자동차 충돌해석을 위한 구조용 접착제 유한 요소 해석 모델 개발

이태현(Taehyun Lee),신성기(Shounggi Shin) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

A very successful approach among the many things done is the use of structural adhesive, which have brought significant improvements in automobile for the reason that adhesive-bonded joints can reduce the stress concentration compared to mechanical joints, increase strength and endure against the environment variable such as corrosion. The objective of this paper is to develop structural adhesive model for car crash analysis. The power of the FEA for predicting the structural integrity of adhesively bonded vehicle structure is apparent. To obtain mechanical properties of the adhesives, First, Tensile test and shear test were carried out for material properties of structural adhesive such as young's modulus, shear modulus, strain- stress curves. Second, correlation between test and FEA is conducted to verify that the adhesive material properties derived earlier do indeed represent the mechanical properties of the physical adhesives in the single lap shear test, T-peel test, wedge impact test, three point bending test and compression test.

복합적 환경인자의 영향에 의한 접착제의 접착전단강도 및 화학구조 변화

황영은 ( Young Eun Hwang ),윤성호 ( Sun Ho Yoon ) 한국복합재료학회 2011 Composites research Vol.24 No.1

본 연구에서는 유도무기의 탐색기에 적용되는 기존 접착제의 대체 가능성을 조사하기 위해 환경인자의 노출시간에 따른 기존 접착제와 대체 접착제의 접착전단강도들을 평가하고 이들의 화학구조 변화를 조사하였다. 이때 접착제는 기존 접착제와 대체 접착제에 대해 각각 구조용 접착제와 실링용 접착제의 두 종류를 고려하였다. 이들 접착제는 온도, 수분, 자외선 등의 복합적인 환경인자에 최대 1000시간 동안 노출시켰다. 환경인자의 노출시간에 따른 접착제의 접착전단강도를 평가하기 위해 접착전단시험을 수행하고 화학구조 변화를 조사하기 위해 ATR 적외선 분광분석을 수행하였다. 연구결과에 따르면 대체 접착제의 접착전단강도는 기존 접착제의 경우에 비해 높으며 환경인자의 노출에도 매우 안정적으로 나타나 대체 접착제는 기존 접착제의 대체용으로 적용이 가능함을 알 수 있었다. Adhesive shear strengths of the established adhesives and the alternative adhesives were evaluated and their chemical structures were analyzed in order to investigate the possibility of replacing the established adhesives with the alternative adhesives applicable to the seeker for the guided missiles. Two types of the adhesives such as the structural adhesives and the sealant adhesives were considered. Those adhesives were exposed to the combined environmental factors consisting of temperature, moisture and ultraviolet over 1000 hours. Adhesive shear test was conducted to evaluate adhesive shear strengths and ATR FT-IR was utilized to investigate chemical structures. According to the results, the adhesive shear strengths of the alternative adhesives revealed higher than those of the established adhesives. Also the alternative adhesives were more stable to the combined environmental condition than the established adhesives. Therefore, it is found that the established adhesives were able to be replaced by the alternative adhesives.

차체 구조용 에폭시 접착제의 접합부 특성에 미치는 Zirconate 첨가효과

정은택,이혜림,이소정,임창용,서종덕,김목순,김준기,Jeung, Eun-Taek,Lee, Hye-Rim,Lee, So-Jeong,Lim, Chang-Young,Seo, Jong-Dock,Kim, Mok-Soon,Kim, Jun-Ki 대한용접접합학회 2013 대한용접·접합학회지 Vol.31 No.5

The effect of zirconate having - NH functional group on the T-peel and lap shear strength of $CaCO_3$ containing structural epoxy adhesive for car body assembly was investigated. Curing behavior of epoxy adhesive samples were investigated by differential scanning calorimeter (DSC) techniques. The addition of zirconate up to 7.5 phr did not affect the curing mechanism of epoxy adhesive. While the small amount of zirconate addition less than 1.1 phr increased the cross-linking density, the excess addition of zirconate resulted in the increase of uncross-linked impurity. From the increase of T-peel and lap shear strength and the change of fracture mode from the adhesive failure to the mixed one, it was considered that the small addition of zirconate was effective in improving the adhesion strength of epoxy adhesive to the adherend and inorganic filler surfaces. The formation of uncross-linked impurity with the excess addition of zirconate was considered to decrease the joint strength by decreasing the cohesive strength of the cured epoxy.

차체 구조용 에폭시 접착제의 접합강도에 미치는 나노 기능성 블록공중합체 첨가의 영향

이혜림(Hye-rim Lee),이소정(So-jeong Lee),임창용(Chang-young Lim),서종덕(Jong-dock Seo),김목순(Mok-soon Kim),김준기(Jun-ki Kim) 대한용접·접합학회 2015 대한용접·접합학회지 Vol.33 No.4

The structural epoxy adhesive used in car body assembly needs the highest level of joint mechanical strength under lap shear, T-peel and impact peel conditions. In this study, the effect of nano functionalized block copolymer addition on the impact peel strength of epoxy adhesive was investigated. DSC analysis showed that the addition of nano functionalized block copolymer did not affect the curing reaction of epoxy adhesive. From single lap shear test, it was found out that the addition of nano functionalized block copolymer slightly decreased the cohesive strength of cured adhesive layer. The addition of nano functionalized block copolymer showed beneficial effect on T-peel strength by changing the adhesive failure mode to the mixed mode. However, the addition of nano functionalized block copolymer just decreased the room temperature impact peel strength. It was considered that the addition of nano functionalized block copolymer could have effect on disturbing the crack propagation only for the case of slow strain rate.

소산입자동역학을 이용한 에폭시 접착 소재 구성에 따른 미시적 모폴로지 분석

최주희,이승걸 한국섬유공학회 2023 한국섬유공학회지 Vol.60 No.6

Epoxy structural adhesives are widely used in various industries due to theirexcellent chemical resistance, thermal properties, high electrical insulation performance,increased joint stiffness, and potential for lightweighting in structural components. Whilethe performance of epoxy adhesives is influenced by various factors such as chemicalstructures and compositions, it is challenging to analyze the structural morphology ofepoxy adhesives at the molecular level. Therefore, in this study, we investigated macroscopicstructural changes in epoxy adhesive materials based on the changes of componentsusing dissipative particle dynamics (DPD) simulations. By calculating DPDparameters and simulating the degree of affinity interaction between the epoxy components,we represented the morphological characteristics according to their chemical structure. Through DPD simulations, we analyzed the number density, density field distribution,and diffusion coefficient of structure for each epoxy compositions, revealing that 3,3’-diamino diphenyl sulfone (3,3’-DDS) strongly interact with triglycidyl aminophenol (TGAP)and diglycidyl ether of bisphenol A (DGEBA), and polyether sulfone (PES) has repulsiveinteraction with TGAP, resulting in significant phase separation.

Efficient dynamic behavior analysis of an adhesive-jointed structure made of composites

Ahmad Burhani Ahmad Basri,Muhamad Norhisham Abdul Rani,이형일 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.4

An inefficiency issue in substructure analysis is caused by a finite element model of an adhesive interface meshed into thousands of degrees of freedom. This paper presents a wave-approach based adhesive interface for efficient dynamic behavior analysis of a large adhesive jointed composite structure. The large adhesive interface is converted into a basis function known as waves. Orthonormalization selects the most important waves and reduces the interface size. Two engineering cases were presented. The predicted results obtained from the approach were compared with the full-size finite element and experimental counterparts to assess their accuracy level. It was discovered that the approach could significantly reduce the need for repeated long-term composite structure optimization analysis.

변형률속도에 따른 차량 구조용 접착제의 동적 인장 특성 연구

임승찬(Seung-Chan Lim),허훈(Hoon Huh),하지웅(Jiwoong Ha),이태현(Taehyun Lee) 한국자동차공학회 2011 한국자동차공학회 학술대회 및 전시회 Vol.2011 No.11

This paper investigates the effect of strain-rate on characteristics of structural adhesive. In order to get an accuracy result from crash simulation, we should have to consider the strain-rate hardening effect of adhesive joint, because it affects the crash energy absorption. Dynamic tensile characteristics of structural adhesive with various strain-rate are needed to apply this effect to crash analysis. Uniaxial tensile tests were carried out for structural adhesive from Henkel at the strain-rate ranged from 0.001/sec to 10/sec to measure the tensile properties; Young’s modulus, tensile strength, fracture strain. Strain was measured by digital image correlation technique. Based on the experimental data, Young’ modulus and tensile strength showed increasing tendency with increasing strain-rate, however fracture strain was slightly decreased with increasing strain-rate.

유효강성을 줄인 새로운 형상의 건식부착물 제작

조영삼(Young-Sam Cho),정대환(Dae-Hwan Jung),한혁섭(Houkseop Han),김완두(Wan-Doo Kim) 대한기계학회 2007 대한기계학회 춘추학술대회 Vol.2007 No.5

In the fabrication of dry adhesive structure, increasing contact-points or contact-area is the primary goal because the adhesive force grows in proportion to the contact-area. The simplest way to extend the contact surface is the fabrication by using soft materials. However, the column-array structure could confront the matting phenomenon which columns are stuck together. Therefore, we need a novel design to reduce the effective stiffness with adequate stiff materials like a gecko’s setae. In this study, we propose a novel design for the dry adhesive structure. Moreover, we analyzed whether the adhesive structure conforms the rough surface sufficiently through finite element method adopted the non-bonding interaction as the body force. Also, we fabricated the novel structures via UV lithography and some techniques. In addition, we examined the adhesive force of the novel structures.

CFRP/금속간 접합력 강화를 위한 접합공정 연구

권동준,박성민,박종만,권일준 한국복합재료학회 2017 Composites research Vol.30 No.6

The structural adhesive have been manufactured for improvement of bonding process between CFRP and metal. The optimal condition for bonding process were investigated by evaluating the lap shear strength with amount of adhesive and curing time and the surface treatment of the CFRP. To confirm proper adhesion conditions, the fracture sections between CFRP and metal was observed using reflection microscope. Not only the improvement of the adhesion condition was important, but surface treatment on CFRP was also important. The optimal curing temperature was at 180oC for 20 minutes. The improvement for adhesive property was confirmed After surface treatment on CFRP. The optimal amount of structural adhesive for bonding between CFRP and metal was 1.5 × 10-3 g/mm2. Through the optimization of bonding process, the improvement of mechanical property over 10% is confirmed in comparison with existing adhesive. CFRP와 금속간의 접합공정이 개선된 구조용 접착제가 제조되었다. 구조용 접착제에 대한 경화시간, 기지재료의 표면상태 그리고 접착제의 양에 따른 최적의 접합공정 조건을 랩쉐어 실험을 통하여 파악하였다. 적합한 접합조건을 확인하기 위해 이종재료간의 접합 파단면 상태를 반사현미경을 이용하여 평가하였다. 이종재료간접합력 향상을 위해 접착제의 개선뿐만 아니라 CFRP의 표면처리 또한 중요하였다. 구조용 접착제의 경우 180도조건에 20분의 경화온도 조건이 최적이였으며, CFRP의 표면 처리에 따라 접합특성이 향상됨을 확인하였다. 이종재료 간 접합을 위해 구조용 접착제의 양은 1.5 × 10-3 g/mm2 조건일 때 최적이었다. 접합공정의 개선 및 최적화를통해 기존의 접착력 대비 10% 이상의 물성 강화를 나타냄을 확인하였다.

Waterproofing performance of waterstop with adhesive bonding used at joints of underground concrete structures

Cho, Byoung Hooi,Nam, Boo Hyun,Seo, Sangyeon,Kim, Jungil,An, Jinwoo,Youn, Heejung Elsevier 2019 Construction and Building Materials Vol.221 No.-

<P><B>Abstract</B></P> <P>Waterstop is a typically used waterproofing material to prevent water leakage through the joints where consecutive concrete casting is not possible during the construction of underground concrete structures. A conventional waterstop, however, frequently allows for water passage through the interface between a waterstop and concrete under a high water-pressure environment owing to a deep excavation depth and high groundwater table. An alternative solution proposed in this study is to use artificial adhesive bonding between the waterstop and concrete using double-sided adhesive tape to actively prohibit water leakage through joints under a high hydrostatic pressure. The performance of the proposed waterproofing system was experimentally evaluated and compared with the control system (without adhesive). The results indicated that the adhesive bonding type resisted water migration under the pressure head of 30 <I>m</I>, whereas the conventional waterstop could not effectively waterproof even at the pressure head of 10 <I>m</I> in the soundly constructed cementitious composite structures. In addition, the peel strength, which is the bonding strength between the adhesive tape and cementitious composite, was measured to quantify the effect of surface contamination of the waterstop on the interface bonding strength. The adhesive tape on the surface of the waterstop was “contaminated” by either or both sand and bentonite slurry for the peel strength test. The results indicate that the surface contamination of the waterstop does not induce a meaningful reduction in the bonding strength for the tested conditions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Introducing newly designed waterstop to prevent water leakage at the joints. </LI> <LI> Introducing a testing device to evaluate the waterproofing performance at the joints. </LI> <LI> Providing the waterproofing level of conventional waterstop and the newly designed one. </LI> <LI> Proving the peeling strength between adhesive tape and cementitious composite for different contamination conditions. </LI> </UL> </P>