A coupled stress and energy criterion for the assessment of crack initiation in single lap joints: A numerical approach

Comparison between models based on a coupled criterion for the prediction of the failure of adhesively bonded joints

“…Indeed, this adhesive is roughly linear elastic until final failure which corresponds to the hypothesis used in the present model. The results obtained using the CDM model could be compared to the ones obtained in [15] with a FFM where the authors take into account the large displacement and the possibility for the crack to be initiated anywhere, not only at the interface. However, in this paper the authors use a constant fracture toughness along the interface.…”

“…This approach has been applied successfully to describe the failure due to a delamination initiated from an edge in laminate composites [10]or the failure of an open-hole in composites in tension [11] [12] or compression [13]. It has also been recently applied to describe the effect of the adhesive thickness on the failure of adhesively bonded joints [14] [15] or the debonding between an inclusion and the matrix [16]. All these studies validate the use of a coupled strength and energy criterion for the prediction of crack initiation.…”

Fast failure prediction of adhesively bonded structures using a coupled stress‐energetic failure criterion

“…The stress distribution is given by the sandwich‐type model for the remaining bonded length denoted as . Based on the maximum values of the normal and shear stresses ( σ max and τ max , respectively) extracted for , the energy release rate G SA (a) is computed according to the following equation: where E a and G a represent the Young's and Shear modulus of the adhesive, respectively. Then, G inc ( a ) is calculated by integrating G SA ( a ) along the considered crack length a as shown in Equation , and the dimensionless coefficient A inc ( a ) can be extracted by means of Equation as explained before in Section 2.1.…”

“…On the other hand, the failure load converges to the value of 10.35 kN for a number of elements equal to 40 or higher. It must be mentioned here that the response of the coupled criterion by means of numerical modelling of the bonded structure has been the subject of other research teams too in the past, mainly for the case of the single lap joint (SLJ) geometry . The authors in Carrere et al and Moradi et al recommended 40 elements along the adhesive thickness in order for convergence to be achieved.…”

Analysis of the metal adhesively bonded double cantilever beam specimen

“…Considerable research has already been conducted on CZM of common structural adhesive lap-joints e.g. [7][8][9][10][11]. The basis of all formulations is the so-called tractionseparation s c -δ c law.…”