振动试验夹具共振频率设计要求研究

为了使振动试验夹具的频率设计要求更加符合工程实际，文章对传统设计要求进行了总结，根据随机振动理论研究了传统设计要求与试验实际情况的差异。研究表明传统设计要满足一阶固有频率最大化的要求，而该要求存在不足：一是建立试验系统动力学模型时未考虑试件的质量及刚度，二是未考虑夹具与振动台连接的边界条件，三是未考虑载荷激励方向与模态关系。针对这些不足，文章提出了夹具共振频率最大化设计要求。分别采用传统的一阶固有频率最大化设计要求和共振频率最大化设计要求对某导弹夹具进行了设计，对比研究结果表明采用共振频率最大化设计要求所设计的夹具共振频率更高、质量更小。

The design requirements of the resonance frequency of vibration test fixtures

In order to make the frequency design requirements of vibration test fixtures more consistent with the engineering practice, the traditional design requirements are compared with the real cases based on the theory of random vibration in this paper. It is shown that the traditional design requirements are defective in three aspects. Firstly, the mass and the stiffness of the testing object are not considered. Secondly, the boundary conditions between the fixtures and the shakers are ignored. Finally, the relationships between the driving direction and the models are not well accounted. The new design requirements of the resonance frequency of test fixtures are proposed. Two missile fixtures are designed according to the traditional design requirements and the new design requirements, respectively. The design results show that the resonance frequency of the fixture designed according to the new design requirements is higher, and its mass is lower.