Fatigue Life Evaluation of Rubber-Clay Nanocomposites

Abstract

The interest of fatigue life evaluation for rubber component such as engine mount was increasing according to the extension of warranty period of the automotive components. A design of rubber components against fatigue failure is one of the critical issues to prevent the failures during the operation. Therefore, fatigue life prediction and evaluation are the key technologies to assure the safety and reliability of mechanical rubber components. In this study, we developed rubber material that is environment-friendly and superior in physical property and fatigue life using rubber-clay nanocomposite. We performed static and dynamic tests of rubber-clay nanocomposite synthesized by inserting nano-filler between silicate layers at the high temperature of +70 ˜+100°C, and verified that their mechanical properties were superior to the existing rubber material. In addition, a new method was developed to estimate fatigue lifetime of rubber parts in a short period in the initial stage of design, assuming that the fatigue damage parameter was Green-Lagrange strain generated at the weak points of parts. As results of estimation of fatigue durability, it was verified that the fatigue lifetime obtained by fatigue tests on actual engine mounts and the expected lifetime relatively match. With the results of finite element analysis of rubber parts using the fatigue lifetime estimation method suggested in this study, the lifetime can be estimated without fatigue tests on rubber parts. Therefore, we can save development time and expense and achieve good quality and reliability of rubber parts.