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Viewing 1 to 30 of 367
2017-03-28
Technical Paper
2017-01-0473
Satoshi Nakada, Toru Furusawa, Eiichiro Yokoi, R Carbas, M Costa, E Marques, G Viana, LFM da Silva
Abstract In recent years, adhesive bonding is increasingly being applied in the construction of vehicle frames in order to improve body stiffness and crash performance. Regarding crash performance, the behavior of impacted components is affected by the fracture energy value of the adhesive. However, the relationship between the ductility and fracture energy values under mixed-mode loadings has not been sufficiently evaluated. In this paper, the fracture energy of three structural adhesives in a static mixed-mode loading using Double Cantilever Beam (DCB) specimens is presented. To derive the fracture energy values, the Compliance Based Beam Method (CBBM) was used, which allowed for precise determination of fracture energy values. Static mixed-mode loading tests were performed in six configurations of mixed-mode loading, ranging from pure peel mode state to almost pure shear mode state.
2017-03-28
Technical Paper
2017-01-0503
Ahmad Waqar Tehami, Kamran Asim, Shahzad Sarwar
Abstract Fiber reinforced laminated materials are becoming popular in applications involving protection against impact loading. Laminates offer many advantages over metal plates in these applications. Laminates are normally non-ricochet, thus offering greater protection against projectiles. Laminates are also lighter in weight and less expensive as compared to the metal panels. In this study, laminated materials were fabricated from two different types of fibers which included short fibers and random fibers. Epoxy and polyester were used as the resin materials in the production of different types of laminates. Test samples were tested according to the available standards to investigate the impact toughness and ballistic resistance of these laminates. Experimental results showed that random fibers and polyester resin absorbed more energy as compared to short fibers and epoxy resin, respectively.
2017-03-28
Technical Paper
2017-01-0254
Sudeep Chavare, Kevin Thomson, Nitin Sharma
Abstract Use of parametric approach to optimize CAE models for various objectives is a common practice these days. In addition to load members, the connection entities such as welds and adhesives play an important role in overall performance matrix. Hence adding the connection entities to the pool of design variables during an optimization exercise provide additional opportunity for design exploration. The method presented in this paper offers a unique approach to parameterize adhesive lines by evaluating the possibility of using structural adhesives as intermittent patches rather than continuous lines. The paper discusses two optimization studies 1) structural adhesive patches along with spot weld pitch as design variables, and 2) structural adhesive patches with gage variables. These studies include the Body in White (BiW) and Trimmed Body in White (TBiW) assessments.
2017-03-28
Technical Paper
2017-01-1461
Sanketh Gowda, Anindya Deb, Goutham Kurnool, Clifford Chou
Abstract Adhesively bonded steel hat section components have been experimentally studied in the past as a potential alternative to traditional hat section components with spot-welded flanges. One of the concerns with such components has been their performance under axial impact loading as adhesive is far more brittle as compared to a spot weld. However, recent drop-weight impact tests have shown that the energy absorption capabilities of adhesively bonded steel hat sections are competitive with respect to geometrically similar spot-welded specimens. Although flange separation may take place in the case of a specimen employing a rubber toughened epoxy adhesive, the failure would have taken place post progressive buckling and absorption of impact energy.
2017-03-28
Technical Paper
2017-01-0351
Guofei Chen, Mingchao Guo
Abstract Advanced high strength steels (AHSS) have been extensively used in the automotive industry for vehicle weight reduction. Although AHSS show better parent metal fatigue performance, the influence of material strength on spot weld fatigue is insignificant. To overcome this drawback, structural adhesive can been used along with spot weld to form weld-bond joints. These joints significantly improve spot weld fatigue performance and provide high joint stiffness enabling down-gauge of AHSS structures. However, modeling the adhesive joints using finite element methods is a challenge due to the nonlinear behavior of the material. In this study, the formulation of cohesive element based on the traction-separation constitutive law was applied to predict the initiation and propagation of the failure mode in the adhesively bonded joints for lap shear and coach peel specimens subjected to quasi-static loadings.
2017-03-28
Technical Paper
2017-01-0331
Qiuren Chen, Haiding Guo, Katherine Avery, Xuming Su, HongTae Kang
Abstract Fatigue crack growth tests have been carried out to investigate the mixed mode fatigue crack propagation behavior of an automotive structural adhesive BM4601. The tests were conducted on a compound CMM (Compact Mixed Mode) specimen under load control with 0.1 R ratio and 3Hz frequency. A long distance moving microscope was employed during testing to monitor and record the real time length of the fatigue crack in the adhesive layer. The strain energy release rates of the crack under different loading angles, crack lengths and loads were calculated by using finite element method. The pure mode I and mode II tests show that an equal value of mode I strain energy release rate results in over ten times higher FCGR (Fatigue Crack Growth Rate) than the mode II stain energy release rate does. The mixed mode tests results show that under a certain loading angle, the mixed mode FCGR is changed by changing the load, which is contrary to the find in pure mode I and mode II tests.
2017-03-28
Technical Paper
2017-01-0255
Malli Kartheek Yalamanchili, Nitin Sharma, Kevin Thomson
Abstract The crashworthiness of body-in-white (BIW) plays a vital role in full vehicle crash performance. The structural integrity of BIW is controlled via strength of the spot welds and adhesives that are the primary entities to join sheet metal. The number of welds and amount of adhesives in the entire BIW directly affects the cost and the cycle time of the BIW; which makes them a good candidate for optimization. However optimization of the welds and/or adhesives not only reduces the number of connections but also provides the opportunity to improve the structural performance and mass saving by placing them optimally for the structural responses. This paper discusses the optimization of full vehicle structural performance for the small overlap crash event using the length of adhesives in the BIW as parameters. Included in the study were length of the adhesives and gage variables, defined in the front-end structure of the vehicle.
2017-03-28
Technical Paper
2017-01-0491
Hyerin Choi, Jaeyong Ko, JunHo Song, SeungKeon Woo
Abstract Recently, it is one of a major problems in automotive industry that wrinkles on seat interior occur at detaching between seat covering and padding foam. The purpose of this research is the way to improve heat resistance and adhesion using polyurethane reactive (PUR) of thermosetting plastic material. We compose PUR that makes thin film and non-tacky characteristic on padding foam. We find optimum situation (method and amount) for leather and padding foam. Viscosity and melting temperature are adjusted to coat with amount. 25~30g/m2 are suitable on padding foam unlike traditional method to coat leather above 100g/ m2. We also verified performances of PUR lamination compared to others. As result, peel strength is strongest at 15.4N/30mm. Heat resistance is also excellent with various padding foams. Furthermore we advance an additional jig to match leather and padding foam by low tacky characteristic of PUR. This jig can increase productivity in seat manufacturing process.
2017-03-28
Journal Article
2017-01-0501
Sajiree Vaidya, Naga Sai Chakravart Velamakuri, Piyush Agarwal, Srikanth Pilla, David Schmueser
Abstract In modern passenger vehicles, A-pillar plays an important role in its passive safety by minimizing the deformation of passenger compartment during the crash. To meet various crash requirements, as well as sometimes due to demand of vehicle styling, A-pillar cross section of modern vehicles is generally wider. This wider cross section acts as an increased obstruction to the field of vision of the driver. It is considered detrimental for the safety of road users. The current work proposes an innovative design solution to reduce the obstruction angle due to an A-pillar. It also addresses the weight reduction objective. This is done by utilizing the noble properties of Carbon Fiber Reinforced Polymers (CFRP). Carbon Fiber Reinforced Polymers (CFRP) offer flexibility for complex design. Due to high specific strength and stiffness, CFRP's are suitable candidate for design considerations presented in this study.
2017-03-28
Journal Article
2017-01-0498
Tomoya Yabu, Shigeto Yasuhara, Masakazu Kashiwagi
Abstract Regulation of automotive CO2 emissions is becoming increasingly stringent throughout the world in response to global warming. For automakers, this means a focus not only on increasing the fuel economy of powertrains, but also on reducing automotive driving resistance. High expectations are held for thermoplastic fiber-reinforced plastics (FRP) for the realization of automotive weight savings while also offering high levels of productivity and recyclability. Thermoplastic FRP crush boxes display a higher level of energy absorption performance than metal (steel, aluminum, etc.) crush boxes. This will contribute to automotive weight savings and improved package design. In the case of automotive front bumper beam systems, it is necessary to realize stable load characteristics irrespective of the use environment. It is therefore necessary to consider the effects of temperature and thermoplastic resin degradation.
2017-03-28
Journal Article
2017-01-0500
Yuksel Gur, David Wagner
Abstract With the continuing challenges of future fuel economy targets carbon fiber composite materials are one facet of a lightweighting strategy to enable reduced fuel consumption. In general, use of lightweight materials such as carbon fiber composites in vehicle design generates vehicle NVH performance degradation. To address this potential issue at the design phase, there is a need to develop correlated CAE models for carbon fiber vehicle parts to evaluate the NVH impact of carbon fiber composite material use in vehicle design. To develop correlated CAE models for lightweight vehicle design with the use of carbon fiber composite vehicle body parts, an experimental study was conducted to determine the material and NVH characteristics of the carbon fiber composite materials. In this paper, the damping properties and NVH modal analysis results for structural carbon fiber thermoset composite panels and body parts (B-pillar upper insert and B-pillar lower insert) is presented.
2017-01-10
Technical Paper
2017-26-0167
Salah M. Khaleel, Bernard Rolfe, Riyadh Al-Ameri, Tim De Susa
Abstract Given the need to reduce mass in products to reduce emissions, particularly in the transportation sector, the application of adhesively bonded joints is becoming more utilised. This is very true for the emerging multi-material structures. The adhesive joint expresses good properties regarding stress distribution, sound isolation and fatigue resistance; these properties are well defined in many applications such as aircraft and car industry. However, the adhesive joints have some drawbacks in regard to the joint strength. One of the keys to strengthening joints is the surface treatment of the adherents. It is found that the surface treatments play an important role in improving the joint strength and durability. Moreover, it is also found that each adhesive material will require different types of surface treatments to make the right balance between the joint strength and fracture modes.
2016-10-25
Technical Paper
2016-36-0462
Cauê Morais, André Pereira, Carlos Ney Mendes, Filipe Diniz, Lincoln Lima, Luiz Gustavo Campos
Abstract Adhesive bonding has gained a lot of popularity on the automotive industry on recent years. The technology has helped OEMs to build lighter vehicles by enabling the joint of dissimilar, lighter materials as well as joints that otherwise could not be welded or bolted together due to the lack of machine and operator access. It has also seen widespread usage to enhance crash performance, due to its ability to distribute stress uniformly and absorb energy. Past test reports had shown that adhesive bonding may have a poor performance when used on Zn-Fe (Galvanneal - GA) coated steel sheets, as the superficial coating layer may delaminate from the base steel, not allowing the adhesive to perform properly. The objective of this paper is to analyze the performance of adhesive bonding on GA coated steels when utilized alongside weld spots.
2016-09-27
Technical Paper
2016-01-2123
Matthias Busch, Benedikt Faupel
Abstract The integration of omega stringers to panels made of carbon fiber reinforced plastic (CFRP) by adhesive bonding, which is achieved by baking in an autoclave, must be subject to high quality standards. Failures such as porosity, voids or inclusion must be detected safely to guaranty the functionality of the component. Therefore, an inspection system is required to verify these bonds and detect different kinds of defects. In this contribution, the advantages of a robotic inspection system, which will be achieved through continuous testing, will be introduced. The testing method is the active thermography. The active thermography has major advantages compared with other non-destructive testing methods. Compared to testing with ultrasonic there is no coupling medium necessary, thus testing will be significantly enhanced.
2016-04-05
Technical Paper
2016-01-0508
Hyung Seok KIM
Abstract This study provides a tire puncture sealant including NR latex and acrylic emersion, which has a reduced viscosity at -40°C, and is also excellent storage stability at -40°C to 70°C, initial sealing performance. Also, this study provides device for sealing inflatable objects. 'One- Piece Tire Repair Kit' can reduce weight and operation steps.
2016-04-05
Technical Paper
2016-01-0395
Anindya Deb, Clifford C. Chou, Gunti R. Srinivas, Sanketh Gowda, Goutham Kurnool
Abstract An attractive strategy for joining metallic as well as non-metallic substrates through adhesive bonding. This technique of joining also offers the functionality for joining dissimilar materials. However, doubts are often expressed on the ability of such joints to perform on par with other mechanical fastening methodologies such as welding, riveting, etc. In the current study, adhesively-bonded single lap shear (SLS), double lap shear (DLS) and T-peel joints are studied initially under quasi-static loading using substrates made of a grade of mild steel and an epoxy-based adhesive of a renowned make (Huntsman). Additionally, single lap shear joints comprised of a single spot weld are tested under quasi-static loading. The shear strengths of adhesively-bonded SLS joints and spot-welded SLS joints are found to be similar.
2016-04-05
Technical Paper
2016-01-0502
Yuyang Song, Umesh Gandhi
Abstract The application of adhesively bonded joints has increased significantly in order to improve the integrity of structural components in vehicle design. In this paper, finite element analysis is used to model the adhesive behavior of the adhesive joining between steel and composite. The cohesive element modeling techniques in Abaqus is used to model the adhesive interface. The standard lap shear and peeling test are first conducted to estimate the adhesive properties using reverse engineering. Next, these adhesive properties are applied and validated on the FE model of a 3D part for complex loading condition. The FEA model using reverse engineered cohesive interface properties get closed match to the test results for joining of the complex shape parts.
2015-09-15
Journal Article
2015-01-2611
Samuel Baha II
Abstract The use of composite materials in aircraft manufactures increases more and more with the need of light weight and efficient airplanes. Combining composite materials with an appropriate joining method is one of the primordial ways of exploiting its light weight potential. Since the widely-established mechanical fastening, which originally, was developed for metallic materials, is not a suitable joining method for composite materials because of its low bearing strength, the adhesively bonding technology might be an appropriate alternative. However, adhesively bonding in the aircraft manufacturing, especially for joining of primary structures is liable to certification requirements, such as testing of every bond up to limit load before the operation begins or non-destructive testing of every bond before the operation begins as proof of the joint characteristics, which cannot be fulfilled with the current state of the art.
2015-04-14
Technical Paper
2015-01-0702
Bita Ghaffari, Jonathan Dekam, Kevin Haddix, Kimberly Lazarz, Sergey Titov, Roman Maev
Abstract Adhesive bonding technology has gained ever-increasing significance in automotive industry, especially with the growing use of aluminum (Al) alloy body structures. The variability in thicknesses of the metal and adhesive layers, as well as in joint geometry, of automotive components has presented challenges in nondestructive evaluation of adhesive joints. Though these challenges were recently overcome for steel-adhesive joints using an ultrasonic pulse-echo technique, the difference in acoustic impedances of steel and Al leads to a lack of robustness in utilizing the same algorithm for Al-adhesive joints. Here, we present the results from using a modified version of this technique to inspect Al-adhesive joints in both laboratory and production environments. A 15-MHz, 52-pixel, 10 mm × 10 mm matrix array of ultrasonic transducers was used to obtain ultrasonic pulse echoes from joint interfaces, analysis of which produced C-scan images of the adhesive bead.
2015-04-14
Technical Paper
2015-01-0592
Mehdi Hajian
Abstract Amid all nondestructive testing (NDT) methods Ultrasound is considered the most practically feasible modality for quality assessment and detection of defects in automobile industry. Pattern recognition of the ultrasonic signals gives us important information about the interrogated object. This information includes size, geometric shape and location of the defect zone. However, this would not be straightforward to extract this information from the backscattered echoes due to the overlapping signals and also the presence of noise. Here in this study, we suggest a new method for classification of different defects in inspection of adhesively bonded joint. At the first step of this method, the problem of parameter estimation of the reflected echoes is defined in a Maximum Likelihood Estimation (MLE) framework. Then a space alternating generalized Expectation Maximization (SAGE) algorithm is implemented to solve the MLE problem.
2015-04-14
Technical Paper
2015-01-0551
Qiuren Chen, Haiding Guo, John V. Lasecki, John Hill, Xuming Su, John J. Bonnen
Abstract The fatigue strength and failure behavior of A5754-O adhesively bonded single lap joints by a hot-curing epoxy adhesive were investigated in this paper. The single lap joints tested include balanced substrate joints (meaning same thickness) and unbalanced substrate joints, involving combinations of different substrate thicknesses. Cyclic fatigue test results show that the fatigue strength of bonded joints increase with the increasing substrate thickness. SEM and Energy Dispersive X-ray (EDX) were employed to investigate the failure mode of the joints. Two fatigue failure modes, substrate failure and failure within the adhesive were found in the testing. The failure mode of the joint changes from cohesive failure to substrate failure as the axial load is decreased, which reveals a fatigue resistance competition between the adhesive layer and the aluminum substrate.
2014-09-16
Journal Article
2014-01-2242
Samuel Baha II
Hybrid (bolted/bonded) joining is becoming one of the innovative joining processes for light weight structures in the transport industry, especially in the aerospace industry where weight reduction and high joining requirements are permanent challenges. Combining the adhesive bonding with the mechanical joining -riveting for instance- can lead to an enhancement of the properties of the joint compared to the wide established riveting, as a result of a synergistic load bearing interaction between the fastener and the adhesive bondline. The influence of the rivet installation process on a hybrid joint regarding the joint stress state, the change of the bondline thickness as well as its effects on the joint performance and load transfer are some of the factors that drive the users to a better understanding of the hybrid joining process.
2014-04-01
Journal Article
2014-01-0797
Binghua Pan, Chee Keng Yeo
Power electronics products such as inverters and converters involve the use of Thermal Interface Materials (TIMs) between high power packages and a heat exchanger for thermal management. Conventional TIMs such as thermal greases, gels, solders and phase change materials (PCMs) face challenges to meet the need of these products to operate reliably at much higher temperatures. This has driven the development of new TIMs such as Transient Liquid Phase Sintering (TLPS) Conductive Adhesives. TLPS adhesives have been developed for many potential applications due to various advantages like lead free, flux-less and particularly their low temperature processability, which enables the use of heat sensitive components in the design. With all these motivations, a project was launched and completed to assess TLPS adhesives as a unique TIM for high temperature automotive applications due to its high bulk thermal conductivity and metallic joint formation at interfaces.
2014-04-01
Technical Paper
2014-01-0811
Horst Lanzerath, Niels Pasligh
Abstract Structural adhesives are widely used across the automotive industry for several reasons like scale-up of structural performance and enabling multi-material and lightweight designs. Development engineers know in general about the effects of adding adhesive to a spot-welded structure, but they want to quantify the benefit of adding adhesives on weight reduction or structural performance. A very efficient way is to do that by applying analytical tools. But, in most of the relevant non-linear load cases the classical lightweight theory can only help to get a basic understanding of the mechanics. For more complex load cases like full car crash simulations, the Finite Element Method (FEM) with explicit time integration is being applied to the vehicle development process. In order to understand the benefit of adding adhesives to a body structure upfront, new FEM simulation tools need to be established, which must be predictive and efficient.
2014-04-01
Technical Paper
2014-01-0828
Guobiao Yang, Yingbin Chi, Qirong Zhu, Lianxiang Yang
Abstract In this paper, Digital Image Correlation Method (DICM) is employed to measure the shear mechanical property of the new style automotive structural adhesive specimens and traditional spot welded specimens under quasi static uniaxial shear tensile test. This experiment adopts a non-contact measuring method to measure the strain of specimens. A CCD and a computer image processing system are used to capture and record the real-time surface images of the specimens before and after deformation. Digital correlation software is used to process the imagines before and after deformation to obtain the specimen's strain of the moment. And then both the force-displacement curve and the stress-strain curve during the tensile process could be obtained. The test and analysis results show that the new style structural adhesive specimens have a great advantage with the spot welded specimens. It provides experimental evidence for further improvement of this structural adhesive.
2014-04-01
Technical Paper
2014-01-0788
Debabrata Ghosh, Lokesh Pancholi, Asmita Sathaye
Abstract Use of adhesives in automotive require in-depth material, design, manufacturing & engineering knowledge. It is also necessary to understand functional requirements. For perfect and flawless adhesive joinery, the exact quantity of adhesive, its material composition, thickness of adhesive layer, substrate preparation methods for adhesive bonding, handling and curing time of the adhesive have to be studied & optimized. This paper attempts to describe different aspects of adhesive bonding in automotive industry to include: Selection of adhesives based on application and design of the components, surface preparation of adherend, designing of adhesive joint, curing conditions of adhesives, testing and validation of adhesive joints. Emphasis was given to study & verify the performance of different adhesive joints to meet end product requirements. Samples were prepared with a variety of adhesive and adherend combinations.
2014-04-01
Technical Paper
2014-01-0790
Jianghui Mao, Sayed Nassar
Abstract In this paper, experimental study and FEA simulation are performed to investigate the effect of three different methods for joining dissimilar metal coupons in terms of their strength and load transferring capacity. The joining techniques considered include adhesive bonding, bolting and hybrid bolting-and-bonding. Elastic-plastic material model with damage consideration is used for each of the joint components. Traction-separation rule and failure criterion is defined for adhesive. Load transfer capacity and the failure mode are assessed for each type of joining. Joint strength is examined in terms of the effects of adhesive property, bolt preload level, and friction coefficient. Results show that load transferred and failure mechanism vary significantly between samples with different joint methods; preload evolution in bolt changes with friction coefficient; hybrid joint generally has advantage over the other two methods, namely, bolting-only and bonding-only.
2014-03-24
Technical Paper
2014-01-2008
Hyun Jin Choi, Chulwoo Park, Jongseo Woo, Jong Gab Kim, SungDae Choi
Abstract Current automobile's auto-transmission has problems of defects and cost reduction because of welding process and very complicated assembly process due to individualized transmission piston and sealing components. Also, size and heavy weight of transmission piston components are the source of low mileage because they are made of aluminum, steel material. In this study, therefore, we perform structure design for piston sealing system which integrates piston and sealing material for automobile's lightweight auto-transmission. Also performed stress analysis through finite element analysis to secure required suitable strength when internal pressure is applied after assemble.
2013-09-17
Journal Article
2013-01-2134
Richard J. Crossley, Svetan Ratchev, Anthony Smith
Several new technologies are now emerging to improve adhesive supply and formulation along with surface treatments that have the potential to offer significant improvements to both surface energy and cleanliness [3]. Additionally, the miniaturisation of laboratory techniques into portable equipment offers potential for online surface energy and chemical analysis measurement for use as quality control measures in a production environment. An overview of newly available technology is given here with several devices studied in further detail. Technologies assessed further in this paper are; portable surface contact angle measurement, ambient pressure plasma cleaning, portable FTIR measurement and adhesive mixing equipment. A number of potential applications are outlined for each device based on the operational technique. The practical aspects of implementation and the perceived technology readiness levels for operation, implementation and results are also given.
2012-04-16
Journal Article
2012-01-0731
Peter Heyes, Gunnar Björkman, Andrew Blows, Tim Mumford, Paul Briskham
Effective use of adhesive bonding in automotive vehicle bodies requires analytical methods for durability, so that potential fatigue problems and unnecessary overdesign may be eliminated before the physical prototype stage and release of product with unquantified safety factors avoided. This paper describes a fracture mechanics-based method for predicting the durability of adhesive joints, based on work previously carried out at Volvo [1]. The method requires relatively modest modifications to a typical vehicle body FE mesh. Adhesive bonds are represented by bar elements around the periphery of each bond. Grid point forces from shell elements adjacent to the adhesive bond are recovered and used to determine line forces and moments at the edge of the glued flange. These forces and moments are then transferred to an analytical sandwich model of the joint.
Viewing 1 to 30 of 367

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