Nonholonomic analysis of elastoplastic frames

Abstract

A procedure for progressive nonholonomic analysis of elastoplastic plane frames neglecting axial force effects is developed. Within the framework of simple plastic theory the governing condition is expressed in terms of total values of loads, bending moments, and hinge rotations. The path-dependent load-deformation behaviour is traced incrementally through linear phases, imposing the yield criterion and flow rule as auxiliary conditions. The method is intended for implementation as an interactive system for analysis and design. Computations are organized as a series of four modules such that a loading data modification can be responded to with little effort and the next fastest response is for changes in member sections, nodal coordinates, and structural connectivity, in that order. Deflection components are computed only as and when queried by the user. A special feature of the approach is that the complete solution can be provided whenever lack of uniqueness of kinematic solution arises. A detailed example is included.