To ensure the accuracy and precision of vibration test,a universal checking method is proposed.The use of the method is discussed and an actual example is given.First,the calibration of the 7703A-500 type sensor is an...To ensure the accuracy and precision of vibration test,a universal checking method is proposed.The use of the method is discussed and an actual example is given.First,the calibration of the 7703A-500 type sensor is analyzed on the basis of frequency response method.The frequency range of normal working can be determined by the exact calibration of sensitivity,frequency response and linearity.For the basic problem of abnormal signals appearing in test system,the method of zero check and loading vibration source are developed.The frequency spectrum of output signals is employed to distinguish the noise signal,unknown source signal and useful signal effectively.Finally,the experimental results reveal the importance to improve the accuracy of the results of practical vibration test.展开更多
基金Shan Dong Scientific Research Foundation for Excellent Young Scientists(Grant No:BS2011ZZ001)National Natural Science Foundation of China(Grant No.51105172)
文摘To ensure the accuracy and precision of vibration test,a universal checking method is proposed.The use of the method is discussed and an actual example is given.First,the calibration of the 7703A-500 type sensor is analyzed on the basis of frequency response method.The frequency range of normal working can be determined by the exact calibration of sensitivity,frequency response and linearity.For the basic problem of abnormal signals appearing in test system,the method of zero check and loading vibration source are developed.The frequency spectrum of output signals is employed to distinguish the noise signal,unknown source signal and useful signal effectively.Finally,the experimental results reveal the importance to improve the accuracy of the results of practical vibration test.
文摘辨识模态参数是准确获得风机塔架结构动态特性的基础。由于风力机叶片上的重力和风切变引起的气动载荷都会周期性地改变大小和方向及受到桨叶螺距等周期载荷的影响,运行中的风力机表现为线性时间-周期(Linear time-periodic)系统。提出一种基于响应信号的运行中风机塔架工作模态分析辨识方法。以长度为60 m的风机塔架结构为研究对象,利用Periodic past output multivariable output-error state space(简称Periodic PO-MOESS)算法,对受到周期激励信号作用的结构进行模态辨识,并比较辨识结果和仿真结果的差异。讨论周期激励下该算法辨识结构模态参数的可行性,并分析在白噪声工况下的辨识结果精度,结果表明该算法可以有效识别运行中风力机系统的模态参数,且具有良好抗噪性能。
