STP972: Instability-Related Delamination Growth in Thermoset and Thermoplastic Composites

    Rothschilds, RJ
    Graduate student, assistant director of research and visiting scientist, Center for Composite Materials, University of Delaware, Newark, DE

    Gillespie, JW
    Graduate student, assistant director of research and visiting scientist, Center for Composite Materials, University of Delaware, Newark, DE

    Carlsson, LA
    Graduate student, assistant director of research and visiting scientist, Center for Composite Materials, University of Delaware, Newark, DE

    Florida Atlantic University, Boca Raton, FL

    Pages: 19    Published: Jan 1988


    Abstract

    Mixed-mode crack propagation in compressively loaded thermoset and thermoplastic composite columns with an imbedded through-width delamination (ITWD) is investigated. Beam theory is used to analyze the geometrically nonlinear load-deformation relationship of the delaminated subregion. The beam-theory model incorporated the effects of elastic restraint at the ends of the delaminated subregion. The elastic restraint model (ERM), combined with existing finite-element modeling of the crack-tip region yields expressions for the Mode I and Mode II components of the strain energy release rate GI and GII to predict the critical load at the onset of delamination growth. Experimental data were generated for geometries yielding a wide range of GI/GII ratios at the onset of crack growth. A linear mixed-mode crack growth criterion (GI/GIc + GII/GIIc = 1) in conjunction with the ERM provides good agreement between predicted and measured critical loads for both materials studied.

    Keywords:

    composite materials, fracture mechanics, delamination, local buckling, compression


    Paper ID: STP26133S

    Committee/Subcommittee: D30.02

    DOI: 10.1520/STP26133S


    CrossRef ASTM International is a member of CrossRef.