A new exponential wear model to analyze precision retention of guideway based on macro-micro multiscale method

At present, wear models and accuracy prediction of guideway are established based on elastoplastic mechanics of continuous media. These methods are limited to describe the process of accuracy degradation by using the material performance defined based on macroscopic hypothesis condition. In this paper, the multiscale method based on quasicontinuum medium(QM) principle is proposed to describe the degradation process of guideway linear precision with an exponential model. According to the wear distribution of the guideway surface with the micro-morphology evolution process, the measurement value of the guideway linear precision is modeled systematically. Then, using the quasicontinuum medium method instead of the continuum hypothesis, the exponential wear model of guideway is established. The exponential wear model uses the wear exponent to describe the wear status based on linear precision measurement rather than tremendous wear volume tests. By means of Depth From Defocus (DFD) method, the micro-topography information of the guideway surface is obtained. Therefore, the wear state of the guideway is verified under different loading conditions, and the validity of using the QM method to establish the guideway exponential wear model is verified.