论文部分内容阅读
多输入多输出(MIMO)振动环境试验是振动试验的新方法,该方法比传统的单输入单输出(SISO)方法更真实地模拟了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MIMO超高斯振动环境试验的研究十分重要。驱动信号的产生是振动环境试验的关键。提出一种基于逆系统的MIMO超高斯驱动信号生成方法。首先,根据给定的响应参考功率谱密度(PSD)和参考峭度值采用相位调节法生成参考响应超高斯伪随机信号;其次,利用逆系统方法生成超高斯伪随机驱动信号;最后,对伪随机驱动信号进行时域随机化处理得到超高斯真随机驱动信号。对一根两输入两输出的悬臂梁模型进行了仿真验证,结果表明,采用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参考谱之间的误差完全满足工程中常用的±3dB的要求,而且峭度也与给定的参考值十分接近,证实了所提方法的有效性。
Multiple Input Multiple Output (MIMO) Vibration Environmental Testing is a new method of vibration test that simulates the vibration environment of the structure under actual work more faithfully than the traditional Single Input Single Output (SISO) method. However, the actual vibration environment is often super-Gaussian, and the damage caused by the super-Gaussian excitation and the Gaussian excitation varies greatly. Therefore, Research is very important. The generation of driving signal is the key of vibration environment test. A new inverse super-Gaussian driving signal generation method is proposed. Firstly, the reference response super-Gaussian pseudo-random signal is generated by the phase adjustment method according to the given PSD and kurtosis. Secondly, the inverse system method is used to generate the super-Gaussian pseudo-random signal. Finally, The random driving signal is time-domain randomized to obtain a super-Gaussian true random driving signal. The simulation results of a two-input and two-output cantilever beam model show that the error between the output response spectrum and the given reference spectrum can be fully satisfied after the driving signal obtained by this method is loaded on the beam Commonly used ± 3dB requirements, and kurtosis is also very close to a given reference value, confirming the effectiveness of the proposed method.