On Modelling Techniques for Mechanical Joints: Literature Study

Abstract

Most mechanical joints are in one way or another exposed to some tear, wear, corrosion and fatigue, and likely to fail over time. If the contacting surfaces in a connection are exposed to tangential loading due to vibrations, small amplitude displacements called fretting can be induced at the surface, and might result in crack nucleation and possible propagation. The review and analysis reported herein are based on study of a wide range of reported literature during the last 25 years, and it looks into which methods, techniques and tools that have been used in those studies, including laboratory and full-scale testing, especially around fretting fatigue issues in interference fit joints, and pre-tension issues in pre-loaded bolts. In modelling of mechanical joints, the main techniques can be categorized under either stochastic (or probabilistic) type, where the random variation is usually based on fluctuations observed in historical data for a selected period of time using standard time-series techniques, or deterministic techniques, with analytical and numerical models and methods, which are widely applied. Analytical techniques typically include models like; Newton’s laws of motion, Laplace transformation methods, Lagrange differential equations, D’Alambert’s principle of virtual work, Hamilton’s principle, Fourier series and transform, Duhamel’s integral and Lame’s equations. Today, computers are widely used to find approximate solutions to complex engineering problems by combining the above-mentioned methods. A large number of these combined methods, also referred to as numerical methods, fall under finite element analysis (FEA). One way to reduce fretting issues in mechanical connections could be to increase the research and investigation effort on expanding pin solutions, which are different from the traditional press and shrink fit methods.