Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Fatigue in Adhesively Bonded Joints: A Review  [PDF]
M. M. Abdel Wahab
ISRN Materials Science , 2012, DOI: 10.5402/2012/746308
Abstract: This paper presents a literature review on fatigue in adhesively bonded joints and covers articles published in the Web of Science from 1975 until 2011. About 222 cited articles are presented and reviewed. The paper is divided into several related topics such as fatigue strength and lifetime analysis, fatigue crack initiation, fatigue crack propagation, fatigue durability, variable fatigue amplitude, impact fatigue, thermal fatigue, torsional fatigue, fatigue in hybrid adhesive joints, and nano-adhesives. The paper is concluded by highlighting the topics that drive future research. 1. Introduction Adhesive bonding has gained lots of popularity during the last few decades due to the many advantages that it offers when compared to classical mechanical fastening techniques. A major advantage of using adhesives is its higher fatigue resistance and longer fatigue life than conventional joining techniques. Other advantages include its light weight, ability to joint thin and dissimilar components, good sealing, low manufacturing cost, and its good vibration and damping properties. Adhesively bonded joints are widely used in many industries, especially automotive and aerospace due to the requirement of lightweight materials. There is, therefore, no wonder that adhesive bonding is the primary joining technique for carbon fibre reinforced polymer (CFRP) used in the aerospace industry. Many other industries make use of adhesives, for example, civil engineering, transportation, biomechanical, marine, electronics, and so forth. Hybrid joints that consist of the combination of mechanical joining and adhesive bonding have attracted the attention of various automotive and transportation industries during the last few decades due to their enhanced performance when compared to only mechanical joining techniques. Fatigue is undoubtedly a very important type of loading for many structural components that contain adhesive bonding systems. In a fatigue loading regime, a structure may fail at a small percentage of static strength. Therefore, fatigue analysis and fatigue strength prediction are highly required especially for the case of fail-safe or damage tolerance design. Accurate prediction of fatigue life is a challenge due to the complicated nature of fatigue crack initiation and propagation, geometry of bonded joints, and complex material behaviour under loading and unloading regimes. This paper covers a literature review on fatigue in adhesively bonded joints during the last few decades and more precisely from 1975 until 2011 (or early 2012). All cited articles, 222
Investigation of aluminum single lap adhesively bonded joints  [PDF]
M. Luci?,A. Stoi?,J. Kopa?
Journal of Achievements in Materials and Manufacturing Engineering , 2006,
Abstract: Purpose: The purpose of research was to find an optimum overlap length ensuring the settled bearing performance of adhesive bonded joint. At the optimum overlap length it is possible to reach a maximum load bearing capacity using a minimum quantity of applied adhesive.Design/methodology/approach: In accordance with experimental test results, an optimum overlap length was achieved. In numerical analysis, the proposed material model (MISO) fits well in simulations.Findings: Mechanical properties of adhesive which are often public unknown have very strong influence on reliability of material models used in numerical analysis. Therefore, it was crucial decision of research to made an adhesive specimen for tensile testing.Research limitations/implications: At the overlap lengths above critical (optimal) ones, the usage of a MISO material model in FEA is not acceptable any more. In further work is of great interest to verify simulation with other materials model approaches.Practical implications: Maximal strength of joint might be reached if optimal overlap length of joint is applied, nevertheless if less adherend material is consumed.Originality/value: Originality is in true stress/strain diagram of adhesive which is based on experimental testing of adhesive specimen. Material model in numerical analysis is based on true stress/strain diagram.
Strength of Adhesive-Bonded Lap Joints in Composite Structures  [PDF]
Mahmoud N. Nahas
Journal of Applied Sciences , 2002,
Abstract: Many fiber-reinforced composite structures are made up of a number of modules for ease of manufacturing and handling. Modular construction requires some form of joining system that will transmit the applied loading between the different modules and give adequate performance over the service life of the component. This paper reviews the different analytical approaches used to study bonded joints and presents a simple analysis to predict failure loads for a specific type of bonded joints, namely the lap joint. The present analysis is compared with two more rigorous analyses and found to give good results. Experiments were also carried out on glass fiber specimens and it is concluded that the present approach compares well with test results.
Eksperimentalna i numeri ka analiza jednostrukih preklopnih lijepljenih spojeva / Experimental and numerical analysis of single lap adhesively bonded joints
Pero RAOS,Franjo MATEJI?EK,Mirjana LUCI?
Polimeri , 2004,
Abstract: Ve i broj faktora utje e na mehani ke karakteristike nosivosti lijepljenoga spoja. imbenici oblika i dimenzija spoja s najve im utjecajem jesu ostvarena duljina preklopa i debljina sloja ljepila. U eksperimentalnom su dijelu rada analizirani ti faktori te definirane njihove optimalne vrijednosti pri kojima se uz najmanji utro ak materijala podloge i ljepila posti e najve a nosivost lijepljenoga spoja. U numeri kom dijelu rada provedene su simulacije optere ivanja spojeva metodom kona nih elemenata (FEM). Simulacije su provedene uporabom komercijalnoga programskog paketa ANSYS. / The load bearing capacity of adhesively bonded joints depends on many factors. The most decisive designing factors are lap length and thickness of the adhesive layer. In the experimental part of the present research these factors were analysed and their optimal values were defined. At these optimum values it is possible to reach the maximum load bearing capacity by using a minimum quantity of applied adhesive. In the numerical part of the paper, loading simulations based on the finite-elements method were carried out. The simulations were performed by using the commercial FEA code ANSYS.
Crack Initiation and Propagation of Bonded Metallic Joints under Mixed-Mode Cyclic Loading
TA Hafiz
International Journal of Engineering Innovations and Research , 2013,
Abstract: Crack Initiation and Propagation of Bonded Metallic Joints under Mixed-Mode Cyclic LoadingDouble Cantilever Beam (DCB) specimens have been used to carry out Fatigue tests to investigate mixed mode crack growth behaviour in bonded joints. Equal thickness mild steel DCB substrates bonded with FM73 adhesive were used. The bonded joints were tested under pure mode I and a range of fatigue mixed-mode conditions using a relatively simple, variable-mode loading fixture as described in [1and 2]. The fatigue testing was carried out at a load ratio (R) of 0.1, in displacement control such that the initial maximum fatigue load was 70 0of the corresponding quasi-static fracture load. The fatigue load decreased as the fatigue crack grew and this load was recorded. Crack growth was monitored and measured using a video microscope. The strain energy release rate components were determined using corresponding values of fatigue crack length and fatigue load. The fatigue crack growth rates were characterised using a Paris Law approach and a significant influence of mode II component on the crack growth rate has been observed.
Study on mechanical properties of self-piercing riveted joints of aluminum alloy metal foam sandwich sheet

- , 2018, DOI: 10.7520/1001-4888-17-020
Abstract: 对AA5052铝合金泡沫金属夹层板进行自冲铆接试验,对接头的可连接性进行探究。通过静力学试验对比各组接头的静力学性能,分析不同种类泡沫金属对自冲铆接头力学性能的影响;用扫描电子显微镜对接头典型断口进行研究,分析其微观失效机理。结果表明:自冲铆技术可以实现泡沫金属夹层板的有效连接,接头具有良好的成形质量;泡沫金属夹层提高了自冲铆接头的静力学性能,其中泡沫镍夹层使AA5052自冲铆接头静失效载荷提高了4.1%;夹层板自冲铆接头失效形式均为铆钉与下板分离,其中泡沫铁镍夹层自冲铆接头下板铆扣断裂区域粘附在铆钉脚底部,为韧性断裂机制;下板内锁区域失效时铆钉与下板发生剧烈刮擦,呈现具有分层现象的片状组织。
Self-piercing riveting tests of AA5052 aluminum alloy metal foam sandwich sheet was carried out to investigate the join-ability. Static properties of each group of joints were compared by static tests, and the influnence of different kinds of metal foam on mechanical properties of self-piercing riveted joints were analyzed. Typical joint fracture was investigated by scanning electron microscope, and the microscopic failure mechanism was analyzed. Results show that self-piercing riveting can realize effective connection of metal foam sandwich sheet, and the joint has good forming quality. The metal foam interlayer improves the static performance of self-piercing riveted joint. Among them, the nickel foam interlayer makes static failure load of AA5052 self-piercing riveted joint to increase by 4.1%. The failure mode of self-piercing riveted joint of sandwich sheet is the separation of rivet from lower sheet. The fracture region of the lower sheet of self-piercing riveted joint of iron-nickel foam sandwich sheet attached at the bottom of the rivet tail, exhibiting ductile fracture mechanism; the rivet and the lower sheet scratch violently when the inner lock region fails, showing a lamellar structure with delamination
Interface Structure and Formation Mechanism of Directly-Bonded Joints of Silicated Graphite to Fe-based Alloys
Jichun CHEN,Chuanyong HAO,Jinsong ZHANG,

材料科学技术学报 , 2007,
Abstract: Commercially available 000Cr30Mo2 ferritic stainless steel and 4J33 ferromagnetic expansion alloy were directly bonded to silicated graphite at 1180-1200℃ and 1100-1150℃, respectively. Interracial microstructures were examined by scanning electron microscopy, electron probe microanalysis, and X-ray diffraction. The results showed that transient liquid-phase present during bonding promoted the interfacial reactions during bonding. Plenty of brittle chromium carbides, such as (Cr, Fe)7C3 and (Cr2.5Fe4.3Mo0.1)C3, were observed in 000Cr30Mo2/silicated graphite joints. Besides, transverse cracks were also found. In case of 4J33/silicated graphite system, well bonded joints free of defects were obtained.
Comparative Modal Analysis of Gasketed and Nongasketed Bolted Flanged Pipe Joints: FEA Approach  [PDF]
Muhammad Abid,Shahid Maqsood,Hafiz Abdul Wajid
Advances in Mechanical Engineering , 2012, DOI: 10.1155/2012/413583
Abstract: It is widely known that resonance can quickly lead to failure in vibrating bolted flanged pipe joints. Condition monitoring is performed time to time in some industries for smooth operation of a system, whereas mostly trial-and-error tests are performed to control vibration. During all this process, the inherent design problems are not considered. A bolted flange joint in piping system is not a simple problem, being the combination of flange, gasket, bolts, and washers. The success of a bolted flanged pipe joint is defined by the “static mode of load” in the joint. However, it has been recognized that a “dynamic mode of load” governs in a gasketed bolted flanged pipe joint, which leads to its failure due to flange rotation, providing flange yielding, fatigue of bolts, and gasket crushing. This paper presents results of detailed 3D finite element and mathematical modal analysis under bolt up to determine natural frequencies and mode shapes of gasketed flanged joints with and without raised face in comparison to the nongasketed flange joint. 1. Introduction Since the advent of bolted flanged pipe joints and their applications in industries, leakage is the major causes of their failure. The problem becomes worst under dynamic loading applications such as in mill digester pipes during transfer of pulp. Traditional gasketed flanged joints are claimed to be problematic even during bolt up due to “dynamic mode of load” [1–6]. This is concluded due to the flange rotation, flexibility of gasket hence bolt loosening and leakage [1, 2, 4]. For large diameter flanges, with bolts diameter more than 18?mm, use of hammering for bolt tightening provides worst effect resulting in gasket crushing and flange yielding [1, 2, 4]. This not only increases maintenance, but also damages the joint permanently. This shows that inherent flange design problem is not considered. To avoid and control flange rotation, raised face of the flange in many industrial applications is machined [1, 2]. Keeping in view the above mentioned problems, associated with the conventional gasketed joints used in industry, several alternatives to these require consideration. For this, a nongasketed joint, concluded as an alternative for its “static mode of load,” during experimental and analytical studies by [1–4], is analyzed using detailed comparative 3D finite element modal analysis in comparison to the conventional gasketed joints with and without raised face to observe behaviour of both the joints in detail under applied bolt-up conditions. Natural frequencies and mode shapes for both the joints
Three-Dimensional in Bonded Joints: A Short Review  [PDF]
Filippo Berto, Relly Victoria V. Petrescu and Florian Ion T. Petrescu
American Journal of Engineering and Applied Sciences , 2016, DOI: 10.3844/ajeassp.2016.1261.1268
Abstract: Distributions of stress 3D in the vicinity of the overlapping corners of joints with a single lap were investigated with accuracy at present the man. A (Fe), model accurately Finite Element 3D has been carried out in order to investigate the intensity of the stress of adjustments in the plan and outside of stress by the width of the plate. The influences of the thickness of the adhesive and the Poisson distribution have been taken into account. Numerical results showed the presence of modes engaged has been detected with precision a sudden rise in the way the out-of-plan is very close to the free surface side of the fitting.
Experimental and numerical analyses of adhesively bonded T-joints under crash loading  [cached]
May M.,Vo? H.
EPJ Web of Conferences , 2012, DOI: 10.1051/epjconf/20122604019
Abstract: Adhesively bonded metallic T-joints were subjected to impact at different loading directions and loading rates ranging from quasi-static to crash. Different damage and failure mechanisms were observed depending on the loading configuration. Finite element simulations were performed with ABAQUS/explicit using a user-defined, fully rate dependent material model for cohesive elements describing the material response of the adhesive bond lines. The FE simulation results were in good agreement with the experimental evidence, capturing both, the observed damage mechanisms, and the recorded force-displacement response.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.