Numerical Simulation And Life Prediction Of Wear Of Unfolding Wheel For Steel Ball Detection

As the core component of the steel ball wheel deployable mechanism,unfolding wheel mainly rely on the friction caused by asymmetric biconical surfaces to make the tested steel ball lateral deflection at the same time rotation caused by driving wheel,so the steel ball surface to achieve full swing,so as to realize the automation of nondestructive testing of steel ball.The unsymmetrical double cone surface of the unfolding wheel is the key to make the surface of the steel ball fully unfold and the friction between the unfolding wheel and the steel ball is easy to cause the wear failure of the unfolding wheel.Therefore,in this paper,the numerical simulation research on the unfolding wheel wear process was established and the mathematic model of the unfolding wheel wear life prediction was established.Based on the theory of bionics and tribology,the surface micro-structure technology was applied to the working surface of the unfolding wheel.The wear life of the smooth surface unfolded wheel and the microstructure surface unfolding wheel is compared and analyzed.First,the wear characteristics of the working surface of the unfolding wheels were observed by microscope,and the wear types were determined based on the analysis of wear mechanism.Based on the classical Archard wear model and the discrete method of finite element,a discrete Archard wear model is proposed.According to the characteristics of the unfolding wheel and the classic wear process curve,the curve of the wear process of the unfolding wheel is put forward.Then,the unfolding wheel paired with the steel ball with the diameter of 16.6688 mm was selected to analyze the operating conditions of the unfolding wheels and reasonably simplify the working conditions.After simplifying the working conditions,using ANSYS software,The numerical simulation of wear process of two kinds of unfolding wheels with smooth surface and surface microstructure was carried out.The relationship between the wear depth and the wear times of the two kinds of surface expansion wheels is fitted by MATLAB software,and the relation equation between the wear depth and the wear times is obtained.The fitting curves verify the curve of the wear process of the unfolding wheel previously proposed.Finally,based on the discretized Archard wear model and the wear curve equation obtained by numerical simulation,the mathematic model of the wear life prediction of the unfolding wheel is established.The life prediction of the unfolding wheel matched with the diameter 16.6688 mm steel ball is carried out.and the wear life of the wheel with smooth surface and the surface microstructure is compared and analyzed.