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Optimization of Slot Disc Shape for Improving Brake Fade Performance

Hyundai Motor Co.-Hyungjoon Kim, Yoon Cheol Kim, Jaekwang Seol, Chul Yoon, Kwang Yun Kim
Sangsin Brake-Hankyo Seo
Published 2018-10-05 by SAE International in United States
Due to improvements in vehicle powertrain performance, friction material fade performance is becoming an important topic. For this reason, needs for studies to improve thermal characteristics of the brake system is increasing. Methods for improving the fade characteristics have several ways to improve the thermal characteristic of friction materials and increase disc capacity. However, increasing disc capacity(size) have some risk of weight and cost rise, and friction factor improvements in friction material tend to cause other problems, such as increasing squeal wire brush noise and increasing metal pick up on disc surface. Therefore, a slot disc study is needed to overcome the problems discussed previously. Currently, there is few research history for slot disc related to fade and metal pickup improvements. Through this study, I found that the slot disc improved the friction material fade properties, but the application of the slot disc could cause air plane noise and worsen the friction material wear characteristic this study shows that optimizing the number of slots and slot profile and slot direction on disc surface minimizes air…
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NASA at 60: 1958-2018 Decades of Discovery

  • Magazine Article
  • TBMG-33099
Published 2018-10-01 by Tech Briefs Media Group in United States

For six decades, NASA has led the peaceful exploration of space, making discoveries about our planet, our solar system, and our universe. At home, NASA research has made great advances in aviation, helped to develop a commercial space industry, enrich our economy, create jobs, and strengthen national security. Here is just some of what NASA has achieved in its first 60 years.

NASA at 60: Celebrating Success

  • Magazine Article
  • TBMG-33109
Published 2018-10-01 by Tech Briefs Media Group in United States

Over the past 60 years, NASA scientists and engineers have developed many advanced technologies and processes. But NASA has also partnered with industry, using commercially available products to complete its missions. Here, some of those companies join NASA in celebrating these collaborative successes.

NASA at 60: The First

  • Magazine Article
  • TBMG-33101
Published 2018-10-01 by Tech Briefs Media Group in United States

The first “A” in NASA stands for aeronautics — the science of travel through the air. It's as much about flying on airplanes and arriving safely at a destination as it is about astronauts in space. NASA's roots go back to the National Advisory Committee for Aeronautics, established in 1915 to “supervise and direct the scientific study of the problems of flight.”

NASA at 60: From Space to Earth

  • Magazine Article
  • TBMG-33110
Published 2018-10-01 by Tech Briefs Media Group in United States

The benefits of NASA's space exploration efforts are not limited to the cosmos. NASA technologies provide innovative solutions for people around the world. NASA missions have generated thousands of spinoffs — commercialized products we use every day. On the following pages, we highight just some of the many innovations that had their origins in NASA programs.

National Renewable Energy Laboratory

  • Magazine Article
  • TBMG-32825
Published 2018-09-01 by Tech Briefs Media Group in United States

In 1977, the National Renewable Energy Laboratory (NREL, Golden, CO) started as the Solar Energy Research Institute (SERI), spurred by national concern during the 1973 oil embargo that caused long lines and high prices at gas stations. Three months after his 1977 inauguration, President Jimmy Carter announced his desire to reduce dependence on foreign oil and invest in alternative energy sources. He created SERI with the mission to launch a new American energy industry, and consolidated oversight of U.S. energy policy into the newly formed U.S. Department of Energy.

Standard Rainflow File Format

Materials, Processes and Parts Council
  • Ground Vehicle Standard
  • J2623_201808
  • Current
Published 2018-08-24 by SAE International in United States
This SAE Standard provides a definition of a rainflow file format. This type of simple text file would contain all relevant information about the rainflow cycle content of a time history. Included information are Comments, Signal Range, Signal Mean, Number of Cycles, Signal Maximum, Signal Minimum. Rainflow cycle counting has become the most accepted procedure for identifying material fatigue relevant cycles in complex variable amplitude load time histories. The cycle counting methods account for the effects of material plasticity and material memory of prior deformation, and the resulting compressed history information is used by durability analysts to estimate the effects of a given service or test history. Standardization of the rainflow counting methods output files, which is the format addressed by the present standard, is important for reliable information transfer between test and design groups, or different calculation software packages, and thus forms a critical step in the evaluation of components and vehicles. Further background information can be found in the SAE publication AE-10 cited in 2.1.1.
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Development and Validation Procedure of a 1D Predictive Model for Simulation of a Common Rail Fuel Injection System Controlled with a Fuel Metering Valve

Politecnico di Torino-Alessandro Ferrari, Pietro Pizzo, Ruggero Vitali
  • Journal Article
  • 03-11-04-0027
Published 2018-07-10 by SAE International in United States
A fully predictive one-dimensional model of a Common Rail injection apparatus for diesel passenger cars is presented and discussed. The apparatus includes high-pressure pump, high-pressure pipes, injectors, rail and a fuel-metering valve that is used to control the rail pressure level. A methodology for separately assessing the accuracy of the single submodels of the components is developed and proposed. The complete model of the injection system is finally validated by means of a comparison with experimental high-pressure and injected flow-rate time histories. The predictive model is applied to examine the fluid dynamics of the injection system during either steady-state or transient operations. The influence of the pump delivered flow-rate on the rail-pressure time history and on the injection performance is analysed for different energizing times and nominal rail pressure values. A comparison between fuel metering valve and pressure-control-valve strategies is also carried out in terms of rail pressure and pump delivered flow-rate time histories. The advantages and the weak points of each strategy are highlighted: the fuel metering valve control is more efficient, due to…
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Reflex Reflectors

Signaling and Marking Devices Stds Comm
  • Ground Vehicle Standard
  • J594_201806
  • Current
Published 2018-06-19 by SAE International in United States
This SAE Standard provides test procedures, requirements, and guidelines for reflex reflectors.
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Active Suspension: Future Lessons from The Past

ZF Commercial Vehicle Technology-Daniel Eugene Williams
  • Journal Article
  • 10-02-02-0010
Published 2018-06-18 by SAE International in United States
Active suspension was a topic of great research interest near the end of last century. Ultimately broad bandwidth active systems were found to be too expensive in terms of both energy and financial cost. This past work, developing the ultimate vehicle suspension, has relevance for today’s vehicle designers working on more efficient and effective suspension systems for practical vehicles. From a control theorist’s perspective, it provides an interesting case study in the use of “practical” knowledge to allow “better” performance than predicted by theoretically optimal linear controllers. A brief history of active suspension will be introduced. Peter Wright, David Williams, and others at Lotus developed their Lotus modal control concept. In a parallel effort, Dean Karnopp presented the notion of inertial (Skyhook) damping. These concepts will be compared, the combination of these two distinctly different efforts will be discussed, and eventual vehicle results presented. Most of the contemporary literature treated active suspension as a theoretical vibration isolation problem, but handling improvements from active suspension were even more impressive. Handling and actual hardware considerations motivated a…
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