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Technical Paper

A comparison of two source characterisation techniques proposed for standardisation

Automotive industry shows an increased tendency towards characterisation of vibration sources by independent quantities such as blocked forces and free velocities. Currently two independent ISO working groups propose standards for this source characterisation process. Both standards are still under development. During this presentation it is shown how the different approaches of both standards can be derived from a general Transfer Path Analysis (TPA) framework and a qualitative comparison will be made. Next, a practical study involving source characterisation and a response simulation using component TPA methodology is shown to illustrate the practical differences between the approaches and their effects when used in response synthesis. In conclusion some best practice approaches and software are discussed.
Training / Education

AS9100D Internal Auditor Training

Internal audits (a requirement of the AS9100 Rev D Standard) are intended to verify the compliance and effectiveness of the organization's quality management system. Internal auditors must be knowledgeable of these requirements and the expectations as identified in the standard. In addition, the audit requirements outlined in the AS9101 Standard have significantly changed the way auditors are expected to conduct audits in the aviation, space and defense industries.
Training / Education

Vehicle Crash Reconstruction Principles and Technology

Crash reconstruction is a scientific process that utilizes principles of physics and empirical data to analyze the physical, electronic, video, audio, and testimonial evidence from a crash to determine how and why the crash occurred. This course will introduce this reconstruction process as it gets applied to various crash types - in-line and intersection collisions, pedestrian collisions, motorcycle crashes, rollover crashes, and heavy truck crashes. Methods of evidence documentation will be covered. Analysis methods will also be presented for electronic data from event data recorders and for video.
Technical Paper

Next generation refrigerant transition: lessons learned from automotive industry experiences with CFC-12, HFC-134a and HFO-1234yf

The Kigali Amendment to the Montreal Protocol requires the global phasedown of HFC-134a in MACs. This paper explores how lessons learned in the transition from CFC-12 to HFC-134a can inform ongoing and future transition to next generation refrigerants with superior environmental performance. In 1987, when the Montreal Protocol was signed, air conditioning was installed on more than 90% of vehicles sold in North America and 50% of vehicles sold in Europe and by 2010 air conditioning was standard equipment on 4-wheel vehicles worldwide To protect the stratospheric ozone layer, automobile manufacturers completed the phaseout of CFC-12 around 1994 in developed countries and around 2006 in developing countries. HFC-134a was selected to replace CFC-12 because it had comparable cooling performance, low toxicity, non-flammability, no ozone depletion potential (ODP), and a GWP about eight times lower than CFC-12 (HFC-134a GWP =1300 vs. 10,200 for CFC-12).
Technical Paper

Validation of the Cycles render engine for creation of physically correct lighting models.

It is often desired to depict an accident scene using images or video in a manner that fairly and accurately represents what an observer could see at the actual scene. This can be accomplished by taking calibrated photographs or video of a recreated scene with substantially similar lighting conditions. This process requires significant coordination of the physical features at the scene. It can also be difficult to precisely control the motion and timing of moving features such as pedestrians and vehicles. The result is fixed in that the you capture specific scenarios with specific conditions with the selected field of view and perspective of the cameras used. Alternatively, three -dimensional computer modeling and physically-based rendering (PBR) can be used to recreate an accident scene to produce images and video that fairly and accurately represents what an observer could see at the actual scene.
Technical Paper

Nighttime Visibility in Moonlight Conditions

This paper presents research on the effect that moonlight has on the visibility of objects in the roadway from a driver’s perspective. Two nighttime moonlight conditions are tested. The first condition involves no moon, and hence no moon light contribution. The second testing condition is during a full moon, and specifically when the moon is closest to the Earth, known as a super moon. Baseline ambient light measurements of illumination arriving at the roadway test area are measured in both lighting scenarios. Additionally, the change in illumination on the roadway is recorded at thirty minute intervals as the moon rises to its highest position in the sky. Luminance readings of the roadway objects are recorded during the same time intervals to record the change in reflected light that is attributable to the moon light.
Technical Paper

Speed Analysis of Yawing Passenger Vehicles Following Tire Tread Detachment

This paper presents yaw testing of vehicles with tread removed from tires at various locations on the vehicle. A 2004 Chevrolet Malibu and a 2003 Ford Expedition were included in the test series. Speeds up to 60 mph were achieved. The vehicles were instrumented to record speed, steering angle, yaw angle, wheel speeds, and other parameters. The tire marks on the roadway were surveyed and photographed. Critical speed analysis has long been used by Accident Reconstructionists for calculating speed at the beginning of a yaw. Traditionally, the method has been used to calculate the speed a vehicle with four intact tires. The critical speed model is extended to include the analysis of speed of vehicles following a tread detachment event. It was found that the critical speed formula produces results of acceptable and known accuracy provided the appropriate inputs are used for the given situation and several guidelines are observed.
Technical Paper

FD&E Total Life T-Sample Residual Stress Analytical Predictions and Measured Results

The SAE Fatigue Design & Evaluation Committee is actively working on a total life project for weldments, in which the welding residual stress is a key contributor to an accurate assessment of fatigue life. Physics-based welding process simulation and various types of residual stress measurement were pursued to provide a sufficiently accurate representation of the residual stress field at the failure location in the fatigue samples. A well-controlled and documented robotic welding process was used for all sample fabrication to provide accurate inputs for the welding simulations. Both destructive (contour method, x-ray diffraction (XRD) with etching) and non-destructive (surface XRD, energy dispersive diffraction (EDD), neutron diffraction(ND)) residual stress measurements were performed on the same or similarly welded samples. The sample is constructed with multiple-pass fillet welds, which induce large gradients in residual stress through the one-inch thickness.
Technical Paper

Survey of Automotive Privacy Regulations and Privacy-Related Attacks

Privacy has been a rising concern. The European Union has established a privacy standard called General Data Protection Regulation (GDPR) in May 2018. Furthermore, the Facebook-Cambridge Analytica data incident made headlines in March 2018. Data collection from vehicles by OEM platforms is increasingly popular and may offer OEMs new business models but it comes with the risk of privacy leakages. Vehicular sensor data shared with third-parties can lead to misuse of the requested data for other purposes than stated/intended. There exists a relevant regulation document introduced by the Alliance of Automobile Manufacturers (“Auto Alliance”), which classifies the vehicular sensors used for data collection as covered and non-sensitive parameters.
Technical Paper

The Auto-Generation of Calibration Guides from MATLAB® Simulink®

With the inception of model-based design and automatic code generation, many organizations are developing controls and diagnostics algorithms in model-based development tools to meet customer and regulatory requirements. Advances in model-based design have made it easier to generate C code from models and help software engineers streamline their workflow. Typically, after the software has been developed, the models are handed over to a calibration team responsible for calibrating the features to meet specified customer and regulatory requirements. However, once the models are handed over to the calibration team, the calibration engineers are unaware of how to calibrate the features because documentation is not available. Typically, model documentation trails behind the software process because it is created manually, most of this time is spent on formatting. As a result, lack of model documentation or up-to date documentation causes a lot of pain for OEM’s and Tier 1 suppliers.
Technical Paper

Automated Requirements and Traceability Generation for a Distributed Avionics Platform

The development and qualification of distributed and highly safety-critical avionics systems implicate high efforts and risks. The resulting costs usually limit implementations like fly-by-wire systems to the military or commercial airliner domains. The aim of previous and ongoing research at the Institute of Aircraft Systems at University of Stuttgart is the reduction of these costs and therefore open up their benefits, inter alia, to general aviation, remotely piloted or unmanned aircraft. An approach for an efficient development is the application of a platform based development which supports the reuse of software and hardware components. The Flexible Platform adopts this approach. It is accompanied by a tool suite which automates the design and parameter instantiation, documentation generation and the generation of verification artifacts for a platform instance. This paper presents the approach for the requirement document generation compliant to ARP4754A and DO-178C.

Friction Coefficient Identification and Environmental Marking System for Brake Linings

This SAE Recommended Practice is intended to provide a uniform means of identification which may be used to classify the friction coefficient of brake linings, based on data obtained from tests conducted in accordance with SAE J661 Brake Lining Quality Test Procedure and SAE J2975 Measurement of Copper and other elements in Brake Friction Materials. NOTE: It is emphasized that this document does not establish friction requirements for brake linings, nor does it designate significant characteristics of brake linings which must be considered in overall brake performance. Due to other factors that include brake system design and operating environment, the friction codes obtained from this document cannot reliably be used to predict brake system performance.

Aerospace Size Standard for O-rings

This SAE Aerospace Standard (AS) specifies the inside diameters, cross-sections, tolerances, and size identification codes (dash numbers) for O-rings used in sealing applications and for straight thread tube fitting boss gaskets. The dimensions and tolerances specified in this standard are suitable for any elastomeric material provided that suitable tooling is available.

Aerospace Standards Index - 2019

This valuable resource lists all Aerospace Standards (AS), Aerospace Recommended Practices (ARP), Aerospace Information Reports (AIR), and Aerospace Resource Documents (ARD) published by SAE. Each listing includes title, subject, document number, key words, new and revised documents, and DODISS-adopted documents. AMS Index - Now Available!