Effect of Twist and Striker Velocity of Torsion Stiff Composite Conical Shells under Multiple Delaminations

The low velocity impact response of torsion stiff composite pretwisted conical shells is portrayed in the present study. The formulation is based on Mindlin's theory incorporating rotary inertia and effects of transverse shear deformation. An eight noded isoparametric plate bending element is employed to satisfy the compatibility of deformation and equilibrium of resultant forces and moments at the delamination crack front. A multipoint constraint algorithm is incorporated which leads to unsymmetric stiffness matrices. The modified Hertzian contact law is employed to simulate the contact force and the time dependent equations are solved by Newmark's time integration algorithm. Parametric studies are conducted with respect to triggering parameters like twist angle, target displacement, initial velocity of striker considering low velocity centrally impacted spherical mass.