Compressive Stability of Delaminated Random Short-Fiber Composites, Part II—Experimental and Analytical Results

Abstract

The basic mechanics and mechanisms of compressive stability of delaminated random short-fiber composites are studied. An experimental program, employing an SMC-R50 composite with built-in delaminations, is conducted to evaluate the validity of the mechanistic model and to demonstrate further the accuracy of the methods of analysis developed in the associate paper [1]. Excellent agreement between experimental results and analytical solutions is observed. Based on the analytical development, the fundamental compressive stability behavior of delaminated short-fiber composites is investigated by a comprehensive parametric study. The influence of delamination length, crack position, number of delaminations, and composite plate length on the critical compressive stress and buckling modes is analyzed in detail. Possible crack growth in the delaminated composite subjected to in-plane compression is also studied.

On the calculation of energy release rates for cracked laminates

“…One way of limiting the problem is to increase the toughness of the matrix resin and this has led to considerable effort in developing tough resins [1] and also in assessing that toughness in laminates in various fracture modes [2,3]. Both the testing and the design of laminates require the ability to calculate the energy release rate for the laminates and loadings used, since this is the driving force of the failure process and there is a considerable literature of numerical analyses aimed at this problem [e.g., [5][6][7]. Most use finite elements and then compute the energy release rate by various schemes based on node forces.…”

Effects of Multiple Delaminations on Compressive Buckling Behaviors of Composite Panels

“…Chai [2][3][4], A. J. Vizzini et al [5] and Kardomateas [6] have studied analytically the buckling and postbuckling behaviors of composite laminates with a delamination under the assumption of onedimensional beam plate. Wang et al [7,8] also studied the mechanisms of compressive buckling of composite beam plate with one and two delaminations under the assumption of symmetric deformation. The results explain well the mechanisms of buckling behavior of the laminate with an interlaminar delamination and two surface delaminations.…”

Determination of critical delamination diameter of laminated composite plates under buckling loads

“…Kutlu and Chang [6] considered the problem of multiple delamination by using non-linear finite element methods. Wang et al [7,8] dealt with delaminated random short-fiber composites by using both the Rayleigh-Ritz method and finite element buckling analysis. Adan et al [9] applied one dimensional beam theory to predict the buckling load of multiple delamination, but overlapping phenomenon was excluded.…”