Critical Analysis of the Theory of the Double Cantilever Method of Measuring Fracture‐Surface Energies

This paper considers the problem of bending of a plate composed of two plates of materials having dissimilar elastic properties, bonded together along a straight line which sustains a crack. Both materials are assumed to be isotropic and homogeneous. Upon obtaining stress solutions, it is found that the significant stresses are inversely proportional to the square root of the radial distance from the crack front and have an oscillatory character, which is shown to be confined to the immediate vicinity of the crack tip. A two-parameter set of equations expressing the general form of the stress distribution around the tip of such a crack is provided as it is of primary importance in predicting the strength of cracked plates. Some analogies are also observed between the characteristic equations occurring in the extension and bending of cracked plates composed of dissimilar materials.