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Viewing 31 to 60 of 15919
2017-06-05
Technical Paper
2017-01-1814
Todd Tousignant, Kiran Govindswamy, Vikram Bhatia, Shivani Polasani, W Keith Fisher
Abstract The automotive industry continues to develop technologies for reducing vehicle fuel consumption. Specifically, vehicle lightweighting is expected to be a key enabler for achieving fleet CO2 reduction targets for 2025 and beyond. Hybrid glass laminates that incorporate fusion draw and ion exchange innovations are thinner and thereby, offer more than 30% weight reduction compared to conventional automotive laminates. These lightweight hybrid laminates provide additional benefits, including improved toughness and superior optics. However, glazing weight reduction leads to an increase in transmission of sound through the laminates for certain frequencies. This paper documents a study that uses a systematic test-based approach to understand the sensitivity of interior vehicle noise behavior to changes in acoustic attenuation driven by installation of lightweight glass.
2017-06-05
Journal Article
2017-01-1813
James M. Jonza, Thomas Herdtle, Jeffrey Kalish, Ronald Gerdes, Taewook Yoo, Georg Eichhorn
Abstract The aerospace industry has employed sandwich composite panels (stiff skins and lightweight cores) for over fifty years. It is a very efficient structure for rigidity per unit weight. For the automobile industry, we have developed novel thermoplastic composite panels that may be heated and shaped by compression molding or thermoforming with cycle times commensurate with automotive manufacturing line build rates. These panels are also readily recycled at the end of their service life. As vehicles become lighter to meet carbon dioxide emission targets, it becomes more challenging to maintain the same level of quietness in the vehicle interior. Panels with interconnected honeycomb cells and perforations in one skin have been developed to absorb specific noise frequencies. The absorption results from a combination and interaction of Helmholtz and quarter wave resonators.
2017-06-05
Journal Article
2017-01-1816
Mahsa Asgarisabet, Andrew Barnard
Abstract Carbon Nanotube (CNT) thin film speakers produce sound with the thermoacoustic effect. Alternating current passes through the low heat capacity CNT thin film changing the surface temperature rapidly. CNT thin film does not vibrate; instead it heats and cools the air adjacent to the film, creating sound pressure waves. These speakers are inexpensive, transparent, stretchable, flexible, magnet-free, and lightweight. Because of their novelty, developing a model and better understanding the performance of CNT speakers is useful in technology development in applications that require ultra-lightweight sub-systems. The automotive industry is a prime example of where these speakers can be enabling technology for innovative new component design. Developing a multi-physics (Electrical-Thermal-Acoustical) FEA model, for planar CNT speakers is studied in this paper. The temperature variation on the CNT thin film is obtained by applying alternating electrical current to the CNT film.
2017-06-05
Technical Paper
2017-01-1815
Pranab Saha, Satyajeet P. Deshpande
Abstract This paper discusses the importance of a dissipative sound package system in the automotive industry and how it works. Although this is not a new technique at this stage, it is still a challenge to meet the subsystem target levels that were originally developed for parts based on the barrier decoupler concept. This paper reviews the typical construction of a dissipative system and then emphasizes the importance of different layers of materials that are used in the construction, including what they can do and cannot do. The paper also discusses the importance of the proper manufacturing of a part.
2017-06-05
Technical Paper
2017-01-1817
Steven M. Gasworth, Vasudev Nilajkar, Matteo Terragni
Abstract Polycarbonate (PC) glazing as a one-for-one glass replacement offers a 50% weight reduction, but exhibits several dB lower sound transmission loss (STL) in the low frequency range where tire and engine noise are dominant. In the high frequency range where wind noise is dominant, PC glazing offers an STL at least comparable to its glass counterpart, and an STL exceeding glass when this frequency range encompasses the glass coincidence frequency. However, a key value proposition of PC glazing is the opportunity for feature integration afforded by the injection molding process generally used for forming such glazing. Two-component (2K) molding fuses a second shot of plastic material behind, and along the perimeter of, the transparent PC first shot. This second shot can incorporate features and implement functions that require additional components attached or peripheral to a glass version.
2017-04-11
Journal Article
2017-01-9177
N. Obuli Karthikeyan, R. Dinesh Kumar, V. Srinivasa Chandra, Vela Murali
Abstract In the modern automotive sector, durability and reliability are the most common terms. Customers are expecting a highly reliable product but at low cost. Any product that fails within its useful life leads to customer dissatisfaction and affects the reputation of the OEM. To eradicate this, all automotive components undergo stringent validation protocol, either in proving ground or in lab. This paper details on developing an accelerated lab test methodology for steering gearbox bracket using fatigue damage and reliability correlation by simulating field failure. Initially, potential failure causes for steering gearbox bracket were analyzed. Road load data was then acquired at proving ground and customer site to evaluate the cumulative fatigue damage on the steering gearbox bracket. To simulate the field failure, lab test facility was developed, reproducing similar boundary conditions as in vehicle.
2017-04-11
Journal Article
2017-01-9452
Wenfeng Zhu, Chunyu LI, Yao Zhong, Peijian Lin
Abstract Automotive window seal has great influence on NVH (Noise-Vibration-Harshness) performance. The aerodynamic effect on ride comfort has attracted increasing research interest recently. A new method for quantifying and transferring aerodynamics-induced load on window seal re-design is proposed. Firstly, by SST (Shear Stress Transport) turbulence model, external turbulent flow field of full scale automotive is established by solving three-dimensional, steady and uncompressible Navier-Stokes equation. With re-exploited mapping algorithm, the aerodynamics pressure on overall auto-body is retrieved and transferred to local glass area to be external loads for seals, thus taking into account the aerodynamics effect of high speed fluid-structure interaction. This method is successfully applied on automotive front window seal design. The re-design header seal decreases the maximum displacements of leeward and windward glass with 9.3% and 34.21%, respectively.
2017-04-11
Journal Article
2017-01-9451
Marouen Hamdi, Drew Manica, Hung-Jue Sue
Abstract Brightness, transparency, and color impact critically the aesthetics of polymeric surfaces. They can significantly change the perception of common damages such as scratch and mar. Particularly, subtle mar damage is more dependent on surface perceptual properties. In this study, we investigate the impact of these attributes on scratch and mar visibility resistance of commercialized polymeric model systems frequently used in automotive industry. Twenty subjects were involved in a psychophysical test based on pairwise comparison, and results were treated using multidimensional scaling (MDS) analysis. A tied ordinal weighted Euclidian MDS model was used to visualize the relational structures of mar perception space. Results show that scratch visibility resistance tends to decrease with dark, more transparent, and green surfaces. Mar perception was reasonably conceptualized by a two-dimensional MDS space.
2017-03-28
Technical Paper
2017-01-0175
Jing He, Bill Johnston, Debasish Dhar, Loren Lohmeyer
The natural refrigerant, R744 (CO2), remains a viable solution to replace the high GWP refrigerant R134a which is to be phased out in light-duty vehicles in EU and US market. In this study, thermodynamic analysis is performed on a R744 parallel compression system to evaluate its potential in automotive climate control. The model adopts a correlation of isentropic efficiency as a function of compression ratio based on a prototype R744 MAC compressor and accounts for the operating limits defined in the latest DIN specifications. Optimization is run over typical MAC operating conditions which covers both transcritical and subcritical domain. Comparing to the conventional single compression cycle, effectiveness of parallel compression is found most pronounced in low evaporating temperature and high ambient conditions, with up to 21% increase in COP and 5.3 bar reduction in discharge pressure observed over the considered parametric range.
2017-03-28
Technical Paper
2017-01-0174
Ravi Rungta, Noori Pandit
Abstract A simple and rapid immersion type corrosion test has been successfully developed that discriminates corrosion performance in condensers from various suppliers and with differing manufacturing processes. The goal is to develop a test specification that will be included in the Ford corrosion specification for condensers so that condensers received from various suppliers may be evaluated rapidly for their relative corrosion performance to each other. Sections from condensers from Supplier A (tube is silfluxed), Supplier B (tube is zinc arc sprayed), and Supplier C (bare folded tube with no zinc for corrosion protection) were tested in 2% v/v hydrochloric acid for 16, 24 and 48 hours. The results showed that in terms of corrosion performance, zinc arc sprayed Supplier B condenser performed the worst while Supplier C condenser performed the best with Supplier A in between.
2017-03-28
Technical Paper
2017-01-0177
Lili Feng, Predrag Hrnjak
Abstract This paper presents the study of refrigerant charge imbalance between A/C (cooling) mode and HP (heating) mode of a mobile reversible system. Sensitivities of cooling and heating capacity and energy efficiency with respect to refrigerant charge were investigated. Optimum refrigerant charge level for A/C mode was found to be larger than that for HP mode, primarily due to larger condenser size in A/C mode. Refrigerant charge retention in components at both modes were measured in the lab by quick close valve method. Modeling of charge retention in heat exchangers was compared to experimental measurements. Effect of charge imbalance on oil circulation was also discussed.
2017-03-28
Technical Paper
2017-01-0150
Ankit Kumar Shukla, Raj Dhami, Aashish Bhargava, Sanjay Tiwari
Abstract In the current landscape of commercial vehicle industry, fuel economy is one of the major parameter for fleet owner’s profitability as well as greenhouse gasses emission. Less fuel efficiency results in more fuel consumption; use of conventional fuel in engines also makes environment polluted. The rapid growth in fuel prices has led to the demand for technologies that can improve the fuel efficiency of the vehicle. Phase change material (PCMs) for Thermal energy storage system (TES) is one of the specific technologies that not only can conserve energy to a large extent but also can reduce emission as well as the dependency on convention fuel. There is a great variety of PCMs that can be used for the extensive range of temperatures, making them attractive in a number of applications in automobiles.
2017-03-28
Technical Paper
2017-01-0184
Miyoko Oiwake, Ozeki Yoshiichi, Sogo Obata, Hideaki Nagano, Itsuhei Kohri
Abstract In order to develop various parts and components for hybrid electric vehicles, understanding the effect of their structure and thermal performance on their fuel consumption and cruising distance is essential. However, this essential information is generally not available to suppliers of vehicle parts and components. In this report, following a previous study of electric vehicles, a simple method is proposed as the first step to estimate the algorithm of the energy transmission and then the cruising performance for hybrid electric vehicles. The proposed method estimates the cruising performance using only the published information given to suppliers, who, in general, are not supplied with more detailed information. Further, an actual case study demonstrating application of the proposed method is also discussed.
2017-03-28
Technical Paper
2017-01-0125
Marco Pizzi, Mauro Zorzetto, Alberto Barbano, Piercarlo Merlano, Luca Vercellotti
Abstract The emission reduction in gasoline and diesel engines is driving the introduction of systems implementing additives in liquid form: in particular water for injection systems in gasoline engines and urea solutions (AD-blue) in SCR (Selective Catalytic Reduction) systems in diesel engines. Owing to water and AD-Blue can freeze in the car operative temperature range, the tanks must be equipped with heaters to guarantee a sufficient amount of additives in liquid form. Currently used technologies are ceramic PTC (Positive Temperature Coefficient) elements and distributed metal resistors. Ceramic PTC based heaters concentrate all the power in small volumes. They need thermally conductive elements distributing the power over a wide area. The assembly is complex and the cost of the metal parts and related packaging technologies used to insulate the heater from the environment (water or urea) is typically high. Metal resistors are cheaper but must be controlled in current.
2017-03-28
Technical Paper
2017-01-0164
Venkatesan Muthusamy, S. Sathish Kumar, Saravanan Sambandan
Abstract In an automotive air-conditioning (AC) system, upfront prediction of the cabin cool down rate in the initial design stage will help in reducing the overall product development (PD) time. Vehicle having higher seating capacity will have higher thermal load and providing thermal comfort to all passengers uniformly is a challenging task for the automotive HVAC (Heating Ventilation and Air conditioning) industry. Dual HVAC unit is generally used to provide uniform cooling to a large cabin volume. One dimensional (1D) simulation is being extensively used to predict the HVAC performance during the initial stage of PD. The refrigerant loop with components such as compressor, condenser, TXV and evaporator was modeled. The complicated vehicle cabin including the glazing surfaces and enclosures were modeled as a three row duct system using 1D tool AMESim®. The material type, density, specific heat capacity and thermal conductivity of the material were specified.
2017-03-28
Technical Paper
2017-01-0121
Zhijia Yang, Jesus PradoGonjal, Matthew Phillips, Song Lan, Anthony Powell, Paz Vaqueiro, Min Gao, Richard Stobart, Rui Chen
Abstract Thermoelectric generator (TEG) has received more and more attention in its application in the harvesting of waste thermal energy in automotive engines. Even though the commercial Bismuth Telluride thermoelectric material only have 5% efficiency and 250°C hot side temperature limit, it is possible to generate peak 1kW electrical energy from a heavy-duty engine. If being equipped with 500W TEG, a passenger car has potential to save more than 2% fuel consumption and hence CO2 emission reduction. TEG has advantages of compact and motionless parts over other thermal harvest technologies such as Organic Rankine Cycle (ORC) and Turbo-Compound (TC). Intense research works are being carried on improving the thermal efficiency of the thermoelectric materials and increasing the hot side temperature limit. Future thermoelectric modules are expected to have 10% to 20% efficiency and over 500°C hot side temperature limit.
2017-03-28
Journal Article
2017-01-0122
Gursaran D. Mathur
Water drainage characteristics are dependent on the design of the evaporator: specifically the design of the fins and plates along with hydrophilic coating. A part of the hydrophilic coating washes off with the moisture that condenses over the evaporator core from the air-stream. Hence, water drainage characteristics of an evaporator changes with the vehicle mileage or the age of the vehicle. Since a part of the hydrophilic coating washes away, more water is retained within the evaporator at this condition. Hence, the effectiveness of the evaporator drainage deteriorates with the age of the vehicles. At this condition, the contact angle measured at the plate increases. Author has conducted an experimental study to measure the effectiveness of hydrophilic coating from evaporators taken out from arid (9 cores) and humid areas (16 cores) as a function of vehicle mileage or vehicle age. Contact angles and water retention were measured for a number of evaporators from different OEMs.
2017-03-28
Technical Paper
2017-01-0172
Suhas Venkatappa, Manfred Koberstein, Zhengyu Liu
Abstract The refrigerant transition from HFC-134a to HFO-1234yf has proven to be more challenging on controlling refrigerant flow-induced noises generated from automotive air-conditioning (A/C) systems than originally anticipated. The objectives of this paper are to describe the noise issues with HFO-1234yf, understand the mechanisms and key factors affecting HFO-1234yf refrigerant flow-induced noise. Finally, the countermeasures and guidelines for attenuating and suppressing the noise are presented.
2017-03-28
Technical Paper
2017-01-0173
Stephen Andersen, Sourav Chowdhury, Timothy Craig, Sangeet Kapoor, Jagvendra Meena, Prasanna Nagarhalli, Melinda Soffer, Lindsey Leitzel, James Baker
Abstract This paper quantifies and compares the cooling performance and refrigerant and fuel cost savings to automobile manufacturers and owners of secondary-loop mobile air conditioners (SL-MACs) using refrigerants hydrofluorocarbon (HFC)-134a and the available alternatives HFC-152a and HFO-1234yf. HFC-152a and HFO-1234yf are approved for use by the United States Environmental Protection Agency (US EPA) and satisfy the requirements of the European Union (EU) F-Gas Regulations. HFC-152a is inherently more energy efficient than HFC-134a and HFO-1234yf and in SL-MAC systems can generate cooling during deceleration, prolong comfort during idle stop (stop/start), and allow powered cooling at times when the engine can supply additional power with the lowest incremental fuel use. SL-MAC systems can also reduce the refrigerant charge, emissions, and service costs of HFO-1234yf.
2017-03-28
Technical Paper
2017-01-0167
Steven Lambert, William Jamo, Mike Kurtz
Abstract The failure of an A/C system often results in the introduction of contaminants to the A/C system. The sources of the contaminants include debris from damaged components and debris from the surrounding environment. Returning the A/C system to service requires the removal of these contaminants from any reused components. The recommended approach to cleaning contaminated components and systems is to flush with a solvent flushing machine. Previous internal studies have concluded that solvent flushing will remove all contaminants, restoring component and system performance. Many commercial refrigerant recovery and recharge machines include a refrigerant “flush” feature which can flush oil from the system and components with the systems refrigerant. The effectiveness of using the “flush” feature of a refrigerant recovery and recharge machine with an added in-line filter to remove contaminants is investigated.
2017-03-28
Journal Article
2017-01-0223
Haolong Liu, Weidong Wen, Xuming Su, Carlos Engler-Pinto, HongTae Kang
Abstract Morphological features of voids were characterized for T300/924 12-ply and 16-ply composite laminates at different porosity levels through the implementation of a digital microscopy (DM) image analysis technique. The composite laminates were fabricated through compression molding. Compression pressures of 0.1MPa, 0.3MPa, and 0.5MPa were selected to obtain composite plaques at different porosity levels. Tension-tension fatigue tests at load ratio R=0.1 for composite laminates at different void levels were conducted, and the dynamic stiffness degradation during the tests was monitored. Fatigue mechanisms were then discussed based on scanning electron microscope (SEM) images of the fatigue fracture surfaces. The test results showed that the presence of voids in the matrix has detrimental effects on the fatigue resistance of the material, depending on the applied load level.
2017-03-28
Journal Article
2017-01-0230
Louise A. Powell, William E. Luecke, Matthias Merzkirch, Katherine Avery, Tim Foecke
Abstract The introduction of carbon fiber reinforced polymer (CFRP) composites to structural components in lightweight automotive structures necessitates an assessment to evaluate that their crashworthiness dynamic response provides similar or higher levels of safety compared to conventional metallic structures. In order to develop, integrate and implement predictive computational models for CFRP composites that link the materials design, molding process and final performance requirements to enable optimal design and manufacturing vehicle systems for this study, the dynamic mechanical response of unidirectional (UD) and 2x2 twill weave CRFP composites was characterized at deformation rates applicable to crashworthiness performance. Non-standardized specimen geometries were tested on a standard uniaxial frame and an intermediate-to-high speed dynamic testing frame, equipped with high speed cameras for 3D digital image correlation (DIC).
2017-03-28
Journal Article
2017-01-0229
Hongyi Xu, Yang Li, Danielle Zeng
Abstract Process integration and optimization is the key enabler of the Integrated Computational Materials Engineering (ICME) of carbon fiber composites. In this work, automated workflows are developed for two types of composites: Sheet Molding Compounds (SMC) short fiber composites, and multi-layer unidirectional (UD) composites. For SMC, the proposed workflow integrates material processing simulation, microstructure representation volume element (RVE) models, material property prediction and structure preformation simulation to enable multiscale, multidisciplinary analysis and design. Processing parameters, microstructure parameters and vehicle subframe geometry parameters are defined as the design variables; the stiffness and weight of the structure are defined as the responses. For multi-layer UD structure, this work focuses on the discussion of different design representation methods and their impacts on the optimization performance.
2017-03-28
Journal Article
2017-01-0228
Yang Li, Zhangxing Chen, Hongyi Xu, Jeffrey Dahl, Danielle Zeng, Mansour Mirdamadi, Xuming Su
Abstract Compression molded SMC composed of chopped carbon fiber and resin polymer which balances the mechanical performance and manufacturing cost presents a promising solution for vehicle lightweight strategy. However, the performance of the SMC molded parts highly depends on the compression molding process and local microstructure, which greatly increases the cost for the part level performance testing and elongates the design cycle. ICME (Integrated Computational Material Engineering) approaches are thus necessary tools to reduce the number of experiments required during part design and speed up the deployment of the SMC materials. As the fundamental stage of the ICME workflow, commercial software packages for SMC compression molding exist yet remain not fully validated especially for chopped fiber systems. In the present study, SMC plaques are prepared through compression molding process.
2017-03-28
Technical Paper
2017-01-0227
Omar Al-Shebeeb, Bhaskaran Gopalakrishnan
Abstract Process planning, whether generative or variant, can be used effectively as through the incorporation of computer aided tools that enhance the evaluator impact of the dialogue between the design and manufacturing functions. Expert systems and algorithms are inherently incorporated into the software tools used herein. This paper examines the materials related implications that influence design for manufacturing issues. Generative process planning software tools are utilized to analyze the sensitivity of the effectiveness of the process plans with respect to changing attributes of material properties. The shift that occurs with respect to cost and production rates of process plans with respect to variations in specific material properties are explored. The research will be analyzing the effect of changes in material properties with respect to the design of a specific product that is prismatic and is produced exclusively by machining processes.
2017-03-28
Journal Article
2017-01-0225
Gabriela Guerra, Ulises Figueroa-López, Andrea Guevara-Morales
Abstract The rapid growth of the emerging markets has pushed the automotive original equipment manufacturers to relocalize production to reduce manufacturing and logistic costs. To ensure an efficient and flexible supply chain, local suppliers are appointed. However, the characteristics of materials available in each region may have minor differences, and when geometry and process design recommendations that were developed for certain materials are implemented for materials under a different regional standard, different results are obtained. Such is the case of the clutch disc spacer bolt, in which its compression during riveting has a direct effect in the noise and vibration isolation of the vehicle.
2017-03-28
Technical Paper
2017-01-0226
Vesna Savic, Louis Hector, Ushnish Basu, Anirban Basudhar, Imtiaz Gandikota, Nielen Stander, Taejoon Park, Farhang Pourboghrat, Kyoo Sil Choi, Xin Sun, Jun Hu, Fadi Abu-Farha, Sharvan Kumar
Abstract This paper presents development of a multi-scale material model for a 980 MPa grade transformation induced plasticity (TRIP) steel, subject to a two-step quenching and partitioning heat treatment (QP980), based on integrated computational materials engineering principles (ICME Model). The model combines micro-scale material properties defined by the crystal plasticity theory with the macro-scale mechanical properties, such as flow curves under different loading paths. For an initial microstructure the flow curves of each of the constituent phases (ferrite, austenite, martensite) are computed based on the crystal plasticity theory and the crystal orientation distribution function. Phase properties are then used as an input to a state variable model that computes macro-scale flow curves while accounting for hardening caused by austenite transformation into martensite under different straining paths.
2017-03-28
Technical Paper
2017-01-0224
Zhangxing Chen, Yi Li, Yimin Shao, Tianyu Huang, Hongyi Xu, Yang Li, Wei Chen, Danielle Zeng, Katherine Avery, HongTae Kang, Xuming Su
Abstract To advance vehicle lightweighting, chopped carbon fiber sheet molding compound (SMC) is identified as a promising material to replace metals. However, there are no effective tools and methods to predict the mechanical property of the chopped carbon fiber SMC due to the high complexity in microstructure features and the anisotropic properties. In this paper, a Representative Volume Element (RVE) approach is used to model the SMC microstructure. Two modeling methods, the Voronoi diagram-based method and the chip packing method, are developed to populate the RVE. The elastic moduli of the RVE are calculated and the two methods are compared with experimental tensile test conduct using Digital Image Correlation (DIC). Furthermore, the advantages and shortcomings of these two methods are discussed in terms of the required input information and the convenience of use in the integrated processing-microstructure-property analysis.
2017-03-28
Technical Paper
2017-01-0255
Malli Kartheek Yalamanchili, Nitin Sharma, Kevin Thomson
Abstract The crashworthiness of body-in-white (BIW) plays a vital role in full vehicle crash performance. The structural integrity of BIW is controlled via strength of the spot welds and adhesives that are the primary entities to join sheet metal. The number of welds and amount of adhesives in the entire BIW directly affects the cost and the cycle time of the BIW; which makes them a good candidate for optimization. However optimization of the welds and/or adhesives not only reduces the number of connections but also provides the opportunity to improve the structural performance and mass saving by placing them optimally for the structural responses. This paper discusses the optimization of full vehicle structural performance for the small overlap crash event using the length of adhesives in the BIW as parameters. Included in the study were length of the adhesives and gage variables, defined in the front-end structure of the vehicle.
2017-03-28
Technical Paper
2017-01-0254
Sudeep Chavare, Kevin Thomson, Nitin Sharma
Abstract Use of parametric approach to optimize CAE models for various objectives is a common practice these days. In addition to load members, the connection entities such as welds and adhesives play an important role in overall performance matrix. Hence adding the connection entities to the pool of design variables during an optimization exercise provide additional opportunity for design exploration. The method presented in this paper offers a unique approach to parameterize adhesive lines by evaluating the possibility of using structural adhesives as intermittent patches rather than continuous lines. The paper discusses two optimization studies 1) structural adhesive patches along with spot weld pitch as design variables, and 2) structural adhesive patches with gage variables. These studies include the Body in White (BiW) and Trimmed Body in White (TBiW) assessments.
Viewing 31 to 60 of 15919