Dynamic studies of angle-ply laminates including flexure–torsion coupling using laser holography

Laser holographic interferometry has been applied to experimentally investigate the effect of flexure–torsion coupling stiffnesses on the vibrational characteristics. Test specimens are two special types of angle-ply laminates, which enables us to examine the influence by a flexure–torsion coupling term alone. The theoretical analysis by a finite element method is also conducted to support the experimental results. It is found that the effect of coupling stiffnesses on the natural frequencies is comparatively small. On the other hand, the mode shapes are strongly affected by the coupling terms depending on both the fiber orientation and the aspect ratio of a cantilevered laminate.