The Normal Dynamic Stiffness Model of Joint Interfaces Based on Fractal Theory

2019 3rd International Workshop on Renewable Energy and Development

能源学;生态环境科学

Liu, Wenwei^1 ; Wang, Yuanhang^1 ; Li, Xiaobing^1 ; Yang, Jianfeng^1 ; Dong, Chengju^1

China Electronic Product Reliability and Environmental Testing Research Institute, Guangzhou, Guangdong

510610, China^1

关键词: Dynamic performance;    Dynamic stiffness;    Elastoplastic deformation;    Excitation frequency;    Fractal functions;    Linearized stiffness;    Static stiffness;    Vibration differential equations;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/267/3/032055/pdf
DOI  :  10.1088/1755-1315/267/3/032055

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

To solve the problem of the poor dynamic performance of the machine due to low stiffness of joint interfaces, a theoretical normal dynamic stiffness model of joint interfaces based on fractal theory was proposed. An improved three-dimensional WM fractal function was used to characterize the contact surface, the vibration differential equation of the sphere-plane dynamic contact was established, the linearized stiffness of asperities in elastic deformation and elastoplastic deformation regime are derived respectively, and the normal dynamic stiffness model of the joint interfaces was established. At the same time, the relationship between the dynamic stiffness and the static stiffness of the joint interfaces was established. The analysis results show that, the dynamic stiffness of the joint was approximately equal to the static stiffness when the excitation frequency was much smaller than the natural frequency, and the dynamic stiffness was much larger than the static stiffness when the excitation frequency is much larger than the natural frequency, there also existed a resonant frequency that minimizes the dynamic stiffness.