Failure modeling and reliability analysis for motion mechanism with clearance joints under plastic deformation and wear

The performance failure and reliability of motion mechanism has a significant effect on industry reliability, operation safety and production economy. Motion precise is one of the typical performance indicators especially for motion mechanism with multibody and joints, which will be influenced by necessary joint clearance. Size of joint clearance degenerates with usage such as wear and deformation. Repeated start-stop lead to impact stress and plastic deformation for clearance joint particularly for mechanism with high load and long working cycles. Nevertheless, current research ignoring the coupling of plastic deformation and wear, which will cause a different wear process and mechanism performance failure. This study attempts to investigate the wear process and performance failure model of multibody mechanism with clearance joints considering plastic deformation and wear. Quantification of plastic deformation caused by repeated impact stress of joints is studied by formulation. Then, a novel wear process model is established on the basis of Archard model, after which performance failure indicator of motion mechanism is conducted. In case study case, a linkage motion mechanism with multi revolution joints used in industry assemble line is studied to demonstrate proposed methods and models. This investigative study provides valuable guidelines for degeneration prediction and failure or reliability analysis of motion mechanism.