Dynamic instability behavior of laminated hypar and conoid shells using a higher-order shear deformation theory

In the present investigation, dynamic instability behavior is studied for the two laminated composite shells having twist radius of curvature, viz., hypar (hyperbolic paraboloid bounded by straight lines, HYP) and conoid (CON). A higher-order shear deformation theory is employed in the C0 finite element formulation. Higher-order terms in the Taylor’s series expansion are used to represent the higher-order transverse cross sectional deformation modes. The formulation includes Sanders’ approximation for doubly curved shells considering the effect of transverse shear. The boundaries of dynamic instability regions are obtained using Bolotin’s approach. The structural system is considered to be undamped. The correctness of the formulation is established by comparing the authors’ results of problems with those available in the published literature. The effects of different parameters are studied on the dynamic instability regions of laminated HYP and CON shells.