多轴向与单轴向随机激励下结构动力学响应对比研究

Dynamic responses of structures under multiaxial and uniaxial random excitations

为了分析结构在多轴向与单轴向振动环境下疲劳失效行为存在的差异,从理论分析、数值仿真以及试验研究三个方面,对典型结构开展了多轴向与单轴向随机振动环境下动力学响应对比研究。研究结果表明:多轴向振动环境能够同时激发结构不同方向的模态振型,在三个轴向互不相关的振动环境下,结构的动力学响应为各个方向单轴向振动时引起的动力学响应的叠加;若各轴向载荷间存在相关性,则其相关性对结构动力学响应存在明显影响,且影响是有规律的。对以上结论产生的原因进行了分析研究,为两种工况下结构振动疲劳失效行为的研究奠定了基础。

In order to evaluate the vibration failure behaviors of structures under multiaxial and uniaxial excitations, contrast theoretical analyses, finite element analyses and experiments on the dynamic responses of structures under multiaxial and uniaxial excitations were performed. The results show that the structural vibration modes in different directions can be excited simultaneously under multiaxial excitations. Under three simultaneous uncorrelated axial excitations, the responses of structures are the square root of the sum of the squares of each uniaxial excitations results. If the random excitations are correlated, there are significant effects of input correlation on the dynamic responses, and the effects are of regularity. In addition, the reasons for the phenomena mentioned above were also analyzed. The study provides references for the vibration failure behavior analysis of structures under multiaxial and uniaxial random excitations.