A Cutting Parameter Optimization Method Based On Machining Dynamic Features For Complex Structural Parts

Complex structural parts are consist of amounts of thin-walled structures,which require high machining accuracy.The cutting parameters have an important effect on the machining quality and machining efficiency of complex structural parts.The machining process of complex structural parts contains a plurality of machining operations,companying with a series of interim machining state.The change of interim machining state leads to the constant change of the dynamic characteristics and stiffness of the workpiece.In order to improve the machining efficiency,the cutting parameter optimization of complex structural parts during the interim machining state has always been a problem in manufacturing industry.In order to solve the problem,the dissertation focuses on the cutting parameter optimization method based on machining dynamic features for complex structural parts.The research achievements include:(1)A dynamic model based on machining dynamic features for complex structural parts is constructed.The interim machining state model is the basis of building the dynamic model for complex structural parts.In order to address the issue of the workpiece dynamic characteristics change constantly with the material removal processing,a polymorphic evolution model based on the interim machining state geometries during the machining process is constructed.Then the dynamic model for complex structural parts in the interim state is constructed,laid the foundation for the cutting parameter optimization.(2)A cutting parameter optimization method based on machining dynamic feature for complex structural parts is proposed.The factors that influence the cutting parameters during the machining process are determined according to the actual situation,and the cutting parameter optimization model based on the genetic algorithm is established.In order to address the issues of workpiece rigid changing constantly with the machining position changing,the optimization of the cutting depth in the interim machining state is implemented based on the dynamic model constructed above.(3)A feed rate adjustment method based on cutting force monitoring data is proposed.For unstable situation in the machining process induced by uneven machining allowance and workpiece material,the adjustment method of feeding speed is studied.A cutting force monitoring data file based on machining dynamic feature is established,giving the largest cutting force of machining feature,and adjust the feed rate through iterative calculation.(4)A cutting parameter optimization system based on dynamic machining features for complex structural parts is developed,and it has been implemented and validated that high machining efficiency and machining stability have been achieved.