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Viewing 211 to 240 of 11129
2016-09-27
Technical Paper
2016-01-8049
Keith Friedman, Khanh Bui, John Hutchinson, Matthew Stephens, Francisco Gonzalez
Abstract Frame rail design advances for the heavy truck industry provide numerous opportunities for enhanced protection of fuel storage systems. One aspect of the advanced frame technology now available is the ability to vary the frame rail separation along the length of the truck, as well as the depth of the frame. In this study, the effect of incorporating the fuel storage system within advanced technology tapered frame rails was evaluated using virtual testing under impact conditions. The impact performance was evaluated under a range of horizontal impacts conditions. The performance observed was quantified and then compared with previous testing of baseline diesel tank systems. Fuel storage system impact performance metrics over the range of crash conditions considered were quantified using virtual testing methods. The results obtained from the application of the impact performance evaluation methodology were then described.
2016-09-27
Technical Paper
2016-01-8141
Brian R. McAuliffe
Abstract With increasing use of boat-tails on Canadian roads, a concern had been raised regarding the possibility for ice and snow to accumulate and shed from the cavity of a boat-tail affixed to a dry-van trailer, posing a hazard for other road users. This paper describes a preliminary evaluation of the potential for ice and snow accumulation in the cavity of a boat-tail-equipped heavy-duty vehicle. A transient CFD approach was used and combined with a quasi-static particle-tracking simulation to evaluate, firstly, the tendency of various representative ice or snow particles to be entrained in the vehicle wake, and secondly, the potential of such particles to accumulate on the aft end of a dry-van trailer with and without various boat-tail configurations. Results of the particle tracking analyses showed that the greatest numbers of particles impinge on the base of the trailer for the no-boat-tail case, concentrated on the upper surface of the back face of the trailer.
2016-09-27
Technical Paper
2016-01-8155
Devaraj Dasarathan, Jonathan Jilesen, David Croteau, Ray Ayala
Abstract Side window clarity and its effect on side mirror visibility plays a major role in driver comfort. Driving in inclement weather conditions such as rain can be stressful, and having optimal visibility under these conditions is ideal. However, extreme conditions can overwhelm exterior water management devices, resulting in rivulets of water flowing over the a-pillar and onto the vehicle’s side glass. Once on the side glass, these rivulets and the pooling of water they feed, can significantly impair the driver’s ability to see the side mirror and to see outwardly when in situations such as changing lanes. Designing exterior water management features of a vehicle is a challenging exercise, as traditionally, physical testing methods first require a full-scale vehicle for evaluations to be possible. Additionally, common water management devices such as grooves and channels often have undesirable aesthetic, drag, and wind noise implications.
2016-09-27
Technical Paper
2016-01-8114
Massimiliano Ruggeri, Pietro Marani, Michele Selvatici
Abstract Stationary (parking) brake is a very important and safety critical function in many classes of machines. The new transmissions and the “by wire” systems increase the criticality of the role of stationary brake, as it is also an emergency (secondary) brake, and it’s often used to hold the vehicle when the transmission is not locking the wheels. As an example, dual clutch and power-shift transmission gear systems, as well as hydrostatic transmissions under certain circumstances, are often unable to hold the vehicle stopped and this function is provided by the stationary brake. Due to the main need of having the brake actuated when vehicle is stopped, without any hydraulic and electric power, the brake configuration is normally a “negative” configuration, usually called “spring applied” because of the actuator configuration, but this configuration causes the brake actuation when de-energized, even in case of system failure.
2016-09-27
Journal Article
2016-01-8098
Satish Jaju, Sahil Pandare
Abstract The regulatory requirement in Economic Commission for Europe (ECE R58) regulation applies to the Rear underrun protection devices which are intended to be fitted to commercial vehicles of N categories. The purpose of this regulation is to offer effective protection against underrunning of vehicles. This paper describes Computer aided engineering (CAE) methodology for testing rear underrun protection devices with loading sequences to be decided by Original equipment manufacturer. A sample model is prepared and analyzed to represent actual test conditions. Constraints and boundary conditions are applied as per test of vehicle. Finite element simulation is carried out using LS DYNA solver. Structural strength and integrity of Rear under protection device assembly is observed for different regulatory load requirement.
2016-09-27
Journal Article
2016-01-8011
Kevin Grove, Jon Atwood, Myra Blanco, Andrew Krum, Richard Hanowski
Abstract This study evaluated the performance of heavy vehicle crash avoidance systems (CASs) by collecting naturalistic driving data from 150 truck tractors equipped with Meritor WABCO OnGuardTM or Bendix® Wingman® AdvancedTM products. These CASs provide drivers with audio-visual alerts of potential conflicts, and can apply automatic braking to mitigate or prevent a potential collision. Each truck tractor participated for up to one year between 2013 and 2015. Videos of the forward roadway and drivers’ faces were collected along with vehicle network data while drivers performed their normal duties on revenue-producing routes. The study evaluated the performance of CAS activations by classifying them into three categories based on whether a valid object was being tracked and whether drivers needed to react immediately.
2016-09-20
Journal Article
2016-01-1976
Kiran Thupakula, Adishesha Sivaramasastry, Srikanth Gampa
Abstract Aviation safety is one of the key focus areas of the aerospace industry as it involves safety of passengers, crew, assets etc. Due to advancements in technology, aviation safety has reached to safest levels compared to last few decades. In spite of declining trends in in-air accident rate, ground accidents are increasing due to ever increasing air traffic and human factors in the airport. Majority of the accidents occur during initial and final phases of the flight. Rapid increase in air traffic would pose challenge in ensuring safety and best utilization of Airports, Airspace and assets. In current scenario multiple systems like Runway Debris Monitoring System, Runway Incursion Detection System, Obstacle avoidance system and Traffic Collision Avoidance System are used for collision prediction and alerting in airport environment. However these approaches are standalone in nature and have limitations in coverage, performance and are dependent on onboard equipment.
2016-09-20
Technical Paper
2016-01-1991
Syed J. Khalid
Abstract Aircraft subsystems essential for flight safety and airworthiness, including flight controls, environmental control system (ECS), anti-icing, electricity generation, and starting, require engine bleed and power extraction. Predictions of the resulting impacts on maximum altitude net thrust(>8%), range, and fuel burn, and quantification of turbofan performance sensitivities with compressor bleed, and with both high pressure(HP) rotor power extraction and low pressure(LP) rotor power extraction were obtained from simulation. These sensitivities indicated the judicious extraction options which would result in the least impact. The “No Bleed” system in Boeing 787 was a major step forward toward More Electric Aircraft (MEA) and analysis in this paper substantiates the claimed benefits.
2016-09-20
Technical Paper
2016-01-2040
Satya Swaroop Panda, Uday Kishore Tammiraju
Abstract Most of the real world problems pose practical challenges for making decisions primarily due to availability of limited data. Quantification of risk and assessment of structural reliability becomes difficult in such scenarios. Techniques for performing safety analysis for such problems are discussed in this paper. While complete characterization of a system behavior may be difficult with limited data of its response, statistical models based on extreme value theory provide the basis for making decisions with reasonable confidence. The same may not be true, however, for such structures early in their design cycle due to limited experience of their performance. In such cases response surface methodology can be very useful in determination of risk and suitably making modifications to the design to improve the reliability of the component or system. Applications of these methods for some real world scenarios are demonstrated.
2016-09-20
Technical Paper
2016-01-2043
Richard C. Millar, Thomas Mazzuchi, Haflidi Jonsson
Abstract The SPA-10 project, sponsored by U.S. National Science Foundation, is to acquire and qualify a replacement for the retired T-28 “storm penetration” aircraft previously used to acquire meteorological data to enable understanding and modelling of mid-continent thunderstorms. The National Science Foundation selected the Fairchild A-10 (bailed from the U.S. Air Force) as the platform to be adapted to perform the storm penetration mission to altitudes of eleven kilometers, and funded Naval Postgraduate School’s Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) as prime contractor. An expert panel conducted a review of the SPA-10 project in 2014 and recommended a risk analysis addressing hazards to the aircraft and pilots, such as icing, hail, turbulence and lightning. This paper presents the results of the risk analysis performed in response to this need, including recommended mitigations.
2016-09-20
Technical Paper
2016-01-1999
Debabrata Pal, Frank Feng
Abstract In 3-phase AC application, there is additional heat dissipation due to skin effects and proximity effects in bus bars. In addition, when the 3- phase AC is used to drive a motor at high fundamental frequency, for example between 666 Hz and 1450 Hz, there are higher bus bar losses due to presence of higher frequency harmonic content. High frequency current carrying bus bars in aircraft power panels are typically cooled by natural convection and radiation. In this paper a thermal and electrical finite element analysis (FEA) is done for a bus bar system. For electrical loss modeling, 3D electromagnetic FEA is used to characterize losses in three parallel bus bars carrying AC at various frequencies. This loss analysis provides correlation of heat loss as function of frequency. A method is presented where this AC loss is incorporated using computational fluid dynamics (CFD) based thermal model.
2016-09-20
Technical Paper
2016-01-2025
Amir Fazeli, Adnan Cepic, Susanne Reber
Abstract Aircraft weight and center of mass are two critical design and operational parameters that have to be within a design envelope to ensure a safe and efficient operation of aircraft. Previous efforts to accurately determine aircraft weight and center of mass before takeoff using landing gear shock strut pressures have failed due to the distortion of measured pressures by shock strut seal friction. Currently, aircraft loading process is controlled with loading sheets and passenger/cargo weight estimation as there are no online measurement systems that can accurately and efficiently estimate aircraft weight and determine the center of mass location before takeoff. However, errors in loading sheets, shifting cargo and errors in weight estimation could lead to incorrect loading of aircraft and, consequently, increase the risk of accidents, particularly in cargo flights.
2016-09-18
Technical Paper
2016-01-1953
Michael Herbert Putz, Harald Seifert, Maximilian Zach, Jure Peternel
Abstract Since more than eight years Vienna Engineering (VE) is working on an electro-mechanical brake (EMB) actuated by eccentrics and a highly non-linear actuation mechanism. The principle allows full braking in approx. 70 milliseconds (including air gap) and only approx. 3 A RMS actuator current at 12 V for classical ABS with oscillations. This EMB reached an elaborated state. Versions for passenger cars, elevators, railway and commercial vehicles (CVs) were derived. Now, as the EMB is going to road tests, it is necessary to fulfill safety requirements closely. What are these safety requirements and how can they be fulfilled? The properties of the overall system, of the mechanics and electronics of the single brake are discussed in this paper. The overall brake system for EMBs needs a truly redundant power supply, a safe control bus and a safe brake pedal. The mechanics of a single brake can be required to release when power is off and it must not get mechanically stuck.
2016-09-16
Journal Article
2016-01-9017
Janka Cafolla, Derick Smart, Barry Warner
Abstract The lifting and excavating industry are not as advanced as automotive in the use of modern CAE tools in the early stages of design and development of heavy machinery. There is still a lack of confidence in the integrity of the results from FE simulations and optimisation and this becomes a barrier to the adoption of virtual prototyping for vehicle verification. R&D of Tata Steel has performed tests on two forklift truck overhead guards supplied by a major manufacturer. Based on the international standard for Falling Object Protective Structures (FOPS) as an initial input to the method of testing, the main aim of this study was to generate as much test data as possible to correlate the Finite Element (FE) simulations of two tests - a static and a dynamic test. The static test was developed to deform the overhead guard plastically in a slow controlled manner, so it would be easier to correlate the measured data to FE simulation.
2016-09-14
Journal Article
2016-01-1877
Jun Hu, Wei Liu, Shuai Cheng, Huan Tian, Huai Yuan, Hong Zhao
Abstract The convolutional neural network (CNN) has achieved extraordinary performance in image classification. However, the implementation of such architecture on embedded platforms is a big challenge task due to the computing resource constraint issue. This paper concentrates on optimization of CNN on embedded platforms with a case study of pedestrian detection in ADAS. The main contribution of this proposed CNN is its ability to run pedestrian classification task in real time with high accuracy based on a platform with ARM embedded. The CNN model has been trained with GPU locally and then transformed into an efficient implementation on embedded platforms. The efficient implementation uses dramatically small network scale and a lightweight CNN is obtained. Specifically, parameters of the network are compressed by adopting integer weights to reduce computational complexity. Meanwhile, other optimizations have also been proposed to adapt the general ARM processor architecture.
2016-06-15
Technical Paper
2016-01-1839
Emar Vegt
Abstract The quiet nature of hybrid and electric vehicles has triggered developments in research, vehicle manufacturing and legal requirements. Currently, three countries require fitting an Approaching Vehicle Alerting System (AVAS) to every new car capable of driving without a combustion engine. Various other geographical areas and groups are in the process of specifying new legal requirements. In this paper, the design challenges in the on-going process of designing the sound for quiet cars are discussed. A proposal is issued on how to achieve the optimum combination of safety, environmental noise, subjective sound character and technical realisation in an iterative sound design process. The proposed sound consists of two layers: the first layer contains tonal components with their pitch rising along with vehicle speed in order to ensure recognisability and an indication of speed.
2016-06-15
Journal Article
2016-01-1784
Alessandro Fortino, Lutz Eckstein, Jens Viehöfer, Jürgen Pampel
Abstract Vehicles powered by electric machines offer the advantage to be more silent than vehicles equipped with an internal combustion engine. On the one hand, the reduced noise levels enable an improvement of the inner-city noise pollution. On the other hand, quiet vehicles entail risks not to be acoustically detected by surrounding pedestrians and cyclists in the lower speed range. The emitted noise can easily be masked by the urban background noise. Therefore, the UNECE has founded an informal working group which is currently developing guidelines in terms of an exterior noise required for detecting Quiet Road Transport Vehicles (QRTV). With the introduction of an Acoustic Vehicle Alerting System (AVAS), not only the exterior noise but also the perceived interior noise for an enhanced driving experience can be considered. Nevertheless, car manufactures have a big interest in maintaining their perceived brand identity.
2016-04-15
Journal Article
2015-01-9020
Emre Sert, Pinar Boyraz
Abstract Studies have shown that the number of road accidents caused by rollover both in Europe and in Turkey is increasing [1]. Therefore, rollover related accidents became the new target of the studies in the field of vehicle dynamics research aiming for both active and passive safety systems. This paper presents a method for optimizing the rear suspension geometry using design of experiment and multibody simulation in order to reduce the risk of rollover. One of the major differences of this study from previous work is that it includes statistical Taguchi method in order to increase the safety margin. Other difference of this study from literature is that it includes all design tools such as model validation, optimization and full vehicle handling and ride comfort tests. Rollover angle of the vehicle was selected as the cost function in the optimization algorithm that also contains roll stiffness and height of the roll center.
2016-04-12
Technical Paper
2016-01-7000
Daniel P. Malone, John F. Creamer
In 1966, Congress boldly reshaped the American approach to road safety and thereby established the United States as the worldwide leader in vehicle safety. Congressional action led to the establishment of the Department of Transportation, the National Highway Traffic Safety Administration (NHTSA), Federal Motor Vehicle Safety Standards, and the motor-vehicle safety defects and recall system. However, the safety environment that gave rise to these responses has evolved substantially. Fifty years later, the United States is unable to properly regulate rapidly advancing safety technologies, and the recall system is wholly unsuited to ensuring the safety of software-driven systems. Congress must act to update the road safety system in order to enable the United States to meet the challenges and seize the opportunities of the new transportation era.
2016-04-05
Technical Paper
2016-01-0725
P.C. Bakker, R.C. Willems, N.J. Dam
Abstract Laser-induced incandescence (LII) is a well-established technique for tracking soot, potentially enabling soot volume fraction determination. To obtain crank angle resolved data from a single cycle, a multi-kHz system should be applied. Such an approach, however, imposes certain challenges in terms of application and interpretation. The present work intends to apply such a high-speed system to an optically-accessible, compression ignition engine. Possible problems with sublimation, local gas heating or other multishot effects have been studied on an atmospheric co-flow burner prior to the engine experiments. It was found that, in this flame, fluences around 0.1 J/cm2 provide the best balance between signal-tobackground ratio, and soot sublimation. This fluence is well below the plateau regime of LII, which poses additional problems with interpretation of the signal.
2016-04-05
Journal Article
2016-01-0857
Muhammad Aqib Chishty, Michele Bolla, Evatt Hawkes, Yuanjiang Pei, Sanghoon Kook
Abstract The importance of radiative heat transfer on the combustion and soot formation characteristics under nominal ECN Spray A conditions has been studied numerically. The liquid n-dodecane fuel is injected with 1500 bar fuel pressure into the constant volume chamber at different ambient conditions. Radiation from both gas-phase as well as soot particles has been included and assumed as gray. Three different solvers for the radiative transfer equation have been employed: the discrete ordinate method, the spherical-harmonics method and the optically thin assumption. The radiation models have been coupled with the transported probability density function method for turbulent reactive flows and soot, where unresolved turbulent fluctuations in temperature and composition are included and therefore capturing turbulence-chemistry-soot-radiation interactions.
2016-04-05
Technical Paper
2016-01-0822
Jongwon Chung, Namho Kim, Hoimyung Choi, Kyoungdoug Min
Abstract Due to the direct injection of fuel into a combustion chamber, particulate emission is a challenge in DISI engines. Specifically, a significant amount of particulate emission is produced under the cold start condition. In this research, the main interest was to investigate particulate emission characteristics under the catalyst heating condition because it is one of the significant particulate-emissionproducing stages under the cold start condition. A single-cylinder optically accessible engine was used to investigate the effect of injection strategies on particulate emission characteristics under the catalyst heating condition. The split injection strategy was applied during intake stroke with various injection pressures and injection timings. Using luminosity analysis of the soot radiation during combustion, the particulate formation characteristics of each injection strategy were studied.
2016-04-05
Technical Paper
2016-01-1683
Blago B. Minovski, Lennart Lofdahl, Peter Gullberg
Abstract Presented are results from numerical investigations of buoyancy driven flow in a simplified representation of an engine bay. A main motivation for this study is the necessity for a valid correlation of results from numerical methods and procedures with physical measurements in order to evaluate the accuracy and feasibility of the available numerical tools for prediction of natural convection. This analysis is based on previously performed PIV and temperature measurements in a controlled physical setup, which reproduced thermal soak conditions in the engine compartment as they occur for a vehicle parked in a quiescent ambient after sustaining high thermal loads. Thermal soak is an important phenomenon in the engine bay primarily driven by natural convection and radiation after there had been a high power demand on the engine. With the cooling fan turned off and in quiescent environment, buoyancy driven convection and radiation are the dominating modes of heat transfer.
2016-04-05
Journal Article
2016-01-1080
Narendra V. Bansode, Arnab Ganguly, Vikas Kumar Agarwal
Abstract A single cylinder gasoline engine of a sports bike generates sufficient hot gases to pose great challenge to the designers of exhaust system. The high temperature exhaust gases in muffler creates thermal elongation on the solid parts of exhaust system, which is mounted on the chassis. This arrangement induces thermal stress in exhaust assembly. It is necessary to analyze this thermal stress to ensure the durability of muffler components. The exhaust design has a diversion at the header pipe to distribute the flow in two branches. This junction and the branches heated up excessively and showed repeated failure. To analyze the thermal stress, the temperature distribution in the muffler components is obtained from Computational Fluid Dynamics (CFD) analysis. The complete motorcycle with detailed exhaust system is modelled in the standard wind tunnel using a commercial CFD software.
2016-04-05
Technical Paper
2016-01-1158
Toshiaki Watanabe, Masaya Ishida
Abstract Wireless charging systems for electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) employing the resonant magnetic coupling method and using induction coils have been intensively studied in recent years. Since this method requires kW class high power to be transmitted using resonant magnetic coupling in the high frequency range, it is necessary to pay attention to the leakage of the magnetic field generated by the coil current, and to its influence on surrounding objects, particularly human bodies. Noting that acceptable values for human body exposure to electromagnetic fields have previously been issued by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) as guidelines, we have developed a method for predicting product compliance with those guidelines at the basic design development stage.
2016-04-05
Technical Paper
2016-01-0538
Cynthia Templeman
Abstract Automotive clearcoats have many purposes, from providing a glossy finish to protecting the underlying paint layers from UV radiation. Yellowing of clearcoats is a natural phenomenon during weathering processes, as well as from extreme baking conditions, due to polymer degradation. However, occasionally yellowing may be caused by unexpected chemical reactions occurring in the clearcoat. These reactions may happen very quickly (within hours or days) or take years to manifest, as other chemicals migrate into the clearcoat. We have investigated one family of these unexpected reactions which occur with certain UV absorbers, as well as how to prevent the reactions from occurring. We found that certain benzotriazole UV absorbers react readily with some common metals, including copper and zinc, provided that the UV absorber is not in its excited state.
2016-04-05
Journal Article
2016-01-0527
Anthony Berejka, Dan Montoney, Dan Dispenza, Len Poveromo, Rick Galloway, Marshall Cleland, Mark Driscoll
Abstract The power demands in terms of kilowatt-hour electrical use were compared for autoclave curing commercial thermosetting carbon fiber pre-pregs with an innovative alternative of high energy X-ray curing. An automotive component, now made with carbon fiber composites, was selected as an illustrative example, an Aston-Martin hood. Temperature resistant polyester molds for these hoods were used and manufacturer recommended autoclave curing conditions were followed. X-rays, which can penetrate about 15 cm (6 inches) in unit density materials (or less into higher density materials as molds), were used to cure pre-pregs made with a specialty matrix material using the same molds, but doing so without adding any heat for curing. High energy X-ray equipment, generated from a 7 MeV, 700 kW electron beam, is in commercial use for medical device sterilization. This same equipment can also be used for composite curing.
2016-04-05
Journal Article
2016-01-0519
Xiaoqing Xu, Bohan Liu, Yan Wang, Yibing Li
Abstract The mechanical behavior of polyvinyl butyral (PVB) film plays an important role in windshield crashworthiness and pedestrian protection and should be depth study. In this article, the uniaxial tension tests of PVB film at various strain rates (0.001 s-1, 0.01 s-1, 0.1 s-1, 1 s-1) and temperatures (-10°C, 0°C, 10°C, 23°C, 40°C, 55°C, 70°C) are conducted to investigate its mechanical behavior. Then, temperature and strain rate dependent viscoelastic characteristics of PVB are systematically studied. The results show that PVB is a kind of temperature and strain rate sensitive thermal viscoelastic material. Temperature increase and strain rate decrease have the same influence on mechanical properties of PVB. Besides, the mechanical characteristics of PVB change non-linearly with temperature and strain rate.
2016-04-05
Journal Article
2016-01-1568
L. Daniel Metz
Abstract Roadway tractive capabilities are an important factor in accident reconstruction. In the absence of full-scale experiments, tire/road coefficient of friction values are sometimes quoted from reference textbooks. For the various types of road construction, the values are given only in the form of a wide range. One common roadway type is oil-and-chip construction. We examine stopping distances for newly-rocked oil-and-chip roads vs. similarly constructed roads that have been traffic-polished. The examination was conducted through full-scale braking experiments with instrumented vehicles. Results show that the differences between newly-rocked oil-and-chip roads when compared to roads that are traffic-polished are on the same order as vehicle, tire and ABS algorithm differences, and that full-scale testing is required for accurate μ-values.
2016-04-05
Technical Paper
2016-01-1535
Linli Tian, Yunkai Gao
Abstract Based on equivalent static loads method (ESL), a nonlinear dynamic topology optimization is carried out to optimize an automotive body in white (BIW) subjected to representative legislative crash loads, including frontal impact, side barrier impact, roof crush and rear impact. To meet the crashworthiness performances, two evaluation indexes are defined to convert the practical engineering problems into mathematic optimization problems. The strain energy is treated as the stiffness evaluation index of the BIW and the relative displacement is employed as the compliance index of the components and parts.
Viewing 211 to 240 of 11129