A Design Study of the Patch Load Instability Phenomenon

ABSTRACT State of the art investigations in the patch load instability phenomenon still did not produce an efficient formula for the prediction of this local buckling. In the present work a non linear finite element program was used to model the phenomenon achieving good results in terms of the ultimate load, collapse configuration and web’s stress distributions. An extensive study was also made comparing the finite element results with critical patch load formulas developed by investigators like: Bergfelt (1979); Roberts et al (1988) and others. Relevant results were found in terms of the influence of parameters like the thickness of the web, and others on the collapse load of the girder.