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• A tribo-dynamic analysis procedure is developed for the predictions of the aero ball bearing with 3D measured roughness. • The influences of structure parameters and running conditions on the bearing dynamic performance have been discussed. • The roughness effects on lubrication state and friction-temperature of the aero ball bearing are investigated. • The 3D dynamic subsurface stress of the aero ball bearing has been researched. Tribological failures, like wear, scuffing and pitting, etc, often occur in aero ball bearings due to large dry contact area, high friction-flash temperature and stress concentration at the interface between the contacting ball and race. In this paper, a numerical tribo-dynamic analysis procedure is developed for the predictions of dynamic performance, lubrication state, friction-temperature, and subsurface stress of the aero ball bearing with 3D measured roughness. The numerical model is verified by comparing the friction coefficients with the testing results, which show well agreements and proves the presented model is available. The dynamic performance of bearing at different azimuth angle are studied, which indicate the increasing radial load and speed result in more asymmetric distributions of the contact load, stress and slide-roll ratio, the maximum values and the unloaded-region become larger. With the increase of the inner race groove coefficient and the contact angle, the pv value and the radial stiffness decrease clearly. The tribology behaviors of the ball bearing are also investigated, the obtained results indicate that the heavy-load and low-speed lead to large dry contact areas, high friction-temperature, and high local stress peaks, the lubrication state become worse, which may further cause the failures of mass wear, scuffing and micro-pitting. [ABSTRACT FROM AUTHOR]

Highlights • The coated asperity contact behaviors are studied for the soft coating cases under frictionless and friction condition. • The effect of the strain hardening exponent of the coating, besides the Young's modulus, yield strength and original thickness on the contact behaviors is explored. • The expressions of the contact area and the coating thickness leading to the maximum weakening effect in the loading process is obtained. • An inflection point of the maximum von Mises stress curve in the coating is found, which is related to the locations of maximum stresses. The expressions of the dimensionless von Mises stress and the interference at the inflection point are acquired. Abstract The contact between a rigid flat and a coated asperity is studied using the finite element method under frictionless and friction condition. The soft coating and hard substrate of the asperity are both considered as the power-law hardening elastic–plastic material, which is commonly used in main bearing of the marine engine. The effect of the material and geometrical properties of the coating, including Young's modulus, yield strength, hardening exponent and original coating thickness, on the contact behaviors is studied under the frictionless condition. The change of the contact area and coating thickness in the loading process is explored, and the expressions of the coating thickness which leads to the maximum weakening effect are obtained. The von Mises stress distribution at yield inception and the maximum stress in the loading process in the coating are researched respectively. Also, the friction effect on the contact parameters was considered by integrating the empirical friction coefficient value into the contact model. This work would be helpful to find the optimal material and geometrical properties for the soft coating on the hard substrate which are power-law hardening elastic–plastic materials. [ABSTRACT FROM AUTHOR]