal loading