Sensitivity analysis for structural frequency response characteristics. (First report. Proposition of new frequency response sensitivity analyses and comparison between some different methods).

Frequency response characteristics of a vehicle's structure affect the vehicle's sound and vibration, such as booming noise, road noise, riding comfort and handling stability. Therefore, a reliable analysis technique to determine the proper means of effectively controlling these factors, is desired. Sensitivity analysis, in the broad sense, is effective to accomplish this purpose, as it shows the change in response when parts of the structure are varied. Sensitivity analysis must be accurate and time-efficient. There are no studies comparing the merits and demerits, of major methods of frequency response sensitivity analysis from these two aspects. In this paper we introduce two new modal frequency response sensitivity analysis methods, and compare them with conventional methods by using the FEM bar model. We define relative advantages of these methods. In addition we clarify the important points when applying the sensitivity analysis to optimize a frequency response of a large scale vehicle model.