An efficient BEM formulation for analysis of bond-line cracks in thin walled aircraft structures

Debonding strength evaluation in terms of the intensity of singular stress at the interface corner with and without fictitious crack

“…A number of studies on debonding strength have been made so far [14][15][16]. Naito investigated the geometrical effect of adhesive thickness on the tensile and shear strength for butt and single lap joints [5].…”

A dual boundary element based implicit differentiation method for determining stress intensity factor sensitivities for plate bending problems

“…When dealing with weakly singular integrals with singularities of the order ln(1/r) or 1/r such as those seen in equations ( 2)-( 4), ( 8), ( 9), ( 12)-( 13), (16), the transformation of variable technique proposed by Telles [28] is used. For equations (2) and (12), rigid body motion is also applied. The strongly singular integrals with singularities of the order of 1/r 2 seen in equations ( 7) and ( 15) only become singular when both the collocation node and the field point are on a crack surface.…”

“…Reissner theory is used instead of Kirchoff theory since it is able to obtain crack tip stress fields that show better agreement to those provided by 3D elasticity [8]. The approach outlined in [7] has since been adapted to a wide range of problems, the most relevant of which include: the analysis of cracks in structures undergoing large deflection [9], dynamic fracture mechanics [10], fatigue crack growth in assembled plate structures [11], and the analysis of bond-line cracks in laminated plates [12]. Among the different Boundary Element methods used to solve problems involving fracture mechanics with Reissner plates, the DBEM is the most commonly used.…”

Intensity of singular stress field for three-dimensional butt joint to evaluate the adhesive strength

“…However, different materials properties cause singular stress at the end of the interface, which may lead to failure of bonding portions in structures. Several problems on debonding strength have been studied recently [1][2][3]. By using butt and single lap joints, the study showed that the tensile strength of the butt joints decreased as adhesive thickness increases while the shear strength did not affected by the adhesive thickness of single lap joints [4].…”