Katsuhiro Temma

A two-dimensional stress analysis of adhesive butt joints of dissimilar adherends subjected to tensile loads

By replacing dissimilar adherends and the adhesive with finite strips, the stress distributions in adhesive butt joints subjected to external tensile loads were analyzed strictly as a three-body contact problem using the two-dimensional theory of elasticity. The effects of the stiffness and the thickness of the adhesive layer, Poissons ratios for the adhesive layer and the adherends, and external load distributions on the stress distributions were investigated by numerical calculations. In addition, the stress singularity formed at the edge of the interface was discussed. The analytical result was in fairly good agreement with the experimental finding concerning the strains produced on the adherends.

Three-Dimensional Stress Analysis of Adhesive Butt Joints of Solid Cylinders Subjected to External Tensile Loads

Abstract This paper deals with a three-dimensional stress analysis of adhesive butt joints of similar solid cylinders subjected to external tensile loads. Similar adherends and an adhesive bond are replaced with finite solid cylinders in the analysis. Stress distributions on adhesive joints are analyzed strictly by using the three-dimensional theory of elasticity. The effects of stiffness, thickness and Poissons ratio of the adhesive bonds and of external load distribution on the normal and the shear stress distributions are shown by numerical calculations. In addition, the analytical result is compared with the result obtained by F.E.M. It is seen that they are in fairly good agreement.

Two-Dimensional Stress Analysis and Strength of Band Adhesive Butt Joints of Dissimilar Adherends Subjected to Cleavage Loads.

The stresses of band adhesive butt joints, in which the interfaces were partially bonded, were analyzed using a two-dimensional theory of elasticity, in order to establish the fracture criteria when the joints of dissimilar adherends were subjected to cleavage loads. In the analysis, the dissimilar adherends and the adhesive were replaced with finite strips when the interfaces were bonded by an adhesive at two regions. In the numerical calculations, the effects of the ratios of Youngs modulus among adherends and an adhesive, and the thickness of the adhesive, the bonding area and the position on the stress distributions at the interfaces were demonstrated. As a result, it was seen that band adhesive joints were available when the bonding area and positions were determined taking into account external loads distributions. For verification, experiments were performed on the strains of adherends and the joint strength. The analytical results were consistent with the experimental ones.

A two-dimensional stress analysis of butt adhesive joints filled with rigid circular fillers in an adhesive subjected to tensile loads

With recent wide use of adhesively bonded structures in many engineering fields, establishments of an estimation method of joint strength and an optimal strength design method for the joints are required. A lot of experimental and analytical investigations have been done concerning the joint strength and some of them have conducted more practical cases, i.e., the joints have some imperfections such as hole defects in an adhesive or debonds at an interface of the joint [1],[2]. Furthermore, modified adhesives by adding fillers such as alumina, silica and rubber are now commonly used in order to improve the static and dynamic joint strength. So far, only a few studies have conducted analytically to the joints which contain fillers in an adhesive and it is needed to examine the mechanical characteristics of such joints under various kinds of loadings for practical use.

Two-dimensional stress analysis of adhesive butt joint subjected to external bending moments. (The case where adherends are dissimilar materials).

In the present paper, the stresses of butt adhesive joints are analyzed by a two-dimensional theory of elasticity in order to establish the fracture criteria when dissimilar adherends are bonded by an adhesive. Dissimilar adherends and an adhesive are replaced with finite strips, respectively, and the analyses are done as a three body contact problem. In numerical computations, the effects of the ratio of Youngs modulus of dissimilar adherends, the ratio of Youngs modulus of adherends to that of an adhesive and the thickness of the adhesives are shown on the distributions at the interfaces of the joints. As a result, it is seen that the principal stress becomes maximum at the interface between the adhesive and the adherend having high Youngs modulus. For verification, experiments are performed. Analytical results are in fairly good agreement with experimental ones.