NONLINEAR IMPACT RESPONSE OF LAMINATED PLATES USING A HIGHER-ORDER THEORY

LOW velocity impact of laminated composite plates is analyzed using a higher order theory. Hamilton's principle is used to derive the transi ent finite element equations of the plate and the motion of the impact or. The model accounts for von Karman nonlinear strain-displacement re lations, rotary inertia and a nonlinear contact law which accounts for permanent deformation. The nonlinear time dependent equations are sol ved using direct iteration scheme in conjunction with the Newmark time integration scheme. A variety of case studies are conducted for conta ct force and center deflection histories of laminated plates. The resu lts indicate that the contact force history is initially influenced by mass properties and impactor velocity, whereas at a later stage lamin ate stiffness plays the more active role. Results are also presented f or the inplane stress and transverse shear stress histories using the higher order theory and are compared with those obtained using the fir st order theory.