• Journal of KSNVE
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• v.8 no.6
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• pp.1093-1102
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• 1998

The success of controllability of smart structures depends on the quality of the bonding along the interface between the main structure and the attached sensing and acuating elements. Generally, the analysis procedures neglect the effect of the interfacial bond layer or assume that this bond layer behaves like viscoelastic material. Three different bond layers. two modified epoxy adhesives, and one isocyanate adhesive were prepared for their toughness and moduli. Bond layer of the chosen adhesive provides an almost perfect bonding condition between the composite structure and the PZT while bended significantly like arrow-shape. The perfect bonding condition is tested by considering various material properties of the bond layers. and based on this perfect bonding condition, the effects of the interfacial bond layer on the dynamic behavior and controllability of the test structure is experimentally studied. Once the perfect bonding condition is achieved. dynamic effects of the bond layer itself on the dynamic characteristics of the main structure is negligible. but the contribution of the attached PZT elements on the stiffness of the multi-layered structure becomes significant when the thickness of the bond layer increased.

• Applied Chemistry for Engineering
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• v.16 no.1
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• pp.81-85
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• 2005

Pressure sensitive adhesive (PSA) was prepared by semi-batch emulsion polymerization of acryl monomers in the presence of reactive and non-reactive carboxylated polyurethane resin (PUR). Effects of the PUR type, its content, and crosslinker feeding method on the adhesive properties of the PSA was investigated. In this experiment, the PSA prepared with the reactive PUR showed better adhesive property then the PSA with the non-reactive PUR. Especially, peel strength of the PSA, where acetoacetoxy ethyl methacrylate and 1,6-hexane diamine as crosslinkers were introduced, was dramatically enhanced in severe humidity condition due to the interfacial crosslinking.

• Journal of Adhesion and Interface
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• v.13 no.1
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• pp.24-30
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• 2012

Morphological changes of polyarylate (PAR) fiber treated with formic acid and ultraviolet (UV) were observed by using a scanning electron microscope (SEM) and an atomic force microscope (AFM). The results were analysed by using root mean square (RMS) roughness. In addition, the chemical changes of surface was investigated using contact angle and the interfacial adhesive strength between PAR fiber and PEN (Polyethylene naphthalate) matrix was calculated using the Pull-out test results. As the acid treatment concentration and UV irradiation time increased, cracks and pores were produced on the PAR fiber surface. Due to the roughness increased, the contact angle was decreased. For this reason, RMS roughness of PAR fiber was increased and the interfacial adhesive strength between the PAR fiber and PEN matrix was improved. The increase of interfacial adhesive strength was responsible for the increase of surface area which have cracks and pores.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.6
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• pp.783-790
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• 2004

Adhesive-bonded joints are widely used in the industry. Recently, applications of adhesive bonding joints have been increased extensively in automobile and aircraft industry. The strength of adhesive joints is influenced by the surface roughness, adhesive shape, stress distribution, and etc. However, the magnitude of the influence has not yet been clarified because of the complexity of the phenomena. In this study, as the fundamental research of adhesive bonding joints, the effects of adhesive shape and loading speed on bonding strength properties and durability of aluminum to polycarbonate single-lap joints were studied. To evaluate the effect of adhesive shape, several modified shapes were used, and loading speeds were varied from 0.05 to 5 mm/min. As a result, the load-displacement distribution was shown a brittle fracture tendency. The trigonal edged single lap and bevelled lap joints showed the higher strength than the plain single lap, trigonal single lap, joggle lap and double lap joints in same adhesive area. The fractures of trigonal single lap and trigonal edged single lap joints that had the higher strength level were shown as the mixture type of the cohesive and interfacial-failure, mostly joggle lap joints that had the lower strength level were shown as the adhesive-failure.

• International Journal of Korean Welding Society
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• v.4 no.1
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• pp.53-60
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• 2004

Adhesive-bonded joints are widely used in the industry. Recently, applications of adhesive bonding joints have been increased extensively in automobile and aircraft industry. The strength of adhesive joints is influenced by the surface roughness, adhesive shape, stress distribution, and etc. However, the magnitude of the influence has not yet been clarified because of the complexity of the phenomena. In this study, as the fundamental research of adhesive bonding joints, the effects of adhesive shape and loading speed on bonding strength properties and durability of aluminum to polycarbonate single-lap joints were studied. To evaluate the effect of adhesive shape, several modified shapes were used, and loading speeds were varied from 0.05 to 5mm/min. As a result, the load distribution showed a brittle fracture tendency. The trigonal edged single lap and bevelled lap joints showed the higher strength than the plain single lap, trigonal single lap, joggle lap and double lap joints in same adhesive area. The fractures of trigonal single lap and trigonal edged single lap joints that had the higher strength level were shown as the mixture type of the cohesive and interfacial-failure, mostly joggle lap joints that had the lower strength level were shown as the adhesive-failure.

• Composites Research
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• v.30 no.4
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• pp.235-240
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• 2017

Animal glue, a water-soluble adhesive, has been used historically for high-performance traditional furniture despite the disadvantage of weakness against moisture. Many scientists studied the ways to improve water resistance of animal glue. Improvements on the interfacial, thermal, and water resistance properties of wood sandwich composites (WSC) was studied with carbon nanotube (CNT) wt% in animal glue. Real-time temperature of WSC was measured after WSC was heated with increasing CNT wt%. Lap shear test was performed to determine the interfacial properties of wood and animal glue with CNTs. Water resistance properties of animal glue were determined by lap shear test using specimens dipped in water and the results were compared with the dry case. Hydrophobicity of animal glue by static contact angle was correlated with the variation of lap shear test. Interfacial, thermal, and water resistance properties for animal glue were improved with properly added CNTs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1479-1487
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• 2011

In the field of the entire electronic component industry including mobile IT products, the importance of a versatile package with the multifunctional or high capacity memories is gradually increased. Multi Chip Package which has several chips in a single package is frequently used for that purpose. In MCP, epoxy adhesive films play a major role in adhesion between the chips or between chip and substrate. A series of silane coupling agents with a functional group such as epoxy, amine, mercaptan, and isocyanate were applied to the epoxy adhesives and material properties such as wettability and reliability of the adhesives were investigated. From the results, the silane coupling agent with an epoxy functional group showed highest wettability and peel strength in epoxy adhesive. For those reasons, it lead to a superior reliability in the epoxy adhesive against interfacial fracture behaviors through moisture resistance test.

• Elastomers and Composites
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• v.40 no.3
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• pp.196-203
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• 2005

In this work, the engine oil resistant evaluation and breakdown analysis of room temperature vulcanizing silicone adhesives were performed through the surface properties, thermal stabilities, adhesive strength, and morphology measurements. As a result, the permeation of engine oil into adhesive specimens was carried out from surface to center in the specimens. And the oil content in the adhesive specimens was increased and the Si-O-Si bond of the adhesives was decomposed with increasing the aging time. The TGA results indicated that the thermal degradation was mainly occurred at under and surfaces of the specimens. The tensile strength, elongation, and adhesive strength of the adhesives were significantly decreased after the engine oil resistant tests, which could be attributed to the initial lose of adhesive properties resulting from the engine oil absorption and thermal aging. And the failure mode of the adhesive specimens was changed from cohesive failure to interfacial failure.

• Coupled systems mechanics
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• v.9 no.5
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• pp.473-498
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• 2020

This paper presents a careful theoretical investigation into interfacial stresses in reinforced concrete foundation beam repairing with composite plate. The essential issue in the analysis of reinforced structures with composite materials is to understand the individual behaviour of each material and its interaction with the remaining ones. The present model is based on equilibrium and deformations compatibility requirements in and all parts of the repaired RC foundation beam, i.e., the reinforced concrete foundation beam, the composite plate and the adhesive layer. The theoretical predictions are compared with other existing solutions, By comparisons between the existing solutions and the present new solution enable a clear appreciation of the effects of various parameters such as the geometric characteristics and mechanical properties of the components of the repaired beam, as well as the geotechnical stresses of the soil are considered. This research is helpful for the understanding on mechanical behaviour of the interface and design of the composite-concrete hybrid structures.

• Geomechanics and Engineering
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• v.18 no.5
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• pp.555-566
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• 2019

The purpose of this paper is to investigate the thermal effects on the behaviour reinforced-concrete beams strengthened by bonded angle-ply laminated composites laminates plate $[{\pm}{\theta}n/90m]_S$. Effects of number of $90^{\circ}$ layers and number of ${\pm}{\theta}$ layers on the distributions of interfacial stress in concrete beams reinforced with composite plates have also been studied. The present results represent a simple theoretical model to estimate shear and normal stresses. The effects the temperature, mechanical properties of the fibre orientation angle of the outer layers, the number of cross-ply layers, plate length of the strengthened beam region and adhesive layer thickness on the interfacial shear and normal stresses are investigated and discussed.