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Frame Structure Durability Development Methodology for Various Design Phases

FCA Engineereing India Pvt., Ltd.-Raghavendra Byali, Venkatesh Naik
FCA US LLC-Chandra Thandhayuthapani, Barry Lin, Jianghui Mao
  • Technical Paper
  • 2020-01-0196
To be published on 2020-04-14 by SAE International in United States
It is a challenging task to find an optimal design concept for a truck frame structure given the complexity of loading conditions, vehicle configurations, packaging and other requirements. In addition, there is a great emphasis on light weight frame design to meet stringent emission standards. This paper provides a framework for fast and efficient development of a frame structure through various design phases, keeping durability in perspective while utilizing various weight reduction techniques. In this approach frame weight and stiffness are optimized to meet strength and durability performance requirements.Fast evaluation of different frame configurations during the concept phase (I) was made possible by using DFSS (Design for Six Sigma) based system synthesis techniques. This resulted in a very efficient frame ladder concept selection process. Frame gauge optimization during the subsequent development phase (II) utilizing a newly developed damage based approach greatly reduced the number of design iterations relative to a typical stress based approach. In the light weighting phase (III) that followed, a method was established to effectively locate and optimize lightening holes using fatigue…
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Efficient Surrogate-based NVH Optimization of a Full Vehicle Using FRF Based Substructuring

Beta CAE Systems USA Inc.-Inseok Park
Oakland University-Dimitrios Papadimitriou
  • Technical Paper
  • 2020-01-0629
To be published on 2020-04-14 by SAE International in United States
The computer simulation with the Finite Element (FE) code for the structural dynamics becomes more attractive in the industry since it enables quickly evaluating the dynamic performances of the mechanical products like automobile in development with improved accuracy owing to modern technological advancements. However, it normally takes a prohibitive amount of computation time when design optimization is performed with conducting a dynamic analysis using a large-scale FE model many times. Exploiting Dynamic Structuring (DS) leads to alleviating the computational complexity since DS necessities iterative reanalysis of only the substructure(s) to be optimally designed. In this research, FRF Based Substructuring (FBS) is implemented to realize the benefits of DS for fast single- and multi-objective evolutionary design optimization. Also, Differential Evolution (DE) is first combined with two sorting approaches of NSGA-II and Infeasibility Driven Evolutionary Algorithm (IDEA) for effective constrained single- and multi-objective evolutionary optimization. The effectiveness of the proposed algorithm (NSGA-II/DE-IDEA) is verified using several test functions for constrained single- and multi-objective optimization. To circumvent the need for frequent time-consuming simulation runs, Kriging surrogate models are…
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Identifying the driving processes of Diesel spray injection through mixture fraction and velocity field measurements at ECN Spray A

Eindhoven University of Technology-Bart Somers
IFP Energies Nouvelles-Louis-Marie Malbec, Gilles Bruneaux
  • Technical Paper
  • 2020-01-0831
To be published on 2020-04-14 by SAE International in United States
Diesel spray mixture formation is investigated at target conditions using multiple diagnostics and laboratories. High speed Particle Image Velocimetry (PIV) is used to measure the velocity field inside and outside the jet simultaneously with a new frame straddling synchronisation scheme. The PIV measurements are carried out in the Engine Combustion Network Spray A target conditions, enabling direct comparisons with mixture fraction measurements previously performed in the same conditions, and forming a unique database at diesel conditions. A 1D spray model, based upon mass and momentum exchange between axial control volumes and near-Gaussian velocity and mixture fraction profiles is evaluated against the data. The 1D spray model quantitatively predicts the main spray characteristics (average mixture fraction and velocity fields) within the measurement uncertainty for a wide range of parametric variations, verifying that a Diesel spray becomes momentum controlled and has a Gaussian profile. A required input to the model is the jet angle, which is obtained experimentally. Although an expected result for a gas jet, this is the first time that combined datasets of velocity and…
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Chassis Lightweighting Hole Placement with Weldline Evaluation

Ford Motor Company-Gavin Song
  • Technical Paper
  • 2020-01-0493
To be published on 2020-04-14 by SAE International in United States
Vehicle weight driven design comes amid rising higher fuel efficiency standard, and must meet the criteria - pass Proving ground test events that is equivalent customer usage. CAE Fatigue analysis for proving ground (CFP) is behind a success push to digitally simulate vehicle durability performance in high fidelity. The need for vehicle weight reduction often arises late in vehicle development phases when CAE Methods, time, and tangible cost effective opportunities are limited or non-existent. It is necessary to deploy a new CAE Method to identify opportunities for light-weighting hole placement in Chassis structures to deliver a cost effective light-weighting opportunity with no impact on fatigue life. The successful application of this methodology is on truck frame, which is key structural parts for vehicle chassis to support body and suspension and powertrain. By means of artificially adjusting the magnitude of load time history and material fatigue properties S-N curve, fatigue life calculation can highlight potential areas for lightweighting holes. Weldline fatigue is further carried on to verify the impact from those lighting holes.
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Impact of Rim Orientation on Road Vehicles Aerodynamics Simulations

Graz University of Technology-Wolfgang von der Linden, Günter Brenn
Magna Steyr Fahrzeugtechnik AG & Co KG-Gernot Bukovnik
  • Technical Paper
  • 2020-01-0674
To be published on 2020-04-14 by SAE International in United States
Aerodynamic CFD simulations in the automotive industry based on the steady-state RANS (Reynolds-averaged Navier–Stokes) approach typically utilize approximate numerical methods to account for rotating wheels. In these methods, the computational mesh representing the rim geometry remains stationary, and the influence of the wheel rotation on the air flow is modelled. As the rims are considered only in one fixed rotational position (chosen arbitrarily in most cases), the effects of the rim orientation on the aerodynamic simulation results are disregarded and remain unquantified. This paper presents a numerical sensitivity study to examine the impact of the rim orientation position on the aerodynamic parameters of a detailed production vehicle. The simulations are based on the steady-state RANS approach. These investigations are carried out for three rim geometries, and for simulation cases with stationary and rotating wheels for comparison, where the Moving Wall (MW) and the Moving Reference Frame (MRF) methods, as well as combinations of the two approaches are used to model the wheel rotation. For the test vehicle, alterations in the flow field, and subsequently an…
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Current control method for asymmetric dual three-phase Permanent Magnet Synchronous Motor

Tongji University-Zhihong Wu, Weisong Gu, Yuan Zhu, Ke Lu
  • Technical Paper
  • 2020-01-0470
To be published on 2020-04-14 by SAE International in United States
Based on the vector space decomposition (VSD) transformation, the phase currents of the asymmetric dual three phase permanent magnet synchronous motor (ADT-PMSM) can be mapped into three orthogonal subspaces, i.e., α–β subspace, x-y subspace and O1-O2 subspace. The mechanical energy conversion takes place in the α–β subspace, while in the x-y and O1-O2 subspaces only losses are produced. With neutral points being isolated, O1-O2 subspace can be omitted. So the vector control algorithm can control the α–β and x-y subspaces separately to realize the four dimensional current control. In the α–β subspace, deviation decoupling control method is employed to realize the mechanical energy conversion, which is robust to the motor parameters. In order to reduce the 5th and 7th harmonic currents caused by the inverter nonlinearity and some other factors, a resonant controller is adopted based on a new synchronous rotating coordinate transformation matrix to implement the current closed loop control strategy in the x-y subspace. The resonant controller can track sinusoidal references of arbitrary frequencies of both positive and negative sequences with zero steady-state…
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Mobile Robot Localization Evaluations with Visual Odometry in Varying Environments using Festo-Robotino

German Jordanian University-Abdallah Abdo, Randa Ibrahim
Michigan Technological University-Nathir A. Rawashdeh
  • Technical Paper
  • 2020-01-1022
To be published on 2020-04-14 by SAE International in United States
Autonomous ground vehicles can use a variety of techniques to navigate the environment and deduce their motion and location from sensory inputs. Visual Odometry can provide a means for an autonomous vehicle to gain orientation and position information from camera images recording frames as the vehicle moves. This is especially useful when global positioning system (GPS) information is unavailable, or wheel encoder measurements are unreliable. Feature-based visual odometry algorithms extract corner points from image frames, thus detecting patterns of feature point movement over time. From this information, it is possible to estimate the camera, i.e. the vehicle’s motion. Visual odometry has its own set of challenges, such as detecting an insufficient number of points, poor camera setup, and fast passing objects interrupting the scene. This paper investigates the effects of various disturbances on visual odometry. Moreover, it discusses the outcomes of several experiments performed utilizing the Festo-Robotino robotic platform. The experiments are designed to evaluate how changing the system’s setup will affect the overall quality and performance of an autonomous driving system. Environmental effects such…
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Wake study on isolated, detailed and rotating car wheels

Audi AG-Lukas Haag, Vincent Zander
Technische Universitat Munchen-Jan Reiß, Jonas Sebald, Thomas Indinger
  • Technical Paper
  • 2020-01-0686
To be published on 2020-04-14 by SAE International in United States
Wheels on passenger vehicles cause about 25% of the aerodynamic drag. The interference of rims and tires in combination with the rotation result in strongly turbulent wake regions with complex flow phenomena. This wake structures interact with the flow around the vehicle. To understand the wake structures of wheels and their aerodynamic impact on the aerodynamic drag of the vehicle, the complexity was reduced by investigating a standalone tire in the windtunnel. Besides the influence of geometry changes on the acting forces, the wake region behind the wheel is investigated via Particle Image Velocimetry (PIV). The average flow field behind the investigated wheels is captured with this method and offers insight into the flow field. The investigation of the wake region allows to attribute changes in the flow field to the change of tires and rims. Due to increased calculation performance sophisticated CFD simulations can capture detailed geometries like the tire tread and the movement of the rim. Therefore, the wake investigation via PIV is a usable basis to compare it to results of such…
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Study of skid steering method for distributed-drive articulated heavy vehicle based on the co-simulation model

Tsinghua University-Tao Xu, Xuewu Ji, Cong Fei, Yanhua Shen
University of Science and Technology Beijing-Yahui Liu
  • Technical Paper
  • 2020-01-0761
To be published on 2020-04-14 by SAE International in United States
Distributed-driver articulated steering vehicles (DASVs), the particular engineering equipment, have good maneuverability and tractability in poor road and narrow space conditions. They are always used in the mining, construction, forest, and agricultural industry. Its structure comprise front and rear frame connected by an articulation joint and two hydraulic struts. In the steering process, these two struts are driven by pump of hydraulic system, and the vehicle will turn following the control of steering wheel with the coupling effects of articulation joint and struts. But due to the high load of the DASVs, the influence of pressure of outlet chamber, and the compressible of the oil, it is easy to cause the high pressure level, the low energy efficiency, and poor stability in hydraulic steering process. This is not conducive to improving the security, economy, and stability of DASVs. Therefore, in order to solve these problems, this paper will make the DASVs as the objective vehicle, and take full advantage of its independent driving method to study the novel skid steering mode. Combining with the discussions…
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DEVELOPMENT OF AN EPOXY CARBON FIBER REINFORCED ROOF FRAME USING THE HIGH PRESSURE RESIN TRANSFER MOLDING (HP-RTM) PROCESS

Hexion Inc.-Cedric A. Ball, Stephen Greydanus, Ian Swentek, Kameswara Rao Nara
  • Technical Paper
  • 2020-01-0773
To be published on 2020-04-14 by SAE International in United States
Composites technology for the automotive market continues to advance rapidly. Increasing knowledge of composite design, simulation tools, new materials and process equipment are all contributing to make composites better performing and more affordable for mass-produced vehicles. In particular, the high pressure resin transfer molding (HP-RTM) and related liquid compression molding (LCM) processes are enabling manufacturers to produce complex composite parts at shorter and shorter cycle times. This paper describes the development of an epoxy carbon fiber roof frame targeted for future vehicle production. Several composite processes were considered for the roof frame. The case illustrates that when the (product) design, material and process are considered together, a high-performing, cost-efficient part can be produced. The resulting carbon fiber roof frame met all OEM performance requirements and economic targets while weighing 44% less than the original design in magnesium and 32% less on the overall assembly. The part was the first HP-RTM part successfully demonstrated in North America and stands as a model for future lightweighting developments. Of equal significance, the development process for the part involved…