Lamb Wave Imaging for Complex Box-Beam Structures Based on Frequency Response Function

The box beam is the key component of box structure hoisting machinery, and its structural integrity and damage detection are extremely important for the safe operation of the hoisting machinery. In this paper, a cross-shaped dense array imaging method based on frequency response function is proposed for the damage location of box girder structure. Firstly, considering the complexity of the box girder structure, the ultrasonic guided wave propagation characteristics of the box girder structure are studied by the finite element analysis method. Secondly, an experiment is designed in the complex structure box beam to verify the effectiveness of the frequency response function (FRF) method and greatly improves the detection efficiency. Then, a cross-shaped dense array is arranged combined with the advantages of dense array according to the demand of damage location of box beam structure. Finally, the damage location of box beam structure is realized by combining the total focusing imaging algorithm and the sign coherence factor imaging method. The number of positioning errors confirms the effectiveness of the proposed method, providing a new approach for solving the problem of damage location of box beam structures.