Experimental Studies of the Strength of an Adhesive Joint in a State of Combined Stress

Abstract

The adhesive strength of a butt-type specimen of two cylinders is experimentally studied. Combined stresses are applied on the adhesive layer by subjecting the specimen to combined axial load, torsion and internal pressure. The effects of the surface roughness, the thickness of adhesive layers and the combined stresses on the adhesive strength are examined for the specimens of various metals bonded with epoxy resin. The adhesive failure locus under the combined stress state are represented by a polynomial equation of stress tensors.

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

“…The same result that related to adhesive strength and adhesive thickness has been observed [5][6][7]. On the other hand, the study of the effects of surface roughness, adhesive thickness and combined stresses on the adhesive strength for various metals bonded with epoxy resin has been also discussed [8].…”

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

“…(16), the singular stress field around the notch tip is defined in terms of notch stress intensity factor K I, 1 λ , which is defined in Eq. (17). Fig.…”

“…It is known that the adhesive strength c σ increases with decreasing the adhesive thickness [2][3][4][5]. The previous studies suggested this is because more defects and cavities are included in the thick adhesive layer [17]. The experimental studies also suggested that the residual strain of adhesive layer may affect the results [18][19][20][21].…”