Damaged composite laminates: Assessment of residual Young's modulus through the Impulse Excitation Technique

The objective of this study is to evaluate the capability of the Impulse Excitation Technique (IET) in assessing the residual elastic properties of damaged composite laminates. To this aim, the Young's modulus in the longitudinal direction of undamaged and damaged thick laminates is evaluated both with the IET and with a tensile test, according to the ASTM standard. The differences between the reference ASTM values and the IET values are then interpreted through a simple mechanical model of the damaged laminate. Potentialities and weaknesses in the application of the IET for the assessment of the residual elastic properties are finally discussed and highlighted in the paper.