• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.13 no.1
• /
• pp.97-103
• /
• 2000

This paper deals with residual stresses induced at the viscoelastic adhesive layer between the semiconductor chip and the leadframe during adhesion process. The adhesive layer has been assumed to be“thermorheologically simple”. The time-domain boundary element method(BEM) has been employed to investigate the behavior of interface stresses. Numerical results show that very large stress gradients are present at the interface corner and such singularity might lead to local yielding or edge delamination.

• Structural Engineering and Mechanics
• /
• v.10 no.2
• /
• pp.125-138
• /
• 2000

The paper analyzes the problem of torsion in an adhesive non-tubular bonded single-lap joint. The joint considered consists of two thin rectangular section beams bonded together along a side surface. Assuming the materials involved to be governed by linear elastic laws, equilibrium and compatibility equations were used to arrive at an integro-differential relation whose solution makes it possible to determine torsional moment section by section in the bonded joint between the two beams. This is then used to determine the predominant stress and strain field at the beam-adhesive interface (stress field along the direction perpendicular to the interface plane, equivalent to the applied torsional moment and the corresponding strain field) and the joint's elastic strain (absolute and relative rotations of the bonded beam cross sections). All the relations presented were obtained in closed form. Results obtained theoretically are compared with those given by a three dimensional finite element numerical model. Theoretical and numerical analysis agree satisfactorily.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.30 no.12 s.255
• /
• pp.1543-1550
• /
• 2006

Since the performance of joints usually determines the structural efficiency of composite structures, an extensive knowledge of the behavior of adhesive joints and the related effect on joint strength is essential for design purposes. In this study, the torque capacity of adhesive joints was predicted using the combined thermal and mechanical analyses when the adherend was a composite tube. A finite element analysis was performed to evaluate residual thermal stresses developed in the joint, and mechanical s stresses in the adhesive were calculated including both the nonlinear adhesive behavior and the behavior of composite tubes. Three different joint failure modes were considered to predict joint failure: interfacial failure, adhesive bulk failure, and adherend failure. The influence of the composite adherend stacking angle on the residual thermal stresses was investigated, and how the residual thermal stresses affect the joint strength was also discussed. Finally, the predicted results were compared with experimental results available in literature.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.14 no.2
• /
• pp.104-109
• /
• 2005

This article has been investigated the use of FFT for adhesive joints analysis between metal sheets. The method is based on the measurement of the reflection wave at the metal/adhesive interface. After describing briefly the physical aspects of the phenomenon, an index is defined to detect defective zone of the joint(both for the lack of adhesive and for insufficient adhesion): the influence of the experimental variables(variable stress...) on the measurement is discussed. By means of a control experiment it is shown that stress variation in adhesive joints are separate to be distinguished. In this paper, Nondestructive evaluation in adhesive joints are evaluated together with ultrasonic testing and finite element analysis.

• Journal of Welding and Joining
• /
• v.20 no.5
• /
• pp.99-105
• /
• 2002

One of the important advantage of adhesive bonded joint can combine the different materials. The joint that bonded by structural adhesive bond must keep a large force and its strength is affected by some environmental factors such as temperature and submergence time in water. In order to advance the fatigue strength of adhesive bonded joint, mostly put a surface treatment on the surface. This study was researched the effect of air temperature, submergence time, submergence temperature and surface treatment on the fatigue strength. We found that submergence temperature has the most effect and low plasma treatment specimens have the most fatigue strength.

• Structural Engineering and Mechanics
• /
• v.88 no.6
• /
• pp.609-623
• /
• 2023

The objective of this study is to investigate the distribution of von Mises stress, peeling stress, and shear stress in the adhesive layer used to bond two composite panels, considering various parameters using a three-dimensional finite element method. The stiffness of the materials and the effect of the stacking order on the amount of load transferred to the adhesive layer were examined to determine which type of laminate generates less stress at the bond line. The study analyzed six different stacking sequences, all with a common first layer in contact with the adhesive and a 0° orientation. Additionally, the impact of using hybrid composites on reducing bond line stress was investigated.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.20 no.1
• /
• pp.42-47
• /
• 2021

Recently, many structures using lightweight materials have been developed. This study was conducted by using Al6061-T6 and carbon fiber reinforced plastic (CFRP), two common lightweight materials. In addition, the failure characteristics of an interface bonded between a single material and a heterogeneous bonding material were analyzed. The specimens bonded with CFRP and Al6061-T6 were utilized by the combination of the heterogeneous bonding material. The specimens had a double cantilevered shape and the bonding between the materials was achieved by applying a structural adhesive. The experiments were conducted in opening mode: the lower part of the samples was fixed, while their upper part was subjected to a forced displacement of 3 mm/min by using a tensile tester. Under the tested amount of strength, energy release rate, and considering the specimens' fracture characteristics in opening mode, the specimen "CFRP-Al" presented the maximum stress, followed by "Al" and "CFRP". We can hence conclude that the inhomogeneous material "CFRP-Al" is useful for the construction of lightweight structures bonded with structural adhesive.

• Fashion & Textile Research Journal
• /
• v.8 no.5
• /
• pp.585-590
• /
• 2006

In the variation of physical properties of adhesive fabrics, the objective of this study is to analyze fitness of fusible interlining to four sorts of fabrics for men's suit with various structural parameters. Four fusible interlinings are used for adhering to fabrics for men's suit. Mechanical properties of these 16 adhesive fabrics fused with these interlinings are measured by KES-FB system for analysing appearance and wearing properties of garments and for examining the fitness of fusible interlining to the fabrics for men's suit. The variation of bending property for adhesive fabrics are found to be higher in the order of interlining 1(Cotton30/Rayon70, plain), interlining 2(Polyester30/Rayon70, warp knit), interlining 4(Polyester, shingosen fabrics with drawing textured yarn) and interlining 3(Polyester, double dot coating interlining). The variation of adhesive effect shows the same results with bending property and shows negative relation with extensibility in weft direction per extensibility in warp direction(EM2/EM1). The variation of peel strength of adhesive fabrics, woolen fabrics in the case of face fabrics and interlining 3 in the case of interlining shows the largest value respectively.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• pp.1410-1414
• /
• 2007

In modern automobile body manufacturing, the structural adhesive bonding is recognized to one of new joining techniques for the purpose of light weight body and its application scope in the automobile body has been gradually magnified. Specially, the structural adhesives have the advantages of not only enhancing the design flexibility of automobile body, but also improving automobile performances such as stiffness, crashworthiness and durability. In order to evaluate the performance simulation of the automobile body applied with structural adhesives, it is necessary to develop modeling techniques in the structural adhesives in advance. This paper aims to investigate modeling methodology of structural adhesive junctions for body stiffness simulation. Two main modeling points are the element selection for adhesives and the connectivity between adhesives and adherends. Both of the 1D element used in classical modeling and the 3D element which are more accurate are considered for the adhesives, and the congruent and incongruent mesh models of the adherends are compared for connectivity modeling. By applying the several kinds of modeling methodology to the simple structures, the simulation results are compared and some modeling guidelines are obtained.

• Structural Engineering and Mechanics
• /
• v.20 no.5
• /
• pp.589-608
• /
• 2005

There is a growing need for the development and implementation of new methods for the rapid and cost-effective rehabilitation of deteriorating steel structural components to offset the drawbacks related to welding and/or bolting in the field. Carbon fiber reinforced polymer (CFRP) composites provide a potential alternative as externally bonded patches for strengthening and repair of metallic structural members for building and bridge systems. This paper describes results of an investigation of tensile and fatigue response of steel/CFRP joints simulating scenarios of strengthening and crack-patching. It is shown that appropriately designed schemes, even when fabricated with levels of inaccuracy as could be expected in the field, can provide significant strain relief and load transfer capability. A simplified elasto-plastic closed form solution for stress analysis is presented, and validated experimentally. It is shown that the bond development length remains constant in the linear range, whereas it increases as the adhesive is deformed plastically. Fatigue resistance is shown to be at least comparable with the requirements for welded cover plates without attendant decreases in stiffness and strength.