A new method of nonlinear analysis for a mechanism with a cylindrical clearance joint using information entropy theory

Many studies have found that the local contact deformation of joints with clearance has obvious nonlinear characteristics and even exhibits chaotic response under certain conditions. In this paper, the information entropy theory that can reflect the uncertainty of system state is applied to quantitatively analyze the nonlinear behavior of a mechanism with a cylindrical clearance joint. A model of a cylindrical joint with radial and axial clearances is developed to reflect complex contact-impact phenomena. This model presents a comprehensive description of contact modes. To demonstrate the application of the information entropy theory and investigate the nonlinear behavior, this model is used in numerical calculation and simulation. The entropy and entropy interval are used as the benchmark for quantitative analysis of nonlinear behavior. The results of the simulation are then analyzed quantitatively. In addition, an experimental setup is designed to reveal the nonlinear behavior between the journal and the bearing. Based on the entropy theory, the results of theoretical and experimental quantitative analysis of nonlinear behaviors under the differences of clearance and velocity are consistent.