一种单输入单输出超高斯振动试验控制方法

Control method for the SISO super-Gaussian random vibration test

振动环境试验的关键是真实地模拟结构在实际工作下的振动环境。传统随机振动试验的频域方法所模拟的是平稳高斯信号,但是实际振动环境往往是超高斯的,且超高斯激励和高斯激励对结构的损害差异很大,因此对超高斯振动环境试验的研究就变得尤为重要。本文根据响应给定的参考功率谱密度和峭度,结合传统的功率谱分解方法和相位调节方法生成超高斯驱动信号。对一根单输入单输出的悬臂梁进行了仿真验证,结果表明,通过本文方法所得到的驱动信号加载在梁上后,其输出响应谱与给定的参考谱之间的误差完全满足工程中±3 d B要求,且峭度与给定的参考值十分接近。最后搭建试验平台,对悬臂梁进行了振动控制试验。试验结果表明响应谱绝大部分被控制在误差带以内,而峭度则满足完全满足参考要求。

The key of the vibration testing is to replicate the practical vibration environment of the structure accurately . The traditional random vibration test with frequency domain method aims to generate a stationary and Gaussian vibration environment .But the practical vibration environments are always super‐Gaussian ,which can cause different damages to the structures compared with Gaussian excitations .Thus ,it is significant to study the super‐Gaussian test method .In this paper ,the phase selection method and the traditional PSD decomposition method are combined to generate super‐Gaussian driving signal according to reference power spectrum density and kurtosis .A cantilever beam is used for the simulation and the results indicate that the error between output response spectrum and reference spectrum based on the proposed control algorithm meets the requirement ± 3 dB in engineering and the kurtosis also satisfies the demands . Finally ,a test with a cantilever beam is completed and the control results indicate that most output response spectrum lines are controlled within the error band ,and the kurtosis meets the reference requirement .