Shear Locking Effect Analysis on Transient Finite Element of Impact on Composite Plates

In this paper, transient impact on a composite plate is studied using the spherical nose . The governing equations of the plate based on the first shear deformation, are discretized using the Galerkin finite element method. The mass, stiffness and force matrices are obtained such that the terms of bending and shear in the matrices are considered separately, and the Gaussian integration method is used to overcome the shear locking phenomena. The model is developed so that it is capable to taking frequent loading and unloading during the impact. The governing equations of the plate and the projectile are solved in the time domain using the Nikolson and Newmark integration methods. The results are compared with the results of other researchers and the accuracy of the model is verified. According to the numerical analysis, it is observed that the present model has accurate results for thick and thin plates. The low velocity impact on a composite plate with clamped and mixed boundary conditions is studied and the time history of response of the plate such as deflection, penetration, contact force and kinetic energy are presented.