Materials Sciences Corp., Spring House, PA
General Electric Co., Valley Forge, PA
University of Illinois at Urbana-Champaign, IL
E. I. du Pont de Nemours & Co., Wilmington, DE
Pages: 23 Published: Jan 1990
The usefulness of a fracture mechanics approach for predicting failure in single lap joints with composite adherends is examined. A finite-element analysis is employed for stress analysis and calculation of strain energy release rates for small disbonds between the adhesive and the adherends. Tests conducted show that delamination growth takes place in the resin-rich areas of the adherends close to the adhesive layer. For this reason, the critical strain energy release rate determined from Mode II tests on composite adherends is used as the fracture parameter and is equated to the total energy release rate for failure prediction. Effects of large out-of-plane deformation in the adherends and nonlinear shear response of the adhesive are also studied. Data from tests with and without major bondline flaws are correlated with the analytical results. The correlations show that with proper material characterization studies and realistic stress analyses, fracture mechanics can be a useful tool for predicting the load-carrying capacity of adhesively bonded joints.
composite materials, fracture mechanics, strain energy release rates, adhesive joints, composite adherends, single lap joint, delamination fracture, bondline flaws
Paper ID: STP24119S