关键词: 耗散模型, 颗粒碰撞阻尼, 塑性变形, 有限元法, 表面质量 , 创成机理, 单晶颗粒, 分子动力学, 微切削

Abstract: To rapidly obtain the moving state of particle impact and simulate the particle impact damping system, a piecewise dynamic model is proposed for collision of two particles in a single period. In this model, a single impact period is divided into three stages, on the basis of which, the moving state of some key points for particles and thus the analytical expressions of velocity after impact, coefficient of restitution and energy dissipation are obtained. Finite element method (FEM) is used to simulate elastoplastic impact process of two particles, and the FEM results show good agreement with the analytical prediction, which verifies the proposed piecewise dynamic model. With the piecewise dynamic model, the influences of particle velocity before impact, particle material parameters including yield strength, elastic modulus, mass density, and particle size on energy dissipation are quantitatively analyzed. The results reveal that materials with low yield strength and high elastic modulus have better attenuation effect. In addition, materials with larger mass density also have better dissipation performance, which can be taken as a reference in choosing the material of impact partners in impact damper design. The study can be applied to predicting the character of particle impact damping and simulate the vibroimpact damping system.

Key words: Dissipation model, Finite element method, Particle impact damping, Plastic deformation, Generative mechanism, Micro cutting , Molecular dynamics , Surface quality , Monocrystalline particles