Non-destructive evaluation of matrix cracking in composites using Lamb wave propagation

Matrix cracking is usually the onset of damage in composites. Identification and classification of this primary damage is thus of great importance. The purpose of this study was to assess the matrix cracking in composites using the guided Lamb wave propagation. Cross-ply composite specimens were fabricated. Matrix cracking with different crack density was induced in specimens using a tensile testing machine. The crack density was first measured by visual inspection and compared with that predicted by Hashin theory for each level of applied stress. Then, anti-symmetric Lamb wave at a frequency of 206 kHz was propagated on the specimens using an ultrasound actuator. The velocity of the propagated wave was measured, using which the shear modulus of the tested specimens was obtained through the solution of the corresponding inverse Lamb wave propagation problem. The crack density was precisely identified via the stiffness reduction measured by the proposed non-destructive evaluation method.

کلیدواژه ها:

Composite materials ، Matrix cracking ، Non-destructive evaluation ، Lamb wave ، Mechanical Properties