Experimental study of cohesive strain prior to crack initiation in constant force single cantilever beam test

Abstract

Retarded deformation at the bond line edge of a thick, viscoelastic adhesive layer is observed using digital image correlation. Such information is required for proposing physical crack onset/propagation parameters which take into account viscoelastic and viscous mechanisms in the evaluation of dissipated energy. A complex stress/strain redistribution is observed in the early stage after specimen loading. The results illustrate that viscoelasticity dissipates a considerable amount of energy prior to crack nucleation and the lack of predictive models to account for that phenomenon.

Testing mechanical performance of adhesively bonded composite joints in engineering applications: an overview

“…With the aim of keeping this section informative and technical, the methods presented are deliberately limited to those consistent with the material systems, loading cases and failure modes observed and outlined in Section 3. For that reasons, as well as to keep this section possibly concise, otherwise important subjects, like effects of thermal, [17] and shrinkage stresses [18,19] or creep behaviour, [20][21][22] are not discussed in greater details. However, the framework proposed, constitute the basis for evaluating mechanical performance of adhesive joints.…”