典型结构在单、多轴随机振动下的动力学特性对比研究

Comparison of dynamic characteristics of a typical structure under single-axial and multi-axial random vibration loads

以某典型线性结构和非线性结构为例,通过理论分析和试验研究,对比结构在单、多轴随机振动载荷下动力学特性的差别。研究结果表明:对于线性结构,单轴和多轴加载时结构的自振频率不发生变化,但由于单轴和多轴加载对结构模态有不同激发效果,振动响应谱会出现不同数量的共振峰;对于刚度非线性结构,由于多轴加载时的变形比单轴加载时大,系统刚性发生变化,自振频率也随之变化。

Linear and nonlinear structure are taken as examples in this paper. The differences of the dynamic characteristics under single-axial and multi-axial random vibration loads are studied through theory analysis and test. The research results show that for the linear structure its resonance frequencies are the same under different loads. However, its response spectrum has different resonance peaks because of the different results excited by single-axial and multi-axial loads. For the nonlinear structure, its inherent rigidity and resonance frequencies would change since the distortion under multi-axial load is larger than that under single-axial loads.