A general analytical model based on elastic foundation beam theory for adhesively bonded DCB joints either with flexible or rigid adhesives

Abstract

A new general analytical model based on elastic foundation beam theory is proposed for adhesively bonded double cantilever beam (DCB) specimens. The new model accounts for any stress state (from plane stress to plane strain) in the adhesive and therefore, the model is able to predict the mechanical response of a DCB specimens whatever the adhesive type (from rigid to flexible), the stress state, and the width/thickness relationship of the specimen are. The model is validated with DCB tests for flexible Silkron-H100 and stiff Araldite-2021 adhesives. A comparison with other models from the literature demonstrates that more accurate predictions in terms of stress distribution in the middle plane of the adhesive layer, adherend deflections and load predictions are obtained. The model is especially suitable when flexible adhesives and/or thick adhesives are used. In addition, a new method to accurately obtain Poisson's ratio for flexible adhesives is proposedThe authors gratefully acknowledge the financial support of the Spanish government through DGICYT under Contract No. TRA2015- 71491-

On the fracture behaviour of CFRP bonded joints under mode I loading: Effect of supporting carrier and interface contamination

“…for an arbitrary interpretation of the crack front stress state [52,53]. In the present case, the plane strain conditions are assumed at the crack tip [54] leading to .…”

Analytical corrections for double-cantilever beam tests

“…The cases are equivalent, and so the relationship E adhesive = 0.5k is a result of equating the two force expressions, with the coefficient's value of 0.5 being due to the symmetric deformation of the DCB and its interface. Cabello et al (2016) reported a general analytical model for the relationship between the Young's modulus of the adhesive E adhesive and the foundation stiffness k under plane-strain conditions.…”

From thin to extra-thick adhesive layer thicknesses: Fracture of bonded joints under mode I loading conditions

“…Research on the effect of the adhesive bond line thickness on mode I fracture behaviour has mainly focused either on joints bonded with structural epoxy adhesives with bond line thicknesses normally ranging between 0.1 and 2 mm -mostly applied to aerospace and automotive applications [1][2][3][4][5][6][7][8][9][10][11][12][13], or on joints with flexible adhesives often with thicker bond lines [14,4,15,16]. However, limited studies were found on joints with extra-thick bond lines ( 10 mm) of epoxy adhesives, relevant for maritime applications.…”