Stress Analysis of Anisotropic Laminated Plates

Membrane and interlaminar stresses in statically loaded and vibrating composite structures are obtained by determining optically and numerically the respective partial derivatives of the holographically recorded transverse displacement field. A clamped, circular, orthotropic boron-epoxy plate under a uniformly applied static pressure and vibration are considered separately. Under uniform static pressure, γ_{r θ} = 0, while the anisotropy of the laminated composite results in τ_{r θ} ≠ 0, which is unlike the corresponding isotropic case. The vibrating plate has complicated, unsymmetrical displacements producing both in-plane shearing strains and stresses. The higher order derivatives are obtained optically by holographic-moire and numerically by employing cubic-spline and discretequadratic differentiate functions.