Display:

Results

Viewing 271 to 300 of 1655
2013-04-08
Journal Article
2013-01-0299
William Barton, Daniel Jason Knapton, Mark Baker, Andrew Rose, Elizabeth A. Schiferl, Michael Huston, Gareth Brown, Gregory Hunt
This paper outlines the second part in a series on the effect of polymeric additives commonly known as viscosity modifiers (VM) or viscosity index improvers (VII) on gear oil efficiency and durability. The main role of the VM is to improve cold temperature lubrication and reduce the rate of viscosity reduction as the gear oil warms to operating temperature. However, in addition to improved operating efficiency across a broad temperature range compared to monograde fluids the VM can impart a number of other significant rheological improvements to the fluid [1]. This paper expands on the first paper in the series [2], covering further aspects in fluid efficiency, the effect of VM chemistry on these and their relationship to differences in hypoid and spur gear rig efficiency testing. Numerous VM chemistry types are available and the VM chemistry and shear stability is key to fluid efficiency and durability.
2013-04-08
Technical Paper
2013-01-0150
Marcella Turano, Fulvio Civera, Guilherme Figueiredo, Marco Margaria, Andre Smith Pereira
Fatigue tests on exhaust system usually require long time to be performed on the proving ground. Road simulation bench test reduces the time needed to execute the entire fatigue test on the proving ground and does not involve the operator presence for long time as proving ground test requires. In order to put on evidence the potentiality of performing the fatigue test with the RSB in substitution of the fatigue test on proving ground, a correlation between virtual analysis, the proving ground test and RSB test are illustrated. A specific component of the exhaust system is studied and specifically the bracket connecting the flexible pipe to the vehicle under body. During the proving ground test several failures occurred on the bracket connecting the exhaust system and the gear box. A virtual FE calculation and a fatigue test on the Road Simulation Bench were required to investigate the failure.
2013-04-08
Technical Paper
2013-01-0151
Lev Klyatis
There are no standards that directly consider practical reliability testing technology (methods and equipment). This void needs to be filled. The SAE G-11 division has approved the development of six new standards to fill this void. This paper discusses these six standards: 1) Reliability Test-Glossary; 2) Reliability Testing-Strategy; 3) Reliability Testing-Procedures; 4) Reliability Testing-Equipment; 5) Reliability Testing-Statistical Criteria for Comparison of Reliability Testing Results and Field Results; 6) Reliability Testing-Collection, Calculation, and Statistical Analysis of Reliability Testing Data, Development Recommendations for Improvement of Test Subject Reliability, Durability, and Maintainability.
2013-04-08
Technical Paper
2013-01-0152
Lev Klyatis
This paper will discuss the first two standards in the six-part series of SAE International reliability testing documents that are being developed by the SAE G11 Reliability Committee. These two documents attempt to standardize the glossary and strategy associated with reliability testing technology. A new Glossary standard has been drafted that defines the most commonly used words and terms associated with reliability (accelerated reliability/durability) testing. It is intended to serve as a basis for reliability testing definitions and to reduce the possibility of conflicts, duplications, and incorrect interpretations either expressed or implied elsewhere in the technical literature. Terms and definitions included in this standard are important in the acquisition of weapon systems (where there is a need for precise and unambiguous technical definitions), and are expressed clearly (and without mathematical symbols whenever possible).
2013-04-08
Technical Paper
2013-01-0153
Lev Gorelik
A powerful methodology of reliability testing is described. This technique is based on the application of dimensional analysis. The whole process of determination of reliability consists of the choosing the relevant physical quantities, calculation the corresponding complete set of dimensionless variables, obtaining the Model Law, and the determination of the limited condition of reliability for the product (prototype). The application of the presented methodology is demonstrated on the example of the determination of reliability of revolving disc.
2013-04-08
Technical Paper
2013-01-0194
Rasmus Adler
A safety concept describes a plan for implementing safety. A bad safety concept compromises the achievement of safety or leads to unnecessarily high costs for implementing and proving safety. However, safety standards and research approaches do not provide any means for developing a good safety concept or for assessing the quality of a safety concept. Consequently, real-world safety concepts often lack information or have low quality. To overcome this practical problem, we systematically derive which fundamental information should be contained in a safety concept and introduce quality attributes for a safety concept. We also evaluate state-of-the-art approaches for developing a safety concept.
2013-04-08
Technical Paper
2013-01-0195
Joseph G. D'Ambrosio, Rami Debouk
ASIL decomposition is a method described in the ISO 26262 standard for the assignment of ASILs to redundant requirements. Although ASIL decomposition appears to have similar intent to the hardware fault tolerance concept of IEC 61508-2, ASIL decomposition is not intended to reduce ASIL assignments to hardware elements for random hardware failures, but instead focuses on functions and requirements in the context of systematic failures. Based on our participation in the development of the standard, the method has been applied in different ways in practice, not all of which are fully consistent with the intent of the standard. Two potential reasons that may result in the use of “modified” ASIL algebra include the need of OEMs to partition a system and specify subsystem requirements to suppliers and the need for designers to construct systems bottom up.
2013-04-08
Technical Paper
2013-01-0513
Aaron Williams, Jonathan Burton, Robert L. McCormick, Todd Toops, Andrew A. Wereszczak, Ethan E. Fox, Michael J. Lance, Giovanni Cavataio, Douglas Dobson, Jim Warner, Rasto Brezny, K. Nguyen, D. William Brookshear
Alkali and alkaline earth metal impurities found in diesel fuels are potential poisons for diesel exhaust catalysts. Using an accelerated aging procedure, a set of production exhaust systems from a 2011 Ford F250 equipped with a 6.7L diesel engine have been aged to an equivalent of 150,000 miles of thermal aging and metal exposure. These exhaust systems included a diesel oxidation catalyst (DOC), selective catalytic reduction (SCR) catalyst, and diesel particulate filter (DPF). Four separate exhaust systems were aged, each with a different fuel: ULSD containing no measureable metals, B20 containing sodium, B20 containing potassium and B20 containing calcium. Metals levels were selected to simulate the maximum allowable levels in B100 according to the ASTM D6751 standard.
2013-03-25
Technical Paper
2013-01-0094
JunHo Song
Seat covering problem is the No.1 Fail-course of seat entry and exit durability test. Seat ingress and egress durability test takes about 100 hours of test time and test samples to be used as a seat module. This paper is drawn the test method which can be reproduced and verified the result of seat ingress and egress durability test about Seat covering by using flat friction test. This test method can reduce test time because to conduct an accelerated test. Using a covering material to the test sample instead of seat module so can save the cost.
2013-03-25
Technical Paper
2013-01-0079
Hyun Kim
The FMVSS 208 advanced air bag rule has brought new technologies into the automotive industry. Low Risk Deployment, Suppression, or a combination of both, have prevailed in the industry to meet the right front passenger requirements for FMVSS 208 compliance. This rule provides the options to conduct low risk deployment (LRD) airbag tests with a 12-months-old infant dummy riding in a rear facing child seat and child dummies representing 3 years and 6 years old children. If the LRD tests do not meet the injury criteria set by NHTSA, vehicle manufacturers have to choose the another option for the suppressing airbag system when infants or children are present at the passenger seat. But this suppressing systems is not the cost effective method, also, contains potential quality problem such as misrecognition passenger age. Thus, the car makers start to choose LRD requirement option and develop new LRD passenger airbag system.
2013-03-25
Technical Paper
2013-01-0076
Baek Ju Sung
The exhaust valve plays a role of reducing the mechanical noise and vibration of vehicle by smooth discharging of the vehicle emissions after combustion process in exhaust system of engine. The torsion spring is one of the most core components in exhaust valve, which generates variable torque for control of opening and closing angle of exhaust valve. Its performance represents all over the performance of exhaust system of vehicle. As it were, the failure of torsion spring means the failure of all exhaust system. So, as well as performance, the reliability of the torsion spring is very important. To secure the reliability is same to secure the security and comfort of passengers including driver. This paper proposed two methods for improvement of torque and reliability characteristics of torsion spring. One is improvement of heat treatment condition for getting of more constant torque characteristic of torsion spring.
2013-03-25
Technical Paper
2013-01-0029
Hyun Jin Choi, Chul Woo Park, Jong Seo Woo, Jong Gab Kim, Byeong Soo Kim, Ik Soo Kang
Automobile's hub bearing seals are the key functional parts that are mounted to 4 driving shaft wheels to prevent muddy water and foreign substances that flow into the wheel bearing, which ensure air tightness of bearing parts and maximize driving efficiency through smooth operation. Especially, design structure of bearing seal, which is the core part of driving wheel, and abrasion characteristics of its rubber material have direct relationship with durability of driving wheel parts and driving efficiency. In this study, we modified the design for existing seal's lip area to minimize the maximum stress applied to bearing seal's lip area which will ensure seal's performance, and to improve durability. After this, we manufactured prototype and carried out seal's performance evaluation.
2013-01-09
Technical Paper
2013-26-0004
Matthew Symonds, Craig Ritchie, Raman Rai
Rising fuel prices and global concern over climate change have resulted in the need to deliver vehicles with improved fuel efficiency. The aim is to achieve this without compromising vehicle performance, durability or cost. Passenger car manufacturers worldwide are looking at various ways to optimize fuel economy performance. One option is for a vehicle OEM to re-design engine componentry in an effort to reduce engine friction and thereby reduce tailpipe emissions. There is also an increased focus on the crankcase lubricant as a potential tool to improve engine efficiency. This has led to a close collaborative working model between equipment manufacturers and engine oil marketers to create state of the art fluids capable of delivering higher fuel economy benefits without compromising engine durability. This paper describes a structured approach to the design of an advanced engine oil for a diesel passenger car.
2013-01-09
Technical Paper
2013-26-0053
Sivanandi Rajadurai, N. Suresh, P. A. Sairaman, S. Ananth
A combined Computer Aided Engineering (CAE) simulation and physical fatigue testing of a passenger car exhaust system resonator with wire mesh seal between the inlet and outlet pipe is performed to evaluate the durability and improvise the design. The outlet pipe end cap of the exhaust system resonator deformed and cracked at the fillet region repeatedly upon the application of the maximum load from a pre developed accelerated specification test. However, the system meets the end usage on-road durability target of 5 years / 1,00,000 km. There is a gap between the accelerated bench test and the end usage durability target. The current study correlates CAE simulation and biaxial fatigue testing and improvise possible alternate resonator design. Conventionally, components passing the accelerated test always meets the end usage durability target whereas components meeting the end usage durability target need not necessarily pass the accelerated test.
2013-01-09
Technical Paper
2013-26-0070
Zoli Gianluigi, Verma Rajeev
Oil is a non-renewable resource and we can not sustain our current rate of use indefinitely. Rising fuel prices, security of fuel supplies and most importantly need to reduce carbon dioxide emissions has put pressure to look at fuel economy more seriously in recent years. As already witnessed in the passenger car industry, motorcycle manufacturers are looking at engine oil as potential tool to improve efficiency and therefore reduce emissions. Carefully formulated low viscosity engine oils can bring increase in engine performance and fuel economy thereby reducing tailpipe emissions when compared with conventional, high viscosity engine oil. However, this approach needs a well balanced formulation technology and thorough testing program since in a typical modern four stroke motorcycle power-train with integrated clutch and gearbox, requirement for low engine friction should be carefully balanced with those for gearbox protection and clutch compatibility.
2013-01-09
Technical Paper
2013-26-0130
Antony Smith, Saurabh Rajauria, Sachin Agarwal
In the growing automobile world, every commercial vehicle manufacturer upgrades their product from their existing product to meet world market demand for high power engine with high torque, most fuel efficient, BS-IV and BS-V emission norms and less cost. In an Engine cylinder block and cylinder head are among the critical parts need to be modified to upgrade the existing engine platform. The VE4101 Engine is a massive 3.8 l 4 Cyl 16 valve engine based on the E483 4 cyl 8 valve engine, which is currently being mass produced in VECV, India. This engine cylinder block and cylinder head are designed with key features such as capable for high peak firing pressure, rigid load structure, curvy envelope and ribs to reduce NVH, light weight 2 split top box manufacturing method. Key strategy is used such as less capital investment in purchasing machines, no/less alteration in current machining and assembly line.
2013-01-09
Technical Paper
2013-26-0137
Sivashankar S, Hari Krishna SV, Alfred Nixon Mendez, Colin J. Dodds
Every class of commercial vehicle has an entirely different usage pattern based on customer application and needs. To perform accurate durability testing, these prototypes should run on real customer usage locations and loading conditions for the target life. However, this is time consuming and not practical, hence resulting in Proving Ground (PG) testing. It is also known that a standard PG durability cycle cannot be valid for every class of vehicle and every application. So a statistical approach was followed to develop an accelerated durability test cycle based on in-house PG test surfaces in order to match the real customer usage to the durability target life. This paper summarizes the methodology to develop Durability Validation test cycles for commercial vehicle based on the work carried out on a heavy duty tipper and an intermediate commercial vehicle.
2013-01-09
Technical Paper
2013-26-0138
S. Sathya Prakash
Arriving at an accelerated durability test cycle either for a laboratory simulation or for an FE-based fatigue simulation is not an easy task. The loading spectra over the entire life span or desired validation cycle needs to be synthesized and the resulting signal is to be used for driving a rig or for Computer Aided Engineering (CAE) simulation, as the case may be. Any structural durability evaluation essentially involves multiple measurements involving strain, acceleration, displacement, force-all of which directly or indirectly are a measure of fatigue damage on the structure. Multi channel dynamic events (time domain based) comprising strain signals can be accelerated by damage-editing, but what if the input time histories are not strains but are displacements, accelerations and forces? A directly “non damaging” parameter like displacement or acceleration or force signal makes an accelerated test synthesis not very easy.
2013-01-09
Technical Paper
2013-26-0139
Sathish Kumar P, Vikram Suryavanshi, Manikandan M, Bollishetty Sreedhar
Evaluation of vehicle structural durability is one of the key requirements in design and development of today's automobiles. Computer simulations are used to estimate vehicle durability to save the cost and time required for building and testing the prototype vehicles. The objective of this work was to find the service life of automotive structures like passenger commercial vehicle (bus) and truck's cabin by calculating cumulative fatigue life for operation under actual road conditions. Stresses in the bus and cabin are derived by means of performing finite element analysis using inertia relief method. Multi body dynamics simulation software ADAMS was used to obtain the load history at the bus and cabin mount locations - using measured load data as input. Strain based fatigue life analysis was carried out in MSC-Fatigue using static stresses from Nastran and extracted force histories from ADAMS. The estimated fatigue life was compared with the physical test results.
2013-01-09
Technical Paper
2013-26-0156
V. V. Shinde, Prashant R. Pawar, Ameen Shaikh, M. R. Saraf
A comprehensive exercise for generation of wheel load database and spectrum of different categories of vehicles was carried out. The vehicles have been chosen so as to represent the best possible variation of vehicles all over the country. Dedicated Wheel Force Transducers (WFT) for all corners of all test vehicles have been utilized along with a host of traditional transducers at identified locations of the test vehicles. An exhaustive survey and data acquisition exercise has also been carried out in different geographical regions of India in order to determine the various attributes related to various types of vehicles, type of usage, driving patterns etc. Instrumented test vehicles have been run on identified routes and regions as deciphered from the survey, as well as on proving grounds. Detailed analysis of the test data from different categories vehicles has been carried out to determine the variation of wheel forces, moments and other vehicle durability parameters.
2012-10-23
Technical Paper
2012-32-0097
Gagandeep Singh Risam, Anil Singanamalli, Sasun C, Rajasekaran T
Ability to meet customer expectations and understand customer usage behavior is fundamental to the delivery of the successful products in the Automobile industry. A combination of data collection tools such as customer survey and customer chasing technique with instrumented vehicle are generally used to get insight into the customer usage pattern and driving style. The available information can be priceless if it is used to tailor laboratory test standards representative of customer usage behavior. Test cycles, tailored based on specific customer usage behavior, have the potential to work as very effective design filter during the validation stage of new product design and development process. In this paper, a method to tailor vehicle level durability driving cycle on a laboratory scale roller Chassis dynamometer has been demonstrated. This cycle is developed based on the data collected with customer for their daily usage routine.
2012-10-23
Journal Article
2012-32-0042
Takao Kudo
In the designing of bearing to use in internal combustion engines, the author has established an assessment method for needle roller bearing considering the slip ratio of needle rollers when operating. Damages sometimes occur in a bearing when continuously operating the engine although the bearing has a basic dynamic load rating. For an example, flaking occurred in the needle rollers during the continuous operation of the engine when a roller bearing was applied to the bearing that supported the gear which transmitted the driving force from the starter motor to the crankshaft when starting the engine. While the bearing is located on the crankshaft, the bearing is not directly subjected to the loads from engine combustion pressures. We therefore focused our attention on the bearing slip ratio as a factor that affects the bearing rather than the loads.
2012-10-22
Technical Paper
2012-01-2141
Vintila Canciu, Alexandru Canciu
Traceability has always been considered a useful but costly activity and different methods have been applied to reduce this cost. The current paper constitutes an attempt to improve these methods by introducing an optimal traceability process to be used in the context of RTCA DO-297 “Integrated Modular Avionics (IMA) Development Guidance and Certification Considerations”. The paper starts by comparing the definitions of traceability from DO-297 and the related development guidelines (i.e. ARP4754A, DO-254 and DO-178B). The paper continues by classifying the traceability methods recommended by the guidelines and introducing a performance criterion for optimal traceability based on category theory. This criterion addresses the possibility of information loss present in the current traceability methods. The paper proposes an optimal traceability process (i.e. that guarantees that information is not lost) and exemplifies it. The paper ends by recommending further enhancements.
2012-10-22
Technical Paper
2012-01-2184
Michael Baldwin
This paper will illustrate how the increasing electrical demands to power military and aerospace applications can successfully be met by high performance electromechanical relays. To meet these higher demands engineering compatibility must be properly understood between the intended application and relay switching performance parameters. With high performance electromechanical relays continuing to play a critical part in military and aerospace applications it is more important than ever before that engineers capture all of the military and aerospace electrical power requirements. A critical area within powering military and aerospace systems is capacitive load switching. Capacitive loads can generate high current levels that are transient in duration and adversely affect the relay at the component level and the military or aerospace applications at the higher systems levels. As capacitance increases the amplitude and duration of the current transient also increase.
2012-10-22
Technical Paper
2012-01-2104
Mitchell Miller, Janice Meraglia, James Hayward
Proposes adoption of an industry standard marking protocol to assure the authenticity of high-reliability electronics. The protocol is seen as a key ingredient in the industry's effort to control counterfeit electronic parts escapes. The specifications of the marking protocol have been informed by the experience of the authors, who are currently participating in a DNA marking program mandated by the Defense Logistics Agency. The protocol would set out these criteria for an effective marking program: Simplicity Proven uncopyability Reportability: transparency and ease of oversight Legal validity: empowering of law enforcement Quick ramp-up and seamless implementation Extreme fidelity and absolute character of results - reliability of the mark at a very high level Universal adoption
2012-10-02
Technical Paper
2012-36-0452
Clodoaldo Borges Chagas, Thiago Caetano Freitas, Renan Francisco Silva, Breno Garcia Carneiro
Industrial applications frequently use interference between shafts and holes to fix parts together. The present work shows the methodology for validation of Finite Element calculus for press fitting a shaft in a dust shield hole. In the case of study the dust shield can be easily hit by shocks during transport and handling of the product. The shocks would change the position of the parts and consequently the new position could become a quality problem. The process of verification determines the factors which become the project more robust using the technical of Design of Experiment (DOE). The test and the computational simulation are shown as parallel way to determine the appropriate friction coefficient which could be used to predict the assembling and disassembling force for current project as well as the new design with similar features.
2012-10-02
Technical Paper
2012-36-0244
Henrique Martinni Ramos de Oliveira, Estephanie Nobre Dantas Grassi, Pedro Augusto Sobral Espindola, Carlos Jose de Araujo
Shape memory alloys (SMA) have a unique behavior due to a reversible phase transformation between two solid crystalline structures: martensite (low temperature and low stiffness phase) and austenite (high temperature and a higher stiffness phase). This transformation can occur either as a result of temperature change or mechanical stress load, both above characteristic critical values of these materials. Due to the reversible nature of this phenomenon, direct transformation occurs when austenite transforms into martensite and reverse transformation when martensite transforms into austenite. The latter is induced by raising the temperature and it is this process that occurs during the generation of significant associated forces through the undergone deformation recovering of the material, being of fundamental importance for the use as actuators.
2012-10-02
Technical Paper
2012-36-0181
Marcelo R. Cavaglieri, Diogo P. Bessa, Alisson C. Portella, Thays G. Wenzel F. Cavaglieri
This paper refers to a developed measurement process able to interact with small plastic parts, with holes about 0.4mm of diameter with a critical function on the vehicle. This method must be similar to the real condition. In other words, it must represent the fuel passing through these parts, though in a clean and faster way. To do this characterization, a light beam was used, in intensity strong enough to pass from side to side of the cavity up to the hole. This way enabling us to measure the light intensity that goes out. The resultant spread light beam is recorded by a digital microscope and converted in a chart by an algorithm. Based on a model developed, that picture is converted or translated in a number which can be used to separate part types, according to correlation of the spray performances. The main purpose of this methodology is a simple and effective way to monitor the produced parts and ensure the proper operation of the component when assembled in the complete system.
2012-10-02
Technical Paper
2012-36-0158
Thais Christina S. Santos, Danilo Mattos Batista, Filipe Marins Maduro
This material presents a project for data acquisition applied to monitoring climatic road simulators. The developed system acquires accelerometers and thermocouple signals from the vehicle suspension and body, point-by-point. This implementation allows real-time monitoring during tests, with the objective of making is autonomous. The platform used for the data-logger and automation system is composed by analog and digital input/output, TCP/IP and OPC protocols. The result obtained by this approach consisted mainly on the possibility of mapping the vehicle response throughout the tests, the integration of climatic and vibration control and overall contribution to a higher use of road simulators.
2012-10-02
Technical Paper
2012-36-0128
Bruno Geoffroy Scuracchio, Robinson Ferrari Barbosa, Jose Roberto Curitiba
The improvement of fatigue life in parts subjected to cyclic stresses by application of mechanical surface treatment processes is already well known, both in the industry and in the academy. Speaking of automotive springs, the shot peening process becomes an essential step in manufacturing these parts. In the case of leaf springs, however, a systematic investigation of the effect of shot peening on fatigue life is still required. The aim of this work is to improve the knowledge of shot peening on leaf springs for vehicles through fatigue tests on a series of samples that were subject to different peening processes. A second shot-peening after a first peening under stress (stress peening) led to a higher durability comparing to the conventional process, opening an opportunity of vehicle weight reduction.
Viewing 271 to 300 of 1655