The Influence of Shot Peening on the Stress State in the Adhesive Layer and the Load Capacity of Adhesive Joints

Abstract

The aim of the article was to determine the influence of shot peening of the outer surface of the overlap on the stress state in the adhesive layer and the load capacity of single lap adhesive joints made of EN AW-2024-T3 aluminum alloy. Experimental investigations and numerical simulations were carried out. According to the results of experimental analyses, shot peening with balls with a diameter of 1 mm for 120 s with a compressed air pressure of 0.5 MPa increased the load capacity of the adhesive joints by 33%. Numerical simulations have shown that shot peening, by deforming the joined elements, reduces the stress perpendicular to the surface of the adhesive layer which results in a reduction of equivalent (von Misses) stress and an increase in strength of adhesive joints.

Experimental study of the impact of chamfer and fillet in the frontal edge of adherends on the fatigue properties of adhesive joints subjected to peel

“…The presented results are the continuation of the research related to the static strength tests [16] and the FEM analysis of adhesive joints with geometrical modifications of an adherend. In this work, experimental studies were carried out to analyze the effect of structural modifications on the front edge of the adherends on the fatigue strength properties.…”

Relationship between 3D surface roughness parameters and load capacity of adhesive joints after shot peening

“…Summing up the stresses from the deformation and from the external load resulted in a reduction of stresses in the bond-line of the joints subjected to shot-peening in comparison to untreated bonds. The mechanism of strengthening of adhesive bonds due to shot peening was investigated and described in more detail in [11].…”

“…In the case of joints not subjected to shot peening, the maximum values of these stresses are about 78 MPa. On the other hand, in the case of connections subjected to shot peeningg, the maximum stress values are only about 28 MPa [11]. Comparison of the values of normal stresses perpendicular to the surface of the bond-line in the adhesive connections: a) not subjected to shot peening, b) subjected to shot peening [11] As a result of reducing the maximum values of normal stresses perpendicular to the surface of the bond-line, the capacity ratio of the bond-line decreases, which in turn translates into an increase in the strength of the adhesive joint [11].…”

“…One of them is shot peening of the outer surface of the overlap [3,4,10]. Shot peening of the outer surface of the overlap leads to the reduction of stresses in the bondline of joints subjected to stretching [9,11]. It has been proven that the greatest stress reduction occurs in the case of normal stresses perpendicular to the bond-line surface.…”

Selected Methods of Modifying the Surface Layer of a Carbon Composite

“…The use of such techniques results in an increase in surface roughness [5,17], and thus an increase in the strength of the adhesive bond. Many studies indicate that the properties of adhesive joints depend on a number of key factors, and these include [18][19][20]: type of adhesive [21], type of hardener, surface condition, adhesive application method, application conditions (temperature, humidity and adhesive open time), curing conditions, operating environment, chemical resistance and joint geometry [22][23][24][25].…”