Senior Research Engineer, NASA Langley Research Center, Hampton, VA
An ASTM round-robin was conducted to evaluate the state of the art in stress analysis of adhesively bonded joint specimens. Specifically, the participants were asked to calculate the strain-energy-release rate for two different geometry cracked-lap-shear (CLS) specimens at four different debond lengths. The various analytical techniques consisted of two- and three-dimensional finite element analysis, beam theory, plate theory, and a combination of beam theory and finite element analysis. The results were examined in terms of the total strain-energy-release rate and the Mode I to Mode II ratio as a function of debond length for each specimen geometry. These results basically clustered into two groups: geometric linear or geometric nonlinear analysis. The geometric nonlinear analysis is required to properly analyze the CLS specimens. The three-dimensional finite element analysis gave indications of edge closure plus some Mode III loading. Each participant described their analytical technique and results. Nine laboratories participated.
Paper ID: JTE11028J