Distribution of Stress in Glass Fabric Reinforced Composite Materials Subjected to Longitudinal Loading

Abstract

The plastics reinforced with glass fibers have recently been attracting general attention as mechanical members. In this paper is presented the report of the study made of the plastics reinforced with woven glass cloth and subjected to the edgewise loading, with a view to finding the stress distribution on the interface of its fiber matrixes and its composite longitudinal stiffness. This analysis was made with the use of the two-dimensional model and the application of the finite element method, and in this connection the following assumptions have been made.(i) That these materials used in the present study are isotropic, homogeneous and elastic.(ii) That these materials are perfectly bonded together on the interface of their fiber-matrixes.(iii) That the state of plane stress has been maintained throughout.The results obtained by the finite element technique are compared with the results obtained by the rule of mixture.The results are as follows.(1) The maximum stress is induced on the concave side of the longitudinal fibers, and the stress concentration factors increase with increasing stiffness ratio Ef/Em and with increasing bent angle β of the longitudinal fibers.(2) The stress concentration factors on the interface of the transverse fiber-matrixes increase with decreasing Ef/Em and with increasing in β (Ef/Em>6).(3) The efficiency of the finite element method is confirmed in the experiment in which the stress and stiffness obtained by that technique agree well with the results obtained by the rule of mixture (β=0).