Material Parameter Identification For Plate Structure Based On Local Vibration Differential Method

Aircraft structures in service are always subject to strong vibration, resulting in material fatigue, which may cause the collapse of the whole structure. Therefore, it is important to periodically evaluate integrity of aircraft structures through non-destructive testing (NDT). "Pseudo-Excitation" (PE), the typical material parameter identification method, has been utilized to detect and evaluate the defects via calculating local vibration displacement response. However, high order derivative of the measured displacement via finite difference scheme is prone to result in measurement noise, which will affect the evaluation accuracy. To solve the problem, weak form of material parameter identification method is proposed in this paper. At the same time, the influences of measurement interval and noise in the finite element method are discussed, and the effectiveness of the proposed method was verified. This paper conducts research and analysis from two aspects: theoretical analysis and numerical simulation.