Elastic Plastic Analysis of Space Frames

Abstract

Section modelling and fibre modelling are the most commonly used approaches in nonlinear analysis. Section models have been found computationally efficient and give sufficiently accurate results with reasonable approximation. Current study emphasises the need for establishing the nonlinear section model for 3-D frames having different properties in three dimensions. In order to satisfy the generality requirements a computer model should incorporate generality in constitutive law, yield criteria and in element choosen to model beams and columns. Under the study reported in this thesis a generalised 2-noded beam-column has been tested for its validity using direct stiffness approach. The element has been compared with Finite Element fomulation and it has been observed that present element gives sufficiently good results at higher computational efficiency. A number of yield criterion have been suggested in the literature but the present model incorporates a multi-interaction criteria to model anisotropic behaviour of different materials.