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2016-04-05
Technical Paper
2016-01-0267
Rahul Rama Swamy Yarlagadda, Efstratios Nikolaidis, Vijay Kumar Devabhaktuni
Over the last two decades inverse problems have become increasingly popular due to their widespread applications. This popularity continuously demands designers to find alternative methods, to solve the inverse problems, which are efficient and accurate. It is important to use effective techniques that are both highly accurate and computationally efficient. This paper presents a method for solving inverse problems through Artificial Neural Network (ANN) theory. This paper also presents a method to apply Grey Wolf optimizer (GWO) algorithm to solve inverse problems. GWO is a recent optimization method demonstrating great results. Both of the methods are then compared to traditional methods such as Particle Swarm Optimization (PSO) and Markov Chain Monte Carlo (MCMC). Four typical engineering design problems are used to compare the four methods' performance. The results show that the GWO outperforms other methods both in terms of efficiency and accuracy.
2016-04-05
Technical Paper
2016-01-0047
Umesh Patel, Sreenivasa Parnasala, Chamaraj melinmath, Khalid KM, Chandrakantha Ursu
RACam is an Active Safety product designed and manufactured at Delphi and is part of their ADAS portfolio. It combines two sensors – Electronically Scanned RADAR and Camera in single box. RADAR and Vision fusion data is used to realize safety critical systems such as Adaptive Cruise Control (ACC), Autonomous Emergency Braking (AEB), Lane Departure Warning (LDW), Lane Keep Assist (LKA), Traffic Sign Recognition (TSR) and Automatic Headlight Control (AHL). With an increase in active safety features in the automotive market there is also a corresponding increase in the complexity of the hardware which supports these safety features. Delphi’s hardware design for active safety has evolved over the years. In Delphi’s RACam product there are a number of critical components required in order to realize Radar and Vision in a single package. RACam is also equipped with a fan and heater to increase the operating temperature range.
2016-04-05
Technical Paper
2016-01-0289
Balakrishna Chinta
Mahalanobis Distance (MD) is gaining momentum in many fields where classification, statistical pattern recognition, and forecasting are primary focus. It is a multivariate method and considers correlation relationships among parameters for computing generalized distance measure to separate groups or populations. MD is a useful statistic in multivariate analysis to test that an observed random sample is from a multivariate normal distribution. This capability alone enables engineers to determine if an observed sample is an outlier (defect) that falls outside the constructed (good) multivariate normal distribution. In Mahalanobis-Taguchi System (MTS), MD is suitably scaled and used as a measure of severity of an abnormality. It is obvious that computed MD depends on values of parameters observed on a random sample. All parameters may not equally impact MD. MD could be highly sensitive with respect to some parameters and less sensitive to some other parameters.
2016-04-05
Technical Paper
2016-01-0276
Mahalingesh Burkul, Hemant bhatkar, Mahesh Badireddy, Narayanan Vijayakumar
In an automotive product development environment, identifying the premature structural failures is one of the important tasks for Body-In-White (BIW), sub-assemblies and components. The integrated car body structure i.e. monocoque structure, is widely used in passenger cars and SUVs. This structure is subjected to bending and torsional vibrations, due to dynamic loads. Normally the stresses due to bending are relatively small compared to stresses due to torsion in Body-In-White under actual road conditions [1]. This paper focuses on evaluating the life of Body-In-White structures subjected to torsional loading. An accelerated test method was evolved for identifying failure modes of monocoque BIW by applying torsion fatigue. The observation of the crack generation and propagation was made with respect to a number of torsion fatigue cycles.
2016-04-05
Technical Paper
2016-01-0320
Tejas Janardan Sarang, Mandar Tendolkar, Sivakumar Balakrishnan, Gurudatta Purandare
In the automotive industry, multiple prototypes are used for vehicle development purpose. One of the challenging issues focused in R&D is the repeatability of durability tests, in order to get proper failure results for lifetime prediction. Durability test of a vehicle should have consistency throughout the testing period to provide accurate results for assessment and validation. The present work deals with more complex situations than what univariate methods can offer in terms of analysis. Hence, univariate analysis gives less accurate results in terms of checking the repeatability of tests. The current work deals with the development of a new repeatability analysis approach using multivariate analysis. The technique is developed with a non-parametric multivariate method called Mantel test which brings down all the complex parameters of the analysis to one number for checking the repeatability and take corrective measures accordingly.
2016-04-05
Technical Paper
2016-01-0271
David A. Warren
The objective of the paper is to outline the steps taken to change the reliability and maintenance environment of a plant from completely reactive to proactive. The main systems addressed are maintenance function fulfillment with existing staffing; work order management, planning, and scheduling; preventive maintenance (PM) definition and frequency establishment; predictive maintenance (PdM) scheduling and method definition; and shutdown planning and execution. The work order management methods were evaluated and modified to provide planning and scheduling of work orders on a weekly basis. The computerized maintenance and management system (CMMS) was updated to automatically insert work orders into the backlog of work for completion. A failure modes and effects analysis (FMEA) was performed and the results of the FMEA led to implementation of the following PM and PdM activities: vibration analysis, thermal imaging, and temperature monitoring.
2016-04-05
Technical Paper
2016-01-0270
Zhigang Wei, Limin Luo, Michael Start, Litang Gao
Statistical parameters, such as mean, standard deviation, in particular, failure probability are of significant interest to durability and reliability engineers. These parameters can be estimated from samples, however, these estimated parameters usually contain significant uncertainties and cannot be fully representative of the population, particularly, for test data with small sample sizes. Generally, sample size is a balanced result between durability/reliability performance and cost. There are several ways to characterize and quantify the uncertainty caused by the sample size effects, and one of the most commonly used engineering approach for failure probability is RxxCyy, in which xx and yy represent xx% reliability (R) and yy% confidence (C). RxxCyy criterion is commonly used in both test-to-failure method and the binomial test method [4-8].
2016-04-05
Technical Paper
2016-01-0283
Joydip Saha, Harry Chen, Sadek Rahman
More stringent Federal emission regulations and fuel economy requirements have driven the automotive industry toward more sophisticated vehicle thermal management systems which may include various new technologies such as active grill shutter, variable coolant flow control devices, PWM controlled fan and control strategies in order to best utilize the waste heat and minimize overall power consumption. With these new technologies and new devices, the comprehensive vehicle-thermal-system simulation tools are essential to evaluate and develop the optimal system solution for new cooling system architectures. This paper will discuss how the model-based vehicle thermal system simulation tools have been developed from analytical & empirical data, and have been used for assessment and development of new cooling system architectures.
2016-04-05
Technical Paper
2016-01-0274
Sharon L. Honecker, David J. Groebel, Adamantios Mettas
In order to accurately predict product reliability, it is best to design a test in which many specimens are tested for a long duration. However, this scenario is not often practical due to economic and time constraints. This paper describes a reliability test in which a limited number of specimens are tested with little time remaining before the scheduled start of production. During the test, an unexpected failure mode that can be mitigated through a product redesign occurs. Because the scheduled start of production is near, there is not time to perform a test with redesigned specimens, so the current test proceeds as planned. We discuss several methods and the associated assumptions that must be made to account for the presence of the unexpected failure mode in the test data in order to make predictions of reliability of the redesigned product.
2016-04-05
Technical Paper
2016-01-0268
Junqi Yang, Zhenfei Zhan, Ling zheng, Helen YU, Yazhou Jiang, Hui Zhao, Jie LI
Computer modeling and simulation have significantly facilitated the efficiency of product design and development in modern engineering, especially in the automotive industry. For the design and optimization of car models, optimization algorithms usually work better if the initial searching points are within or close to a feasible domain. Therefore, finding a feasible design domain in advance is beneficial. A data mining technique, ID3 (Iterative Dichotomizer 3), is exploited in this paper to identify a set of reduced feasible design domains from the original design space. Within the reduced feasible domains, optimal designs can be efficiently obtained while releasing computational burden in iterations. A mathematical example is used to illustrate the proposed method. Then an industrial application about automotive structural optimization is employed to demonstrate the proposed methodology. The results show its potential in practical engineering.
2016-04-05
Technical Paper
2016-01-0279
Chong Chen, Zhenfei Zhan, Jie Li, Yazhou Jiang, Helen YU
To reduce the computational time in the iterations of reliability-based design optimization, surrogate models are frequently utilized to approximate time-consuming computer aided engineering models. However, surrogate models introduces additional sources of uncertainty, such as model uncertainty. In this paper, an efficient uncertainty quantification method considering both model and parameter uncertainties is proposed. Firstly, the uncertainty of input parameters are represented in the form of Probability Density Function (PDF). Then, bias correction is then performed to improve the predictive capabilities of the surrogate models, whose uncertainty can be quantified as confidence intervals. Finally, Monte Carlo sampling is utilized to quantify the compound uncertainties. A numerical example and a real-world vehicle weight reduction design example are used to demonstrate the validity of the proposed method.
2016-04-05
Technical Paper
2016-01-0266
Greg K. Caswell, James McLeish
Package technology is constantly improving in order to keep up with the advances in silicon technology. MEMS packages exhibit several failure modes that can be predicted using modern software tools. This paper provides a methodology for creating a high-fidelity model of the interposer with all the conductor geometries. The two failure modes that are explored with this model are package warpage prediction due to actual copper imbalance and filled microvia delamination. Each layer can meshed based on the actual geometry in the layout design. Package warpage is caused by copper imbalance between the two sides of the interposer. The CTE mismatch between the two sides can bend the package to such a degree that it becomes impossible to assemble the solder interconnects. The filled microvias have copper structures that can delaminate from the copper traces in the conductor layers.
2016-04-05
Technical Paper
2016-01-0277
Xingxing Feng, Kaimin Zhuo, Jinglai Wu, Vikas Godara, Yunqing Zhang
Interval inverse problems can be defined as problems to estimate input through given output, where the input and output are interval numbers. Many problems in engineering can be formulated as inverse problems like vehicle suspension design. Interval metrics, instead of deterministic metrics, are used for the suspension design of a vehicle vibration model with five degrees of freedom. The vibration properties of a vehicle vibration model are described by reasonable intervals and the suspension interval parameters are to be solved. A new interval inverse analysis method, which is a combination of Chebyshev inclusion function and optimization algorithm such as multi-island genetic algorithm, is presented and used for the suspension design of a vehicle vibration model with six conflicting objective functions. The interval design of suspension using such an interval inverse analysis method is shown and validated, and some useful conclusions are reached.
2016-04-05
Technical Paper
2016-01-0269
Zhigang Wei, Michael Start, Jason Hamilton, Limin Luo
Durability and reliability performance is one of the most important concerns for vehicle components and systems, which experience cyclic fatigue loadings and may eventually fail over time. Durability and reliability testing is a critical process in product validation but it is usually costly and time consuming. Therefore, accelerated testing methods are often used to shorten the development time, reduce the associated cost while not significantly sacrifice the accuracy of the assessment. There are several commonly used accelerated testing methods available: accelerated test-to-failure, accelerated binomial testing (bogey testing), and accelerated degradation testing etc. However, these accelerated testing methods are often used separately and independently. Therefore, the maximum potential, in terms of efficiency and economy, of these accelerated testing methods has not been fulfilled. In this paper, a general framework for accelerated testing and data analysis is established.
2016-04-05
Technical Paper
2016-01-0281
Alaa El-Sharkawy, Dipan Arora, Abd El-Rahman Hekal, Amr Sami, Muhannad Hendy
In this paper, transient component temperatures in the vehicle under-hood and underbody are estimated. The main focus is on the component temperatures as a result of radiation from exhaust, convection by underbody or under-hood air and heat conduction through the components. The exhaust surface temperature is simulated as function of time and for various vehicle duty cycles such as city traffic, road load and grade driving conditions. At each time step the radiation flux to the surrounding component is estimated, heat addition or removal by convection is evaluated based on air flow, air temperature and component surface area. Geometrical properties of the components are obtained by fitting them into pre-set shapes (e.g., cylinders, spheres, ellipsoids, etc.).
2016-04-05
Technical Paper
2016-01-0280
Alaa El-Sharkawy, Amr Sami, Abd El-Rahman Hekal, Dipan Arora, Masuma Khandaker
`In this paper, the development a transient thermal analysis model for the exhaust system is presented. Given the exhaust gas temperature out of the engine, a software tool has been developed to predict changes in exhaust gas temperature and exhaust surface temperature under various operating conditions. The software is a thermal solver that will predict exhaust gas and wall surface temperature by modeling all heat transfer paths in the exhaust system which includes multi-dimensional conduction, internal forced/natural convection, external forced/natural convection, and radiation. The analysis approach involves the breaking down of the thermal system into multiple components, which include the exhaust system (manifold, takedown pipe, tailpipe, etc.), catalytic converter, DPF/GPF (diesel particulate filter or gasoline particulate filter), if they exist, thermal shields, etc.
2016-04-05
Technical Paper
2016-01-0282
Julio Abraham Carrera
Recent emissions standards have become more restrictive in terms of CO2 and NOx reduction. This has been translated into higher EGR rates at higher exhaust gas temperatures with lower coolant flow rates for much longer lifetimes. In consequence, Thermal Load for EGR coolers has been increased and boiling and its interaction with thermal fatigue are now a critical issue during their development. It is almost impossible to avoid localized boiling inside an EGR cooler and, in fact, it would not be strictly necessary when it is below the Critical Heat Flux (CHF). However when CHF is exceeded, film boiling occurs leading to the sudden drop of the heat transfer rate and the metal temperature rise. In consequence, thermal stress increases even when film boiling is reached only in a small area inside the part. It is very difficult to accurately predict under which conditions CHF is reached and to stablish the margins to avoid it.
2016-02-03
Standard
J1555_201602
This SAE Recommended Practice applies to all portions of the vehicle, but design efforts should focus on components and systems with the highest contribution to the overall average repair cost (see 3.7). The costs to be minimized include not only insurance premiums, but also out-of-pocket costs incurred by the owner. Damageability, repairability, serviceability and diagnostics are inter-related. Some repairability, serviceability and diagnostics operations may be required for collision or comprehensive loss-related causes only. Some operations may be for non-collision-related causes only (warranty, scheduled maintenance, non-scheduled maintenance, etc.). Some may be required for both causes. The scope of this document deals with only those operations that involve collision and comprehensive insurance loss repairs.
2016-01-07
WIP Standard
ARP1247E
This SAE Aerospace Recommended Practice (ARP) outlines the basic general design requirements for ground support equipment used in the civil air transport industry. It is intended to assist the airlines in standardizing requirements for various configurations of equipment. For procurement of equipment, sections of this document should be specified with due consideration of the functional and environmental requirements of the equipment, and to the relative cost of satisfying those requirements.
2016-01-04
WIP Standard
AIR5552A
This information report provides general guidance for the design considerations, qualification in endurance, strength and fatigue of landing gear using composite components as principle structural elements. The information discussed herein includes the development and evaluation of design data considering: the potential for imbedded manufacturing defects, manufacturing process variations, the component operating environment, potential damage threats in service, rework and overhaul, and inspection processes. This AIR mainly discusses the use of thick composites for landing gear structural components. Considerations and recommendations provided in this AIR may therefore differ greatly from considerations and recommendations found in widely accepted composite design references such as CMH-17 and Advisory Circulars such as AC 20-107(B).
2016-01-03
WIP Standard
AIR6900
This AIR will address the need for a strategy to achieve aircraft operating certificate holder maintenance efficiencies within the existing regulatory environment as well as the need for regulation, policy, and guidance changes in the long-term to accommodate more complex IVHM solutions. This document will analyse which IVHM solutions can be incorporated within existing maintenance procedures and which also comply with regulations, policy, and guidance. One of the AIR’s objectives is to define best practices for aircraft operating certificate holders to engage with regulators to get approval for simpler IVHM applications leading to maintenance efficiencies. Additionally, this document will analyse the barriers that existing regulations, policy, and guidance present to the implementation of more advanced IVHM solutions. The result is a set of recommendations to certify and implement end-to-end IVHM solutions for the purpose of gaining maintenance efficiencies.
2015-12-09
WIP Standard
AS6372
This standard shall apply to all commercial human suborbital spaceflights governed by the Commercial Space Launch Amendments Act of 2004.
2015-11-23
Book
John Day
Sophisticated infotainment systems, lane departure warning, adaptive cruise control, and blind-spot monitoring are increasingly common in cars today. The proliferation of automotive electronics and other “smart” features has increased the market for automotive semiconductor devices and the number of sensors per vehicle. Yet, more chips and greater functionality translate to further networking/communications activity within the car, and that raises the prospect of potentially serious errors.
2015-10-23
WIP Standard
AS6896
Definition of target design and location on aircraft, that will be used: - To provide correct GSE alignment support and docking when approaching the aircraft in automatic, semi-automatic or manual mode - by GSE autoleveling system to detect and follow aircraft vertical movements
2015-10-21
WIP Standard
ARP1804B
This SAE Aerospace Recommended Practice (ARP) outlines the design and performance requirements for a battery-powered electric tow tractor for the handling of baggage or cargo trailers in airline service. The use of "shall " in this document indicates a mandatory requirement. The use of "should " indicates a recommendation or that which is advised but not required.
2015-10-19
WIP Standard
AS6350
Recent Salt-Fog environmental qualification testing in accordance with RTCA/DO-160G, Paragraph 14, Category S identified both discrepancies in the performance specification documents and potential in-service corrosion problems with the charging valve. A new SAE AS for Valve; Aircraft, Pneumatic, High-Pressure Charging is necessary to resolve these items.
2015-10-14
WIP Standard
ARP4754B
This document discusses the development of aircraft systems taking into account the overall aircraft operating environment and functions. This includes validation of requirements and verification of the design implementation for certification and product assurance. It provides practices for showing compliance with the regulations and serves to assist a company in developing and meeting its own internal standards by considering the guidelines herein.
2015-10-02
WIP Standard
AIR4905A
The purpose of this document is to present general considerations for the design and use of aircraft wheel chocks. The design and use of aircraft wheel chocks is a good deal more complicated than it may appear at first glance.
2015-09-15
Technical Paper
2015-01-2556
Thomas Rousselin, Guillaume Hubert, Didier Regis, Marc Gatti
Abstract The changes brought by the increasing integration density and the new technological trends have pushed the reliability at its limit. Safety analysis for critical system such as embedded electronics for avionics systems needs to take into account these changes. In this paper, we present the consequences on the deep sub-micron (DSM) CMOS devices concerning their single event effect (SEE) sensitivity. We also propose a new modeling method in order to address these issues.
2015-08-04
WIP Standard
AIR4730A
This document provides information on the preparation and use of video for operational and maintenance training of personnel associated with GSE.
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