Abstract
To estimate the sound radiation power as an objective function in noise reduction design, vibration characteristics of the structure and the force exciting it need estimating. However, as the vibration characteristics of the structure change, the exciting force also changes, therefore the estimated exciting force cannot be directly applied to the structure after it changed for noise reduction design. In this paper, we propose a method to estimate the response of the structure after its vibration characteristics are changed considering the change of exciting force. By introducing an exciting source that generates exciting force, the excitation force is expressed using the frequency response function of the structure. The exciting source is modeled as having a vibration system showing a linear response to the input, and the number of points connected to the structure is not limited. We can identify the vibration characteristics of the exciting source and the input applied to it by measuring the response with a known structural change. In experiments on cantilevered flat plates, changing structure by adding mass to several different positions, identify characteristics of the exciting source and estimate the responses considering the exciting force change. Moreover, applying this method to the search for the attachment position of the rib which minimizes the sound radiation power, we verify the validity of the method.
