Indentation Analysis of an In-Plane Prestressed Spherical Composite Sandwich Shell Subjected to a Rigid Cylindrical Indenter

In this article a closed form solution is derived for the deformation response of a spherical composite sandwichshell subjected to static indentation of a rigid blunted cylindrical indenter. The facesheet deflection is several times thelaminate thickness so that bending moments may be neglected and only membrane forces are considered in thefacesheet. In contrast to the existing analytical model for the indentation of spherical composite sandwich shells, in thepresent model, the stacking sequence of the facesheets can be completely arbitrary, so that the shear-extension couplingterms, i.e.16 A and 26 A , can also be included in the analysis. Furthermore, in the present model the effects of the initialin-plane normal and shear forces on the edges of the sandwich shell are also considered. An improved contact law isderived based on the minimum total potential energy principle. The elastic strain energy, the plastic work dissipated incrushing the core and the external work are calculated using an appropriate shape function for the facesheet deflection.The relation between the indentation load and the transverse deflection is obtained by minimization of the total potentialenergy. Analytical predictions of the load-indentation response compare well with FEM results. The effects of plythickness, stacking sequence, radius of the spherical shell and initial in-plane forces on the load-indentation responseare studied and discussed.

Indentation Analysis of an In-Plane Prestressed Spherical Composite Sandwich Shell Subjected to a Rigid Cylindrical Indenter Keywords:

spherical composite sandwich shell , indentation response