STP981

    Factors Influencing Elastic Stresses in Double Cantilever Beam Specimens

    Published: Jan 1988


      Format Pages Price  
    PDF (240K) 14 $25   ADD TO CART
    Complete Source PDF (5.6M) 14 $55   ADD TO CART


    Abstract

    An elastic stress analysis was conducted for a double cantilever beam (DCB) specimen using finite-element methods. The purpose of this study was to identify the important parameters that influence stresses ahead of the delamination front. The study focused on an aluminum DCB specimen, typical of adhesively-bonded joints, and on a graphite/epoxy specimen representing a co-cured composite. Opening mode σy stresses ahead of the crack tip were calculated and compared with those for a monolithic reference specimen. Beyond the singularity-dominated region very near the crack tip, the σy distribution was elevated compared to the monolithic case. Both the adhesive thickness and the adherend transverse (thickness-direction) stiffness were found to influence the elevation of σy. In contrast, the thickness of the adherend and its longitudinal stiffness had very little effect on this stress distribution. Estimates for adhesive yielding beyond the aluminum DCB crack tip showed that both the area and height of the plastic zone increased to a peak value for increasing adhesive thicknesses. Results from this study should provide insight for comparing data from different DCB specimens and for designing new DCB specimens.

    Keywords:

    DCB specimen, crack tip, finite-element analysis, stress distributions, elastic properties


    Author Information:

    Crews, JH
    NASA Langley Research Center, Hampton, VA

    Shivakumar, KN
    Analytical Services & Materials, Inc., Hampton, VA

    Raju, IS
    Analytical Services & Materials, Inc., Hampton, VA


    Paper ID: STP30332S

    Committee/Subcommittee: D14.03

    DOI: 10.1520/STP30332S


    CrossRef ASTM International is a member of CrossRef.