Analytical Modeling of Circular Glare Laminated Plates under Lateral Indentation

Abstract

INTRODUCTION GLARE is a Fibre-Metal Laminated material used in aerospace structures which are frequently subjected to various impact damages [1-5]. A high percentage of the total energy absorbed by GLARE plates during impacts is due to the static deformation of the plate [1, 6-7]. Hence, response of GLARE plates subjected to lateral indentation is very important as far as their overall impact behaviour is concerned. This paper deals with the static response of thin circular clamped GLARE fibre-metal laminated plates under the action of a lateral hemispherical indentor located at the centre of the plate. In reference [1] Vlot used an elastic-plastic impact model to solve this problem numerically assuming a deformation profile based on experimental data. Hoo Fatt et al. [6] used the principle of minimum potential energy to model analytically the response of fully clamped square GLARE panels assuming a deformation profile which resembles that of a stretched membrane. They also calculated the first failure load due to glass-epoxy tensile fracture. The objective of this paper is to develop an analytical model for the calculation of static load-indentation curve and the first failure due to glass-ep

Response of GLARE fiber–metal laminates under radial in-plane preloading and lateral indentation

“…5,28,31,32 In this article, by examining FEM plots of lateral plate deflections, it is found with very good accuracy that thin circular clamped GLARE plates under the simultaneous application of radial preloading and lateral indentation have also axisymmetrical deflection shape. In Figure 7, representative lateral deflections plot of a preloaded GLARE plate is depicted.…”

“…Solutions of similar problems have been published in the literature 5,10,28,29 but without any preloading. The work of Vlot, 6 deals with the impact response of preloaded fiber-metal laminates.…”

Analytical and Finite Element Modelling of Circular Glare Plates under Indentation Loading and Unloading

“…From the experimental data in reference [1] it is concluded that GLARE plates subjected to lateral indentation will undergo very large deflections, several times the plate thickness, before first failure due to tensile fracture of glass-epoxy occurs. It was concluded in [8] that, for large plate deflections, P during loading can be calculated up to the point of first failure considering only one Ritz parameter and only the membrane stiffness of the GLARE plate. This conclusion will be used here for the calculation of P during loading.…”

“…The first failure load and deflection can be calculated using the corresponding analytical formulas derived in reference [8]. Remaining assumptions concerning the calculation of P during loading and the point of first failure made in [8] are considered valid. The maximum applied indentation is considered to be less than the first failure deflection.…”

“…Considering negligible bending stiffness of the GLARE plate due to large deflections and taking into account that the material behaviour of aluminum is idealized as rigid-perfectly plastic [8] , aluminum layers are considered to be in a state of membrane yield with a yield stress equal to σ ο . Since aluminum layers are in a state of membrane yield, the plastic work during loading is given by:…”