Normal Stiffness model of bolted joint based on the modified three-dimensional elastic-plastic contact fractal model

2018 International Conference on Advanced Materials, Intelligent Manufacturing and Automation

材料科学;机械制造;运输工程

Yin, Yunyao^1,2 ; Cai, Ligang^1,2 ; Liu, Zhifeng^1,2 ; Zhao, Yongsheng^1,2 ; Cheng, Qiang^1,2

Institute of Advanced Manufacturing and Intelligent Technology, Beijing University of Technology, Beijing

100124, China^1

Mechanical Industry Key Laboratory of Heavy Machine Tool Digital Design and Testing, Beijing University of Technology, Beijing

100124, China^2

关键词: Assembled structures;    Contact deformation;    Dynamic characteristics;    Dynamic performance;    Dynamical behaviours;    Elastic-plastic contact;    Experimental set up;    Normal contact stiffness;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/382/3/032042/pdf
DOI  :  10.1088/1757-899X/382/3/032042

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Bolted joints have a significant effect on the dynamical behaviour of assembled structures. Accurate contact stiffness model of bolted joint is crucial in predicting the dynamic performance of bolted structures. In this research, a modified three-dimensional fractal model of normal contact stiffness is presented to more accurately predict the dynamic characteristic of a bolted assembly. In the present model, while the contact deformation exceed the critical value the elastic-plastic contact is used to take the place of Hertz elastic contact in the traditional M-B model, and revise the drawback that elastic-plastic contact occurs before elastic contact in existing elastic-plastic fractal models. As the increase of contact force, the plastic deformation of single asperity is considered again, which is omitted in the two type fractal models. An experimental set-up with two T-shaped specimen is designed conducted to verify the efficiency of the proposed model. Comparing with the ZX elastic-plastic fractal model, the present model can predict contact stiffness and dynamic performance more accurately, particularly, while for higher contact loads. The results show that the modified elastic-plastic fractal contact model can be used to more accurately predict the stiffness and dynamic characteristic of bolted structures in the machine tools.