Abstract
In this paper, we propose a new approach to identify the error factor of frequency response function (FRF) between actual acoustic field and finite element (FE) model. The model updating approach using sensitivity and optimization algorithm that have been conventionally applied for making it more accurately. Usually, the parametric design variable like acoustic impedance is adopted as updating variable which generates the calculation easier. However, the actual error factor is included in non-parametric. For that reason, its application is limited. Accessible concept which utilizing the driving point FRF that is often practiced in engineering. In this technique, a driving point FRF of each point in the acoustic field is compared in an actual acoustics and FE model to identify the error factors. Nevertheless, it is difficult to recognize it precisely. Since, the FRF is calculated from the time history which contains of reflection wave from the whole system, and the driving point FRF involves not only influence around excited point, yet whole system. Therefore, we propose a new approach using driving point transient response. When a certain point is excited, the sound wave propagates from excitation point to the whole system. A driving point transient response which was immediately measured after excitation, includes only influence around excitation point. By comparing the driving point transient response from those main concern, it is possible to verify whether the excited segment is an error factor or not. In addition, to confirm its influence to the measured transient response, the panel participation in the time domain was employed. The driving point transient response were utilized on a simple acoustic box to verify the proposed approach.
