• 대한기계학회논문집
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• 제17권8호
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• pp.1980-2000
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• 1993

The stresses and torque transmission capabilities of adhesively bonded circular, hexagonal and elliptical lap joints were analyzed by the finite element and compared with the experimental results. The adherends of the joints were composed of carbon fiber/epoxy composite shafts and steel shafts. In calculating the torque transmission capabilities, the linear laminate properties of the composite material and the nonlinear shear properties of the adhesive were used. Using this method, the torque transmission capabilities of adhesively bonded lap joints could be obtained within 10% error compared to the experimental results except some single lap joints. The experiments revealed that the hexagonal joint had the best torque transmission capability from the single lap joints and the double lap joint had better torque transmission than the single lap joint.

• 대한기계학회논문집
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• 제19권7호
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• pp.1651-1656
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• 1995

The adhesively bonded tubular single lap joint shows large nonlinear behavior in the loaddisplacement relation, because structural adhesives for the joint are usually rubber toughened, which endows adhesives with nonlinear shear properties. since the majority of load transfer of the adhesively bonded tubular single lap joint is accomplished by the nonlinear behavior of the adhesive, its torque transmission capability should be calculated incorporating nonlinear shear properties. However, both the analytic and numerical analyses become complicated if the nonlinear shear properties of the adhesive are included during the calculation of torque transmission capabilities. In this paper, in order to obtain the torque transmission capabilities easily, an iterative solution which includes the nonlinear shear properties of the adhesive was derived using the analytic solution with the linear shear properties of the adhesive. Since the iterative solution can be obtained very fast due to its simplicity, it has been found that it can be used in the design of the adhesively bonded tubular single lap joint.

• 한국생산제조학회지
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• 제7권1호
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• pp.58-68
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• 1998

Advantages of adhesively bonded joints and techniques of weight reduction have led to increasing use of structural adhesives such as LSI(large scale integration) package, automobile, aircraft in the various industries. In spite of such wide applications of adhesively bonded joints, the evaluation method of bonding strength has not been established. Stress singularity occurs at the interface edges of adhesively bonded joints and it is required to analyze it. In this paper, the stress singularity using 2-dimensional elastic boundary element method (BEM) with the changes of the lap length and adhesive for single lap joint was analyzed, and experiments of strength evaluation were carried out. As the results, the evaluating method of bonding strength considering stress singularity at interface edges of adhesively bonded joints and stress intensity factor of interface crack have been proposed in static and fatigue test.

• 대한기계학회논문집
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• 제19권8호
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• pp.1869-1875
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• 1995

The adhesively bonded tubular single lap joint shows a nonlinear relationship between the applied torque and the resulting displacement under the static-torsional loading, which is induced from the nonlinear properties of the adhesive. However the torque transmission capability in the case of the dynamic-torsional loading is much less than that in the case of the static-torsional loading, the stress level of the adhesive is usually in the region of the linear stress and strain relation and the stress distributions of the joint can be obtained by the linear analysis. In this paper, a failure model for the adhesively bonded tubular single lap joint under the torsional fatigue loading was developed with respect to the adhesive thickness that was a critical factor in predicting the static torque transional-cyclic loadings was proposed.

• 대한기계학회논문집
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• 제18권6호
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• pp.1412-1420
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• 1994

The adhesively bonded tubular double lap joint has better torque transmission capability and reliability in bonding operation than the single lap joint. In this paper, an analytic solution for the torque transmission capabilities and stress distributions of the adhesively bonded tubular double lap joint was derived assuming the linear properties of the adhesive and adherends. From the calculation, it was found that the torque transmission capabilities of the double lap joint was more than 40% larger compared to that of the single lap joint.

• 대한기계학회논문집
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• 제18권4호
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• pp.835-845
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• 1994

In this paper, the effects of the adhesive thickness and adherend roughness on the static and fatigue strengths of the adhesively bonded circular single lap joints has been investigated by an experimental method. The stacking sequence effect of the composite adherend on the static and fatigue strength and the fracture patterns of the adhesive failure were also observed. Since the circular single lap joint fails catastrophically beyond the static strength of fatigue limit, the tubular polygonal adhesively bonded joints such as triangular, tetragonal, pentagonal, hexagonal as well as elliptical joints were manufactured in order to give partial mechanical characteristics to the adhesively bonded tubular joints. These joints were tested both in static and fatigue modes. From the experimental investigations, it was found that the fatigue strength of the circular adhesively bonded joints was much dependent on the arithmetical average surface roughness of the adherends and the polygonal adhesively bonded joints had better fatigue strength characteristics than the circular adhesively bonded joints.

• 한국해양공학회지
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• 제23권6호
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• pp.124-130
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• 2009

This study presents a finite element simulation of elastic waves for detecting anti-symmetric damages in an adhesively-bonded single lap joint. Plane strain elements were used for modeling adherents (aluminum) and adhesives (epoxy). Three types of damage were introduced: thickness reduction, elasticity deterioration, and voids in the adhesive layers, and two excitation and reception arrangements (ER1 and ER2) were used to investigate the detectability of the damage. The simulation showed that symmetrically located damage, such as a thickness reduction, can be detected by one excitation and one reception arrangement (ER1) and anti-symmetric damages, such as elasticity deterioration and voids, can be detected by modified two-point elastic wave excitation (ER2). Compared with the ER1 arrangement, the ER2 arrangement does not require a baseline signal for damage detection; hence, an efficient method of anti-symmetric damage detection in an adhesively-bonded single lap joint is proposed.

• Journal of Welding and Joining
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• 제30권6호
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• pp.62-67
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• 2012

In this study, the bonding strengths of adhesively bonded joints are experimentally investigated. A series of lap-shear tests are conducted using single lap type adhesive joints. In order to analyse the joint fabrication factors that affected the bonding strength, the parametric tests are conducted with various thickness of adhesive, surface roughness and fillet of adhesive. In addition, for the comparative study with the welded joint, lap-shear tests using specimens with 2 welded sides and 4 welded sides are also carried out. The quantitative results of the strength analysis are summarized, and some proposals are made on setting up testing standards for adhesively bonded joints.

• 대한기계학회논문집A
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• 제24권8호
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• pp.2022-2031
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• 2000

Since the surface roughness of adherends affects much the strength of adhesivelybonded joints, the effect of surface roughness on the fatigue life of adhesively bonded tubular single lap joints was investigated analytically and experimentally by fatigue torsion test. The stiffness of the interfacial layer between adherends and adhesive was modeled as a normal statistical distribution function of surface roughness of adherends. From the investigation, it was found that the optimum surface roughness of adherends for the fatigue strength of tubular single lap joints was dependent on bondthickness and applied load.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.465-470
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• 2001

The adhesively-bonded joints considered in this investigation include single-lap joint and double-lap joint. For an adhesively bonded double-lap joint, end mismatch between the two cuter adherends(upper, lower) can not removed completely although it can be controlled within a manufacturing tolerance. This paper shows that the end mismatch introduces local bending and end mismatch affects the shear and peel stresses in the adhesive. The double-lap joint with an end mismatch is affected of adhesive thickness, material properties of adhesive and adherend etc. Also, we concluded that there are critical value of an end mismatch to provoke the interface fracture.