Analysis of the post-crack behaviour of a laminated glass beam

The post-crack behaviour of laminated glass depends on the mechanical properties of the interlayer, that bears large deformations, and on the adhesion properties of the interface. These two characteristics are generally coupled in the real phenomenon but, in view of realizing a comprehensive model, it is necessary to investigate them sequentially. The constitutive behaviour of a polymer material, usually employed as the interlayer of laminated glass, is investigated; uniaxial tension tests have been performed both with constant load and with constant strain rate and relaxation steps, in order to identify the elastic part of deformation. Adhesion tests on pre-craked laminated glass specimens were performed according to the so called bridge link test; a global measure of the interfacial crack energy was obtained. An exponential potential was chosen to reproduce the adhesion properties of laminated glass and both mechanical models were employed to numerically reproduce the experiments.