STP972: Growth of Elliptic Delaminations in Laminates Under Cyclic Transverse Shear Stresses

    Chatterjee, SN
    Staff scientist and engineer, Materials Sciences Corporation, Spring House, PA

    Ramnath, V
    Staff scientist and engineer, Materials Sciences Corporation, Spring House, PA

    Dick, WA
    Assistant director, Center for Composite Materials, 201 Spencer Laboratory, University of Delaware, Newark, DE

    Chen, YZ
    E. I. DuPont de Nemours and Company, Inc., Wilmington, DE

    Pages: 17    Published: Jan 1988


    Abstract

    Models for predicting growth of delaminations in laminated composites under fatigue loading are needed for development of different types of criteria, namely, (1) design criteria for damage tolerance and durability of composite components, (2) accept/reject criteria for manufactured parts, and (3) repair/replace decision making for components damaged in service. For this reason, various studies have been and are being conducted to study one-dimensional growth of delaminations in coupons or beam specimens for obtaining semi-empirical growth laws. In this study, two-dimensional growth patterns of single as well as multiple delaminations (through the thickness of the laminate) under mixed-mode loading conditions are predicted using such a growth law, and the results are compared with data from a series of test specimens. The growth law is obtained from measured growths of the major axis of implanted (double-layer trifluoroethylene resin sealed at edges) elliptic delaminations in the midplane of 76-mm-wide (04/±452)s4 AS-1/3501 plates loaded in three-point bending reported in a previous study.

    Keywords:

    laminated composites, elliptic delaminations, multiple delaminations, fatigue, growth law, mixed-mode effects, nondestructive evaluation, transverse shear


    Paper ID: STP26141S

    Committee/Subcommittee: D30.02

    DOI: 10.1520/STP26141S


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