Research On A Numerical Approach Of Loss Factor Estimation Based On Power Injection Method

Aviation and space's technology developed rapidly in the 60s of the last century, require analysis and predictive methods of the complex thin-walled structure's mid-frequency and high-frequency response having urgent corresponding development. Statistical energy analysis becomes the mainstream method to solve such problems as its own unique advantages. Loss factor is extremely important parameter of the statistical energy analysis. As to the actual system, if know the changes of the power flow and structure's parameter between the coupled systems, we can effectively and accurately predict the structural vibration and acoustic response.The actual system's diversity and complexity make it difficult to calculate the loss factors by theoretical formulas, and no theoretical method to guarantee the precision and accuracy even though obtain the loss factors by complex theory. In addition to theoretical analysis methods, the actual measurement of loss factors is quite popular in the field of SEA. The method of actual measurement can work after the complex systems produced, which do not meet the requirement of rapid design. This paper has proposed a numerical solution of the loss factors based on the power injection method. Firstly, testify the advantage of adopting the rapid harmonic sweep signal as the excitation signal by the experiment of coupled thin-walled folded plates. and then through the numerical solution of the thin-walled folded plates and thin-walled U-shape pipe to verify the feasibility of this approach.The vibration energy of the coupled thin-walled folded plates are almost the same with the ones which the AutoSEA calculate, proved that adopting the rapid harmonic sweep signal as the excitation signal is reasonable. The numerical solution of loss factors have also been proven applicable in the scope of software computing capacity. This paper also analyse the causes of errors and the method's development trend.