Investigation on Void Effect on Shear Stress Field in Bonded Stepped-Lap Joint

Abstract

In this paper, an adhesively-bonded stepped-lap joint suffering from a void within its adhesive layer is investigated. The void separates the layer into two sections. The joint is under tensile load and materials are isotropic and assumed to behave as linear elastic. Classical elasticity theory is used to determine shear stress distribution in the separated sections of adhesive layer along the overlap length. A set of differential equations was derived and solved by using appropriate boundary conditions. Finite element solution was used as the second method to verify the obtained results by analytical method. A two-dimensional model was created in ANSYS and meshed by PLANE elements. A good agreement was observed between two methods of solutions. Results revealed that the stepped-lap joint performed better in stress distribution with a void rather than single-lap and double-lap joints.

Stress analysis of adhesively-bonded single stepped-lap joints based on three-parameter fractional viscoelastic foundation model

“…Both finite element analysis and the proposed model suggest various peel stresses in the TA/BA interfaces unlike, most current viscoelastic solutions that disregard the peel stress or only predict one value for both interfaces. 18–20…”

“…Both finite element analysis and the proposed model suggest various peel stresses in the TA/BA interfaces unlike, most current viscoelastic solutions that disregard the peel stress or only predict one value for both interfaces. [18][19][20] Comparison between single stepped-lap and single-lap model In this section, the stress distribution in the single stepped-lap and the single-lap adhesive joints is compared under axial load. For this purpose, the shear stress in the adhesive mid-plane and the peel stresses in the TA and BA interfaces in both models (single stepped-lap and single-lap) with similar material and dimensions are calculated using the 3PFVF model and relevant results at t = 0 are shown in Figures 11-13.…”

“…The parameter ϵ z can be eliminated by substituting equation (19) into equations (18a) and (18c). Then, the differential equation can be achieved for the fractional Zener by substituting the expression for the differential operator into equations ( 16) and ( 17) and rearranging them, as follows:…”

“…An adhesively bonded stepped-lap joint under tensile loading, with a void in its adhesive layer, has been examined by Ghoddous and Shishesaz. 19 They investigated the shear stress distributions in both sections of the adhesive layer separated by the void along the overlap length using the classical elasticity theory. A modified analytical model has been proposed by Wang et al 20 with a closed-form solution to examine the strength, stiffness, and failure mode of the adhesively bonded stepped-scarf joints under unidirectional stresses, concerning the shear deformation in the composite laminated plates, the nonlinear behavior of adhesive and ignoring peel stress.…”

Analysis of the influence of damp-heat aging on the shear failure of the adhesive joint of composite materials

“…[6] . Ghoddous et al [7] conducted a study on the influence of the gap in the bonding layer of the lap joint on the performance of the joint, and the study showed that the stress distribution of the stepped lap joint with the gap was better than that of the single lap joint and the double lap joint. Han et al [8] revealed the tensile failure mechanism of the stepped bond structure of composite materials by using FEM static stress analysis, experimental research, and CDM methods.…”