An effective stress/strain concept in the mechanical characterization of structural adhesive bonding

Abstract An extended modified effective stress/strain concept is presented, which takes into account the effects, throughout the linear, non-linear and plastic failure levels, of both the deviatoric and the volumetric stress components on the mechanical behaviour of an adhesive material. This approach, which relates the tensorial components of stress and strain at each element to their respective effective values, promises to lead to a successful stress analysis and structural design of bonded joints. It permits the numerical study of the behaviour of the interlaminar adhesive layer under a state of multiaxial stress with the aid of the empirical data obtained from simple uniaxial loading. By an experimental investigation, which was conducted on bulk and in situ structural adhesives specimens, the authors were able to verify the hypothesis.