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Technical Paper

Optimisation of Process Parameters of EDM on Al6082/SiC Metal Matrix Composite

2016-04-05
2016-01-0533
In the present investigation AA6082/ SiC MMC composite is fabricated using electromagnetic stir casting technique. Silicon carbide (SiC) of 40 μm size is used as reinforcement and is varied by weight percentage as 0%, 2.5%, 5%, 7.5%, 10% in alloy AA6082. The microstructure of the fabricated composite is studied by scanning electron microscopy (SEM) which shows even distribution of the reinforcement. The mechanical properties improve with SiCp till 7.5%, after that the properties decreases which may be due to presence of porosity during the composite manufacturing. A comparative study of mechanical properties such as tensile strength, hardness and toughness has been done between the composite and base aluminium alloy. After the comparative study it was found that the composite having AA6082/SiC-92.5%/7.5% is best suited. So, it is used for optimization of Electrical Discharge Machining (EDM) process parameters using Taguchi’s design of experiment.
Technical Paper

Analytical Design and Development for Automobile Powertrain Mounts Using Low Fidelity Calculators

2016-02-01
2016-28-0185
The excitation to a vehicle is from two sources, road excitation and powertrain excitation. Vehicle Suspension is designed to isolate the road excitation coming to passenger cabin. Powertrain mounts play a vital role in isolating the engine excitation. The current study focuses on developing an analytical approach using Low-Fidelity computer programs to design the Powertrain Mount layout and stiffness during the initial stage of product development. Three programs have been developed as a part of this study that satisfy the packaging needs, NVH requirements and static load bearing requirements. The applications are capable of providing the Kinetic Energy Distribution and Static Analysis (Powertrain Enveloping and Mount Durability) for 3-point and 4-point mounting systems and the ideal mount positions and stiffness for 3-point mounting systems.
Technical Paper

Prediction of Wheel Forces and Moments and Their Influence to the Interior Noise

2016-06-15
2016-01-1834
This paper describes the prediction process of wheel forces and moments via indirect transfer path analysis, followed by an analysis of the influence of wheel variants and suspension modifications. It proposes a method to calculate transmission of noise to the vehicle interior where wheel forces and especially moments were taken into account. The calculation is based on an indirect transfer path analysis with geometrical modifications of the frequency response functions. To generate high quality broadband results, this paper also points out some of the main clearance cutting criteria. The method has been successfully implemented to show the influence of wheel tire combinations as well as the influence of suspension modifications. Case studies have been performed and will be presented in this paper. Operational noise and vibration measurements have been carried out on Daimler NVH test tracks. The frequency response functions were estimated in an acoustic laboratory.
Journal Article

Source Separations and Identification by Structural Holography

2016-06-15
2016-01-1798
The source field reconstruction aims at identifying the excitation field measuring the response of the system. In Near-field Acoustic Holography, the response of the system (the radiated acoustic pressure) is measured on a hologram using a microphones array and the source field (the acoustic velocity field) is reconstructed with a back-propagation technique performed in the wave number domain. The objective of the present works is to use such a technique to reconstruct displacement field on the whole surface of a plate by measuring vibrations on a one-dimensional holograms. This task is much more difficult in the vibratory domain because of the complexity of the equation of motion of the structure. The method presented here and called "Structural Holography" is particularly interesting when a direct measurement of the velocity field is not possible. Moreover, Structural Holography decreases the number of measurements required to reconstruct the displacement field of the entire plate.
Technical Paper

Relationship Between Driver Eyes-Off-Road Interval and Hazard Detection Performance Under Automated Driving

2016-04-05
2016-01-1424
Partially automated driving involves the relinquishment of longitudinal and/or latitudinal control to the vehicle. Partially automated systems, however, are fallible and require driver oversight to avoid all road hazards. Researchers have expressed concern that automation promotes extended eyes-off-road (EOR) behavior that may lead to a loss of situational awareness (SA), degrading a driver’s ability to detect hazards and make necessary overrides. A potential countermeasure to visual inattention is the orientation of the driver’s glances towards potential hazards via cuing. This method is based on the assumption that drivers are able to rapidly identify hazards once their attention is drawn to the area of interest regardless of preceding EOR duration. This work examined this assumption in a simulated automated driving context by projecting hazardous and nonhazardous road scenes to a participant while sitting in a stationary vehicle.
Technical Paper

Driving Style Identification Algorithm with Real-World Data Based on Statistical Approach

2016-04-05
2016-01-1422
This paper introduces a new method for driving style identification based on vehicle communication signals. The purpose of this method is to classify a trip, driven in a vehicle, into three driving style categories: calm, normal or aggressive. The trip is classified based on the vehicle class, the type of road it was driven on (urban, rural or motorway) and different types of driving events (launch, accelerating and braking). A representative set of parameters, selected to take into consideration every part of the driver-vehicle interaction, is associated to each of these events. Due to the usage of communication signals, influence factors, other than vehicle speed and acceleration (e.g. steering angle or pedals position), can be considered to determine the level of aggressiveness on the trip. The conversion of the parameters from physical values to dimensionless score is based on conversion maps that consider the road and vehicle types.
Technical Paper

Driver Demand: Eye Glance Measures

2016-04-05
2016-01-1421
This study investigated driver glances while engaging in infotainment tasks in a stationary vehicle while surrogate driving: watching a driving video recorded from a driver’s viewpoint and projected on a large screen, performing a lane-tracking task, and performing the Tactile Detection Response Task (TDRT) to measure attentional effects of secondary tasks on event detection and response. Twenty-four participants were seated in a 2014 Toyota Corolla production vehicle with the navigation system option. They performed the lane-tracking task using the vehicle’s steering wheel, fitted with a laser pointer to indicate wheel movement on the driving video. Participants simultaneously performed the TDRT and a variety of infotainment tasks, including Manual and Mixed-Mode versions of Destination Entry and Cancel, Contact Dialing, Radio Tuning, Radio Preset selection, and other Manual tasks. Participants also completed the 0-and 1-Back pure auditory-vocal tasks.
Journal Article

Reliability Evaluation of Thin, Lightweight Laminates for Windshield Applications

2016-04-05
2016-01-1398
The use of lightweight materials to produce automotive glazing is being pursued by vehicle manufacturers in an effort to improve fuel economy. As glazing’s become thinner, reduced rigidity means that the critical flaw size needed to create fracture becomes much smaller due to increased strain under load or impact. This paper documents experiments focused on the impact performance of several alternative thin laminate constructions under consideration for windshield applications (including conventional annealed soda-lime glass as well as laminates utilizing chemically strengthened glass), for the purpose of identifying new and unique failure modes that result from thickness reduction. Regulatory impact tests and experiments that focused on functional performance of laminates were conducted. Given the increased sensitivity to flaw size for thin laminates, controlled surface damage was introduced to parts prior to conducting the functional performance tests.
Technical Paper

Light Weight Structures - Structural Analysis for Weight Optimization and Joining Techniques of Dissimilar Materials

2016-04-05
2016-01-1394
Light weight structures give significant advantages to products in the Industrial sector. Component weight-saving plays a major role in improving the efficiency and performance of assembled systems. The introduction of lighter materials into products using dissimilar material joining techniques can create more weight savings and leads to lighter structures. Structural optimization is another method to optimize the material layout without affecting overall performance of the product. This paper discusses the methods to create lighter structures by the introduction of lighter materials in structures and structural optimization methods. Lighter materials are introduced in the structure using dissimilar material joining techniques. Joining processes such as thermal shrink-fit and mechanical press-fit are useful for metal to metal components. Similarly, adhesively bonded joints are useful for both metal and non-metal (plastics and composites) components.
Journal Article

Novel Retroreflective Micro-Optical Structure for Automotive Lighting Applications

2016-04-05
2016-01-1407
Retroreflective (RR) optical elements play a critical role in signaling, safety, and aesthetic/styling functionality of automotive lighting. The commonly-used inverted corner cube (ICC) RR structures with hexagonal aperture have several critical limitations that are primarily rooted in their manufacturing technique that involves complex assemblies/shapes of hexagonal pins and electroforms, particularly in case of freeform surfaces. This study introduces a novel RR micro-optical structure, namely: right triangular prism (RTP). The geometric model underlying this new geometry is defined as the intersection between a cube and a plane placed in a particular relative orientation with respect to each other. Following this, non-sequential optical simulation studies were performed analyzing the effect of incident light orientation. Advanced optical functionality of the RTP with a width of 450 μm was obtained as practically unattainable through conventional hexagonal pin-bundling technology.
Technical Paper

Future Requirements of Automotive Front Lighting

2016-04-05
2016-01-1406
Adaptive driving beam (ADB), which was first homologated in the ECE world (ECE 123) in 2012 has changed the automotive Front Lighting philosophy completely. Whereas we currently live with separate low beam and high beam features, also used in a combined way, we will have in the future a camera driven light distribution, which is a kind of modified high beam light pattern. ADB is a camera based lighting system, which enables the driver to achieve at night nearly high beam visibility without glaring oncoming or proceeding vehicles and road users. Once the presence of other vehicles is detected the headlamps change the light pattern and block the light where the oncoming or proceeding vehicles are located. The typical low beam light distribution with given and specified cutoff line will only be used in small speed areas. In US this development was well recognized and NHTSA is preparing a way to enable and approve the ADB systems with specific boundary conditions also for the US market.
Technical Paper

Statistical Tolerance Analysis of Flexible Assemblies with Contact Effects

2016-04-05
2016-01-1380
One of the most important characteristics of industrial products, especially mechanical set-ups, is considering the tolerances of production and assembly of these set-ups, which directly influences the products’ operations. In sheet metal structures, due to the high flexibility of the sheets, the errors appeared while assembly will be as highly influential as the errors due to the production tolerance of the sheets. As a result, having a comprehensive model which could analyze the assembly process of these structures and also clarifies the relation between the tolerance of the parts and the ultimate changes of the set-up will be of considerable importance. During the assembly process, the contact effect between the components is inevitable. If such effect is not considered, the contact surfaces will permeate. The purpose of this paper is to present a method to analyze the tolerance of flexible sheet structures, considering the contact effect between surfaces.
Journal Article

Enhanced Heat Transfer Coefficient (HTC) Method to Model Air Quench Process: HTC Patching for More Accurate FEA Temperature Calculation

2016-04-05
2016-01-1383
Air quenching is a common manufacturing process in automotive industry to produce high strength metal component by cooling heated parts rapidly in a short period of time. With the advancement of finite element analysis (FEA) methods, it has been possible to predict thermal residual stress by computer simulation. Previous research has shown that heat transfer coefficient (HTC) for steady air quenching process is time and temperature independent but strongly flow and geometry dependent. These findings lead to the development of enhanced HTC method by performing CFD simulation and extracting HTC information from flow field. The HTC obtained in this fashion is a continuous function over the entire surface. In current part of the research, two patching algorithms are developed to divide entire surface into patches according to HTC profile and each patch is assigned a discrete HTC value.
Technical Paper

Meshing Considerations for Automotive Shape Design Optimization

2016-04-05
2016-01-1388
High quality mesh generation technology coupled with a robust shape deformation technique enables large design space exploration for optimization without the need to remesh the geometry. To demonstrate this, we present a collection of best practices for cleaning complex analytic CAD data that together with a robust grid generation algorithm enable the automatic generation of high quality boundary layer resolved grids that retain their quality when morphed during the optimization process. The case study for this work is the DrivAer model developed by the Institute of Aerodynamics and Fluid Mechanics at the Technische Universität München. The first step in the proposed automated optimization framework is to use a technique called Solid Meshing to heal faults in the provided geometry and recover its original engineering intent.
Technical Paper

Track Bar Bracket Development with the Help of Advanced Optimization Techniques

2016-04-05
2016-01-1390
The advanced Optimization techniques help us in exploring the light weight architecture. This paper explains the process of designing a lightweight track bar bracket, which satisfies all durability performance targets. The mounting locations and load paths are critical factors that define the performance and help in the development of weight efficient structure. The process is to identify the appropriate bolt location through Design of Experiment (DOE) and topology based studies; followed by section and shape optimization that help to distribute material in a weight efficient manner across the structure. Load path study using topology optimization is performed to identify the load path for durability load cases. Further shape optimization is done using hyper study to determine the exact thickness of the webs and ribs. A significant weight reduction from the baseline structure is observed. This process may be applicable for all casting components.
Technical Paper

The Finite Element Analysis of Planetary Gear Pinion Shaft Staking

2016-04-05
2016-01-1358
During the planetary gear assembly, staking is a widely-used method for affixing pinion shafts onto the position. A reliable staking process not only prevents the movement of shaft during transmission operation, but also minimizes the distortion of the assembly due to the staking process. The quality of staking operations is determined by the component designs, the process parameters, and the staking tool geometry. It would be extremely time-consuming and tedious to evaluate these factors empirically; not even mention the requirement of prototypes in the early stage of a new program. A Finite Element methodology is developed to simulate the complete staking process including shaft press in, staking, and after staking tool release. The critical process parameters, such as staking force, staking length, shaft and holes interference amount, etc., are then evaluated systematically.
Journal Article

Fast Crank-Angle Based 0D Simulation of Combustion Engine Cold Tests including Manufacturing Faults and Production Spread

2016-04-05
2016-01-1374
During series production of modern combustion engines a major challenge is to ensure the correct operation of every engine part. A common method is to test engines in end-of-line (EOL) cold test stations, where the engines are not fired but tugged by an electric motor. In this work we present a physically based 0D model for dynamic simulation of combustion engines under EOL test conditions. Our goals are the analysis of manufacturing faults regarding their detectability and the enhancement of test procedures under varying environmental conditions. Physical experiments are prohibitive in production environments, and the simulative approach reduces them to a minimum. This model is the first known to the authors exploring advanced engine test methods under production conditions. The model supports a wide range of manufacturing faults (with adjustable magnitude) as well as error-free production spread in engine components.
Technical Paper

The Cyclic Strain Life Physical Test Correlation Using CAE

2016-04-05
2016-01-1369
Fatigue life predictions using the strain-life method are used in the design of modern light weight vehicle, for the complex loading that occur with the structural durability tests that these vehicles undergo. The accuracy of these predictions is dependent upon the many factors; geometry, loads & materials etc. This paper details a new procedure to ensure the quality and accuracy of the material parameters for the fatigue life prediction software. The material parameters for the solver are obtained by performing strain-controlled fatigue tests. The geometry of the coupons tested is determined by size and thickness of the material specimen that they are machined from and the loading regime in the test. Detailed data analyzed is conducted on these tests and the parameters that are used as input into the CAE strain-life fatigue prediction software are generated.
Journal Article

Identification of Vortical Structure that Drastically Worsens Aerodynamic Drag on a 2-Box Vehicle using Large-scale Simulations

2016-04-05
2016-01-1585
It is important to reduce aerodynamic drag for reducing fuel consumption. Conventionally reduction of aerodynamic drag has been carried out by shape optimization of each part of a vehicle based on the investigations of the time-averaged flows around the vehicle. However, the general tendency of drag reduction has been saturated recently and it is required to develop a new flow-control technique to achieve further reduction in aerodynamic drag. We therefore focus on the unsteadiness of the flow around a vehicle to achieve it because the aerodynamic drag of a vehicle fluctuates over time due to repetitions of generation, growth, merging and disappearance of various sizes of vortices around it. These vortices are formed by flow separations, for which the longitudinal coherent vortices inside turbulent boundary layers on vehicle surfaces are presumably playing an important role.
Journal Article

Suspension Variables Influencing Static Vehicle Wheel Alignment Measurements

2016-04-05
2016-01-1571
This paper is part of a bigger research effort that aims to capture the influences of static wheel alignment measurement accuracy for road going vehicles. Vehicle alignments can and often are the bottleneck in automotive and truck assembly lines and a greater understanding of the issues are very valuable. The alignment equipment in this research has been tuned and adjusted to minimize external variables and the team of authors have 300+ vehicle measurements. Of the many things that influence the accuracy and repeatability of vehicle suspension alignment measurement and adjustment, the measurement procedures can be the most significant. This includes but is not limited to alignment machine setup and vehicle tire pressures.
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