ON THE INFLUENCE OF THE MECHANICAL CHARACTERISTICS OF A THIN ADHESION LAYER ON THE COMPOSITE STRENGTH. PART 1. ELASTIC DEFORMATION

The problem of deformation a DCB sample, which is composition bodies bound by an adhesive layer finite thickness, considered. Based on the variational equilibrium equation containing thickness as linear parameter, element solution loading with normal discontinuity in plane strain state constructed. stresses averaged over are related to along boundary equations. form conditions for mating bodies. In layer, shear stresses, orthogonal also taken into account. constitutive relations represented terms average stresses. With significant difference Young's moduli and bodies, convergence value J-integral decrease shown. To find J-integral, its representation used product specific free energy at end thickness. It has been established that Poisson's ratio affects almost no effect J-integral. Using theory plates Mindlin - Reisner zero adhesive, analytical obtained. includes pull-off stress axial layer. this case, term associated proportional square it. From obtained, it follows mechanical properties small compared do not affect if elastic modulus significantly less than Thus, use replacing correct under these restrictions.