基于主轴动态响应的车削加工精度可靠性及灵敏度分析

摘要

The effects of a spindle’s forced vibration on cutting precision reliability and reliability sensitivity of random parameters were studied in consideration of random factors.The forced vibration of the lathe spindle took place under the action of dynamic cutting force in the cutting process.The frequency response of the spindle was calculated with the finite element method.The randomness of cutting parameters was considered and the frequency responses were calculated under different parameters based on the random sampling.The relation expression between frequency responses and random parameters was fitted by using the neural network training method.The reliability performance function of the cylindricity error caused by the forced vibrations of the spindle during cutting process was established,and the reliability and reliability sensitivity were calculated with the linear second order moment method.%考虑随机因素的影响，研究主轴受迫振动对车削精度可靠性的影响及随机参数的可靠性灵敏度。车床主轴加工时受到动态切削力作用，使主轴产生受迫振动。利用有限元方法计算主轴振动频率响应。考虑到加工过程切削参数的随机性影响，对切削参数进行随机抽样，计算不同参数条件下的频率响应。采用神经网络训练方法拟合频率响应与随机参数之间的关系式。建立车削加工时主轴受迫振动产生圆柱度误差的可靠性功能函数，并采用一次二阶矩法计算可靠度与随机参数的可靠性灵敏度。