• Title/Summary/Keyword: single lap

Search Result 198, Processing Time 0.037 seconds

Effect of Graphite/Epoxy (CERP) Surface Treatment on the Shear Strength of CERP/Metal Composites (탄소섬유/에폭시 복합재(CFRP)의 표면처리가 금속재/CFRP의 전단강도에 미치는 영향에 대한 연구)

  • 지창헌;양준호
    • Journal of the Korean institute of surface engineering
    • /
    • v.34 no.3
    • /
    • pp.225-230
    • /
    • 2001
  • In this study, the effect of surface treatment of CFRP (Carbon Fiber Reinforced Composites) on the shear strength of CFRP/metal composites was investigated. The surface of 14 plied unidirectional (0-dog ) CFRP was treated by an $Ar^{/}$ + ion beam under an oxygen environment. Shear strength tests were performed using SLS (Single Lap Shear) specimens based on the ASTM D906-94a procedure. The shear strength of the surface-treated CFRP/metal composites was compared with that of the untreated CFRP/metal composites. The results showed that the shear strength of surface-treated CFRP/metal composites was 36% greater than that of untreated CFRP/metal composites.

  • PDF

Fabrication of superconducting Joints Between PIT Processed BSCCO 2223 Tapes by Single and Multiple Press & reaction Annealing (고온초전도 BSCCO 2223 선재간의 초전도 접합부 제조연구)

  • Yu, Jae-Mu;Go, Jae-Ung;Jeong, Hyeong-Sik
    • 연구논문집
    • /
    • s.27
    • /
    • pp.175-181
    • /
    • 1997
  • Superconducting joints between Bi-2223/Ag tapes are fabricated by a press & reaction anneal and a multiple press & anneal. The silver sheath was mechanically or chemically removed from one side of each tape without altering the superconducting core. The exposed superconducting core of the two tapes were brought into contact and pressed so as to form a lap joint. The joined tapes were then subjected to a series of different thermomechanical treatments to achieve optimum heat treatment condition. The result from transport measurements shows that critical current ($I_c$) transmitting through joined area reaches 9A, approximately 60% of the current capacity of the tapes themselves. The critical current through joined area was improved by repeated press and reaction annealing. Measurements of the current-voltage relationship were made with several configuration of the voltage probes to characterize the critical current variation and I-V curve along the joint. Also discussed are microstructural aspects of the superconducting joint.

  • PDF

Realtime Detection of Damage in Composite Structures by Using PVDE Sensor (압전고분자 센서를 이용한 복합재 구조의 실시간 손상탐지)

  • ;Y. A. Dzenis
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • 2002.10a
    • /
    • pp.118-121
    • /
    • 2002
  • Polyvinylidene di-fluoride (PVDF) film sensor appeared to be practically useful for the structural health monitoring of composite materials and structures. PVDF film sensors were either attached to or embedded in the graphite/epoxy composite (CFRP) samples to detect the fatigue damage at the bondline of single-lap joints or the tensile failure of unidirectional laminates. PVDF sensors were sensitive enough to detect and determine the crack front in linear location since composites usually produce very energetic acoustic emission (AE). PVDF sensors are extremely cost-effective, as flexible as other plastic films, in low profile as thin as a few tens of microns, and have relatively wide-band response, all of which characteristics are readily utilized for the structural health monitoring of composite structures. Signals due to fatigue damage showed a characteristics of mode II (shear) type failure whereas those from fiber breakage at DEN notches showed that of mode I (tensile) type fracture.

  • PDF

A Study on the Bond Properties of Carbon Fiber Sheets used for Strengthening Structures (구조물 보강용 탄소섬유쉬트의 부착특성에 관한 연구)

  • 황진석;김지영;백명종;박형철;박칠림
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 1997.10a
    • /
    • pp.653-658
    • /
    • 1997
  • Recently, carbon Fiber sheet (CFS) is frequently used for strengthening deteriorated concrete structures. To strengthening damaged structures, the property and characteristic of the bond between CFS and the concrete surface must be understood. The tensile test of single lap shear specimen was performed to study bond strength, bond stress distribution and stress transfer between CFS and concrete surface according to the bond length. Based on the test results, there were ultimate influence length (UIL) in which bond stress was distributed, and ultimate strain reduction ratio (USRR) by which strain was reduced linearly. Bond resisting force (BRF) was estimated by UIL and USRR, and which was compared with ultimate loads. According to the results of comparison, it was shown that ultimate bond strength could be estimated reasonablely by BRF.

  • PDF

EFFECT OF SURFACE ROUGHNESS ON ADHESIVE STRENGTH OF HEAT-RESISTANT ADHESIVE RTV88

  • Cho, Tae-Min;Choo, Yeon-Seok;Lee, Min-Jung;Oh, Hyeon-Cheol;Lee, Byung-Chai;Park, Tae-Hak;Shin, Young-Sug
    • Proceedings of the KSME Conference
    • /
    • 2008.11a
    • /
    • pp.115-120
    • /
    • 2008
  • In this study, effects of surface roughness on adhesive strength of heat-resistant adhesive RTV88 were examined. Sandblast was used to generate rough surfaces on aluminum adherends, and then tensile-shear tests of Al/RTV88 single lap joints were performed. The shear strength was shown to be affected by the surface roughness. Effective area, peel failure area, and cohesive failure area were introduced to explain the effects of surface roughness on the adhesive strength. An empirical relation for the failure force was proposed based on these parameters and verified by the test results.

  • PDF

An Experimental Study of Disc Warping in Slim-type Optical Disc Drive (Slim-type 광학식 정보저장기기에서의 디스크 변형에 관한 실험적 연구)

  • Lee, Jae-Sung;Rhim, Yoon-Chul
    • Proceedings of the KSME Conference
    • /
    • 2003.11a
    • /
    • pp.676-681
    • /
    • 2003
  • In this paper, we investigated the disc warping in high-speed slim-type optical disc drive. Recently, the information storage devices are increasing track density and higher rotation speed to enhance their recording capacity and their data transfer rate. Generally, ODD used in the Lap-top Computer has small inner space. So, the flow instability of inner space is rapidly increased as its higher rotation speed. An extreme case, the flow instability causes the malfunction of readout at pick-up of drives. The experiments and numerical analysis were carried out for several cases, the result shows the influence of airflow to the disc warping.

  • PDF

Prediction of Arc Welding Quality through Artificial Neural Network (신경망 알고리즘을 이용한 아크 용접부 품질 예측)

  • Cho, Jungho
    • Journal of Welding and Joining
    • /
    • v.31 no.3
    • /
    • pp.44-48
    • /
    • 2013
  • Artificial neural network (ANN) model is applied to predict arc welding process window for automotive steel plate. Target weldment was various automotive steel plate combination with lap fillet joint. The accuracy of prediction was evaluated through comparison experimental result to ANN simulation. The effect of ANN variables on the accuracy is investigated such as number of hidden layers, perceptrons and transfer function type. A static back propagation model is established and tested. The result shows comparatively accurate predictability of the suggested ANN model. However, it restricts to use nonlinear transfer function instead of linear type and suggests only one single hidden layer rather than multiple ones to get better accuracy. In addition to this, obvious fact is affirmed again that the more perceptrons guarantee the better accuracy under the precondition that there are enough experimental database to train the neural network.

Study on Optimaization of Heating Element Gap in Resistance Welding using Thermoplastic resin (열가소성 수지 저항용접에서 발열체 간격의 최적화에 관한 연구)

  • Yun, Ho-Cheol;Im, Pyo;Im, Jae-Gyu
    • Proceedings of the KWS Conference
    • /
    • 2007.11a
    • /
    • pp.26-28
    • /
    • 2007
  • This research is concerned with a study of failure strength evaluation on heat element gap at resistance welding. The failure strength of resistance welded joint is changed by welding factor like as current(power level), welding time(total energy), pressure etc. and another heat element factor like as number of element line, element gap etc. Tensile-shear tests were carried out with the single-lap specimen using polypropylene(PP). The failure mechanism and optimization of gap was discussed in order to explain the tensile-shear strength evaluation on heat element gap at resistance welding. Orthogonal array was used by fractional factorial design for efficient experiments.

  • PDF

Joints Strength Evaluation of light Structure material (경량 구조재료의 접합강도평가)

  • Jang C. S.;Yi W.;Oh S. K.
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
    • /
    • 2005.05a
    • /
    • pp.234-238
    • /
    • 2005
  • One approach to testing the suitability of a adhesive joint for a particular application is to build and test to destruction of a representative sample of the joint. The nondestructive test will not measure strength directly but will measure a parameter which can be correlated to the strength. It is therefore, essential that a suitable nondestructive test is chosen and its results are correctly interpreted. In this paper, typical ultrasonic signal analysis in adhesive joints are evaluated together with interface stress from the result of finite element analysis.

  • PDF

A Study on the Analysis of 3 Dimensional Substrate Behaviour of Complex Environmental Deterioration and the Analysis of Results (복합열화분석용 3차원 거동대응성 시험을 통한 결과분석)

  • Song, Je-Young;Seo, Hyun-Jae;Kim, Bum-Soo;Choi, Eun-Kyu;Lee, Jung-Hun;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2017.11a
    • /
    • pp.219-220
    • /
    • 2017
  • Current domestic waterproofing market in Korea mainly uses single-ply waterproofing materials comprised of coatings or waterproof sheets and two or more-ply composite waterproofing methods. In order to evaluate these types of composite waterproofing systems, a new test equipment and method that incorporates various deterioration conditions (joint displacement, chemical exposure, water pressure etc) was developed. In a comparison testing, the results showed that flexible type materials have higher response performance towards joint displacement than the hardened material. Furthermore, the importance of securing the stability of the waterproofing method in the vulnerable over-lap joint areas of waterproofing sheets is emphasized.

  • PDF