公差分析中的非理想表面模型技术研究现状与展望

As the actual surfaces of manufactured parts are inevitably different from the designed ideal ones, how to quickly and accurately establish a model that can describe such differences as geometric defects, has always been challenging in tolerance analysis. Current geometric defect models usually simplify geometric errors into rigid translation and rotation of ideal surfaces, ignoring the influence of surface topography on the relative position among parts, which in turn restricts the accuracy of tolerance analysis results. As a model of geometric defects based on the discrete geometry framework, skin model shapes (SMS) enable to reflect the geometric deviations more realistically in tolerance analysis. Therefore, the emergence of SMS has attracted widespread attention from scholars. However, the current research on SMS is characterized by a lack of systematic organization, and there is no consensus regarding its relative importance. This study systematically reviews the origin of SMS. The characteristics and connotations of SMS are further clarified. A technical framework of SMS technology is proposed, extracting three technical issues of SMS, including the definition of non-ideal surfaces, the law of geometric error distribution and the mechanism of multi-physical fields. Three types of methods, in the context of feature operations, geometric error modelling and multi-physical field characterization, are summarized as key enablers in the framework. Then, existing modelling methods for geometric defects and their typical applications are analysed in detail. Three core challenges currently faced by SMS at the theoretical level, technical level and application level are pointed out. Finally, three directions for the future development of SMS technology are highlighted.