负损耗因子的成因分析

本文根据双耦合系统的经典统计能量平衡方程分析了利用该方程进行SEA参数测量中产生负损耗因子的可能性;通过对双非保守耦合线性振子的振动分析,从理论上分析了负损耗因子形成的条件。结果证明:非保守强耦合是产生负损耗因子的必要条件;而测量频率带宽内不同时包含两振子的固有频率或两振子的参数存在较大差异是产生负损耗因子的充分条件。负损耗因子的绝对值随耦合参数的增大而增大。

Analysis of causes of formation of negative loss factors

Based on energy balance equations for two coupled systems in Statistical Energy Analysis (SEA),the posslbility of causing negative loss factors in measuring SEA parameters by using the equations is analyzed.The physical causes of formation of negative loss factors are theoretically investigated by vibration analysis of the two non-conservatively coupled oscillator sets From the analytical results;it is shown that the necessary condition of forming negative loss factors is that the coupling of the coupled systems is non-conservative and strong and the sufficient condition is that the excitation frequency of the external force is not equal to the natural frequencies of the two oscillators at the same time or the parameters of the two oscillators are much different.The absolute values of the negative loss factors increase with the increase of the coupling parameters.