Assessment of load distribution and fatigue life of bolts and joints of different configurations

Abstract

The development of fixture technology, such as the use of bolts and joints has as one of its functions form a set of mechanical components that combine a high mechanical strength and stiffness, to accommodate the loads, stresses, strains and life specified for a particular application.The junction of parts through the use of bolts is one of the most used process that combines versatility and low cost, and the failure of a single bolt can compromise the entire structure or machine.In most applications, the bolts used for fixing joints are subjected to cyclic loads and therefore are subject to fatigue failure.This project has the objective to discuss the application of finite element method in the analysis of fatigue failure in bolts and joints of different configurations, varying the material and thickness of sheet. Specifically we will evaluate the influence of some design parameters on load distribution and stress in bolts, which is one of the most important aspects in the durability of these components. As also will study the effects of assembly torque in life specified of bolted joints subjected to cyclic loading. The effect of assembly torque on the fatigue life of bolted joints is a complex subject, because until this time it was not possible to equate this relationship.The analysis of the life of bolts and joints will be realized through mechanical fatigue tests for obtained the curves S x N and the use of commercial software ANSYS, based in the finite element method in a virtual environment.It is hoped that the results to be obtained in this study are useful indevelopment of a practical methodology, reliable and efficient, that can predict the fatigue life of bolted joints subjected to cyclic loading.Still, it will mean a notable impulse to the formation and consolidation of a academic research group in the Faculdade de Engenharia, Campus de Guaratinguetá, Unesp, in computational methods applied to modeling and simulation of structures and machines, generating the training of human resources in the Vale do Paraíba. (AU)