Damage identification of low-density material–filled sandwich panels with truss core based on vibration properties

A damage-identification method based on flexibility matrix and Teager energy operator is proposed for low-density material–filled sandwich panels with truss core. In the proposed damage index, weight coefficient r is introduced to consider the effect of damages on both high-order and low-order modes. Numerical simulations and experiments are conducted to assess the performance of the proposed method. Effects of Young’s modulus of the filler material on the accuracy of the proposed method are also discussed. Results reveal that the method is reliable and effective for single-damage and multiple-damages identification of filled sandwich panels with truss core, and weight coefficient plays an important role, especially for cases with multiple damages or damages of small extent. Damage identification becomes more difficult as Young’s modulus of the filler increases, and there is a critical value, after which the damage could not be identified by the proposed method.