薄铝板统计能量参数的测试方法研究

On the Parameters Measurement Method in Statisitical Energy Analysis of a Thin Aluminum Plate

内损耗因子和模态密度都是统计能量分析(SEA)方法的关键参数,它们分别反映了振动结构系统的能量损耗与存储能力,对预示结构的振动响应有重要的影响。目前获得它们最常用和最可靠的方法还是通过实验来测量。本文分别采用了瞬态衰减法和稳态能量流法测试薄铝板的内损耗因子,并阐述了这两种方法实施过程中的注意事项,对比分析了它们的测试结果;又采用导纳法测试了薄铝板的模态密度,并对其测试结果进行了附加质量修正。实验结果表明:内损耗因子的两种测试结果一致性较好,经过质量修正后的模态密度与理论值吻合良好。

Both internal loss factor and modal density are the key parameters of statistical energy analysis （SEA） method. They reflect the energy loss and energy storage capacity in structural vibration, so have important influences on predicting the vibration response of structure. At the present time, the most common and most reliable way to obtain these parameters is experimental measurement. The authors adopted transient decay method and steady-state energy flow method to measure the internal loss factor of a thin aluminum plate. Some items needed to pay attention in both methods＇ implement are elaborated and the measured results are compared in this paper. The modal density of a thin aluminum plate was also measured by using point admittance method, and the mass correction was added to its results. Experimental results show that the results from both transient decay method and steady-state energy flow method for internal loss factor have a good coincidence and modal density agrees well with the theoretical value after mass correction.