Indentation failure of circular composite sandwich plates

Ski boards, helmets are sandwich structures and prone to core indentation failure under localized loads. In this work, axisymmetric response of a circular composite sandwich plate subjected to indentation by a rigid flat/hemi-spherical punch is examined. Flat punch is assumed to impose an axisymmetric line load, whereas spherical indentor imposes point load. Small deformation response is investigated by solving the equilibrium equations exactly, while large deformation response is estimated using Berger's method. The indentation behaviour is predicted numerically by modelling core as (i) a continuum foam and (ii) a plate on foundation with reaction force (i.e. interaction problem) by employing user interaction subroutine in commercial finite element package Abaqus®. Derived analytical estimates for the indentation loads and the corresponding finite element predictions are found to be in good agreement with the experimental measurements. [Display omitted] •Indentation failure of circular composite sandwich plates is investigated.•Core behaves as either elastic or rigid perfectly plastic material.•Berger's approximation of composites large deformation predicts stretching response.