舰用中低频伪速度谱测量摆性能研究

Performances of a novel pendulum for measuring ship low-middle frequency pseudo-velocity spectrums

以校验压电加速度计所测量的中低频段伪速度谱和取代传统低频振子、簧片仪为目的,设计一种新型测量装置-测量摆,用于测量横向冲击环境的伪速度谱。建立测量摆运动微分方程,采用Ritz-Galerkin方法进行近似求解模态频率,并用杜哈美积分方法求解冲击载荷下的最大角度响应;利用有限元软件ANSYS动力学模块建立有限元模型计算其模态频率和最大角度响应;通过振动台对测量摆原理样机进行扫频和冲击实验最终验证其测量性能。理论计算和实验结果表明,测量摆不仅能较好地校验加速度计所测的中低频段伪速度谱曲线;而且与低频振子相比,具有重量轻体积小的优势;与簧片仪相比,具有测量频域范围广的优点。

Aiming at verifying the low-middle frequency pseudo-velocity spectrums measured by piezoeletric accelerater and replacing the conventional low-frequency oscillator and reed, a novel measuring pendulum was proposed. The equation of motion of the measuring pendulum was derived. The Ritz-Galerkin method was used to solve the equation to obtain the modal frequency, and the Duhamel integral method was used to obtain the maximum angle response of the system. To verify the analysis method, the finite element software ANSYS was used to calculate the modal frequency and maximum angle response. The performance of a measuring pendulum prototype was tested on a vibration excitation platform. The results demonstrate that the measuring pendulum can well verify the low-middle frequency pseudo-velocity spectrums measured by piezoeletric accelerater. It has the smaller volume than the low-frequency oscillator and the larger measuring frequency field than the reed.