基于FRF的螺栓结合部动力学问题的研究

Research on Dynamics of Bolted Joint Based on FRF

螺栓联接是机床结合部的重要形式之一,其动力学特性对机床动态特性影响显著。从子结构综合的思想出发,通过FRF法建立了螺栓联接结合部动力学的理论模型,并基于力学平衡方程和位移兼容方程,推导了结合部动刚度的辨识方程;进而,基于最小二乘法提出了结合部动刚度的等效计算方法;最后,规划了基于LMS振动测试环境的动力学试验,测试结果显示:有限元预测值与试验实测值之间一致度良好,验证了方法的可行性。

Bolt connection is one of the important forms of contact surface of machine tool,and its dynamic characteristics have great influence on dynamic characteristics of machine tool.In this paper,the theory model of bolted joint is established based on substructure synthesis method of FRF,and the fundamental formulas are deduced via the mechanical equilibrium equation and the displacement compatibility equation.The equivalent calculation method of the dynamic stiffness is proposed based on the least square method.The dynamic test is planed based on LMS vibration testing platform.The test results show that the predicted value of finite element is in good agreement with the measured value,and the feasibility of the method is verified.