Rotating as well as static components of aero engines such as rotors and casings must be capable of withstanding vibrations which arises from various engine order excitations. HCF is attributed as one of the major failures due to its high crack propagation rate. The tolerances to vibration have become a key point to avoid resonance in operating range. Analytical predictions of individual components gives better accuracy and good agreement with test data. However, when the components are assembled, the accuracy of analyses can considerably depreciate since models describing stiffness and friction properties of joints are linearized. In such conditions proper predictions of dynamic response becomes difficult and may lead to under prediction or over prediction of dynamic response.
A nonlinear analysis is required to study the influence of joints flexibility on dynamic response. In this paper different nonlinear joint models are investigated to assess the dynamic behavior of the contact interface in terms of slipping and sticking contact parameters. The study shows significant changes over dynamic characteristics when compared to linear analysis. From this study, it is evident that nonlinear behavior of the contact in dynamic analysis phase due to slip and separation plays vital role over the dynamic characteristics of the component. This study emphasizes to consider physical behavior of joints in dynamic analysis to avoid catastrophic HCF failures.
