A novel approach for the evaluation of frequency-band loss factor based on last decay rate of vibrational amplitude

作者：Gu, Jintao; Sheng, Meiping^*; Guo, Zhiwei; Guo, Hanbei

来源：Journal of Vibroengineering, 2015, 17(8): 4377-4389.

• frequency-band loss factor
• initial decay rate method
• last decay rate separation method
• process loss factor

A novel approach namely last decay rate separation method (LDRSM) is introduced to evaluate frequency-band loss factor. First of all, frequency-band loss factor is derived and discussed, and it shows that frequency-band loss factor is not always among all the modal loss factors but may exceed the boundary of modal loss factors, with relation to contributions of modal vibrational amplitudes and loss factors. Then process loss factor, which is related to each modal loss factor, modal displacement and time, has been introduced in such a way that it has the same value as frequency-band loss factor obtained by initial decay rate method (IDRM) at the initial moment of decay. However, it tends to frequency-band loss factor due to the contribution from smallest modal loss factor with time going. Moreover, the system error of IDRM is discussed that there are two maximum values of the error when modal amplitude ratio increases. One increases rapidly with increased disparity of the two modal loss factor, and the other is rarely affected by the disparity. After that discussion, LDRSM is derived from the characteristics of process loss factor. By implementing numerical simulation and experimental test, it is clear that LDRSM can significantly reduce the error of IDRM with satisfied accuracy.

• 出版日期2015-12
• 单位西北工业大学