Effects of adhesive thickness on global and local Mode-I interfacial fracture of bonded joints

Abstract

a b s t r a c tThe interfacial fracture of adhesively bonded structures is a critical issue for the extensive applications to a variety of modern industries. In the recent two decades, cohesive zone models (CZMs) have been receiving intensive attentions for fracture problems of adhesively bonded joints. Numerous global tests have been conducted to measure the interfacial toughness of adhesive joints. Limited local tests have also been conducted to determine the interface traction-separation laws in adhesive joints. However, very few studies focused on the local test of effects of adhesive thickness on the interfacial traction-separation laws. Interfacial toughness and interfacial strength, as two critical parameters in an interfacial traction-separation law, have important effect on the fracture behaviors of bonded joints. In this work, the global and local tests are employed to investigate the effect of adhesive thickness on interfacial energy release rate, interfacial strength, and shapes of the interfacial traction-separation laws. Basically, the measured laws in this work reflect the equivalent and lumped interfacial fracture behaviors which include the cohesive fracture, damage and plasticity. The experimentally determined interfacial traction-separation laws may provide valuable baseline data for the parameter calibrations in numerical models. The current experimental results may also facilitate the understanding of adhesive thicknessdependent interface fracture of bonded joints.

Fracture toughness determination of adhesive and co-cured joints in natural fibre composites

“…7 and Fig. 8 are consistent with the work of Ji et al [27], with emphasis on the exponential shape of the d n -testing time plot. The final adjustment was carried out so that d n (testing time = 0) = 0.…”

Integral procedure to assess crack filling and mechanical contribution of polymer-based healing agent in encapsulation-based self-healing concrete

“…Nevertheless, the result from Fig. 13 agrees with findings related to the influence of adhesive thickness on the strength developed by adhesive joints [11,12].…”

Modelling adhesive joints with cohesive zone models: effect of the cohesive law shape of the adhesive layer

“…For the adhesive characterisation, bulk tests were performed to characterise the adhesives in tension and Thick Adherend Shear Tests (TAST) were chosen for shear characterisation. It should be pointed out that the cohesive strengths of thin adhesive layers and the bulk strengths of adhesives are different quantities [30]. This is because bulk adhesives are homogeneous materials cracking perpendicularly to the maximum principal stress direction, while adhesives as thin layers are highly constrained between stiff adherends and damage growth under these conditions occurs under mixed-mode (tension plus shear) and along the predefined path of the bonding direction.…”