ANALYSIS OF A MIXED-MODE FRACTURE SPECIMEN - THE ASYMMETRIC DOUBLE CANTILEVER BEAM

An asymmetric double cantilever beam (ADCB) is a simple but effective specimen for the measurement of polymer/polymer and polymer/non-polymer bimaterial interface fracture toughness. In order to characterize fully the bimaterial interface strength, and to control the crack trajectory, the critical energy release rate, C(c), and the phase angle, psi, of the applied stress field as functions of loading and geometry of the specimen should be obtained. For most practical cases, psi has to be evaluated numerically. In this work, a boundary element analysis is carried out to obtain G and psi for the ADCB specimen at different material and geometry combinations. An expression for the energy release rate, G, based on Kanninen's beam on elastic foundation model is compared with the numerical results. Limitations on the use of the ADCB specimen are also discussed.