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Training / Education

AS91002016 Rev D Understanding the Requirements

2021-06-17
Individuals responsible for quality management system, implementation, and auditing to the AS9100:2016 series of standards for Aviation, Space, and Defense will require an understanding of the requirements for the preparation and execution of the audit process as defined in these revised standards. Management and implementers of AS9100:2016 Rev. D within these organizations must also be aware of what these requirements mean for their company.
Training / Education

Applying DO-254 for Avionics Hardware Development and Certification

2021-05-06
The avionics hardware industry world-wide is now commonly required to follow DO-254 Design Assurance Guidance for Airborne Electronic Hardware for literally all phases of development: Safety, Requirements, Design, Logic Implementation, V&V, Quality Assurance, etc. The DO-254 standard is a companion to the software DO-178B standard; however, there are many differences between hardware and software which must be understood. This basic course introduces the intent of the DO-254 standard for commercial avionics hardware development.
Technical Paper

Free Multibody Cosimulation Based Prototyping of Motorcycle Rider Assistance Systems

2020-10-30
2020-32-2306
Due to the increasing computational power, significant progress has been made over the past decades when it comes to CAD, multibody and simulation software. The application of this software allows to develop products from scratch, or to investigate the static and dynamic behavior of multibody models with remarkable precision. In order to keep the development costs low for highly sophisticated products, more precisely motorcycle rider assistance systems, it is necessary to focus extensively on the virtual prototyping using different software tools. In general, the interconnection of different tools is rather difficult, especially when considering the coupling of a detailed multibody model with a simulation software like MATLAB Simulink. The aim of this paper is to demonstrate the performance of a motorcycle rider assistance algorithm using a cosimulation approach between the free multibody software called FreeDyn and Simulink based on a sophisticated multibody motorcycle model.
Training / Education

Critical Concepts of Tolerance Stacks 2009 3-day

2020-10-20
This course, based on the ASME Y14.5-2009 standard, provides an in-depth explanation of how to use tolerance stacks to analyze product designs and how to use geometric tolerances in stacks. You will learn the essential methods and concepts used for creating 1D part and assembly tolerance stacks.
Technical Paper

Transitioning from IC Engine to Electric Vehicle: An Optimized Wheel End Solution

2020-10-05
2020-01-1632
This paper discusses the change in vehicle parameters when moving from a conventional internal combustion engine to electric motor. It discusses the impact on the wheel end bearings. Typically these include higher GAWRs (Gross Axle Weight Rating) at lower center of gravity heights. These changes require bearings to handle higher loads. Typically, larger loads will increase the bearing size and with it the mounting interface dimensions to auxiliary components. Timken demonstrates an alternative bearing design that can handle higher vehicle GAWRs but would allow for continuity in the surrounding brake corner components – saving OEMs significant design costs and delays.
Technical Paper

Novel Modelling Techniques of the Evolution of the Brake Friction in Disc Brakes for Automotive Applications

2020-10-05
2020-01-1621
The aim of the presented research is to propose and benchmark two brake models, namely the novel dynamic ILVO model and a neural network based regression. These can estimate the evolution of the brake friction between pad and disc under different load conditions, which are typically experienced in vehicle applications. The research also aims improving the knowledge of the underlying mechanism related to the evolution of the BLFC (boundary layer friction coefficient), the reliability of virtual environment simulations to speed up the product development time and reducing the amount of vehicle test in later phases and finally improving brake control functions. With the support of extensive brake dynamometer testing, the proposed models are benchmarked against State-of-the-Art. Both approaches are parametrised to render the friction coefficient dynamics with respect to the same input parameters.
Technical Paper

Development of Friction Materials Regulations for Four Latin American Countries

2020-10-05
2020-01-1615
Brakes are the most important safety device in a vehicle, however there are few barriers to manufacture, import, or sell friction materials in most of the countries, including USA. European countries, with the ECE R90 program, are a big exception. International Transport Forum published in 2016 the “Benchmarking of road safety in Latin America” report, it mentions that worldwide 17.5 people in every 100,000 die in road accidents, however Andean countries mortality rate is 23.4 and South American 21.0, considerably higher than the worldwide average.
Technical Paper

A Full-System Approach to Maximise Energy Efficiency of a Wheel Bearing

2020-10-05
2020-01-1631
Environmental sustainability is morphing Automotive technical development strategies and driving the evolution of vehicles with a speed and a strength hardly foreseeable a decade ago. The entire vehicle architecture is impacted, and energy efficiency becomes one of the most important parameters to reach goals, which are now not only market demands, but also based on regulatory standards with penalty consequences. Therefore, rolling drag from all bearings in multiple rotating parts of the vehicle needs to be reduced; wheel bearings are among the biggest in size regardless of the powertrain architecture (ICE, Hybrid, BEV) and have a significant impact. The design of wheel bearings is a complex balance between features influencing durability, robustness, vehicle dynamics, and, of course, energy efficiency.
Technical Paper

Study on the Effect of Structural Parameters on the Linear Control Performance of High Speed On-Off Valve Based on Flow Field Analysis

2020-10-05
2020-01-1644
High speed on-off valve under the control of high frequency pulse width modulation (PWM) can make control linearly as proportional valve does. It is because its valve opening is adjusted linearly by duty ratio within a certain range. It is significant for high speed on-off valve to achieve precise linear control performance. In practice the performance is influenced not only by control strategy, but also the structural parameters of the valve, such as seat angle, spool diameter of valve and so on. In this paper, it is indicated that the effects of structural parameters on linear control performance of high speed on-off valve is exerted by flow force since different structural parameters bring about different valve opening-flow force characteristics. Accordingly, the relationship between the valve structural parameters and flow force is emphasized.
Technical Paper

Comparison of Particulate Matter and Number Emissions from a Floating and a Fixed Caliper Brake System of the Same Lining Formulation

2020-10-05
2020-01-1633
The particulate emissions of two brake systems where characterized in a dilution tunnel optimized for PM10 measurements. The larger of them employed a fixed caliper (FXC) and the smaller one a floating caliper (FLC). Both used ECE brake pads of the same lining formulation. Measured properties included gravimetric PM2.5 and PM10, Particle Number (PN) concentrations of both untreated and thermally treated (according to exhaust number regulation) particles using Condensation Particle Counters (CPCs) having 23 and 10 nm cut-off sizes, and an Optical Particle Sizer (OPS). The brakes were tested over a novel test cycle developed from the database of the Worldwide harmonized Light-Duty vehicles Test Procedure (WLTP). A series of WLTP tests were performed starting from unconditioned pads, to characterize the evolution of emissions until their stabilization. Selected tests were also performed over a short version of the Los Angeles City Cycle.
Technical Paper

A Study on Optimization of Brake Feeling and Method for Flexible Brake with Integrated Electronic Booster

2020-10-05
2020-01-1642
Throughout the automotive industry, the application of an integrated electronic booster (IEB) system has been actively applied following with diversify powertrain types and expand autonomous vehicles. Compared to the existing vacuum boosters, the performance advantages of IEB are 1) robustness against environmental changes, 2) rapid hydraulic reactivity, etc., and the advantages of cost / university are 1) flexibility for powertrain changes 2) weight saving 3) package simplification. Although IEB has a great advantage in performance and cost, it still needs a lot of research in various fields to realize the braking feeling, which is the performance of the emotional aspect, similar to the existing system. The braking feeling of the existing system was determined by the mechanical action of the hardware connected from the input device, the brake pedal to the hydraulic line. However, IEB system has a completely different structure from the existing system.
Technical Paper

A Generic Testbody for Low-Frequency Aeroacoustic Buffeting

2020-09-30
2020-01-1515
Raising demands towards lightweight design paired with a loss of originally predominant engine noise pose significant challenges for NVH engineers in the automotive industry. From an aeroacoustic point of view, low frequency buffeting ranks among the most frequently encountered issues. The phenomenon typically arises due to structural transmission of aerodynamic wall pressure fluctuations and/or, as indicated in this work, through rear vent excitation. A possible workflow to simulate structure-excited buffeting contains a strongly coupled vibro-acoustic model for structure and interior cavity excited by a spatial pressure distribution obtained from a CFD simulation. In the case of rear vent buffeting no validated workflow has been published yet. While approaches have been made to simulate the problem for a real-car geometry such attempts suffer from tremendous computation costs, meshing effort and lack of flexibility.
Technical Paper

Advanced CAE Methods for NVH Development of High Speed Electric Axle

2020-09-30
2020-01-1501
The rate in the electrification of vehicles has risen in recent years. With intensified development more and more attention is paid to the noise and vibration in such vehicles especially from the EDU (Electric Drive Unit). In this paper the main NVH simulation process of a high-speed E-axle up to 30,000 rpm for premium class vehicle application is presented. The high speed, high-power density and lightweight design introduces new challenges. Benchmarking of different EDUs and vehicles leads to targets which can be used at the early stage of development as subsystem targets. This paper shows the CAE methodology which can be used to verify the design and guarantee the target achievement. Using CAE both source and structure can be optimized to improve the NVH behavior.
Technical Paper

Numerical Analysis of the Influences of Wear on the Vibrations of Power Units

2020-09-30
2020-01-1506
Numerical Analysis of the Influences of Wear on the Vibrations of Power Units Yashwant Kolluru, Rolando Doelling eBike Department Robert Bosch GmbH Kusterdingen, Germany yashwant.kolluru@de.bosch.com rolando.doelling@de.bosch.com Lars Hedrich Institute of Informatics Goethe University Frankfurt Frankfurt, Germany hedrich@em.informatik.uni-frankfurt.de The prime factor, which influences vibrations of electro-mechanical drives, is wear at the components. This paper discusses the numerical methods developed for abrasion, vibration calculations and the coupling between wear and NVH models of drive unit. Wear is a complex process and understanding it is essential for vibro-acoustics. The paper initially depicts finite element static model used for wear calculations. The special subroutines developed, aids in coupling the wear equations, various contact and friction formulations to the numerical model.
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