数控插齿机全域静刚度快速预估及分析

Rapid prediction and analysis of the static stiffness in the full working space of the CNC gear shaping machine

  • 摘要: 针对机床整机全域静刚度分析中难以在保证计算精度的同时实现快速预估的问题,以数控插齿机为研究对象,提出了一种机床整机全域静刚度快速预估及分析的方法。首先,基于静态缩聚与代理模型的方法建立子结构的静刚度模型,并基于静态缩聚与集中参数法建立结合部的静刚度模型。其次,组合所得到的子结构静刚度矩阵与结合部静刚度矩阵,建立位置相关的机床整机半解析静刚度模型。再次,通过对比有限元模型与所提出模型的计算效率与计算结果,验证模型的正确性与有效性,分析特定工况下工作空间中机床整机末端相对位移分布规律。最后,基于灵敏度分析的方法找出机床整机静刚度的薄弱环节,通过提升对应环节的刚度参数,有效地降低了机床整机末端相对位移。

     

    Abstract: In order to solve the problem that it is difficult to achieve rapid prediction while ensuring the calculation accuracy in the analysis of the global static stiffness of the whole machine tool, a method for rapid prediction and analysis of the global static stiffness of the CNC gear shaping machine is proposed. Firstly, a static stiffness model of the substructure was established based on the static condensation and surrogate model, and a static stiffness model of the joint was established based on the static condensation and lumped parameter method. Secondly, the obtained substructure static stiffness matrix was combined with the joint static stiffness matrix to establish a semi-analytical static stiffness model of the entire machine tool that is position dependent. Thirdly, by comparing the computational efficiency and results of the finite element model with the proposed model, the correctness and effectiveness of the model were verified, and the distribution law of relative displacement at the end of the machine tool in the workspace under specific working conditions was analyzed. Finally, based on sensitivity analysis, the weak links in the static stiffness of the machine tool were identified. By improving the stiffness parameters of the corresponding links, the relative displacement at the end of the machine tool was effectively reduced.

     

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