Studies of bolted joints of dissimilar materials in fatigue: a numerical and finite element approach to connection modelling

A number of finite element and mathematical models have been produced to estimate the stress distribution and failure processes of mechanical and adhesive joints under quasi-static loading. In particular, studies have focused on producing accurate models of bolted joints in quasi-static loading, but insufficient emphasis has been placed on modelling fatigue of these joints. This research topic looks to investigate the stress distribution and failure of dissimilar composite joints in fatigue (e.g. carbon fibre/epoxy to steel).

Finite element analysis and mathematical models will be produced for a variety of conventional joining techniques. For validation and refinement of these, a number of joints will then be manufactured and fatigue-tested before being experimentally tested. The following fatigue phenomena will also be considered: thermal degradation, corrosion (primarily by salt water), effect of assembly/manufacturing variability (e.g., varying bolt pre-stress). Test results will then provide a further basis for altering initial FEA/matlab stress models such that they are analogous with experimental results. Overall, the project aims to identify the effects of different fatigue mechanisms on joint strength and subsequently model these variations computationally. The proposal looks to provide novel insight into the modelling of fatigue mechanisms commonly encountered in aerospace, wind and wave power applications.