Modelling of Non-Newtonian Starved Thermal-elastohydrodynamic Lubrication of Heterogeneous Materials in Impact Motion

Abstract

This study presents a numerical model for the thermal-elastohydrodynamic lubrication of heterogeneous materials in impact motion, in which a rigid ball bounces on a starved non-Newtonian oil-covered plane surface of an elastic semi-infinite heterogeneous solid with inhomogeneous inclusions. The impact–rebound process and the microscopic response of the subsurface inhomogeneous inclusions are investigated. The inclusions are homogenized according to Eshelby’s equivalent inclusion method. The Elrod algorithm is adopted to determine the lubrication starvation based on the solutions of pressure and film thickness, while the lubricant velocity and shear rate of the non-Newtonian lubricant are derived by using the separation flow method. The dynamic response of the cases subjected to constant impact mass, momentum, and energy is discussed to reveal the influence of the initial drop height on the impact–rebound process. The results imply that the inclusion disturbs the subsurface stress field and affects the dynamic response of the contact system when the surface pressure is high. The impact energy is the decisive factor for the stress peak, maximum hydrodynamic force, and restitution coefficient, while the dynamic response during the early approaching process is controlled by the drop height.

Molecular Dynamics Investigation on Micro-Friction Behavior of Cylinder Liner-Piston Ring Assembly

“…The lubricant supply amount is the other another critical operational factor that in uences the lubrication regime of friction pairs. Researchers [37][38][39][40] have employed various methods to control the lubricant supply in their models, including specifying the lm thickness or ow rate of the lubricant at the inlet point. In MD simulations, the impact of lubricant supply amount on micro-friction properties has been studied by adjusting the number of lubricant molecules.…”

Numerical investigations on the lubrication characteristics of involute harmonic gears

“…Bai et al (2021a) developed the TEHL model for impact motion conditions integrates the non-Newtonian, thermal and other effects together in a strongly nonlinear equation system. Later, Bai et al (2021b) developed a finite element model for non-Newtonian starved TEHL and concluded that non-Newtonian behavior has a minor influence on pressure and film thickness but a significant influence on lubricant temperature, viscosity, velocity and shear stress.…”

Preface to the Special Issue on the Dynamic Behaviors and Energy Absorption of Materials and Structures

“…Liu and coworkers [12] experimentally and numerically studied the dynamic response and energy absorption performance of foam-filled tubes under lateral external blast loading. Bai and coworkers [13] presented a numerical model for the thermal-elastohydrodynamic lubrication of heterogeneous materials in impact motion. Wang and coworkers [14] developed a new electrical power generation device based on the high-frequency dynamic piezoelectric shear deformation under friction.…”