STP677: An Analysis of Tapered Double-Cantilever-Beam Fracture Toughness Test for Adhesive Joints

    Wang, SS
    Assistant professor, University of Illinois, Urbana, Ill.

    Pages: 17    Published: Jan 1979


    Abstract

    This paper presents an analytical study of the tapered double-cantilever-beam (DCB) fracture mechanics test of polymeric adhesives and joints. The test specimen consists of high modulus metal adherends bonded together by a thin layer, low modulus adhesive. The fracture of the joint is modeled by the growth of a cohesive crack in the adhesive bond. The analysis employs an advanced hybrid-stress finite element method based on the formulation of Muskhelishvili's complex stress functions through a modified complementary energy principle. Numerically exact solutions are obtained for the joints with various geometries and material parameters. The crack-tip stress field, the associated stress intensity factor, and the energy release rate are determined quantitatively for each case. Characteristics of the specimen response and fundamental differences in the crack-tip behavior between a monolithic material and the joint are revealed. Effects of the adherend/adhesive modulus ratio, adhesive layer thickness, specimen geometry, and crack length on the tests are studied. Approximations involved in test results due to the specimen design by a simple beam theory are determined also.

    Keywords:

    adhesive, adherend, joints, tapered DCB specimen, fracture mechanics, hybrid-stress finite element method, crack-tip stress field, stress intensity factor, energy release rate, crack propagation, fatigue (materials)


    Paper ID: STP34941S

    Committee/Subcommittee: E08.08

    DOI: 10.1520/STP34941S


    CrossRef ASTM International is a member of CrossRef.