摘要
基于分形几何理论和接触力学理论,用分形理论表征粗糙表面微凸体参数,考虑微凸体由弹性变形向弹塑性变形以至最终向完全塑性变形转化的过程,建立各变形阶段微凸体的接触刚度模型。在此基础上,提出机械结合面法向接触刚度计算模型,该模型揭示了在不同的塑性指数下,结合面法向接触载荷与法向接触刚度之间的关系。结果表明,在塑性指数较小时,微凸体的变形以弹性为主,法向接触载荷与接触刚度之间表现为近似线性关系;随着塑性指数的增加,微凸体变形主要以塑性为主,法向接触载荷与接触刚度之间表现为较强非线性关系。对已有的铣削加工和磨削加工情况下的结合面法向接触刚度试验结果,利用该模型进行数值计算、仿真和分析。结果表明:提出的模型更与试验曲线吻合。
Rough surface asperity parameters are characterized based on fractal geometry theory. Asperity normal contact stiffness model is developed based on contact mechanics that the deformation transitions from elastic, through elastic-plastic, to eventually to the plastic, respectively. The mechanical joints normal contact stiffness calculation model is presented based on fractal geometry and contact mechanics theory. In different plastic index, the model is developed the relationship between the joint normal contact load and contact stiffness. The result shows that plastic index is lesser, asperity is mainly elastic deformation, and the relationship between normal contact load and stiffness is the approximate linear, that, with the plastic index increase, asperity is mainly plastic deformation, and the relationship between normal contact load and stiffness is the strongly nonlinear. At last, normal contact stiffness which machining surface are milling and grinding are calculated and analyzed for existed experimental parameters used the model. The comparison result indicates that the present model is consistent with experiment result.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2013年第1期102-107,共6页
Journal of Mechanical Engineering
基金
国家自然科学基金(51275407)
国家重点基础研究发展计划(973计划
2009CB724406)
国家重大科技专项课题(2009ZX04014-32)资助项目
关键词
分形几何
微凸体
弹塑性变形
结合面
法向接触刚度
Fractal geometry Asperity Elasticoplastic deformation Mechanical joints Normal contact stiffness
