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The doubly ruled hypar shell, being one of the most feasible shell roof configurations, enjoys industrial preference for covering large column free areas. This class of shells is unique as the only curvature here is the cross curvature and these do not admit easy closed form solution particularly when the boundary conditions are complicated. Laminated composite, an innate choice to different industrial sectors for its huge specific strength and stiffness, good weathering resistance, is now being extensively employed in civil engineering. However the low transverse shear strength of the composite shell impelled the researchers to study the response of the same under the action of impact loads. In the present study, a finite element code is functioned to investigate the impact induced stress history generated in simply supported laminated composite hypar shell for different impact velocities of a spherical solid striker. Contact behavior is described by modified Hertzian contact law where as time dependent equations are solved using Newmark’s time integration algorithm in present analysis. A practicing engineer often has to select a particular shell option consisting stacking sequence among a number of possibilities. The present paper discusses the behaviour of composite hypars under low velocity impact and different stresses induced due to the same from engineering standpoint to propose a selection guide line among the available options and to proposes values of practical parameters like the equivalent static loads and dynamic magnification factors for designing such shells through static simplification of the problems.

The present work aims to study and report the first ply failure load of laminated composite skew plate of different laminations and stacking sequences with a practical boundary condition. The finite element model is developed using eight noded isoparametric curved quadratic shell element with five degrees of freedom per node (with three translations and two rotations). Numerical experiments are conducted considering skew plates of varying skew angles, laminations and stacking patterns. First ply failure loads are evaluated for seven different failure criteria such as maximum stress, maximum strain, Tsai-Wu, Tsai-Hill, Hoffman, Puck and Hashin’s failure criteria. The minimum value of load obtained from different failure criteria is chosen as the governing first ply failure load value. Benchmark problems are solved to validate the correctness of the present approach of evaluation of first ply failure load and incorporation of skew geometry in the present model. The results of authors’ own problems are finally studied meticulously and relative performance matrix of skew plate options of different combination of skew angle and stacking sequences are reported.