【作者】 隋秀凛；

【导师】 张家泰；

【作者基本信息】 哈尔滨工程大学 ， 机械设计及理论， 2011， 博士

【摘要】 虚拟制造技术是传统制造技术与信息技术结合的产物,近年来已迅速发展成为制造业的热点和前沿学科,虚拟制造的研究与开发利用已受到世界各国的高度重视。虚拟数控加工技术是虚拟制造的核心内容,对充分发挥数控机床的潜能,提高数控加工效率和质量具有重要意义。本文采用理论分析与实验研究相结合的思路,针对数控铣削加工的特点,研究了铣削力建模、铣削温度建模、刀具磨损建模、加工质量预测、加工误差分析及补偿、加工参数优化等数控铣削物理仿真关键技术,论文的研究内容主要包括以下几个部分：虚拟数控铣削物理仿真系统总体规划研究。提出虚拟数控铣削物理仿真系统的体系结构,设计了系统仿真与分析流程；构建了仿真数据库的结构及功能模型；建立虚拟数控铣削仿真环境,实现了几何仿真与物理仿真的数据共享及高效集成,为进行虚拟数控铣削物理仿真研究奠定了基础。数控铣削过程物理仿真建模研究。综合考虑实际铣削加工过程中的各种影响因素,在实验的基础上建立与实际切削拟合程度高的铣削力、铣削温度及刀具磨损物理仿真数学模型。针对任意进给方向的球头铣刀切削微元进行铣削力分析及建模,在建模过程中综合考虑了主轴偏心、刀具受力变形和振动等因素对铣削力模型的影响；在实验的基础上建立球头铣刀铣削温度模型,提出应用移动热源法建立球头铣刀铣削过程中工件的温度场的数学模型,对铣削过程中的移动面热源的温度场进行动态仿真及有限元分析；充分考虑各种因素对刀具磨损的影响,选用不同的加工参数和刀具参数组合进行数控铣削实验,实现球头铣刀磨损建模与预测。通过实验验证了所建模型的正确性。数控铣削加工质量预测及加工误差分析。提出了基于有限元法的加工质量预测方法,在分析实际加工中影响加工质量的主要因素及有限元模拟关键技术的基础上,对加工质量中的表面粗糙度及形状精度进行算法评定理论及预测算法的研究,实现了数控铣削加工质量的分析及预测；对铣削过程中产生加工误差的主要因素进行分析,建立了球头铣刀受力变形、受热变形、刀具磨损及工件受热变形的加工误差模型,并建立了综合误差模型；针对综合误差补偿进行研究,在获得各影响因素综合误差补偿值的基础上,修改刀具轨迹坐标,实现对数控程序的调整。结合具体加工工件对主要模型及方法的正确性和可靠性进行了验证。数控铣削加工参数的优化研究。提出基于物理仿真的数控铣削加工参数优化建模方法,建立了较全面完善的目标函数、决策变量及约束条件优化模型；针对切削参数优化模型决策变量非负值、约束多、目标函数复杂等问题,对遗传算法进行改进,提出了改进的多目标优化并列选择遗传算法；建立基于改进的并列选择遗传算法的铣削参数多目标优化模型,基于虚拟数控铣削物理仿真系统预测出的仿真结果数据,获得最优的切削参数,通过加工实验验证优化效果,实现了提高加工质量、生产率和节约加工成本的目标。最后实现了虚拟数控铣削物理仿真原型系统。设计了系统的运行流程,实现了系统加工过程的几何仿真和物理仿真的集成,在XH715加工中心工艺系统下实现了产品几何建模,虚拟加工过程仿真、干涉、过切及欠切检验,铣削力仿真、铣削温度预测、表面粗糙度预测及加工误差分析,通过加工误差补偿及铣削参数优化,实现了对数控加工程序的调整和优化,通过系统仿真及预测结果与实际切削实验的对比分析,验证了系统的可靠性。更多还原

【Abstract】 Virtual manufacturing technology is the integration of traditional manufacturing technology and information technology. In recent years it has been rapidly developed and become a focus and advanced subject in manufacturing. The research and development of virtual manufacturing has been attached great importance to countries in the world. Virtual NC machining technology is the core of virtual manufacturing. It has great significance to display NC machine tools’s potentiality fully, and improve the efficiency and quality.In this dissertation, the idea of combining theoretical analysis and experimental research is used. Aiming at the characteristics of NC milling, the key technologies of physical simulation for NC milling including milling forces modeling, milling temperature modeling, cutter wear modeling, machining quality prediction, machining error analysis and compensation, machining parameter optimization are researched. The dissertation fastens on the following issues:The overall plan of physical simulation for virtual NC milling is researched. System structure of physical simulation for virtual NC milling is proposed. Process of system simulation and analysis is designed. The simulation database structure and function model is built. Simulation environment of virtual NC milling is built. Data sharing and efficient integration of geometric simulation with physical simulation is realized, by which laid the foundation for physical simulation for virtual NC milling.Physical simulation model of NC milling process is researched. Considering a variety of factors in the actual milling process, the physical simulation model fitted a high degree with actual cutting of milling forces, milling temperature and cutter wear are built based on test. Milling force acting on a cutting edge element of ball-end cutter at arbitrary feed direction is analyzed. Milling forces model of ball-end cutter cutting edge element is established by considering the impact of deformations caused by the milling forces, spindle eccentricity and vibration. Temperature simulation model of ball-end cutter milling is established on the basis of experiment. Mathematical model of temperature field when work piece is milled by ball-end milling cutter is established by using moving heat source theory. Then finite element analysis and dynamic simulation of the temperature field is carried out on the basis of considering the impact of various factors. Tool wear simulation model of ball-end milling is established by using different processing parameters and tool parameters for NC milling experiments, and by using multiple linear regression model to determine the various coefficients of tool wear. The experiment results show that the model is correct.A more comprehensive optimization model of objective function, decision variables and constraints is established. Genetic algorithm is improved for the non-negative, more constraints and more complex objective function of cutting parameters optimization model. An improved parallel multi-objective optimization genetic algorithm selection is established. A multi-objective optimization model of milling parameters selection based on improved genetic algorithm parallel is established. The optimal cutting parameters are obtained based on the simulation results predicted by physical simulation system for virtual NC milling. The machining experiments verify the effect of optimization. The target of machining quality improving, productivity and processing cost savings is achieved.Finally, the prototype system of physical simulation for virtual NC milling is implemented. Operation and implementation process of the system is designed. The integration of simulation and physical simulation in machining process is achieved. Product geometric modeling, virtual machining process simulation, interference, undercutting and less cutting test, milling force simulation, milling temperature prediction, prediction of surface roughness and machining error analysis are achieved in the technology system of XH715 processing center. NC program is adjusted and optimized by machining error compensation and milling parameter optimization. The reliability of the system is verified by analyzing the comparative results of simulation and the actual cutting tests.更多还原