Affiliations: Mechanical Engineering Department, Jadavpur
University, Kolkata 700032, India | Department of Mechanical and Control Engineering,
Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8552,
Japan
Abstract: In this paper a transient dynamic finite element analysis is
presented to study the response of delaminated composite pretwisted rotating
shallow shells subjected to low velocity normal impact. Lagrange's equation of
motion is used to derive the dynamic equilibrium equation and moderate
rotational speeds are considered wherein the Coriolis effect is negligible. An
eight noded isoparametric plate bending element is employed in the finite
element formulation incorporating rotary inertia and effects of transverse
shear deformation based on Mindlin's theory. 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 which
accounts for permanent indentation is utilized to compute the contact force,
and the time dependent equations are solved by Newmark's time integration
algorithm. Parametric studies are performed in respect of location of
delamination, angle of twist and rotational speed for centrally impacted
graphite-epoxy composite cylindrical shells.
