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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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Investigation of Fracture Behavior of Deep Drawn Automotive Part affected by Thinning with Shell Finite Elements

General Motors-Hwawon Lee, Shengjian li, Hui-Min (Emmy) Huang, Parvath Police
  • Technical Paper
  • 2020-01-0208
To be published on 2020-04-14 by SAE International in United States
In the recent decades tremendous effort has been made in automotive industry to reduce vehicle mass and costs in order to improve fuel economy and develop safer vehicles than any other decades. An accurate modeling approach of sheet metal fracture behavior under plastic deformation is one of the key parameters affecting optimal vehicle development process. FLD (Forming Limit Diagram) approach which plays an important role in judging forming severity has been widely used in forming industry and localized necking is the dominant mechanism leading to fracture in sheet metal forming and crash events. FLD is known as limited only to deal with the onset of localized necking and could not predict shear fracture. Therefore it is essential to develop accurate fracture criteria beyond FLD for vehicle development. To enhance the accuracy of crash simulations, forming results from stamping process are generally introduced to consider work hardening and thinning/thickening of a stamped part during the simulations. However fracture criteria is only applied to the original design thickness not thinned or thickened gage after forming process. It…
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Finite Element Analysis Technique To Roll Crimp Solenoid’s Can

BorgWarner Inc.-Chandreshwar Rao
  • Technical Paper
  • 2020-01-0749
To be published on 2020-04-14 by SAE International in United States
Roll forming assemblies are generally neat and robust, but there are structural integrity risks involved too if the forming procedures and design features do not complement each other. Specifically, in solenoid valves, an imprecised roller crimping (or forming) adversely affect the desired magnetic performance of the valves. Furthermore, in-depth evaluations of the formed shape using hardware and lab testing are extremely challenging cost wise and time consuming as well. However, utilizing simulation technique such as finite element analysis (FEA) to understand the in-sights of roller formed assemblies of a solenoid valve (or other products) could be an effective way to minimize overall cost and time involved in the product development. Therefore, a three-dimensional non-linear FEA model of roller crimping simulation was established in ANSYS Workbench Mechanical, and the predicted results were correlated with real hardware data to prove the technique & process adopted. Then the design was improved computationally to eliminate the magnetic Core's flux-bridge distortion issue of a solenoid valve, and finally the design was validated through hardware testing.
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Spatially Optimized Diffusion Alloys: A Novel Multi-Layered Steel Material for Exhaust Applications

Arcanum Alloys Inc.-Zachary Detweiler, David Keifer, Daniel Bullard
Tenneco Inc.-Adam Kotrba, Tony Quan, Winston Wei
  • Technical Paper
  • 2020-01-1051
To be published on 2020-04-14 by SAE International in United States
A novel Spatially Optimized Diffusion Alloy (SODA) material has been developed and applied to exhaust systems, a very aggressive environment with high temperatures and loads, as well as excessive corrosion. Traditional stainless steels disperse chromium homogeneously throughout the material, with varying amounts ranging from 11% to 18% dependent upon its grade (e.g. 409, 436, 439, and 441). SODA steels, however, offer layered concentrations of chromium, enabling an increased amount along the outer surface for much needed corrosion resistance and aesthetics. This outer layer, approximately 70µm thick, exceeds 20% of chromium concentration locally, but is only 3% in bulk, offering selective placement of the chromium to minimize its overall usage. And, since this layer is metallurgically bonded, it cannot delaminate or separate from its core, enabling durable protection throughout manufacturing processes and full useful life. The core material may be of various grades, however, so this study employs interstitial free steel (low carbon), which offers not only commercial advantages, but also eases manufacturing operations, as it is more formable than stainless steel grades. The material and…
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Interactive Effects between Sheet Steel, Lubricant and Measurement System

General Motors-Jatinder P Singh
University of Colorado Denver-Luis Rafael Sanchez Vega, Eduardo Corral
  • Technical Paper
  • 2020-01-0755
To be published on 2020-04-14 by SAE International in United States
This study assessed the interaction between sheet steel, lubricant and measurement system under typical sheet forming conditions. Deep Drawing Quality Bare, Electrogalvanized and Hot Dip Galvanized mild sheet steel, were tested under a Draw Bead Simulator (DBS). Lubricant conditions varied from thoroughly dry (0% lube) to overlubricated (>6 g/m2); with 1g of lubricant per m2 as the target of general usage. Mixed lubrication cases, with incremental amounts of a lubricant applied over an existing base of 1 g/m2 rust protection oil, were analyzed. The results show distinctive differences and similarities on friction between the bare material and the coatings. While friction on the bare substrate was higher than the coatings under lubricated conditions, it was significantly more tolerant to dry conditions. Stick-slip behavior was studied as a measurement system response to intermittent friction between the testing tools. These measurement test responses, and sheet surface texture changes during testing were discussed.
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Multi-Objective Optimization of Sheet Metal-Polymer Hybrids Manufactured by The Integrated Process of Deep Drawing-Back Injection Molding

Clemson University (CUICAR)-Saeed Farahani, Farzam Malmir, Deepak Aggarwal, Srikanth Pilla
  • Technical Paper
  • 2020-01-0622
To be published on 2020-04-14 by SAE International in United States
Lightweight constructions can no longer be achieved solely through material substitution. To stay competitive, design parameters and manufacturing technologies should be taken into consideration as well. The integrated process of Deep Drawing-Injection Molding (DDIM) is such an advanced process in which the sheet metal blank is first deformed by tool movement and then calibrated to the shape of the cavity using polymer melt pressure during the injection process. Therefore, the traditional processes of sheet metal forming and injection molding are combined into one step operation, thus reducing the process steps and required machinery. Even though the process has its own challenges, the best combination of weight, performance, cost, and quality can be achieved by defining a multi-objective optimization problem with respect to the influencing design parameters. This study aims to optimize the various parameters of the sheet metal-polymer structure using Taguchi-based Grey optimization. A system of orthogonal arrays is used as the design of experiment (DOE) in order to evenly distribute the design variables in the design space. Moreover, S/N ratio graphs and ANOVA tool…
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Innovative Passive Exhaust Valve Improves Sound Quality and Reduces Muffler Volume without a Backpressure Penalty

Tenneco Inc.-Adam Kotrba, Stephen Thomas, Gabriel Ostromecki, Asela Benthara, Nicholas Morley
  • Technical Paper
  • 2020-01-0410
To be published on 2020-04-14 by SAE International in United States
Exhaust systems traditionally require a given amount of muffler volume to reduce sound levels appropriately. However, as hybridization continues, package space is limited, reducing available muffler space, requiring alternative solutions to attenuate exhaust sound with less volume. Passive exhaust valvesare a key solution, leveraging the physics of the exhaust (flow, temperature, and pressure) to cycle the valve. Passive exhaust valves are typically closed under low flow conditions (low engine speeds and loads), which helps reduce low-frequency boom, moderately increasing backpressure when it is not detrimental to engine efficiency. Conversely, under higher engine speed and load operating conditions, as when power is on demand, exhaust flow increases, and backpressure is critical to achieve desired power output, thus the passive valve opens to reduce its impact. And, such valves are often positioned within the muffler, fully immersed and exposed to exhaust heat, humidity, and corrosion, as well as the vibrations from road and engine loads. A next-generation passive valve is detailed in this paper, describing the engineering development to evolve the design, as well as the operating…
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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 38% 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…
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Hybrid forming – a novel Manufacturing Technique for metal-LFT structural parts

University of Siegen-Daniel Heidrich, Tobias Kloska, Xiangfan Fang
  • Technical Paper
  • 2020-01-0235
To be published on 2020-04-14 by SAE International in United States
Hybrid structural parts combining aluminum or steel sheets with long glass fiber reinforced thermoplastics (LFT) offer a great opportunity to reduce component weight for automotive applications. But due to high manufacturing cost, metal-LFT hybrid components are still scarcely used in automotive large-scale production. Thus in this work a novel cost- and time efficient manufacturing process for simultaneous metal sheet forming and compression molding of long fiber reinforced thermoplastics to manufacture automotive lightweight components is presented. In this manufacturing process, which is referred to as “Hybrid forming”, the molten LFT is used as a forming medium in the manner of well-known hydroforming processes. After forming the metal sheet by the molten LFT in combination with the rigid die, the LFT solidifies and forms a local reinforcement structure in the hybrid component. Since the metal sheet can be pre-coated with a bonding agent prior to the forming process, a firmly bonded connection between metal and LFT can be achieved. For proof of concept a longitudinal control arm in a multi-link rear axle is chosen. By utilizing Hybrid…
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Multi-Material Topology Optimization Considering Symmetry and Extrusion Design Constraints

General Motors Canada Ltd-Manish Pamwar
General Motors of Canada-Balbir Sangha
  • Technical Paper
  • 2020-01-0628
To be published on 2020-04-14 by SAE International in United States
The field of topology optimization (TO) has been evolving rapidly, notably due to the emergence of multi-material topology optimization (MMTO) algorithms. These developments follow the establishment of TO tools within the industry, which has been accelerated and promoted through the introduction of various manufacturing constraints within algorithms. The integration of manufacturing constraints within MMTO is critical for promoting industry usage and adoption of these new software algorithms, as current usage of MMTO is dissuaded by the typically complex design solutions. The presented MMTO implementation is an extension of classical single-material topology optimization (SMTO). The TO problem is expanded to consider both material existence and selection, solid isotropic material with penalization (SIMP) is utilized for material interpolation. The method of moving asymptotes (MMA) has been integrated into MMTO as the optimization algorithm as it can handle large-scale problems with many design variables. A design variable mapping system has been incorporated into MMTO, which determines element groups based on symmetry or extrusion manufacturing constraints. The design variables of the group elements are constrained to equivalent values, resulting…