The influence of geometric effects on the behavior of strain softening frames

摘要

This paper presents a mathematical programming based approach for the analysis of elastoplastic softening frames in the presence of geometric nonlinearity. Arbitrarily large deformations, albeit within a small strain regime, can be accommodated, if necessary. For the sake of efficiency, and without undue loss of accuracy, the algorithm processes the nonholonomic (path-dependent) problem in a stepwise holonomic (path-independent) fashion. This analysis capability has been used to investigate what level or order of geometric nonlinearity needs to be adopted to obtain sufficiently accurate results for practical frames. Two examples are provided for illustrative purposes.