• Title/Summary/Keyword: Adhesive Joint

Search Result 309, Processing Time 0.032 seconds

Reliability Monitoring of Adhesive Joints by Piezoelectricity (압전특성을 이용한 접착 조인트의 안전성 모니터링)

  • Kwon, Jae-Wook;Chin, Woo-Seok;Lee, Dai-Gil
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.27 no.8
    • /
    • pp.1388-1397
    • /
    • 2003
  • Since the reliability of adhesively bonded joints for composite structures is dependent on many parameters such as the shape and dimensions of joints, type of applied load, and environment, so an accurate estimation of the fatigue life of adhesively bonded joints is seldom possible, which necessitates an in-situ reliability monitoring of the joints during the operation of structures. In this study, a self-sensor method for adhesively bonded joints was devised, in which the adhesive used works as a piezoelectric material to send changing signals depending on the integrity of the joint. From the investigation, it was found that the electric charge increased gradually as cracks initiated and propagated in the adhesive layer, and had its maximum value when the adhesively bonded joint failed. So it is feasible to monitor the integrity of the joint during its lifetime. Finally, a relationship between the piezoelectric property of the adhesive and crack propagation was obtained from the experimental results.

Bonding Strength Analysis and Ultrasonic Testing of Structural Adhesive Joints (구조접착 이음에서의 접합강도해석과 초음파실험)

  • 장철섭;오승규;김종현;황영택;이원
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2004.10a
    • /
    • pp.860-864
    • /
    • 2004
  • This article discusses the use of pulse-echo ultrasonic testing for the stress analysis of adhesive bonds 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(variables 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 distingguished. In this paper, Quantitative Nondestructive Evaluation in Adhesive Joints are together with Ultrasonic Testing and Finite Element Method.

  • PDF

Relaxation of Singular Stress in Adhesively Bonded Joint at High Temperature

  • Lee, Sang Soon
    • Journal of the Semiconductor & Display Technology
    • /
    • v.17 no.1
    • /
    • pp.35-39
    • /
    • 2018
  • This paper deals with the relaxation of singular stresses developed in an epoxy adhesive at high temperature. The interface stresses are analyzed using BEM. The adhesive employed in this study is an epoxy which can be cured at room temperature. The adhesive is assumed to be linearly viscoelastic. First, the distribution of the interface stresses developed in the adhesive layer under the uniform tensile stress has been calculated. The singular stress has been observed near the interface corner. Such singular stresses near the interface corner may cause epoxy layer separated from adherent. Second, the interfacial thermal stress has been investigated. The uniform temperature rise can relieve the stress level developed in the adhesive layer under the external loading, which can be viewed as an advantage of thermal loading. It is also obvious that temperature rise reduces the bonding strength of the adhesive layer. Experimental evaluation is required to assess a trade-off between the advantageous and deleterious effects of temperature.

Strength evaluation of adhesive joint with thermal stress using ultrasonic signal processing method (열응력이 발생하는 접착이음부에서의 초음파 신호처리기법을 이용한 강도평가)

  • Oh, Seung-Kyu;Hawng, Yeong-Taik;Jang, Chul-Sub;Oh, Sun-Sae;Yi, Won
    • Proceedings of the KSME Conference
    • /
    • 2001.06a
    • /
    • pp.534-540
    • /
    • 2001
  • One approach to testing the suitability of an adhesive joint for a particular application is to build and test to destruct ion a representative sample of the joint. The nondestructive test will not measure strength directly but will measure a parameter which can be correlated to strength. It is therefore, essential that a suitable nondestructive test is chosen and that its results are correctly interpreted. In this paper, typical defects found in adhesive joints are described together with their significance. The limits and likely success of current physical nondestructive tests are described, and future trends outlined.

  • PDF

Updates on the treatment of adhesive capsulitis with hydraulic distension

  • Jang Hyuk, Cho
    • Journal of Yeungnam Medical Science
    • /
    • v.38 no.1
    • /
    • pp.19-26
    • /
    • 2021
  • Adhesive capsulitis of the shoulder joint is a common disease characterized by pain at the insertional area of the deltoid muscle and decreased range of motion. The pathophysiological process involves fibrous inflammation of the capsule and intraarticular adhesion of synovial folds leading to capsular thickening and contracture. Regarding the multidirectional limitation of motion, a limitation in external rotation is especially prominent, which is related to not only global fibrosis but also to a localized tightness of the anterior capsule. Ultrasound and magnetic resonance imaging studies can be applied to rule out other structural lesions in the diagnosis of adhesive capsulitis. Hydraulic distension of the shoulder joint capsule provides pain relief and an immediate improvement in range of motion by directly expanding the capsule along with the infusion of steroids. However, the optimal technique for hydraulic distension is still a matter of controversy, with regards to the infusion volume and rupture of the capsule. By monitoring the real-time pressure-volume profile during hydraulic distension, the largest possible fluid volume can be infused without rupturing the capsule. The improvement in clinical outcomes is shown to be greater in capsule-preserved hydraulic distension than in capsule-ruptured distension. Moreover, repeated distension is possible, which provides additional clinical improvement. Capsule-preserved hydraulic distension with maximal volume is suggested to be an efficacious treatment option for persistent adhesive capsulitis.

Effect of Finger Dimensions of Tip and Root Widths on Bending Strength Properties (핑거공차가 휨강도성능에 미치는 영향)

  • 변희섭;류현수;안상열;이균필;박한민;김종만
    • Journal of the Korea Furniture Society
    • /
    • v.12 no.2
    • /
    • pp.1-10
    • /
    • 2001
  • As finger joint method has a high rate of yield and high strength and ease in working, it has been widely used as an end joint method for solid wood and wood based-material. Therefore, we end-joined the material of Pinus densiflora, Quercus variabilis and populus euramericana with polyvinyl acetate adhesive and resorcinol phenol resin adhesive. The effect of difference (0, 0.15, 0.3, 0.45mm) between the dimensions of tip width and root width of the finger (DTRW) on bending strength properties was as follows: 1. In the case of polyvinyl acetate adhesive, DTRW had no effect on bending modulus of elasticity(MOE) and modulus of rupture(MOR) of the three kinds of species, because their bonding layers were destroyed by slippage, not their woody parts. 2. In the case of resorcinol phenol resin adhesive, the material of Quercus variabilis showed an optimal result at 0.15 or 0.3 of DTRW, while the poplar did at 0 of DTRW 3. The differences in efficiency ratio of bending MOR of populus euramericana, Pinus densiflora and Quercus variabilis species according to the kind of adhesive were 13-29%, 23-30% and 45-53%, respectively.

  • PDF

Adheive Joining Technique for Composite/Aluminum Joint in Carbody of Tilting Train (틸팅차량 차체의 복합재/알루미늄 접합을 위한 접착체결기법)

  • Yoon Sung-Ho;Shin Kwang-Bok;Han Seong-Ho
    • Proceedings of the KSR Conference
    • /
    • 2003.10c
    • /
    • pp.395-400
    • /
    • 2003
  • Adhesive joining technique is considered as one of hot issues in developing advanced composite structures. The designer should be familiar with important guidelines of fundamental principles and ideas underlying the design and application of adhesive joints for a correct joint design. This study deals with the following characteristics of adhesive joining techniques: (1) design parameters the affect the performance of joining, (2) fundamental principles and design methods of joining, (3) adhesive selection, (4) surface pre-treatment of the adherand, and (6) test methods. The results would be used to predict the performance of adhesive joints subjected to a thermal aging.

  • PDF

An Analytic Study for the Adhesively Bonded Tubular Double Lap Joint (원형 이중겹치기 접착조인트의 해석해에 관한 연구)

  • 이수정;이대길
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.18 no.6
    • /
    • pp.1412-1420
    • /
    • 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.

A Study on Failure Strength of Single Lap Adhesive Joint with Thick Adherend (후판 단일 겹침 접착 조인트의 파손강도에 관한 연구)

  • Park, Jae-Hyun;Choi, Jin-Ho;Kweon, Jin-Hwe
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.38 no.2
    • /
    • pp.111-118
    • /
    • 2010
  • The joints are often the weakest areas in composite structures. In this paper, the thick aluminum-aluminum joint specimens and thick composite-aluminum single lap adhesive joint specimens were manufactured and the tensile tests were performed. The fracture mode of each specimen was investigated and the modified damage zone theory based on the yield strain was proposed and compared with experimental failure load of each mode. The failure loads of the thick aluminum-aluminum joint and composite-aluminum joint were predicted by the same failure criterion and they could be predicted to within 19.3% using the damage zone ratio method for all 14 cases investigated.

A new analytical approach for optimization design of adhesively bonded single-lap joint

  • Elhannani, M.;Madani, K.;Mokhtari, M.;Touzain, S.;Feaugas, X.;Cohendoz, S.
    • Structural Engineering and Mechanics
    • /
    • v.59 no.2
    • /
    • pp.313-326
    • /
    • 2016
  • In this study the three-dimensional nonlinear finite element method was used to analyze the stresses distribution in the adhesive layer used to joint two Aluminum 2024-T3 adherends. We consider in this study the effect of different parameters witch directly affect the values of different stresses. The experimental design method is used to investigate the effects of geometrical parameters of the single lap joint in order to achieve an optimization of the assembly with simple lap joint. As a result, it can be said that both the geometrical modifications of the adhesive and adherends edge have presented a significant effect at the overlap edge thereby causing a decrease in peel and shear stresses. In addition, an analytical model is also given to predict in a simple but effective way the joint strength and its dependence on the geometrical parameters. This approach can help the designers to improve the quality and the durability of the structural adhesive joints.