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Business Modeling / Operation Research / Big Data Analytics, 2017

2017-03-28
Business Modeling/Operation Research/Big Data Analytics are key enablers for the next wave of innovation and growth across most industries and will address complex issues and systems that involve multiple objectives, alternatives, trade-offs, and large amounts of data and situations involving uncertainty or risk. These papers address new technical advances in these areas and provide valuable insights through the applications of real-world case studies.
Collection

Advanced Analysis, Design, and Optimization for Materials, Restraints, and Structures for Enhanced Automotive Safety and Weight Reduction, 2018

2018-04-03
Papers with an emphasis on, but not limited to, innovative ideas to enhance automotive safety with improved material constitutive modeling, analysis method developments, simulation and pre/post processing tools, optimization techniques, crash code developments, finite element model updating, model validation and verification techniques, dummies and occupants, restraint systems, passive safety as well as lightweight material applications and designs are included in the collection.
Collection

Advanced Analysis, Design, and Optimization for Materials, Restraints, and Structures for Enhanced Automotive Safety and Weight Reduction, 2017

2017-03-28
Papers with an emphasis on, but not limited to, innovative ideas to enhance automotive safety with improved material constitutive modeling, analysis method developments, simulation and pre/post processing tools, optimization techniques, crash code developments, finite element model updating, model validation and verification techniques, dummies and occupants, restraint systems, passive safety as well as lightweight material applications and designs are included in the collection.
Video

Introduction of New Concept U*sum for Evaluation of Weight-Efficient Structure

2011-11-01
A new index for evaluating load path dispersion is proposed, using a structural load path analysis method based on the concept of U* , which expresses the connection strength between a load point and an arbitrary point within the structure enables the evaluation of the load path dispersion within the structure by statistical means such as histograms and standard deviations. Presenter Tadashi Naito, Honda R&D Co., Ltd.
Standard

Diagnostic and Prognostic Metrics for Engine Health Management Systems

2017-01-24
WIP
AIR7999
This SAE Aerospace Information Report (AIR) presents metrics for assessing the performance of diagnostic and prognostic algorithms applied to Engine Health Management (EHM) functions. This document consolidates and expands upon the metric information previously contained in AIR4985 and AIR5909. The emphasis is entirely on metrics and as such is intended to provide an extension and complement to such documents as ARP4176, which provides insight into how to create a cost benefit analysis to determine the justification for implementing an EHM system.
Standard

Prognostics and Health Management Guidelines for Electro-Mechanical Actuators

2017-09-21
WIP
AIR8012
The purpose of the document is to provide the guidelines of the technological approach for developing a PHM system for EMAs with particular reference to their possible use as primary flight control actuators. It provides a basic description of the physics of the most common degradation processes,a reliability assessment and a discussion on the signals, with the associated data processing, required to build up an effective health monitoring system.
Standard

Guidelines for Implementation of Structural Health Monitoring on Rotorcraft

2015-04-28
WIP
AIR6892
This SAE Aerospace Information Report (AIR) is applicable to rotorcraft structural health monitoring (SHM) applications, both commercial and military, where end users are seeking guidance on the definition, development, integration, qualification, and certification of SHM technologies to achieve enhanced safety and reduced maintenance burden based on the lessons learned from existing Health and Usage Monitoring Systems (HUMS). While guidance on SHM business case analysis would be useful to the community, such guidance is beyond the scope of this AIR. For the purpose of this document, SHM is defined as “the process of acquiring and analyzing data from on-board sensors to evaluate the health of a structure.” The suite of on-board sensors could include any presently installed aircraft sensors as well as new sensors to be defined in the future. Interrogation of the sensors could be done onboard during flight or using ground support equipment.
Standard

Guidelines for the Development of Architectures for Integrated Vehicle Health Management Systems

2013-12-19
WIP
ARP6290
This SAE Aerospace Recommended Practice (ARP) provides best practices and guidance for creating an architecture for integrated vehicle health management systems. Where possible, this document will also provide references to tools to conduct architectural trades. Finally, this document will provide use cases to expose considerations and stakeholders to be included in these trades and utilization of an IVHM system (which may lead to new functional or non-functional requirements).
Technical Paper

Parametric Modeling for Semi-trailer Tank Vehicle

2001-03-05
2001-01-3860
This paper treats the study case of semi-trailer structures by using Finite Element Method (FEM). It has the main proposal to stablish an automatic procedure for model preparation, that means: meshing generation, design loads and constraints applications, for a family of semi-trailer from 15000 to 35000 dm3 capacity, automatically built by the computer program GERTAP with a very few user interference. For this reason, the program does not demand any FEM expertise so that engineers can focus main construction problems without excessive concerning about model theoretical characteristics and model mistakes. At present moment, we are able to develop static analysis, with use of equivalent accelerations, in order to compute weighting, braking and turning loads. Soon, in a very near future, we are going to apply dynamics analysis that will simulate the actual bad conditions of Brazilian roads, so that fatigue-cracking problems could be prevented in design stage.
Training / Education

Materials Degradation in Mechanical Design: Wear, Corrosion, Fatigue and their Interactions Web Seminar RePlay

Anytime
Materials degradation from environmental conditions is a common factor that will often occur in mechanical equipment used in every type of environment. These processes can frequently materialize in unpredicted and harmful ways, especially when they interact and lead to early component damage or failure. Captured from five, two-hour sessions, this course summarizes the mechanisms that cause materials and mechanical components to degrade in service through exposure to deleterious mechanical and environmental conditions.
Technical Paper

Innovative Material Characterisation Methodology for Tyre Static and Dynamic Analyses

2020-09-30
2020-01-1519
Tyre structures are based on composite materials that constitute numerous layers, each providing specific properties to the tyre mechanic and dynamic behaviour. In principle, the understanding of the partial contributions of the individual layers requires knowledge of its mechanical properties. In case of non-availability of such critical information, it is difficult to perform tyre FE analyses. In the current work, a methodology is proposed to study the tyre static and dynamic behaviour to estimate its constituents properties based on the measured quasi-static responses of the tyre for certain specific loads. As a first step, a simplified tyre numerical model with standard rubber material properties is modeled that can substantively predict the necessary tyre static responses, i.e. radial, longitudinal and lateral stiffness. These responses are correlated with the physical tyre response that are measured using a kinematic and compliance (K&C) test rig in the laboratory.
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

Appropriate Damping Loss Factor of Vehicle Interior Cavity For Valid Application of Statistical Energy Analysis

2020-09-30
2020-01-1524
By using a method of a previous study (SAE 2014-01-2081), sound transmission loss (STL) of vehicle panel structure could be calculated with an FEM model. The FEM model is consisting of the body in white, a hemispehere-shaped exterior cavity, and the interior cavity. The exterior cavity is excited and Statistical Energy Analysis (SEA) principle is applied for the calculation of STL of vehicle panel structure. It is known that SEA is a rapid and simple methodology for analyzing the complex vibroacoustic system. However, SEA principle is not always valid and one has to be careful about the physical conditions at which SEA principle is acceptable. In this study, the appropriate damping loss factor of the vehicle interior cavity is studied in the viewpoint of the modal overlap factor of the cavity and the decay per mean free path (DMFP) of the cavity. It is found that DMFP is appropriate between 0.5 ~ 1 dB for applying SEA principle.
Technical Paper

Using Statistical Energy Analysis to Optimize Sound Package for Realistic Load Cases

2020-09-30
2020-01-1525
The statistical energy analysis (SEA) is widely used to support the development of the sound package of cars. This paper will present a model prepared to investigate the sound package of the new Audi A3 and its correlation against measurements. Special care was given during the creation of the model on the representation of the structure to able the analysis of structure borne energy flow on top of the classical airborne analysis usually done with SEA. The sound package is also detailed in the model to allow further optimization and analysis of its performance. Two real life load cases will be presented to validate the model with measurements. First, the dominating powertrain and second, a case with dominating rolling noise. An analysis of the contribution of the different source components and a way to diagnose the weak paths of the vehicle will be presented. The focus of this investigation is the application of optimally adjusted treatment.
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.
Technical Paper

Analytical Prediction of Acoustic Emissions From Turbocharger Bearings

2020-09-30
2020-01-1504
Turbochargers are progressively used in modern automotive engines to enhance engine performance and reduce energy loss and adverse emissions. Use of turbochargers along with other modern technologies has enabled development of significantly downsized internal combustion engines. However, turbochargers are major sources of acoustic emissions in modern automobiles. Their acoustics has a distinctive signature, originating from fluid-structure interactions. The bearing systems of turbochargers also constitute an important noise source. In this case, the acoustic emissions can mainly be attributed to hydrodynamic pressure fluctuations of the lubricant film. The developed analytical model determines the lubricant pressure distribution in the floating journal bearings used mainly in the modern turbocharges. This allows for an estimation of acoustic emissions.
Technical Paper

Characterisation of Brake Creep Groan Vibrations

2020-09-30
2020-01-1505
Creep Groan is an impulsive brake noise at very low velocities of the vehicle. Generally, stick-slip between brake disc and brake pads is assumed as the most dominating vibration mechanism of creep groan. This contribution will show by sophisticated measurement techniques, that stick-slip and speed dependent friction is an important trigger of this annoying vehicle noise. However, the overall vibration is much more complex than common stick-slip vibration models. It turns out, that in typical brake systems of passenger vehicles creep groan occurs around 15-20 Hz and 70-90 Hz. The mechanism at 15-20 Hz is an impulsive noise. Transitions between stick and slip phases trigger complex nonlinear vibrations of the complete brake and suspension system. At 70-90 Hz, the vibrations show a more harmonic-like behaviour, caused primarily by speed-dependent friction characteristics.
Technical Paper

Analytical Rotordynamic Study of a High-Speed Gear Transmission System for Race Applications

2020-09-30
2020-01-1502
In motorsport power transmission systems, high-speed operation can be associated with significant rotordynamic effects. Changes in the natural frequencies of lateral (bending) vibrational modes as a function of spin speed are brought about by gyroscopic action linked to flexible shafts and mounted gear components. In the investigation of high-speed systems, it is important that these effects are included in the analysis in order to accurately predict the critical speeds encountered due to the action of the gear mesh and other sources of excitation. The rotordynamic behaviour of the system can interact with crucial physical parameters of the transmission, such as the stiffnesses of the gear mesh and rolling element-to-raceway contact in the bearings. In addition, the presence of the gear mesh acts to couple the lateral and torsional vibration modes of a dual-shaft transmission through which a torque flows.
Technical Paper

Finite Element Model Reduction Applied to Nonlinear Impact Simulation for Squeak and Rattle Prediction

2020-09-30
2020-01-1558
Increasing demand for simulation accuracy often leads to increased model complexity, which in turn, results in higher computational costs. As a provision, Component Mode Synthesis approaches are employed to approximate the system response by using dynamic substructuring and model reduction techniques in linear systems. However, the use of available model reduction techniques in nonlinear problems has not been completely addressed. In this paper, the application of a Component Mode Synthesis method in squeak and rattle nonlinear simulation has been investigated. Critical regions for squeak and rattle of the side door model of a passenger car were modelled by nonlinear contact interfaces in finite element solution. Craig-Bampton model reduction method was employed to substructure the finite element model, while keeping the nonlinear contacts in the model.
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