控制箱夹具传递特性及对振动信号失真的影响分析

文章针对某控制箱夹具非主振方向运动过大致振动台信号传递失真问题进行有限元仿真分析。在分析控制箱夹具传递特性的基础上,通过大质量法探讨基于实测加速度数据直接加载的振动台-夹具-试验件耦合模型的响应计算方法,分析夹具致信号传递失真原因,并通过厚度优化提高夹具的固有频率。研究结果表明,夹具在激励频段内的非主振方向共振将导致试验件在该方向的过考核;模态贡献量分析可以更具针对性地设计或改进夹具结构。

Transfer characteristics and influence analysis on vibration signal distortion of control box fixture

The FEM analysis is applied to study the vibration signal distortion due to the excessive motion of the control box fixture in a direction other than the principal vibration direction. The transfer characteristics of the control box fixture are analyzed first. And then the vibration response of a vibration table-fixture-product coupling model based on the measured acceleration data is calculated by the large mass method. The signal transmission distortion is shown to be caused by the fixture. By the thickness optimization, the natural frequency of the fixture is effectively improved. It is shown that the resonant vibration of the fixture in a direction other than the principal vibration direction within the excitation frequency range causes an over-rigorous examination of the product, and the modal contribution analysis can be more targeted to the design or the improvement of the fixture structure.