基于灰色理论的数控机床复合结构床身优化设计及其性能分析

为探索提高数控机床的综合性能,以某卧式加工中心铸铁床身为原型,设计了一种钢板-混凝土复合结构床身.采用正交实验、灰色关联和组合赋权相结合的方法对其结构进行优化并得到了最优的参数组合,对复合结构床身进行有限元仿真分析,并将结果与原型铸铁床身比较.结果表明:在床身质量仅增加2.3%的情况下,复合结构床身的最大静应力和最大静变形分别降低了51.3%和82.9%;前三阶固有频率提高了143.9%、156.8%和148.7%;x轴导轨和z轴导轨中心节点在x、y、z方向上的最大振幅降低了97.6%、97.1%、94.0%和99.6%、97.9%、85.4%;导轨滑块连续在导轨表面摩擦1800s时导轨的最大热-结构耦合变形量降低了7.3%.

Optimization design and performance analysis of CNC machine tools composite structure bed based on grey theory

To improve the comprehensive performance of CNC machine tools, a steel-concrete composite structure bed is designed, based on a certain horizontal machining center cast iron bed. The method of orthogonal experiment, grey theory and combination weighting is used to optimize its structure, the optimal parameter combination is obtained. Finally, the finite element simulation analysis of the composite structure bed is carried out, and the results are compared with the prototype cast iron bed. The results show that: when the bed mass is increased by 2.3%, the maximum static stress and the maximum static deformation of the composite structure bed are reduced by 51.3% and 82.9%, respectively. The first three natural frequencies are increased by 143.9%, 156.8% and 148.7%, respectively. The maximum amplitudes of the center nodes of x-axis guide rail and z-axis guide rail in x, y and z directions are decreased by 97.6%, 97.1%, 94.0% and 99.6%, 97.9% 85.4%. When the sliding block of the guide rail continuously rubs on the guide rail surface for 1 800 second, the maximum thermal-structural coupling deformation of the guide rail is reduced by 7.3%.