Strength Of Adhesive-bonded Joints Research Articles

Strength Analysis of Dissimilar Adhesive-Bonded Joints

The article discusses aspects related to material surface engineering and the strength of adhesive-bonded joints as well as presents results concerning the surface wetting angle and the free surface energy of steel S335, aluminium alloy AW7075 (T6) and the CFRP composite material in relation to three surface treatment conditions. The authors emphasize that surface preparation is of key importance as regards the obtainment of potentially high-strength joints. The article also discusses results concerning the roughness of the surface of the steel and the aluminium alloy in relation to various grades of abrasive paper granularity. The final part of the article presents test results concerning the shear strength of dissimilar adhesive-bonded joints (i.e. steel S335 – CFRP composite and aluminium alloy AW 7075 (T6) – CFRP composite) and discusses related images of ruptured joints.

Design and Determination of Strength of Adhesive Bonded Joints

The paper deals with methodology of prediction of adhesive bonded joints strength. Problematics of adhesive bonded joints is a very complex task. There are several different (different precision and different complexity) mathematical models of adhesive bonded joints, which attempts to describe the real behavior of adhesive and adhesive bonded joints during load as accurately as possible. This article presents a comprehensive overview of what to take into account and to with designing/controlling the strength of adhesive bonded joints. Mathematical models are supplemented by material data from experimental tests. The proposed methodology takes into account both adhesive and cohesive properties (material of bonded parts, surface treatment of bonded material, type of adhesive, thickness of adhesive, bonding technology, loading modes etc.). Methodology how to proceed is described in detail and is complemented with a flowchart.

酸性水と塩水中でのＣＦＲＰ接着継手の強度低下

酸性水と塩水中でのＣＦＲＰ接着継手の強度低下

Effects of curing conditions and test temperatures on the strength of adhesive-bonded joints

This paper deals with a structural adhesive, epoxy-polyamideamine, and a non-structural adhesive, α-cyanoacrylate. The effects of curing temperature, cure time, opening time, setting time, test temperature and resin-hardener mixing ratio on modulus of transverse elasticity ( G a ) and shear strength ( τ B ) of the adhesives are experimentally investigated. Some experimental relations are proposed. Substituting the predicted values of G a and τ B by experimental relations, the effects of curing conditions and test temperatures on the strength of joints are investigated.

Effects of curing conditions and test temperatures on the strength of adhesive-bonded joints

Effects of curing conditions and test temperatures on the strength of adhesive-bonded joints

A Method of Estimating the Strength of Adhesive Bonded Joints of Metals

Abstract The strength of adhesive bonded joints is investigated both analytically and experimentally. The deformed states of lap joints under tensile shear loading are analysed by the finite element method on the assumption of elastic deformation. A method of using the adhesive strength law is proposed to estimate the joint strength. The adhesive strength law is experimentally determined by subjecting butt joints of two thin-walled tubes to combined axial load and torsion. The strength of lap joints is determined by adopting the adhesive strength law to the adhering interface as well as the strength law of adherend and adhesive resin. The calculated strain distribution and strength of the joints are compared with the experimental results. The effects of the joint configurations on the deformation and strength are discussed. It is shown that the proposed method is useful to predict the joint strength.

突合せ接着継手の疲労挙動に関する研究（接着層内の気ほうの影響について）

For the purpose of the strength evaluation and quality control of adhesive joints, it seems important to obtain the systematic knowledge on the influence of the bonding defects existing in the adhesive on the strength of adhesive-bonded joint, or, in other word, to do research on how the strength behavior of adhesive butt joint is affected by such defects. In this paper, the effect of dispersed bubbles in the adhesive on the fatigue strength of adhesive joint is investigated experimentally under a full reversed push-pull fatigue load condition by using butt joint specimens bonded with epoxy-polyamide adhesive.In order to examine the effect of dispersed air bubbles, two sorts of adhesive manufacturing processes were adopted; one was given degassification treatment to remove bubbles in the adhesive and another was not given degassification treatment to disperse bubbles in the adhesive layer. From the strength behavior on S-N diagram for the adhesive bonded butt joints with these two processes, it was revealed that the fatigue strength of the adhesive joint whose adhesive does not contain bubbles was higher than that of the bubbles dispersed adhesive joint in a relatively low stress cycles range, but the difference of fatigue strength between both joints diminished in a relatively high stress cycles range, and the 107 time strength of the both joints showed close agreement.Furthermore, in order to evaluate such fatigue characters from the view-point of inelastic strain behavior, the total and inelastic strain ranges of the adhesive layer were measured for these two sorts of adhesive joints.As the results, it was found that the values and the variation trends of these strain ranges of the adhesive joint with no bubbles were somewhat different from those of the joint of bubbles dispersed adhesive layer, and detailed discussions from such a view-point were made in this paper.Then, it was confirmed that the cumulative hysteresis energy could not play a role of the fatigue failure criterion, when the adhesive layer condition was different with each other.

Effect of the substrate on the strength of adhesive-bonded joints

The possibility of the adhesion failure of adhesives is discussed. It is shown that the properties of the adhesive film depend on the physicomechanical characteristics of the substrate as a result of the action of molecular forces.

Influence of stress distribution on fatigue strength of adhesive-bonded joints

A study was made of the fatigue behavior of three types of 2024-T3 aluminum-alloy adhesive-bonded joints: single-lap joint, scarf joint and butt joint bonded with two kinds of adhesives, a vinyl-phenolic type, FM-47 and a nitride rubber-phenolic type, Metlbond 4021. Two different modes of fatigue failures of the single-lap joints, i.e., sheet-metal failure and adhesive-bonding failure, were caused by the different stress components in the joint. The influence of the variations of stress distribution caused by the difference in mechanical properties of the adhesive, geometry of the joints, and the type of loading on fatigue strength of the adhesive-bonded joints, were analyzed.

Effect of molecular structure on mechanical properties of epoxy resins

AbstractThe effect of varying the molecular structure of epoxy resins on their mechanical properties when used as adhesives was studied. The work was directed toward preparation of bisphenols of the general formula HOϕCR(R′)ϕOH where R and R′ are either alkyl or alicylic substituents, in which case the benzhydryl carbon is incorporated in a cyclopentane or cyclohexane ring for use in the preparation of glycidyl polyethers having the formula: magnified image where B is the divalent hydrocarbon radical of the bisphenol and n is an integer of the series 0, 1, 2, 3… Preparation of 13 epoxy resins which are liquids at room temperature is described. The effect of varying the structure of the dihydric phenol in the epoxy resin on the strength of adhesive‐bonded joints was determined. The results indicate that relative bonding strengths of epoxy resins synthesized from various bisphenols can probably be attributed to the symmetry and chain length of the substituents attached to the carbon atom connecting the two aromatic nuclei. There is a high correlation between adhesive properties and steric influence of a substituted methyl group. Although the qualitative features of substitution on the central carbon atom are shown to be fairly well understood, there are a number of points that still require clarification. For instance, a more conclusive picture of the effect of branching is desirable. Also, there are uncertainties about the magnitude of the temperature effect and the influence of the substituent on the impact values.