Criteria

Text:
Topic:
Display:

Results

Viewing 1 to 30 of 90
2017-11-07
Technical Paper
2017-36-0080
Edinilson Alves Costa, Rogério Nalin
Abstract Although ignored by most people not directly involved with highway and off-road commercial trucks operation the accumulation of dust and mud on cabin side can become a rather annoying issue. Besides adhering to the passengers clothes dirt contamination may also compromise driver visibility constituting a safety concern. For a truck manufacturer it can revert into quality complaints and negatively influence customers’ future buying decisions. In this context, fascia air deflectors are common devices used in truck industry to control the airflow over the cabin panels and ultimately prevent contamination deposition. This paper presents a methodology to avoid dust and mud accumulation on commercial trucks cabin doors based on the predicted airflow field by computational fluid dynamics (CFD) and a reference flow metric defined through a simple bench test.
2017-03-28
Journal Article
2017-01-1511
Anton Kabanovs, Graham Hodgson, Andrew Garmory, Martin Passmore, Adrian Gaylard
Abstract The motivation for this paper is to consider the effect of rear end geometry on rear soiling using a representative generic SUV body. In particular the effect of varying the top slant angle is considered using both experiment and Computational Fluid Dynamics (CFD). Previous work has shown that slant angle has a significant effect on wake shape and drag and the work here extends this to investigate the effect on rear soiling. It is hoped that this work can provide an insight into the likely effect of such geometry changes on the soiling of similarly shaped road vehicles. To increase the generality of results, and to allow comparison with previously obtained aerodynamic data, a 25% scale generic SUV model is used in the Loughborough University Large Wind Tunnel. UV doped water is sprayed from a position located at the bottom of the left rear tyre to simulate the creation of spray from this tyre.
2017-03-28
Journal Article
2017-01-1543
Jonathan Jilesen, Adrian Gaylard, Jose Escobar
Abstract Vehicle rear and side body soiling has been a concern since the earliest cars. Traditionally, soiling has been seen to be less importance than vehicle aerodynamics and acoustics. However, increased reliance on sensors and cameras to assist the driver means that there are more surfaces of the vehicle that must be kept clean. Failure to take this into consideration means risking low customer satisfaction with new features. This is because they are likely to fail under normal operating conditions and require constant cleaning. This paper numerically investigates features known to have an influence on side and rear face soiling with a demonstration vehicle. These changes include rim design, diffuser strakes and diffuser sharpening. While an exhaustive investigation of these features is beyond the scope of this study, examples of each feature will be considered.
2017-01-10
Technical Paper
2017-26-0234
Arun Narayanan, Sagar Bhojne
Abstract In Earth Moving Machines, performance of an attachments play crucial role in determining the machine performance. Application of the machine is one of the main factors to be considered for bucket design. Different types of buckets are offered in the market to suit the particular application. Trenching, digging, moving loose material are some of the operations done with the backhoe bucket. While operating in these areas bucket handles intact soil, granules, loose rocks etc. Properties of these materials play important role in bucket design methodology. In this paper efforts are made towards understanding the properties of soil along with soil failure mechanism and utilizing these inputs to design a backhoe bucket for better machine productivity. Mathematical modeling and Discrete Element Modeling (DEM) are the tools used for design and validation of this work.
2016-09-27
Journal Article
2016-01-8029
Chrysostomos-Alexandros Bekakos, George Papazafeiropoulos, Dan J. O'Boy, Jan Prins, George Mavros
Abstract A novel semi-analytical solution has been developed for the calculation of the static and dynamic response of an off road tire interacting with a deformable terrain, which utilizes soil parameters independent of the size of the contact patch (size-independent). The models involved in the solution presented, can be categorized in rigid and/or pneumatic tires, with or without tread pattern. After a concise literature review of related methods, a detailed presentation of the semi-analytical solution is presented, along with assumptions and limitations. A flowchart is provided, showing the main steps of the numerical implementation, and various test cases have been examined, characterized in terms of vertical load, tire dimensions, soil properties, deformability of the tire, and tread pattern. It has been found that the proposed model can qualitatively capture the response of a rolling wheel on deformable terrain.
2016-09-27
Technical Paper
2016-01-8024
Saurabh Gupta, Gopichand Vunnava
Abstract In search of higher productivity, farmers are taking more than two crops in a year. In this farming pattern they don’t have much time for field preparation due to which rear mounted plough have become longer and heavier, necessitating the use of additional front-end weights and assister rams on the hydraulic lift. As plough length increases, the evenness of working depth over the full length of the implement deteriorates. To complete the farm work in one or two passes by utilizing maximum tractor power in order to save the fuel as well as time. The usage of front hitch and front PTO system on tractor forms a gateway for farmers to control the traffic on farm fields which is responsible for the soil compaction and emissions of greenhouse gases into the atmosphere by reducing the number of passes in agricultural field operations.
2016-04-05
Journal Article
2016-01-0539
Yuko Kajiyama, Toshikazu Obata, Tsuyoshi Sugimoto, Masahiro Nakamura, Motohide Mori
Abstract The dissolution and exfoliation of chromium plating specific to Russia was studied. Investigation and analysis of organic compounds in Russian soil revealed contents of highly concentrated fulvic acid. Additionally, it was found that fulvic acid, together with CaCl2 (a deicing agent), causes chromium plating corrosion. The fulvic acid generates a compound that prevents reformation of a passivation film and deteriorates the sacrificial corrosion effectiveness of nickel.
2016-04-05
Technical Paper
2016-01-1514
Varun Bollapragada, Taewung Kim, Mark Clauser, Jeff Crandall, Jason Kerrigan
Abstract Some rollover testing methodologies require specification of vehicle kinematic parameters including travel speed, vertical velocity, roll rate, and pitch angle, etc. at the initiation of vehicle to ground contact, which have been referred to as touchdown conditions. The complexity of the vehicle, as well as environmental and driving input characteristics make prediction of realistic touchdown conditions for rollover crashes, and moreover, identification of parameter sensitivities of these characteristics, is difficult and expensive without simulation tools. The goal of this study was to study the sensitivity of driver input on touchdown parameters and the risk of rollover in cases of steering-induced soil-tripped rollovers, which are the most prevalent type of rollover crashes. Knowing the range and variation of touchdown parameters and their sensitivities would help in picking realistic parameters for simulating controlled rollover tests.
2015-09-27
Journal Article
2015-01-2663
Pavlina Peikertova, Peter Filip
Abstract Automotive brake linings are complex composite materials. Some raw materials used by manufacturers or the compounds created during the friction process might be potentially hazardous and may cause various adverse effects. Different fractions of the brake wear debris can be released during braking: i) the airborne and ii) the nonairborne. Due to the small size and minimum gravitational action, the airborne particles could be spread for long distances from a source and typically remain suspended in the air for long periods of time. Our previous research demonstrated that the airborne fraction contains considerable amounts of different nanoparticulates. On the other hand, the emitted nonairborne fraction typically settles on vehicle/brake hardware surfaces and in the vicinity of roads. The nonairborne particles are considered to be relatively large, but it was shown that nano-sized particles readily attach to them and can be released later.
2015-04-14
Journal Article
2015-01-1478
Michelle Heller, Sarah Sharpe, William Newberry, Alan Dibb, John Zolock, Jeffrey Croteau, Michael Carhart, Jason Kerrigan, Mark Clauser
Abstract Occupant kinematics during rollover motor vehicle collisions have been investigated over the past thirty years utilizing Anthropomorphic Test Devices (ATDs) in various test methodologies such as dolly rollover tests, CRIS testing, spin-fixture testing, and ramp-induced rollovers. Recent testing has utilized steer maneuver-induced furrow tripped rollovers to gain further understanding of vehicle kinematics, including the vehicle's pre-trip motion. The current study consisted of two rollover tests utilizing instrumented test vehicles and instrumented ATDs to investigate occupant kinematics and injury response throughout the entire rollover sequences, from pre-trip vehicle motion to the position of rest. The two steer maneuver-induced furrow tripped rollover tests utilized a mid-sized 4-door sedan and a full-sized crew-cab pickup truck. The pickup truck was equipped with seatbelt pretensioners and rollover-activated side curtain airbags (RSCAs).
2015-04-14
Technical Paper
2015-01-1477
Robert Larson, Jeffrey Croteau, Cleve Bare, John Zolock, Daniel Peterson, Jason Skiera, Jason R. Kerrigan, Mark D. Clauser
Abstract Extensive testing has been conducted to evaluate both the dynamic response of vehicle structures and occupant protection systems in rollover collisions though the use of Anthropomorphic Test Devices (ATDs). Rollover test methods that utilize a fixture to initiate the rollover event include the SAE2114 dolly, inverted drop tests, accelerating vehicle body buck on a decelerating sled, ramp-induced rollovers, and Controlled Rollover Impact System (CRIS) Tests. More recently, programmable steering controllers have been used with sedans, vans, pickup trucks, and SUVs to induce a rollover, primarily for studying the vehicle kinematics for accident reconstruction applications. The goal of this study was to create a prototypical rollover crash test for the study of vehicle dynamics and occupant injury risk where the rollover is initiated by a steering input over realistic terrain without the constraints of previously used test methods.
2015-01-14
Journal Article
2015-26-0072
Suresh Kumar Gurusamy, G Devaradjane
Abstract Agriculture Tractors are widely used as prime mover either to pull or drive the “Implements” in the farms, apart from custom made equipments like Transplanter, Manure Spreader, Combine Harvester, Cotton Picker, mobile irrigation etc. which are used for particular operations in large production capacities. For larger landholdings, timely completion of the operation within the window period is the major decisive factor that drives agriculture tractor design. For small farms like in India, the productivity requirement was offset by the versatility of the equipment. Also, the farming practice varies in India due to geographical conditions such as soil types and demographic conditions such as crops types. Hence, the mechanisation level of matured market was not yet achieved in India, though the technologies are available for implementation.
2015-01-14
Technical Paper
2015-26-0148
Jagadeesh Selvaraj, Dayalan Purushothaman, P T Haridas
Abstract Fuel economy is an important customer requirement which determines the position of earth-movers such as backhoe loaders in the market. Earth-movers are heavy duty machines that are used for construction works. Currently fuel consumption in earth-movers is quantified as fuel consumed per unit time (Liters per hour). Similarly, conventional measure of productivity of the earth-movers is in terms of volume of soil trenched per hour. Measurements using the above scales showed wide variations in measured fuel consumption and productivity, For the same equipment between measurements Two equipment of same make at different trench locations and Against the competitor equipment This inconsistency and lack of a proper measuring system made logical decision making extremely difficult. This paper describes the step by step procedures involved in deriving the methodology for robust fuel consumption measurement of earth-mover vehicles.
2015-01-14
Technical Paper
2015-26-0144
Pankaj Brijbihari Sharma, Prafulla Dahiwade
Abstract This paper discusses the off-road performance prediction of military application mini UGVs using terramechanics work deals with the development of performance simulation model for mini UGV in the Matlab/Simulink Software. Transient forward vehicle propulsion model and soil terrain interaction model have been built in the Simulink® software. It is a semi-empirical mobility model which predicts mini UGV performance on given terrain. The interaction between vehicle and the terrain causes resistances to vehicle propulsion. The model calculates these resistances, compares them to both the power limitations of the vehicle and the tractive limitations of the soil/terrain, to determine if the vehicle is immobilized. If not, then the vehicle speed is calculated based on available drawbar pull. The terrain is defined in terms of the soil parameters measured by the Bevameter. Semi-empirical equations suggested by Bekker have been used to model the soil terrain interaction.
2014-09-30
Technical Paper
2014-36-0156
Júlio Cesar de Souza, Lorena D'Avila do Carmo Andrade, Daniel Bastos de Rezende
Abstract When not disposed properly, the frying oil from the household or restaurants may cause clogging of waste drainage pipes and sewage systems, water contamination and soil sealing. The production of biodiesel from frying oil and its utilization for energy generation is a potential alternative to disposal, adding value to this waste and using it as an energy source. This article presents a case study of a proposal to produce biodiesel from frying oil for fuel up vehicles used to the employees transport inside Fiat's plant in Betim, Brazil. Besides the technical and economic evaluation, a life cycle assessment (LCA) was performed to examine the environmental viability of producing the biodiesel from cooking oil and its use for fuel up the minibuses replacing conventional diesel B5 for B50.
2014-04-01
Technical Paper
2014-01-0878
Adam C. Reid, David Philipps, Fredrik Oijer, Inge Johansson, Moustafa EL-Gindy
Abstract The rigid-ring tire model is a simplified tire model that describes a tire's behaviour under known conditions through various in-plane and out-of-plane parameters. The complex structure of the tire model is simplified into a spring-mass-damper system and can have its behaviour parameterized using principles of mechanical vibrations. By designing non-linear simulations of the tire model in specific situations, these parameters can be determined. They include, but are not limited to, the cornering stiffness, vertical damping constants, self-aligning torque stiffness and relaxation length. In addition, off-road parameters can be determined using similar methods to parameterize the tire model's behaviour in soft soils. By using Finite Element Analysis (FEA) modeling methods, validated soil models are introduced to the simulations to find additional soft soil parameters.
2014-04-01
Technical Paper
2014-01-0873
Daniel J. Melanz, Hammad Mazhar, Dan Negrut
Abstract 1 This paper describes a modeling, simulation, and visualization framework aimed at enabling physics-based analysis of ground vehicle mobility. This framework, called Chrono, has been built to leverage parallel computing both on distributed and shared memory architectures. Chrono is both modular and extensible. Modularity stems from the design decision to build vertical applications whose goal is to reduce the end-to-end time from vision-to-model-to-solution-to-visualization for a targeted application field. The extensibility is a consequence of the design of the foundation modules, which can be enhanced with new features that benefit all the vertical applications. Two factors motivated the development of Chrono. First, there is a manifest need of modeling approaches and simulation tools to support mobility analysis on deformable terrain.
2014-04-01
Technical Paper
2014-01-0530
Taewung Kim, Jason Kerrigan, Varun Bollapragada, Jeff Crandall, Ravi Tangirala, Michael Guerrero
Abstract Some rollover test methods, which impose a touchdown condition on a test vehicle, have been developed to study vehicle crashworthiness and occupant protection in rollover crashes. In ground-tripped rollover crashes, speed, steering maneuver, braking, vehicle inertial and geometric properties, topographical and road design characteristics, and soil type can all affect vehicle touchdown conditions. It is presumed that while there may be numerous possible combinations of kinematic metrics (velocity components and orientation) at touchdown, there are also numerous combinations of metrics that are not likely to occur in rollover crashes. To determine a realistic set of touchdown conditions to be used in a vehicle rollover crash test, a lateral deceleration sled-based non-destructive rollover initiation test system (RITS) with a fully programmable deceleration pulse is in development.
2014-04-01
Journal Article
2014-01-0610
Adrian P. Gaylard, John Pitman, Jonathan Jilesen, Adriano Gagliardi, Bradley Duncan, John Wanderer, Alex Konstantinov
Contamination of vehicle rear surfaces is a significant issue for customers. Along with being unsightly, it can degrade the performance of rear camera systems and lighting, prematurely wear rear screens and wipers, and transfer soil to customers moving goods through the rear tailgate. Countermeasures, such as rear camera wash or automated deployment add expense and complexity for OEMs. This paper presents a rear surface contamination model for a fully detailed SUV based on the use of a highly-resolved time-accurate aerodynamic simulation realised through the use of a commercial Lattice-Boltzmann solver, combined with Lagrangian Particle Tracking to simulate droplet advection and surface water dynamics via a thin film model. Droplet break-up due to aerodynamic shear is included, along with splash and stripping from the surface film. The effect of two-way momentum coupling is included in a sub-set of simulations.
2013-10-15
Journal Article
2013-32-9173
John W. Zellner, Scott A. Kebschull, R. Michael Van Auken
An updated evaluation of the effects on predicted injuries of an example crush protective device (CPD) proposed for application to All-Terrain Vehicles (ATVs) is described. As in previous evaluations, this involved extending and applying the test and analysis methods defined in ISO 13232 (2005) for motorcycle impacts, to evaluate the effects of the example CPD in a sample of simulated ATV overturn events. Updated modeling refinements included lowering the energy levels of the simulated overturn events; accounting for potential mechanical/ traumatic (compressive) asphyxia mechanisms; refining and calibrating the force-deflection characteristics of helmet, head, legs and soil so as to reduce potential over-prediction of head and leg injuries; and calibrating the simulation against aggregated injury distributions from actual accidents.
2013-10-07
Technical Paper
2013-36-0389
Tadeu Miguel Malagó de Amaral, Anton Zeller, Edson Valdomiro de Azevedo, Fernando Jun Yoshino, Gisela Ablas Marques, Johnny Ossami Kagawa, Marcos Jose Dantas de Oliveira
Air cleaners are used in a wide range of automotive applications. From passenger cars to heavy duty trucks, there is always an air cleaner to keep inlet air free of impurities and air flow passage obstruction in low levels. Today's automotive air intake systems are developed to deliver maximum filtration efficiency, maximum dust holding capacity and maximum service interval range based on engine performance and reliability requirements [1]. In Brazil, some applications require outstanding performance for the air cleaners. One of them is at harvester application. In this case, vehicles are exposed to thin soil particles in high quantities due to harvester movement at plantation work. At the same time, engine performance needs to be kept during long journeys. According to this limitation, re-fuelling and components replacements are done direct at field. Any vehicle stop means lower productivity and more costs.
2013-09-24
Journal Article
2013-01-2411
Tatsuya Yoshida, Takayuki Koizumi, Nobutaka Tsujiuchi, ZhongMou Jiang, Yozo Nakamoto
Researches for automated construction machinery have been conducted for labor-saving, improved work efficiency and worker's safety, where a tracking control function was proposed as one of the key control system strategies for highly automated productive hydraulic excavators. An optimized digging trajectory that assures as much soils scooped as possible and less energy consumption is critical for an automated hydraulic excavator to improve work efficiency. Simulation models that we used to seek an optimized digging trajectory in this study consist of soil models and front linkage models of a hydraulic excavator. We developed two types of soil models. One is called wedge models used to calculate reaction forces from soils acting on a bucket during digging operation, based on the earth pressure theory. The other is called Distinct Element Method (DEM) model used to analyze soil behaviors and estimate amounts of soils scooped and reaction forces quantitatively.
2013-09-24
Journal Article
2013-01-2410
Tatsuya Yoshida, Takayuki Koizumi, Nobutaka Tsujiuchi, ZhongMou Jiang, Yozo Nakamoto
Researches for automation of hydraulic excavators have been conducted for laborsaving, improved efficiency of operations and increased worker's safety improvement. Authors' final goal is to develop automatic digging system which can realize the high efficiency. Therefore, it is thought that appropriate digging control algorithm is important for the automation. For this goal, this paper shows a dynamics model of the backhoe excavator and simulations using such models. Detailed dynamic models are needed from the point of view of the control engineering. Authors evaluate effectiveness of automatic digging algorithm by simulation models. In this research, the linkage mechanism which contains the closed loops is modeled based on the Newton-Euler formulation, where motion equation is derived. Moreover, we apply a soil model for simulation, based on the two dimensional distinct element method (DEM), in order to reproduce reaction force from grounds.
2013-09-24
Journal Article
2013-01-2384
Peter Jesson, Dongpu Cao
This study analyzes the power consumption of a specific Planetary Exploration Vehicle (PEV) subsystem known as Flexible-Wheel (FW) suspension, more specifically the interaction between a FW and the deformable terrain upon which it traverses. To achieve this a systematic and analytical calculation procedure has been developed, which culminates in the definition of three dimensionless properties to capture the FW-soil interaction. Aimed towards the design engineer participating in concept evaluation, and the control engineer conducting initial analyses, this study has found that the resistance coefficient for the interaction between a FW and the deformable terrain can, in general, be several orders of magnitude higher than the rolling resistance of a pneumatic tire operating upon rigid terrain.
2013-09-24
Journal Article
2013-01-2383
Antoni Pakowski, Dongpu Cao
This study analyzes the effect of soil deformation on ride dynamics of off-road vehicles using a quarter-vehicle model integrating different equivalent soil stiffness models. Soil deformation has an effect on the tire sinkage, wheels contact area and the wheels dynamic interaction with the terrain, which affects the overall ride dynamics of the vehicle. Apart from the very simplified equivalent soil stiffness model documented in the literature, a new equivalent soil stiffness model is developed in this study, which encompasses the effect of soil deformability on tire-soil contact area. Two measured ground roughness profiles are then used for vehicle ride dynamics simulation.
2013-04-08
Technical Paper
2013-01-0625
Ranvir S. Dhillon, Rustam Ali, Moustafa El-Gindy, David Philipps, Fredrik Oijer, Inge Johansson
Modern Finite Element Analysis (FEA) techniques allow for accurate simulation of various non-linear systems. However they are limited in their simulation of particulate matter. This research uses smooth particle hydrodynamics (SPH) in addition to FEA techniques to model the properties of soils, which allows for particle-level replication of soils. Selected soils are simulated in a virtual environment and validated using the pressure-sinkage and shear tests. A truck tire model is created based on standard heavy vehicle tires and validated using static deflection, contact footprint, and dynamic first mode of vibration tests. The validated tires and soils are used to create a virtual terrain and the tire is placed on the soil, loaded, and run over the soil at various speeds. The results of these simulations show that the SPH modeling technique offers higher accuracy than comparable FEA models for soft soils at a higher computational cost.
2013-04-08
Technical Paper
2013-01-0632
Hossam Ragheb, Moustafa El-Gindy, Hossam Kishawy
Off-road vehicle performance of a multi-wheeled 8×8 combat vehicle is strongly affected by the tire-terrain interaction characteristics. Soft soil reduces traction and modifies vehicle handling; therefore tire dynamics play a strong role in off-road mobility evaluation. In this paper three-dimensional, non-linear Finite Element Analysis (FEA) off-road tire models are developed using PAM-CRASH and the general trends of vertical load-deflection, cornering characteristics and aligning moment on rigid terrains are predicted and compared with published, measured data of a similar tire for validation purposes. The FEA off-road tire models are used to investigate the multi-pass behavior of the wheels running and steering on soft terrain. The steering characteristics of the multi-wheels are also predicted for the purpose of the development of tire-soft soil empirical equations for future research work.
2013-04-08
Technical Paper
2013-01-1197
Justin Madsen, Andrew Seidl, Dan Negrut
This paper discusses the development of a novel deformable terrain database and its use in a co-simulation environment with a multibody dynamics vehicle model. The implementation of the model includes a general tire-terrain traction model which is modular to allow for any type of tire model that supports the Standard Tire Interface[1] to operate on the terrain. This allows arbitrarily complex tire geometry to be used, which typically has a large impact on the mobility performance of vehicles operating on deformable terrains. However, this gain in generality comes at the cost that popular analytical pressure-sinkage terramechanics models cannot be used to find the normal pressure and shear stress of the contact patch. Pressure and shear stress are approximated by combining the contributions from tire normal forces, shear stresses and bulldozing forces due to soil rutting.
2013-04-08
Journal Article
2013-01-0459
Tatsuya Fukushima, Masafumi Shitamichi, Toshikazu Torigaki, Hidetoshi Sokusai, Masato Nishi, Takahiko Miyachi
FMVSS 226 will become effective on September 1, 2013 with the purpose of mitigating occupant ejections through the vehicle side windows. In order to use deployable counter measures to mitigate ejection, vehicle rollover tests are needed to design deployment algorithms for rollover condtions. Vehicle manufacturers have to define their own test procedures, because FMVSS 226 does not define any rollover test methods. The soil trip rollover test is a vehicle rollover test method in which a vehicle is propelled into a soil pool to measure its rollover characteristics. Some of difficulties in soil trip rollover tests include proper maintenance of soil, for example, under fluctuating humidity and homogeneity of soil in the pool, so as to ensure stable repeatability of test results. Protection of onboard measurement equipment in a test vehicle from soil incursion when the vehicle rolls over can also be a challenge.
2012-11-25
Technical Paper
2012-36-0610
Pedro Cobo, David Ibarra, Teresa Bravo, Jose Antonio Calvo, Carolina Alvarez, Alejandro Quesada, Jose Luis San Roman
Our research group is currently involved in the identification of aggressive drivers by means of the near field vehicle noise picked up by two onboard microphones, one for the rolling noise and another for the engine noise. We have demonstrated that aggressive drivers radiate to the near field noise levels 5-9 dB higher than the average of normal drivers [1]. In order to relate these near field measurements with the vehicle noise radiated to the far field, we must provide the corresponding extrapolation filter. This filter should contain the effects of geometrical spreading, air absorption and ground interaction. Whilst the first two are easily implemented taking into account soundly based international standards, the effect of the ground on the propagated sound from the near field to the far field depends on its intrinsic characteristics such as the type (local or extended reaction), layering and acoustical impedance of the soil.
Viewing 1 to 30 of 90

Filter