Thermoelastic Stress Analysis of a Mechanical Fastener

Abstract

Bolted connections are prevalently used to fasten separate mechanical or structural members together. Lack of knowledge of the contact stresses at the bolt-plate interface can make it difficult to stress analyze bolted connections theoretically or numerically. Thermoelastic stress analysis (TSA) is therefore utilized to stress analyze a plane-stressed pin-loaded plate. The approach involves processing the recorded temperatures gradients throughout the plate with an Airy stress function, plus imposing the traction-free conditions discretely on the non-contacting edge of the hole and on the external boundaries of the plate. In addition to agreeing with the frequently assumed interface contact stresses in mechanical connections having zero bolt-hole clearance, the TSA stresses satisfy force equilibrium and are correlated with FEM results. TSA is convenient in that the technique provides the individual components of stress full-field without necessitating any photoelastic model or surface pattern or ruling. Unlike with moiré, holography, speckle or digital image correlation, TSA necessitates neither knowing the elastic constitutive properties nor differentiating the recorded information.