Finite Element Analysis of Laminated Composite Skewed Hypar Shell Roof Under Oblique Impact with Friction

Impact of foreign objects on laminated composite has become a great concern despite its other advantages. Hypar (hyperbolic-paraboloid), a preferred shell roof geometry is frequently subjectedto such impacts. In most of the practical situations such impacts are oblique. Present study investigates dynamic behaviour of a simply supported composite hypar shell roofs under oblique impact, considering modified Hertzian contact law, for different impact velocities and impact angles allowing for anisotropic friction. Time dependent equations are solved using Newmark's time integration algorithm. Time histories of contact force at point of impact and that of displacement are presented to extract significant engineering conclusions. There are also proposals of practical parameters for designing such shells through static simplification of the problems.