An Assessment of Damping Measurement in the Evaluation of Integrity of Composite Beams

Abstract

The measurements of vibration frequency and damping coefficient have been used to assess the integrity of composite materials and structures by quite a few investigators. In this study, an impulse technique which uses a displacement transducer as a non-contact probe for the measurements of damping up to the third modes has been presented. Com posite beams with structural discontinuity, damage, and imperfection have been investi gated. This study assesses the utility and sensitivity of the impulse technique in the damping measurements for composite beams. Results have shown good correlation be tween the increases in damping and the severity of damage caused by notches and artificial delamination. However, there is no significant change in damping for the composite beams with matrix cracking and inclusion.