悬挂式测力天平频响函数研究

Frequency Response Function of Suspended Balance

对风洞天平进行动态特性研究有助于评估天平结构设计的合理性,频响函数可以直观反映测试系统的动态特性。针对一种新型悬挂式测力天平,设计一种动态标定装置并进行了相关实验。采用电磁铁和砝码对飞行器模型施加负阶跃载荷,由输入载荷和天平输出辨识频响函数。辨识频响函数时,通过布莱克曼窗和数据段重叠对数据进行预处理以回避周期延拓问题。在时域中模拟了时域频响函数和输入数据乘积的输出曲线,数据在非振荡环节的相似度为91.7%,说明天平在低频下的线性度良好,满足工程要求。

The study of the dynamic characteristics of the wind tunnel balance is helpful to evaluate the structure design of balance,while the frequency response function can directly reflect the dynamic characteristics of the system.A dynamic calibration device was designed and related experiments were carried out for the suspended balance.A negative step load is applied to the aircraft model using electromagnets and weights.The frequency response function is recognized by the input load and the balance output.Before the frequency response function is recognized,the data is preprocessed by the Blackman window and the data segment overlap to avoid the cycle extension problem.In the time domain,the output curve of the time domain frequency response function multiplying the input data is simulated.The similarity of the data in the non-oscillating block is 91.7%,which indicates that the linearity of the balance is good at low frequencies and meets the engineering requirements.