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Viewing 31 to 60 of 23978
2016-04-05
Technical Paper
2016-01-1313
Brian Pinkelman, Woo-Keun Song
Most methods of vibration analysis focus on measuring the level of vibration. Some methods like ISO-2631 weigh vibration level based on human sensitivity of location, direction, and frequency. Sound can be similarly measured by sound pressure level in dB. It may also be weighted to human frequency sensitivity such as dBA but sound and noise analysis has expanded to measure sound quality. The characteristic and the nature of the sound are studied. As an example equal or near equal sound levels can provide different experiences to the listener. Such was the question for vibration, “can vibration quality be assessed just as sound quality is assessed?” Early on in our studies vibration sensory experts found a difference in 4 seats yet we could find no objective measurement of vibration level that could reliable confirm the sensory experience. Yet these particular experiences correlated to certain verbal descriptors including smoothness or roughness.
2016-04-05
Technical Paper
2016-01-0453
Yingxiao Xu, Xuexun Guo, Gangfeng Tan, Jiawei Li, Yongchi Zhou, Yangjie Ji, LiWen Yu
Eddy current retarder(ECR) shares a large domestic market of auxiliary brakes in China, but shortcomings of the short continuous braking time and the high additional energy consumption are also obvious. The propose of combined braking partakes the braking torque of ECR, while the existing serial-parallel braking strategy can't balance the relationship between the braking stability and the efficiency of energy recovery well. This research puts forward an energy management strategy of combined braking system which aims to maximize energy recovery while ensure the brake stability. The motor speed, braking request and the state of charge(SoC) of storage module are analyzed synthetically to calculate the reasonable braking torque distribution proportion. And the recovered energy is priority for braking unit to reduce the additional energy consumption in this strategy.
2016-04-05
Technical Paper
2016-01-1084
Chendi Sun, Vinson Jia
With rigorous fuel consumption regulation and emission law implemented, accuracy requirement of design and measurement signal is increasing, it becomes more and more indispensable to consider the influence on pressure loss and flow behavior coming from the incrementally loaded dust on filter element of Air Intake System (AIS). Dust is composed of many different sizes of particles, and studies shows that these different sizes of particles have very distinct influence on pressure loss of filter elements, which makes dust a challenge to model in Computational Fluid Dynamics (CFD) simulation. In order to precisely simulate pressure loss behavior of dust loaded filter element, a methodology for 3-D CFD dust loading simulation is developed, where the influence of particles sizes on pressure loss of filter element are taken into consideration by introducing a pressure loss weighting factors.
2016-04-05
Technical Paper
2016-01-0272
Huairui Guo, David Dronzkowski
Vehicle level road test probably is the most important test before a vehicle model goes to mass production. Failures found during the test are fixed and reliability of the vehicle is then improved. This test-fix-test process is often called reliability growth test. To achieve effective reliability growth, two things are critical. One is how and under what condition vehicles are tested; the other is having a formal Failure Report and Corrective Action System (FRACAS) in place. The topic of this paper is related to the former. We will discuss methods of determining the proper road profiles used in reliability growth tests. The goal of a reliability growth test is to find failures that customers will be experiencing and fix them. Therefore the road profiles used in the test should represent how actual customer usage. This data is typically compiled using customer surveys.
2016-04-05
Technical Paper
2016-01-1607
David Soderblom, Per Elofsson, Ann Hyvärinen
The effect of blockage due to the presence of the wind tunnel walls has been known since the early days of wind tunnel testing. Today there are several blockage correction methods available for correcting the measured aerodynamic drag. However, due to the shape of the test object, test conditions and wind tunnel dimensions the effect on the flow may be different for two cab variants. This will result in a difference in the drag delta between so-called open-road conditions and the wind tunnel. Which makes it difficult to evaluate the performance of two different test objects when they are both tested in a wind tunnel and simulated in CFD. For example, the acceleration of the flow around the front corner radius will be enhanced in blocked test conditions, and in most correction methods these effects are not considered. In this study numerical simulations were performed in order to compare the blockage effects on several different cab shapes.
2016-04-05
Technical Paper
2016-01-1007
Benjamin Ellies, Charles Schenk, Paul Dekraker
As part of its technology assessment for the upcoming midterm evaluation of the 2017-2025 LD vehicle GHG emissions regulation, EPA has been benchmarking engines and transmissions to generate inputs for use in its ALPHA model, a physics-based, forward-looking, full vehicle computer simulation tool. One of the most efficient engines today, a 2.0L Mazda SkyActiv engine, is of particular interest due to its high geometric compression ratio and use of an Atkinson combustion cycle. EPA benchmarked the 2.0L SkyActiv at its National Vehicle and Fuel Emissions laboratory. EPA then incorporated ALPHA into an engine dynamometer control system so that vehicle chassis testing could be simulated with a hardware-in-the-loop (HIL) approach.
2016-04-05
Technical Paper
2016-01-1582
Dirk Wieser, Sabine Bonitz, Lennart Lofdahl, Alexander Broniewicz, Christian Nayeri, Christian Paschereit, Lars Larsson
In this experimental investigation the surface flow pattern is visualized on a full scale passenger car in the Volvo wind tunnel in Gothenburg. The entire rear end of a Volvo S60 was equipped with a large amount of tufts. The movement of the tufts is recorded by a single lens reflex camera which takes pictures continuously. A new and efficient tuft image processing algorithm has been developed to calculate the statistical behavior of the tuft orientation. This allows the extraction of the mean angle and the standard deviation for individual tufts. This information on the surface flow can be used to identify unsteady and steady flow phenomena such as separation and reattachment lines, flow direction, stagnation points, and regions with increased turbulence and footprints of vortices. The main advantages over other flow visualization methods such as oil paint is that experimental facilities are not soiled and that statistical data can be extracted.
2016-04-05
Technical Paper
2016-01-0920
Bradford A. Bruno, Ann M. Anderson, Mary Carroll, Thomas Swanton, Paul Brockmann, Timothy Palace, Isaac A. Ramphal
Aerogels are nanoporous structures with a unique combination of physical characteristics that make them very promising for use in automotive exhaust catalysis systems. Their highly porous nature gives aerogels very low densities (<0.1 g/mL) and their extremely high surface area per unit mass (>300 m2/g) is a very favorable characteristic for catalysis of gaseous pollutants. Ceramic aerogels are also highly thermally insulating (~0.015 W/mK) and able to withstand very high temperatures. Beyond this, aerogels can be made of a wide variety of ceramics (e.g. alumina, silica, titania) with other catalytically active metals (e.g. copper, cobalt, nickel) incorporated into their structures. Aerogels can be manufactured using several techniques; however, rapid supercritical extraction (RSCE) offers significant advantages by reducing the processing time and solvent waste associated with more conventional techniques.
2016-04-05
Technical Paper
2016-01-1355
Jeffrey R. Hodgkins, Walter Brophy, Thomas Gaydosh, Norimasa Kobayashi, Hiroo Yamaoka
Current CAE (computer aided engineering) methods used to develop vehicle interior noise performances have always had the reputation for being inaccurate in predicting acoustic behavior in the mid-frequency range (300 to 1000 Hz). It is in this frequency range where the overall acoustic performance becomes sensitive to not only the contributions of structure-borne noise components, which CAE has proven capable of predicting, but also the growing contributions of air-borne noise components, where CAE usually lacks the capability to accurately reflect the physics involved in complex vibro-acoustic systems. This paper will discuss a study that was undertaken to test the capability of a finite element modeling method that can accurately simulate air-borne noise phenomena in the mid-frequency range. This modeling method was used to create a model of an enclosed simple box-shaped vibro-acoustic system fit with various acoustic trim parts (carpet and under body covers).
2016-04-05
Technical Paper
2016-01-0411
Yosuke Akita, Kenji Abe, Yoshitsugu Goto, Yuji Nagasawa, Satoshi Wakamatsu, Noboru Sugiura, Kyoko Kosaka, Yoshihiro Osawa
The coefficient of friction between disc rotor and pad often increases under wet condition, and the increase of the coefficient of friction may causes the brake noise. In this paper, in order to clarify the cause of the coefficient of friction variation with Moisture between friction surfaces, the in-situ observation is performed using a glass rotor. Survey test of the frictional surface observation is performed under dry condition using two kinds of pad which varied in a wear type and the pad which is suitable for frictional surface observation is selected. The observation results with moisture between friction surface using selected pad showed that wet wear debris on the friction surfaces affected the μ variation.
2016-04-05
Technical Paper
2016-01-1622
Miroslav Mokry
Lagally outlined his theory in the early 1920s, with no particular application in mind. Several decades later it became near indispensable in naval hydrodynamics, for calculating forces and moments exerted by the boundaries of narrow channels on passing vessels, effects of the ground or free surface on submerged bodies, etc. In wind tunnel testing, Lagally's theory has never really ‘caught on’. Assuming the model to be small relative to the test section, preference was given to the evaluation of the aerodynamic force increment from the ambient pressure gradient. However, as will be demonstrated in the paper, this approach is inaccurate for wind tunnel testing of larger blockage-ratio models even when their virtual masses can be established. The essence of the method presented here is as follows. By the Lagally theorem, the force exerted on a solid body by an external source is equal to the mass flow rate of the source times the induced velocity at the source location.
2016-04-05
Technical Paper
2016-01-0439
Tianqi Lv, Peijun Xu, Yunqing Zhang
The powertrain mounting system plays a very important role in controlling the NVH performance of a vehicle. The simulation analysis of powertrain mounting system adopts the linear rotation approximation model based on the premise of powertrain with small rotation angle assumption, but in some extreme loading conditions, powertrain will happen larger angle rotation, so the approximate model calculation results will be inaccurate, the calculation results of inaccurate is likely to cause powertrain interferes with the surrounding parts. This paper build a calculation model of powertrain rigid body dynamics with consideration nonlinear stiffness of the mount, and through the Newton-Raphson's iterative algorithm to solve the displacement and loads of mount system.
2016-04-05
Technical Paper
2016-01-0899
Takashi Hoshino, Farrukh Qureshi, Nicholas Virostko, Elizabeth Schiferl, Ananda Gajanayake, Motoji Hiroki, Tomoya Higuchi, Keita Ishizaki
The growing need for improved fuel economy is a global challenge due to continuously tightening environmental regulations targeting lower CO2 emission levels via reduced fuel consumption in vehicles. In order to reach these fuel efficiency targets, it necessitates improvements in hardware by applying advanced technologies in design, materials and surface treatments etc., as well as matching lubricant formulations with appropriate chemistry in. Axle lubricants have a significant impact on fuel economy. Importantly, they can be tailored to deliver maximum operation efficiency over either specific or wide ranges of operating conditions. The proper lubricant technology with well-balanced chemistries can simultaneously realize both fuel economy and hardware protection, which are commonly known to be having a trade-off relationship.
2016-04-05
Technical Paper
2016-01-0416
Eduardo Bustillos, Haley Linkous, Xin Xie, Laila Guessous, Lianxiang Yang
This paper presents the measurement and analysis of the edge stretching limit of aluminum alloy using digital image correlation. The edge stretching limit, also known as the “edge thinning limit,” is the maximum thinning strain at a point of edge failure resulting from tension; which may be predisposed by edge quality. Edge fracture is a vital failure mode in sheet metal forming, however it is very difficult to measure. A previous study enabled the measurement of edge thinning strain by using advanced digital image correlation but it did not consider how the edge quality could affect the edge stretching limit of aluminum alloy. This paper continues to measure edge thinning strain by comparing polished to unpolished AA5754, thus determining the effect edge quality has on the edge stretching limit. To enable the measurement by optical method for a very long and thin sample, a notch is used to localize where edge failure occurs.
2016-04-05
Technical Paper
2016-01-0451
Fu Wenkui, Liu Ligang, Shu Jin, Wang Dawei, Xu Long
Virtual Road Load Data Acquisition(vRLDA) is to replace traditional Road Load Data Acquisition(RLDA) thus become the important method to obtain the load for the fatigue analysis of the vehicle components. This paper makes a simulation analysis for pothole based on Adams/Car, a typical loadcase in road load data acquisition. Flex-body is adopted in the full vehicle model in order to improve the simulation accuracy. Flexible ring tire model, ftire, is used for the benefit of valid in higher frequency domain. The result shows that simulation result correlated well in wheel center travel and load of tire and suspension parts. Consequently, it is available to predict the max effective jounce travel and body max load in the early phase of vehicle development thus decrease the potential risk in the late phase and the total research cost. The vRLDA is also proven as a reliable and effective method to obtain the load.
2016-04-05
Technical Paper
2016-01-0450
Somnath Sen, Paulson Parayil
In order to ensure a comfortable space inside the cabin, it is very essential to design an efficient heating, ventilating and air-conditioning (HVAC) system which can deliver uniform temperature distribution at its mouth. There are several factors which impact on uniformity of temperature distribution. Airflow distribution is one of the key parameter in deciding the effectiveness of temperature distribution. Kinematics links and linkage system typically termed as ‘kinematics mechanism’ is one of the critical sub-systems which greatly affects the airflow distribution. It is not the temperature uniformity but also the HVAC temperature linearity also depends on airflow distribution. Hence the design of link mechanism is incomparably of paramount importance to achieve the desired level of airflow distribution at HVAC mouths. The present paper describes the design methodology of automotive HVAC linkage system.
2016-04-05
Technical Paper
2016-01-0445
Brian Paul Wiegand
Evaluation of the performance potential of an automotive conceptual design requires some initial quantitative estimate of numerous relevant parameters. Such parameters include the vehicle mass properties, frontal and plan areas, aero drag and lift coefficients, available horsepower and torque, and various tire characteristics such as the rolling resistance... A number of rolling resistance models have been advanced since Robert William Thomson first patented the pneumatic rubber tire in 1845, most of them developed in the twentieth century. Most early models only crudely approximate tire rolling resistance behavior over a limited range of operation, while the latest models overcome those limitations but often at the expense of extreme complexity requiring significant computer resources.
2016-04-05
Technical Paper
2016-01-0323
Sashank Mani Vedula, Nabal Kishore Pandey, KumarPrasad Tellikepalli, Satish Thimmalapura
Owing to high development cost and complexity in achieving the repeatability during testing phase of vehicle development, OEMs these days are focussing on front loading the activities to virtual test environment based development. This process not only helps in reducing the cost and time but also helps in increasing the maturity and confidence levels of the developed system before actual prototype is built. In the past, much extensive research has happened for increasing fidelity of virtual test environment by improving plant model efficacy which involves powertrain and other vehicle systems. On other hand, improving the precision of driver model which is one of the most complex nonlinear systems of virtual environment still remains a paramount challenge. It is apparent that various drivers show different behaviours in real world for a given drive profile. While driver model for a virtual test environment, the real world driver attributes are seldom considered.
2016-04-05
Technical Paper
2016-01-1072
Peter Schaal, Byron Mason, Sotiris Filippou, Ioannis souflas, Mark Cary
The paper presents a measurement methodology which combines an ultra-fast thermocouple with an input reconstruction technique in order to measure crank angle resolved temperature phenomena in an engine air-intake system. Thermocouples that are of practical use in engine experiments tend to have a large time constant which affects measurement accuracy during rapid temperature transients. Input reconstruction methods have previously been applied for use on larger diameter thermocouples but have not been applied to ultra-thin uninsulated wire thermocouples to investigate cyclic intake temperature behaviour. Accurate measurement results are of interest to improve the validity of many crank-angle resolved engine models. An unshielded thermocouple sensor has been developed which is rigid enough to withstand the aerodynamic forces of the intake air.
2016-04-05
Technical Paper
2016-01-0646
Pablo Olmeda, Jaime Martin, Antonio Garcia, Diego Blanco, Alok Warey, Vicent Domenech
Regulated emissions and fuel consumption are the main constraints affecting engine design. Over the years, many techniques have been used with the aim of meeting these limitations. In particular, EGR has demonstrated to be a necessary solution to reduce NOx emissions, becoming a widely used technique in production diesel engines. However, its application has a direct effect on fuel consumption due to both the changes in the in-cylinder processes, affecting indicated efficiency, as well as air management. An analysis, based on the engine Global Energy Balance, is presented to thoroughly assess the behavior of a HSDI diesel engine under variable EGR conditions at different operating points. The tests have been carried out, while keeping combustion phasing and conditions at intake valve closing (IVC) fixed.
2016-04-05
Technical Paper
2016-01-1365
Siddharth Bhupendra Unadkat, Suhas Kangde, Mahalingesh Burkul, Mahesh Badireddy
The overall automotive industry is moving toward first time right test which in turn needs first time right analysis. This is due to the enormous pressure of cost, mass, time to market and availability of prototype vehicles for testing. Use of finite element methods enables to upfront predict the system behavior in operating conditions and evaluation of structural strength. In vehicle product development process, hood slam durability evaluation is one of the important test for body closure structure. Current work showcases an effort made for developing virtual Hood slam test. The virtual model consists of BIW, hood, hinge joint, interface like CRFM and latch mechanism with spring preload. Analysis performed with LSDyna solver. An impact loading is applied by converting potential energy to kinetic energy, mimicking the hood dropping from a specified height on the hood latch.
2016-04-05
Technical Paper
2016-01-0274
Sharon L. Honecker, David J. Groebel, Adamantios Mettas
In order to accurately predict product reliability, it is best to design a test in which many specimens are tested for a long duration. However, this scenario is not often practical due to economic and time constraints. This paper describes a reliability test in which a limited number of specimens are tested with little time remaining before the scheduled start of production. During the test, an unexpected failure mode that can be mitigated through a product redesign occurs. Because the scheduled start of production is near, there is not time to perform a test with redesigned specimens, so the current test proceeds as planned. We discuss several methods and the associated assumptions that must be made to account for the presence of the unexpected failure mode in the test data in order to make predictions of reliability of the redesigned product.
2016-04-05
Technical Paper
2016-01-0484
Chad W. Chichester
Silicone fluids are known to have high Viscosity Indices (VI), and high Oxidation Onset Temperatures (OOT). Silicone VI and OOT characteristics make those fluids appealing for use as lubricants in high temperature applications, and where lubricant longevity is desired. Despite thermal and oxidative benefits, silicones lubricants have a reputation as being poor lubricants in metal-to-metal applications, and are typically only selected for use in plastic applications. Most industrial knowledge about silicone lubricants is based on characteristics of PolyDiMethyl Siloxanes (PDMS), in which case, lubricity limitations do exists. However, there are other silicone based lubricating fluid technologies, that have been commercially available for decades, that far exceed known lubricity performance of PDMS, and in some ways can rival traditional synthetic hydrocarbon.
2016-04-05
Technical Paper
2016-01-0905
Robert J. Middleton, Omnaath Guptha Harihara Gupta, Han-Yuan Chang, George Lavoie, Jason Martz
This study evaluates powertrain technologies capable of reducing light duty vehicle fuel consumption for compliance with 2025 CAFE standards. In a companion paper, a fully integrated GT-Power engine model was used to evaluate the effectiveness of a plausible series of engine technologies, including valve train improvements such as dual cam phasing and discrete variable valve lift, and engine downsizing with turbocharging and cooled EGR. In this paper, those engine efficiency/performance results are used in a vehicle drive cycle simulation to estimate the impact of engine and transmission technology improvements on light duty vehicle fuel consumption over the EPA’s FTP and HWY test schedules. The model test vehicle is a midsized sedan based on the MY2012 Ford Fusion with constant test weight of 3625 lbs, with constant drag and rolling resistance characteristics.
2016-04-05
Technical Paper
2016-01-0414
Nehal Sardar Rahim
"The Aisin A465 6-Speed Diesel Hybrid powertrain started production in early 2012 and is available in the North American market in the Hino 195 COE truck.  The suitability, and added fuel efficiency, of a Hybrid powertrain for Class 5 Box truck is very dependent on fleet usage conditions and duty cycle.  Aisin has undertaken real-world, extended mileage, durability testing on public roads to determine the operational modes for which such a powertrain is most suitable, and for which a fleet owner can expect significant fuel savings that will result in a payback period that justifies the higher initial cost of a hybrid system equipped commercial truck.  Data collected on the same Aisin proprietary durability test routes with a conventional Class 3-5 Cab Chassis truck provides insights into truck usage parameters that differ between Hybrid and conventional Class 3-5 commercial trucks.
2016-04-05
Technical Paper
2016-01-0463
Juan Sierra, Camilo Cruz, Luis Munoz, Santiago Avila, Elkin Espitia, Jaime Rodriguez
Brake systems are strongly related with safety of vehicles. Therefore a reliable design of the brake system is critical as vehicles operate in a wide range of environmental conditions, fulfilling different security requirements. Particularly, countries with mountainous geography expose vehicles to aggressive variations in altitude and road grade. These variations affect the performance of the brake system. In order to study how these changes affect the brake system, two approaches were considered. The first approach was centered on the development of an analytical model for the longitudinal dynamics of the vehicle during braking maneuvers. This model was developed at system-level, considering the whole vehicle. This allowed the understanding of the relation between the braking force and the altitude and road grade, for different fixed deceleration requirement scenarios. The second approach was focused on the characterization of the vacuum servo operation.
2016-04-05
Technical Paper
2016-01-1534
Rudolf Reichert, Pradeep Mohan, Dhafer Marzougui, Cing-Dao Kan, Daniel Brown
A detailed finite element model of a 2012 Toyota Camry was developed by reverse engineering. The model consists of 2.3M elements representing the geometry, thicknesses, material characteristics, and connections of relevant structural, suspension, and interior components of the mid-size sedan. This paper describes the level of detail of the simulation model, the validation process, and how it performs in various crash configurations, when compared to full scale test results. Under contract with the National Highway Safety Administration and the Federal Highway Administration, the Center for Collision Safety at the George Mason University has developed a fleet of vehicle models which have been made publicly available. The updated model presented in this paper is the latest finite element vehicle model with a high level of detail using state of the art modeling techniques.
2016-04-05
Technical Paper
2016-01-0273
Richard DeJong, Se Ge Jung, John Van Baren
Methods for conducting accelerated vibration fatigue testing of structures, such as MIL-STD-810G, allow for the non-linear scaling of the test time with the inverse of the rms vibration amplitude based on the slope of the material S-N curve obtained from cyclic fatigue tests. The Fatigue Damage Spectrum (FDS) is used as a method to allow for different level scalings at different frequencies in a broadband vibration environment using the relative responses of resonances in the structure. A recent development in industry has been to mix impulses with random excitations to increase the vibration peak levels (as measured by the kurtosis), thereby accelerating the fatigue even more than would occur with a Gaussian excitation. This paper presents results from a study to determine the conditions under which high kurtosis, impulsive excitations actually produce high kurtosis responses in structural resonances thus increasing the level of the FDS.
2016-04-05
Technical Paper
2016-01-0440
Li Jie, Wang Wenzhu, Gao Xiong, Zhang Zhenwei
The heavy truck often moves in a poor, long-distance and high-speed freight state environment, so drivers are easy to fatigue and goods are easily damaged. At the same time, compared to the passenger car, the ride comfort of heavy trucks has a lot of room for improvement. Therefore, the research on the ride comfort of heavy trucks becomes crucial.Based the elastic theory of Euler-Bernoulli beam with both free ends, a 6 DOF half rigid-elastic vibration model of the vertical dynamic response is developed, which is more suitable to the actual movement of heavy trucks. The DOFs include: vertical displacements of the body and each of two axles; the pitch displacement of the body; the first and second order bending displacements of the body. The root mean square values of body acceleration, dynamic deflections and relative dynamic loads act as evaluation index.
2016-04-05
Technical Paper
2016-01-0139
Andreas Himmler, Klaus Lamberg, Tino Schulze, Jann-Eve Stavesand
Developers of safety-critical systems need to verify the output of software tools in order to ensure their suitability for safety-relevant applications. The importance of verification holds specifically for test automation tools that are used to run hardware-in-the-loop (HIL) tests of safety-related software automatically 24/7. This paper will focus on two aspects that maximize the productivity of a COTS test automation tool: (a) Minimize the efforts for tool users for tool certification and (b) maximize the productivity for tool application. The latter refers to a new concept of signal-based test description. It is common sense that a test automation tool that automatically performs tests 24/7 has a tool confidence level of TCL 3. This causes a major initial hurdle for tool users, since the resulting required tool qualification is time-consuming and requires advanced knowledge.
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