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Viewing 1 to 30 of 2886
2013-10-07
Technical Paper
2013-36-0472
Paulo César Sigoli, Mauro Moraes de Souza, Juliano Savoy
The main characteristics required when fastening racing cars wheel are the resistance to self-loosening plus high-speed to assembling and disassembling of the wheel. To attend these two contradictory characteristics, it is necessary to develop differentiated fastening solutions. This work presents a new concept of fastening central wheel nuts for racing cars with improved fastening efficiency regard safety and assembly speed in comparison to the current fastening. The new wheel nut was designed and validated through analytical and FEM analysis as well as real tests.
2012-10-02
Technical Paper
2012-36-0288
Juvencio Pereira de Faria, Mauro Moraes de Souza, Paulo Cesar Sigoli, Juliano Savoy
Wheel hubs typically are set in vehicles through nuts with self-locking feature to assure safety. That feature may be done by an external component like a cotter pin, a deformable element incorporated to the nut like polyamide or metallic insert or some controlled mechanical deformation applied right on nut body. Nuts with some self-locking elements are being used in order to eliminate cotter pins from the system. However, during the maintenance of vehicles, some disadvantages appear like damage in thread axle due disassembling, considering controlled mechanical deformation nuts or the replacement of nut with polyamide insert to assure self-lock featuring. This paper presents a solution to replace a fastening in a current front and rear wheel-hub for a passenger vehicle. The study is made comparing a current solution, a controlled mechanical deformed nut - stover type - from a polyamide insert nut and an innovative prevailing torque nut with incorporated washer.
2015-11-17
Journal Article
2015-32-0743
Hiroyuki Yoshida, Hiroshi Hirayama, Shinsuke Mochizuki, Manabu Inoue, Yasuhiro Kato, Toshiki Inomata
A black surface treatment without using hexavalent chromium and applicable to bolts of motorcycles has been developed. The surface treatment also satisfies the requirements of bolts for motorcycles such as fastening performance, corrosion resistance, weather resistance and appearance of outer finish. There is a method of coating a black chemical conversion film using trivalent chromium on the zinc-plated surface as one of the surface treatments that do not use the hexavalent chromium. Such a black film, however, is thinner than the film using hexavalent chromium, and unable to ensure satisfactory black appearance. Meanwhile, although the dip-coating using a black paint can provide a sufficient black color, it is necessary to apply coating two times to eliminate an irregular color. As a result, thick paint films are formed on the roots of thread, making it difficult to fit into the internal thread. To simultaneously solve the above-mentioned two issues, two measures were executed.
2014-05-07
Technical Paper
2014-36-0024
Marcos dos Santos, Ricardo Guedes Manini, Jayme B. Curi, Cleber Chiqueti
Abstract ”U” bolts are fixing elements and they are used to clamp an elastic joint. From the past, they still looking as an old design and unfortunately, suspension engineers are not specialists in fasteners and elastic joints. That is why we will show important assumptions and concepts to design and specifications this clamp element “U” bolt and its influence over leaf-springs. Currently, “U” bolt is used to clamp an elastic or elastic-plastic joint of heavy duty suspension, formed by leaf-spring, axle, spring pad, “U” bolt plate. This kind of suspension is typically used to trucks, buses and trailers. We are wondering, which one important assumption that an engineer must be careful when designs a new suspension changing from old designs to an updated technology. We provide a theoretical analysis and a FEA analysis to compare torque efficacy x leaf-spring reactions and what are effects this relationship can cause in a suspension.
2014-04-28
Technical Paper
2014-28-0010
Saral Bhanshali
Abstract This breakthrough development involves material conversion from aluminum die cast to polypropylene long fiber thermoplastic (40% long glass filled) for a two wheeler bracket of a leading automotive OEM. The plastic bracket was developed working in collaboration with the molder, glass supplier, technology collaborator and the OEM. The new part needed to be designed lighter in weight, easier to process and suitable for painting, outdoor exposure and stringent dynamic conditions. The scope of this study includes the evaluation of the new material from different viewpoints and comparison of the same with the existing material. The submission will go through the intricate analyses carried out in the development process and highlight the key advantages over aluminum. Studies will include static and dynamic analysis, fiber orientation studies, gate location studies, etc.
2014-04-28
Technical Paper
2014-28-0035
Shiva Kumar Manoharan, Christoph Friedrich
Abstract Self-loosening of bolted connections is a crucial failure mode for joints under transverse dynamic load. For some years, three dimensional finite element analysis has been enabled for avoiding experimental investigations of self-loosening. The aim of this paper is to emphasize the effect of joint design on the self-loosening of bolted connections, which is important for product development in early design stage. Joints consisting of internally threaded nut components are often heavier and stiffer as compared with light weight designs consisting of a separate nut. The difference of self-loosening is significant between arrangements with nut thread component and separate nut, although the design versions only contain slight modifications. Hence it is necessary to evaluate the effect of light weight design on self-loosening.
2016-04-05
Journal Article
2016-01-0501
Seung Hoon Hong, Frank Yan, Shin-Jang Sung, Jwo Pan, Xuming Su, Peter Friedman
Abstract Failure mode and fatigue behavior of flow drill screw (FDS) joints in lap-shear specimens of aluminum 6082-T6 sheets with and without clearance hole are investigated based on experiments and a structural stress fatigue life estimation model. Lap-shear specimens with FDS joints were tested under cyclic loading conditions. Optical micrographs show that the failure modes of the FDS joints in specimens with and without clearance hole are quite similar under cyclic loading conditions. The fatigue lives of the FDS joints in specimens with clearance hole are longer than those of the FDS joints in specimens without clearance hole for the given load ranges under cyclic loading conditions. A structural stress fatigue life estimation model is adopted to estimate the fatigue lives of the FDS joints in lap-shear specimens under high-cycle loading conditions.
2016-04-05
Technical Paper
2016-01-0510
Praveen Mishra, Subramanian Ganeshan
Abstract An automobile outer rear view mirror (ORVM) is fixed at the front exterior of the vehicle for helping the driver see areas behind and sides of the vehicle which are outside of their peripheral vision. Mirror Scalp is the cover which protects the components inside from human and other environmental damage. Hence the scalp must be properly designed and fitted to the rest of the assembly so that it allows the safe functioning of the ORVM, which is an active safety device. During automatic car washing, sometimes the scalp may get removed due to the huge force exerted by the scrubber, if the scalp is not fitted properly. Mirror scalp is fitted to the rest of the ORVM through snap-fits. Snap-fits are the simplest, quickest and most cost effective method of assembling two parts. When designed properly, parts with they can be assembled and disassembled numerous times without any adverse effect on the assembly and hence are most environmentally friendly.
2015-09-22
Technical Paper
2015-36-0112
Fernando de Azevedo Silva, Erick Siqueira Guidi
Abstract The union of parts by using bolts is one of the most used, which combines versatility and low cost, and the failure of a single bolt can cause failure of the entire structure or machine. Several factors influence the effectiveness of these bolted joints, including the material of the washer. During the process of applying torque to the bolted joint, an elastic deformation occurs in the bolt and a plastic deformation in the washer while applying the external force. This plastic deformation which occurs in the washer causes a reduction of the elastic deformation of the bolt and, consequently, of the assembly torque, and depending on the values of external loading and deformation of the washer occurs the separation of the pieces of the joint, causing overload in the bolt and a reduction in your fatigue life. The use of numerical simulation using the finite element method makes it possible to change the model variables, such as the geometry and materials of the components.
2016-01-01
Journal Article
2015-01-9085
Vinod Upadhyay, Xiaoning Qi, Nick Wilson, Dante Battocchi, Gordon Bierwagen, Joy Forsmark, Robert McCune
Abstract This work reports on measurement and analysis of the galvanic interaction between steel self-piercing rivets (SPRs) having several different surface conditions and magnesium alloy substrates under consideration for use in automotive structural assemblies. Rivet surface conditions included uncoated steel, conventional Zn-Sn barrel plating and variations of commercial aluminizing processes, including supplemental layers and sealants. Coating characteristics were assessed using open circuit potential (OCP) measurement, potentiodynamic polarization scanning (PDS), and electrochemical impedance spectroscopy (EIS). The degree of galvanic coupling was determined using zero-resistance ammeter (ZRA) and the scanning vibrating electrode technique (SVET), which also permitted characterization of galvanic current flows in situ.
2008-04-14
Technical Paper
2008-01-1288
Steven R. Sopher, Gary Granthen
The industry demand for improved material properties and performance, as well as the ever increasing demand for weight and cost reduction has presented challenges for the automotive industry as a whole. From the plastic materials side, the challenge has been incorporating new fastening and assembling technology into existing applications, all while reducing cost and improving performance. This paper will explore new approaches for assembly and attachment methods for Shape Molded Expanded Polypropylene (EPP) Foam products used in automotive interiors. As EPP foam becomes more widely used throughout the automotive interior, it has become necessary to provide innovative ways of attachment and joining. Recent innovations have allowed for the insert molding of EPP using wireframes, plastic inserts, metal brackets, and bars.
2013-11-27
Technical Paper
2013-01-2899
Parul Chandak, Raghavendra K. Katti, Sandeep Raina
Fasteners performance on account of rust is not consistent and conductivity is a concern. A surface coat is applied on fasteners to provide corrosion protection, i.e., protection against rust. When a metal comes in contact with Oxygen present in the air, it gets corroded. So, an extra protective layer is required to prevent the contact of metal with air, hence preventing corrosion. However, surface coating peel-off is a persistent problem observed while assembly of fasteners, which leads to impetuous rusting of parts. So, repeated use of fasteners in service life becomes a matter of concern. At the same time, it is important to provide conductive surface coating to fasteners used in fuel filler area. When a human body comes in contact with fuel filler area, it is necessary to discharge the static electricity of humans, in order to avoid explosion, due to generation of spark in presence of fuel fumes.
1938-01-01
Technical Paper
380031
Ralph H. Upson
2005-11-01
Technical Paper
2005-01-3506
Nancy Heimann, George T. Simpson
The purpose of this paper is to examine the use of a surface mineralization process for general corrosion protection. More specifically, this paper describes the use of surface mineralization (SM) as a non-hazardous and environmentally benign alternative to cadmium plating and hexavalent chromate treatment for protecting fasteners from corrosion in off highway applications. An engineered surface is founded on a mineral-based product that forms a thin metal silicate surface fully involving the substrate metal. Completed laboratory cyclic testing of SM treated fasteners compared with cadmium plated and hexavalent-chromate treated fasteners to 180 cycles using the GM 9540P protocol have demonstrated a significant increase in corrosion resistance of components protected by the SM process.
2008-04-14
Technical Paper
2008-01-0252
Murali M. R. Krishna
A Mega-bracket is a cast bracket which connects a chassis frame of a truck to the front bumpers and usually there are two of these for a truck. The mega-brackets help provide clearance for the engine radiator and hence it has a curved shape. It is usually designed to support the towing load when a fully loaded truck needs to be towed following a break-down. A general method of designing a mega-bracket, using shape optimization techniques, is described with a case study. A preliminary design was found to be unsatisfactory to support the tow loads. Finite Element (FE) Topology optimization techniques were used to give us directions as to where ribs should be provided to support the tow loads. FE Shape optimization techniques were then applied to size the ribs and also the rest of the structure using shape variables, which are possible design variations. Since the mega-bracket is irregular in shape, it is extremely difficult and time consuming to generate shape vectors.
2007-10-30
Technical Paper
2007-32-0063
Volkhard WALTHER, Erhard LEIDICH
A simple and cost-effective approach to connect the sprocket wheels or belt pulleys of the engine's auxiliaries drive system to the crank-shaft is fastening the parts using a central bolt. In this case, load transmission is carried out exclusively by the friction among the parts' frontal contact surfaces. Consequently, such connections are typically dimensioned according to the torque load and the governing coefficient of friction. The auxiliaries' increasing power demands involve much higher loads on such connections which may lead to severe failures, such as relative motions between the timing-sprocket and the crank-shaft. In order to understand and avoid those problems, the transmission behaviour of the contact surfaces has been investigated by means of analytical, experimental, and finite-element analyses.
2006-12-05
Technical Paper
2006-01-3616
B. L. Holloway, D. W. Radford, L. R. Weidner
It is not uncommon in motorsport for a team to chase a chassis setup throughout a race weekend, changing many different suspension settings, yet not getting consistent response from the chassis. In at least some of these cases it has been later determined that these inconsistencies stemmed from either chassis damage or fastener loosening, leading to a decrease in chassis stiffness. The current research investigates a method for quickly and accurately measuring the torsional stiffness, or static compliance, of a racecar chassis and suspension at various stations along the length, which can be utilized in the paddock area. When compared to baseline measurements of a newly assembled racecar, the post-race static compliance of the vehicle can be used to reveal the length-wise region of new damage or softening of components.
2005-05-16
Technical Paper
2005-01-2388
John Hicks, Kurt Schneider
Often components or subsystems are attached to other systems through multiple fasteners at multiple locations. Examples may include things like compressors, alternators, engine cradles, powertrain mounting systems, suspension systems, body structures or almost any other interface between components or subsystems. Often during early design stages, alternative component or subsystem configurations are being considered that can have very different interface characteristics, such as alternators with different number of mounting fasteners, or suspension systems with different number of body structure interface attachments. Given these different mounting configurations, it can be difficult to meaningfully compare the interface performance of the two components or subsystems.
2005-05-16
Technical Paper
2005-01-2286
Nicholas J. Oosting, Julie Hennessy, David T. Hanner, Dave Fang
Constrained Layer Damping (CLD) treatments have long provided a means to effectively impart damping to a structure [1, 2 and 3]. Traditionally, CLD treatments are constructed of a very thin polymer layer constrained by a thicker metal layer. Because the adhesion of a thin polymer layer is very sensitive to surface finish, surfaces that a CLD treatment can be effectively applied to have historically been limited to those that are very flat and smooth. New developments in material technology have provided thicker materials that are very effective and less expensive to apply when used as the damping layer in a CLD treatment. This paper documents the effectiveness of such a treatment on a cast aluminum front cover for a V6 engine. Physical construction of the treatment, material properties and design criteria will be discussed. Candidate applications, the assembly process, methods for secondary mechanical fastening will be presented.
2005-05-16
Technical Paper
2005-01-2272
Vikrant Palan, W. Steve Shepard, J. Gregory McDaniel
The work presented here is an experimentally-based parametric study of a layered viscoelastically-damped system containing intermediate structural fasteners. The effect of fastener preload, fastener location and the number of fasteners on the loss factor are examined. The loss factor is found to change by as much as 22% with change in some of these parameters. Two different approaches are used to measure loss factor. The first method uses the internal algorithm from a signal analyzer. The second method is an iterative algorithm that estimates the complex wavenumber, which is then used to find the damping loss factor. An advantage of the latter technique is the ability to measure loss factor over a range of frequencies. This research also investigates the effect of the number of measurement positions on the accuracy of loss factor. It is shown that the accuracy has a strong dependence on the number of measurement locations, particularly at low frequencies.
2007-04-16
Technical Paper
2007-01-1362
Francesco Vivio
Riveting is a well established technology in the manufacturing of aeronautical structures as well as in the automotive industries. Despite its simplicity, the rivet presents a local stiffness that is not easy to properly model within a large finite element analysis. However, precision in the local stiffness evaluation is essential to perform any structural analysis when several rivet are applied in a joint structure. The result is that any rivet requires a local mesh refinement or, and this is the most common case, a drastic simplification of its structural modelling characteristics. In the present paper a new rivet element is introduced, able to precisely evaluate both local and overall stiffness of riveted joints; this finite element can be applied when dealing with 3D riveted shell structures. The modelling approach is similar to that, developed also by the author for spot welds.
2006-04-03
Technical Paper
2006-01-0915
Eddie Cooper, Anne M. Curzon, Micky Marine, Jeffrey Wirth, William W. Van Arsdell
The increasing prominence of end-release buckles in automotive restraint systems has been accompanied by criticisms that they are susceptible to inertial unlatching in collisions due to transfer of vertical impulses from the vehicle body or chassis through the buckle stalk to the buckle. It has been asserted that the accelerations imparted to the buckle are significantly amplified relative to the initial input to the vehicle body or chassis. In this study, a test procedure was developed to measure the in-situ dynamic response of restraint system buckles to vertical impulse. The procedure was used to evaluate buckle assembly response to impulses input at, or near, the buckle stalk floor anchors in several vehicles. The advantage of this technique over full-scale drop testing and component-level shock table impacts is that the desired response information may be acquired in-situ without damage to the vehicle.
2006-04-03
Technical Paper
2006-01-1268
Mike Guo, Shujath Ali
In this paper, mechanism of fastened joints is described; numerical analyses and testing calibrations are conducted for the possible simplified finite element simulation approaches of the joints; and the best simplified approach is recommended. The approaches cover variations of element types and different ways that the joints are connected. The element types include rigid elements, deformable bar elements, solid elements, shell elements and combinations of these element types. The different ways that the joints are connected include connections of one row of nodes, two row of nodes and alternate nodes in the first and second rows. These simplified simulation approaches are numerically evaluated on a joint of two plates connected by a single fastener. The fundamental loads, bending with shear, shear and tension are applied in the numerical analyses. A detailed model including contact and clamp load are analyzed simultaneously to provide “accurate results”.
2008-04-14
Technical Paper
2008-01-0548
Edward J. Vinarcik
As many underhood products have shifted from metal to plastic designs over the last decade, often parts break during assembly due rough handling conditions and less than ideal manufacturing practices. In particular assemblies often crack during screw torquing at the mounting tabs. The goal of this study is to determine how different mounting tab designs compare in strength. Designs with an external rib on the perimeter of the mounting tab behave differently than designs without a complete or lacking an external rib on the perimeter of the mounting tab. A positive correlation was found between knit line cross-sectional area and mounting tab strength for designs with an external rib on the perimeter of the mounting tab. A positive correlation was found between tab thickness and mounting tab strength for designs lacking an external rib. Material type was found to impact mounting tab strength.
2008-04-14
Journal Article
2008-01-0545
Sayed A. Nassar, Xianjie Yang, Saravanan Ganeshmuthy
In this paper, an emphasis is put on describing the elastic and plastic deformation behavior of the bolted joint. The bolt material is assumed to be plastic hardening. A nonlinear combined stress model is established for a typical bolted joint for the purpose of studying its behavior under a yield tightening. The combined effect of axial and torsional stresses in the tightened threaded fastener is considered. A new approach for yield tightening under ideal plastic bolt was proposed, and the effects of the thread and bearing frictional coefficients on the clamp load prediction are evaluated. The prediction precision of deformation behavior of the bolted joint under yield tightening for the strain hardening bolt material are studied experimentally.
2008-04-14
Technical Paper
2008-01-0715
Edward J. Vinarcik
Plastic underhood components often crack when fastened to mating components. The goal of this study is to determine what variables are most important with relation to this problem. To maximize the efficiency of testing, an L18 orthogonal array was used to structure the experiment. Experiments were conducted using a computer-controlled electric driven screwdriver and a manual torque wrench. Control factors were adjusted by using hardware as specified for each trial. The torque value at failure was recorded for all samples. The “larger the better” S/N equation was utilized for data analysis in this study. Optimizing the design and process was found to increase the S/N by 6.9dB when verified experimentally. Fastener washer thickness, joint fit-up, and screw setting speed contribute to the gain by 46%, 28%, and 27%, respectfully.
2008-04-14
Journal Article
2008-01-1089
Ramakrishna Koganti, Joseph Weishaar
Aluminum materials are very attractive for lightweight applications. Aluminum usage in automotive vehicles has increased over time as manufacturers search for affordable weight reduction applications and high-performing, low-investment construction methods. Further application of aluminum is likely with the discussion of increased tailpipe emission requirements and increased fuel economy regulations. Currently, the Audi A8, Audi R8, Ferrari F430, Lamborghini Gallardo and Jaguar XJ8 are aluminum intensive vehicles that are in production. In this paper, manufacturing methods in forming and joining technologies for body construction is discussed. Various forming technologies for body in white construction and body closures are discussed as well as joining technologies for body closures and body structures. Application of materials and processes in the current automotive applications as well as economic analysis for spaceframe and unibody body construction is discussed.
1992-02-01
Technical Paper
920531
C.I. Garcia, T.M. Maguda, A.K. Lis, A.J. DeArdo
A new microalloyed, multi-phase low carbon steel has been developed as an alternative to the QT steels which have traditionally been used in the fabrication of high strength cold forged products. The benefits of this new steel include: (1) the elimination of spheroidize annealing prior to cold forming; (2) the elimination of the QT heat treatment after the deformation; and (3) the ability to achieve in the final component yield strengths of desired levels, high fatigue resistance and very high notch toughness. The excellent properties exhibited by this steel are a direct result of the advanced thermomechanical or controlled processing of the austenite during bar and/or rod rolling. This paper will first briefly review the physical metallurgy of this steel as it pertains to cold forming. This will be followed by a review of industrial trials where various components have been cold forged from this steel.
1995-02-01
Technical Paper
950887
Edward A. Moffatt, Terry M. Thomas, Eddie R. Cooper
Laboratory testing measured the response of a 1984 Chevrolet S-10 Blazer seatbelt buckle to impact on the back of the buckle. The peak acceleration, pulse duration and webbing tension were recorded to map the unique circumstances necessary to inertially unlatch the buckle. The conditions necessary to inertially unlatch the buckle in the laboratory were compared with the measured buckle responses in fifteen sled tests and six rollover crash tests using anthropomorphic dummies. All of the crash tested buckles remained latched and all had dynamic responses well below those required to produce inertial unlatching. Dummy hip areas were measured to be significantly stiffer than humans. Buckle accelerations measured in the “parlor trick” of intentionally striking the hip with a buckle are not representative of crash conditions.
1995-02-01
Technical Paper
950810
C. Bartos, R. Leung, R. Rozmus, M. Trapp, R. Hoy
To minimize warranty costs, due to squeak and rattle from ill fitting joints, automotive OEMs are requiring increased durability of thermoplastic attachments. There are several evaluation techniques for determining thermoplastic joint durability performance such as: strip-to-drive torque, screw pull-out force, and clamp load fall-off. A thermoplastic attachment (i.e. boss) which experiences clamp load fall-off will result in a loose fitting joint and subsequently lead to squeaks and rattles. In conjunction with the boss's performance the type of captured material between the screw and the joint can also contribute significantly to the overall retention qualities of the attachment. The purpose of this paper is to evaluate: 1.) strip-to-drive ratios for thermoplastic bosses, and 2.) changes in clamp load with respect to environmental effects (i.e. thermal exposure) on thermoplastic bosses.
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