복합적층판의 저속충격 거동에 대한 비선형 해석

Abstract

The nonlinear dynamic behavior of graphite/epoxy laminated composite subjected to low velocity impact is investigated suing a finite element method. The dynamic von-Karman plate equations considering large deflection of a plate are modified to include the effect of transverse shear deformations as in the Mindlin plate theory and also the rotary inertia effect is considered. In the finite element analysis, the Newmark``s constant acceleration time integration algorithm is used. For an efficient and accurate iteration, Akay``s skim is used. An experimentally established contact law through the statical indentation test is incorporated into the present finite element program. The impact responds such as contact force, central deflection and dynamic strain history from the nonlinear analysis are compared with those from the linear analysis. The effects of impact velocity and mass of the impactor on the responds of laminate are discussed.