Browse Topic: Failure modes and effects analysis (FMEA)

Items (765)
Opening a tailgate can cause rain that has settled on its surfaces to run off onto the customer or into the rear loadspace, causing annoyance. Relatively small adjustments to tailgate seals and encapsulation can effectively mitigate these effects. However, these failure modes tend to be discovered relatively late in the design process as they, to date, need a representative physical system to test – including ensuring that any materials used on the surface flow paths elicit the same liquid flow behaviours (i.e. contact angles and velocity) as would be seen on the production vehicle surfaces. In this work we describe the development and validation of an early-stage simulation approach using a Smoothed Particle Hydrodynamics code (PreonLab). This includes its calibration against fundamental experiments to provide models for the flow of water over automotive surfaces and their subsequent application to a tailgate system simulation which includes fully detailed surrounding vehicle geometry
Gaylard, Adrian PhilipWeatherhead, Duncan
Several challenges remain in deploying Machine Learning (ML) into safety critical applications. We introduce a safe machine learning approach tailored for safety-critical industries including automotive, autonomous vehicles, defense and security, healthcare, pharmaceuticals, manufacturing and industrial robotics, warehouse distribution, and aerospace. Aiming to fill a perceived gap within Artificial Intelligence and ML standards, the described approach integrates ML best practices with the proven Process Failure Mode & Effects Analysis (PFMEA) approach to create a robust ML pipeline. The solution views ML development holistically as a value-add, feedback process rather than the resulting model itself. By applying PFMEA, the approach systematically identifies, prioritizes, and mitigates risks throughout the ML development pipeline. The paper outlines each step of a typical pipeline, highlighting potential failure points and tailoring known best practices to minimize identified risks. As
Schmitt, PaulSeifert, Heinz BodoBijelic, MarioPennar, KrzysztofLopez, JerryHeide, Felix
This paper presents Matchit, a novel method for expediting issue investigation and generating actionable insights from textual data. Recognizing the challenges of extracting relevant information from large, unstructured datasets, we propose a domain-adaptable approach by integrating expert domain knowledge to guide Large Language models (LLMs) to automatically identify and categorize key information into distinct topics. This process offers two key functionalities: fully automatic topic extraction based solely on input data, providing a concise overview of the problem and potential solutions, and user-guided extraction, where domain experts can specify the type of information or pre-defined categories to target specific insights. This flexibility allows for both broad exploration and focused analysis of the data. Matchit's efficacy is demonstrated through its application in the automotive industry, where it successfully extracts repair diagnostics from diverse textual sources like
Wang, LijunArora, Karunesh
Continuing prior work, which established a simulation workflow for fatigue performance of elastomeric suspension bushings operating under a schedule of 6-channel (3 forces + 3 moments) road load histories, the present work validates Endurica-predicted fatigue performance against test bench results for a set of multi-channel, time-domain loading histories. The experimental fatigue testing program was conducted on a servo-hydraulic 3 axis test rig. The rig provided radial (cross-car), axial (for-aft), and torsional load inputs controlled via remote parameter control (rpc) playback of road load data acquisition signals from 11 different test track events. Bushings were tested and removed for inspection at intervals ranging from 1x to 5x of the test-equivalent vehicle life. Parts were sectioned and checked for cracks, for point of initiation and for crack length. No failure was observed for bushings operated to 1 nominal bushing lifetime. After 3 nominal bushing lifetimes, cracks were
Mars, WillBarbash, KevinWieczorek, MatthewPham, LiemBraddock, ScottSteiner, EthanStrumpfer, Scott
The modern luxurious electric vehicle (EV) demands high torque and high-speed requirements with increased range. Fulfilling these requirements, arises the need for increased electric current supply to motors. Increased amperage through the stator causes higher losses resulting in elevated temperature across the motor components and its housing. In most of the cases, stator is mounted on the housing through interference fit to avoid any slippage during operation conditions. High temperature across the stator and housing causes significant thermal expansions of the components which is uneven in nature due to the differences in corresponding coefficient of thermal expansion (CTE) values. Housings are generally made of aluminium and tends to expand more having higher value of CTE than that of steel core of stator which may give rise to a failure mode related to stator slippage. To address this slippage if the amount of interference fit is increased, that’ll result in another failure mode
Karmakar, NilankanPrasad, Praveen
Vibration qualification tests are indispensable for vehicle manufacturers and suppliers. Carmakers’ specifications are therefore conceived to challenge the mechanical endurance of car components in the face of numerous in-service detrimental phenomena: In automotive industries, components are commonly qualified by means of a test without failure, the goal being to determine whether it will or not "pass" customer requirements. Validation of newly designed components is obtained via bench test and structural simulation. Simulation has gained traction in recent years because it represents the first step of the design validation process. In particular, FEA simulations are powerful to predict the dynamic behavior of physical testing on prototypes, enable engineers to optimize the design and predict the durability. This paper illustrates how FEA simulations were applied to product validation in the pre-serial phase to optimize manufacturing process. In particular, we will focus on the PCB of
Duraipandi, Arumuga PandianLeon, RenanBonato, MarcoRaja, Antony VinothKumar, LalithNiwa, Takehiro
A key challenge for manufacturers of automotive systems, hardware components and software products with no contribution to driving automation is the stringent requirements imposed on elements while being integrated into vehicles with driving automation. The result is increased development cost and low reusability. For such elements or components with no contribution to driving automation, their functions and failure modes remain unchanged when comparing vehicle integration with and without driving automation. The influence of driving automation is not accounted for in the current approach of classifying risk while conducting a Hazard Analysis and Risk Assessment (HARA). Functional safety standards for on-road vehicles rely on human intervention as a parameter to classify risk. Since current safety standards for on-road vehicles are not inclusive of driving automation concepts, classification of risk, based on existing definitions of parameters such as controllability, leads to
Shah, MihirIbarra, Ireri
As electric vehicles (EVs) become increasingly prevalent, ensuring the safety of their battery systems is paramount. Lithium-ion batteries, present unique safety challenges due to their high energy density and the potential for failure under certain conditions. There is an extensive amount of research on pouch and cylindrical cells, however, prismatic cells have not received similar attention. This study presents an extensive series of experimental tests conducted on prismatic cells from two different manufacturers. These tests include flat punch, hemispherical punch, axial compression and three-point bending tests, all designed to assess the cells’ mechanical properties and failure behavior. A model was developed simulating the behavior of the cell under local loading scenarios. While this paper focuses primarily on testing methodologies, initial findings and an introductory FEA model, future work will incorporate these experimental results into detailed FEA models across all loading
Patanwala, HuzefaSong, YihanSahraei, Elham
Designing for the durability of motor vehicles requires accounting for various stress factors, including tractive loads, electrical loads, thermal loads, and structural loads. For electric vehicle propulsion systems, it is crucial to consider not just the magnitude and repeats of these loads but also their temporal sequence throughout the vehicle’s lifespan. The order and timing of these loads influence factors such as, charge and discharge cycles or active motor heating, which ultimately impact the damage to the propulsion system components like the cell and the motor. Traditionally, lifetime loads for durability assessments are derived from a single-user load profile consisting of a set of ‘representative’ drive cycles accounting for the cumulative damage equivalent to the real-world damage covered under warranty. This profile is typically based on historical usage data, user scenarios, and industry experience, but may not capture the diverse failure modes of the different propulsion
Ramakrishnan, SankaranKhapane, Prashant
The automotive industry leverages Fused Filament Fabrication (FFF) -based Additive Manufacturing (AM) to reduce lead time and costs for prototypes, rapid tooling, and low-volume customized designs. This paper examines the impact of print orientation and raster angle on the tensile properties of Polylactic Acid (PLA), selected for its ease of use and accessibility. Dog bone samples were designed to the ASTM D638 tensile testing standard and printed solid with a 0.2 mm layer height, two outer walls, and varying raster-fill angles, with layers alternating by 90°. Testing was conducted on the MTS Criterion Model 43, 50 kN system. Varying print orientation along the X and Y axes (double angle builds) produced a Young's modulus (YM) range of 0.7519, reflecting a 34.42% increase between the witnessed minimum and maximum values. These builds exhibited more brittle behavior than most single angle builds, except for X10 Y10 Z0 at a 45° raster (the lowest recorded YM) and X0 Y15 Z0 at a 30
Strelkova, DoraUrbanic, Ruth Jill
With the development of automated vehicle (AV), it is essential to ensure their safety even in the presence of system faults or function inefficiency. Safety controllability refers to the ability to manage and control the vehicle, ensuring that it remains safe even in the presence of faults with unexpected conditions. This study proposed a data driven method to evaluate quantitatively safety controllability for AVs. Safety analysis is conducted to identify the potential hazard events. Taking system function and architecture into consideration, the failure modes of the vehicle hazards are identified with hazardous driving situation. Based on the identified failure modes, fault injection tests are conducted with critical scenarios. According to the vehicle dynamic performance, the improved analytic hierarchy process (AHP) can be explored to quantitatively evaluate the safety controllability based on fault injection test results. In particular, this study focuses on the case study to
Ye, XiaomingYang, YandingLi, LingyangZhang, YaguoWang, Yongliang
Introducing connectivity and collaboration promises to address some of the safety challenges for automated vehicles (AVs), especially in scenarios where occlusions and rule-violating road users pose safety risks and challenges in reconciling performance and safety. This requires establishing new collaborative systems with connected vehicles, off-board perception systems, and a communication network. However, adding connectivity and information sharing not only requires infrastructure investments but also an improved understanding of the design space, the involved trade-offs and new failure modes. We set out to improve the understanding of the relationships between the constituents of a collaborative system to investigate design parameters influencing safety properties and their performance trade-offs. To this end we propose a methodology comprising models, analysis methods, and a software tool for design space exploration regarding the potential for safety enhancements and requirements
Fornaro, GianfilippoTörngren, MartinGaspar Sánchez, José Manuel
In the Agricultural tractor- transmission system plays major role to transfer power from Engine to final drive through gear box enabling Forward/Reverse (F/R) movements during field operations and transportation conditions. The F/R retainer plate with idler gear, shaft is located between clutch housing and transmission gear box housing. If the retainer housing plate gets failure, then power will not be able to transfer from engine to transmission gear box main drive. In one of the tractor model retainer plate failures was observed during field testing. To simulate the failure mode from field to lab condition, the resultant forces and angle were calculated based on the drive line assembly. Resultant loads were applied on Idle gear shaft assembly through servo actuator in cyclic mode at lab. The failure was observed in the retainer plate and the location of failure was matching with field failure. CAE virtual simulation was carried out for measured load as per the laboratory boundary
V, SaravananMani, SureshKumar, SasiMore, AmitDumpa, Mahendra Reddy
In some IC engines, fuel injection pump is driven by camshaft; thus, these camshafts are designed for bending and torsional loads. Conventionally, camshafts are built-to-specification. Typically, durability assessment of camshaft happens at engine level, this calls for proto or calibration engine to be made and available for testing. As there are limited number of engine level proto testing, the overall scatter in camshafts due to manufacturing/process variations is not possible to be covered. This poses a risk of camshaft failures in the final stages of product development. To mitigate this risk, a component level standard test method is needed for quickly validating design and manufacturing process of camshafts for second source suppliers. The current paper discusses the process followed for arriving at a standard test setup and overcoming the challenges in terms of capturing the appropriate physics for camshaft failure during the engine level testing. Camshaft rear end experiences
Chakraborty, AbhirupS, AravamuthanK, Karthikeyan
A 20-cell self-humidifying fuel cell stack containing two types of MEAs was assembled and aged by a 1000-hour durability test. To rapidly and effectively analyze the primary degradation, the polarization change curve is introduced. As the different failure modes have a unique spectrum in the polarization change curve, it can be regarded as the fingerprint of a special degradation mode for repaid analysis. By means of this method, the main failure mode of two-type MEAs was clearly distinguished: one was attributed to the pinhole formation at the hydrogen outlet, and another was caused by catalyst degradation only, as verified by infrared imaging. The two distinct degradation phases were also classified: (i)conditioning phase, featuring with high decay rate, caused by repaid ECSA change from particle size growth of catalyst. (ii) performance phase with minor voltage loss at long test duration, but with RH cycling behind, as in MEA1. Then, an effective H2-pumping recovery is conducted
Pan, ChenbingWu, HailongRuyi, Wang
This document presents minimum criteria for the design and installation of LED assemblies in aircraft. The use of "shall" in this specification expresses provisions that are binding. Nonmandatory provisions use the term "should."
A-20C Interior Lighting
SBW(Steer-by-wire) is a steering system that transmits the driver’s request and gives feedback to the driver through electrical signals. This system eliminates the mechanical connection of the traditional steering system, and can realize the decoupling of the steering wheel and the road wheel. In addition, this system has a perfect torque feedback system, which can accurately and delicately feedback the road surface information to the driver. However, vehicle driving deviation is one of the most common failure modes affecting vehicle performance in the automotive aftermarket, this failure mode can exacerbates tire wear, reducing their life cycle, at the same time, the driver must apply a counter torque to the steering wheel for a long time to maintain straight-line travel during driving. This increases the driver’s operational burden and poses safety hazards to the vehicle’s operation. Based on the steer-by-wire system and vehicle driving deviation characteristics, this paper proposes
Xiangfei, XuQu, Yuan
In demanding automotive coolant applications characterized by extreme pressure and temperature conditions, a variety of Mechanically Attached Fittings (MAFs) are offered by multinational corporations (MNCs). These engineered fittings have been designed to meet the rigorous requirements of various industries, providing a cost-effective and reliable means to seal engine/motor coolant hose joints. Mechanical fitting assemblies are critical in various engineering systems and are used for connecting various fluid-carrying locations. Understanding leakage phenomena from MAFs is essential for ensuring their reliability and efficiency. This study explores the deployment of Fluid Pressure Penetration Technique (FPPT) available in Abaqus FEA software to comprehensively analyze leakage paths in mechanically joined fittings. The FPPT offers a systematic approach to model fluid penetration behavior within fitting joints under many loading conditions. By utilizing Abaqus software, a powerful finite
Aher, Ravi KautikJivani, ChinmayOlesnavich, MichaelLima, JosePillai, Pramod
Transit agencies around the world have been investing in more battery electric buses (BEB) in an effort to combat the growing negative externalities stemming from the use of petrochemicals in combustion transit vehicles. These buses use new propulsion systems based primarily on lithium-ion batteries to cut carbon pollution and promote cleaner, faster, and safer rides. As new electrification technologies continue to penetrate the bus transit market, there is a continuous need to evaluate the safety and performance of these battery electric systems. To meet the safety and performance needs of technologies in transit buses, regulations and standards have been established to define best testing and industry practices. This paper details the current state of battery standards and regulations in automotive and transit vehicles, with consideration of battery failure modes and effects. Various governments and standard organizations have established numerous different regulations and standards
Jankord, GregoryGravante, EmanueleD'Arpino, Matilde
This SAE Aerospace Standard (AS) defines the requirements for air cycle air conditioning systems used on military air vehicles for cooling, heating, ventilation, and moisture and contamination control. General recommendations for an air conditioning system, which may include an air cycle system as a cooling source, are included in MIL-E-18927E and JSSG-2009. Air cycle air conditioning systems include those components which condition high temperature and high pressure air for delivery to occupied and equipment compartments and to electrical and electronic equipment. This document is applicable to open and closed loop air cycle systems. Definitions are contained in Section 5 of this document.
AC-9 Aircraft Environmental Systems Committee
The purpose of air conditioning (AC) duct packing is multifaceted, serving to prevent condensation, eliminate rattle noise, and provide thermal insulation. A critical aspect of duct packing is its adhesive quality, which is essential for maintaining the longevity and effectiveness of the packing's functions. Indeed, the challenge of achieving adequate adhesivity on AC ducting parts is significant due to the harsh operating conditions to which these components are subjected. The high temperatures and presence of condensation within the AC system can severely compromise the adhesive's ability to maintain a strong bond. Moreover, the materials used for these parts, such as HDPE, often have low surface energy, which further hinders the formation of a durable adhesive bond. The failure of the adhesive under these conditions can lead to delamination of the duct packing, which can result in customer inconvenience due to rattling noises, potential electrical failures if condensed water
M, Amala RajeshSonkar, SurabhiKumar, Mukesh
In the rapidly evolving landscape of electronic engineering, the reliability of electronic components under varying thermal conditions has emerged as a paramount concern. This paper presents an integrated approach for the reliability analysis of electronic components, emphasizing thermal impacts. Our methodology synergizes computational thermal analysis, experimental stress testing, and Failure Modes, Effects, and Diagnostic Analysis (FMEDA) to offer a comprehensive framework for assessing and enhancing component reliability, specifically focusing on a case study of motorcycle hand control switches. The approach begins with a detailed thermal simulation to identify potential hot spots and thermal gradients across electronic components under different operational scenarios. For the case study, motorcycle hand control switches a critical interface between the rider and the motorcycle's electrical system were subjected to this analysis to predict thermal behavior under varied
Mote, ShwetaJadhav, ShantaramChaudhari, VijayMhaske, Aashay
This standard defines requirements for the identification, assessment, mitigation, and prevention of risk in the manufacturing process through the application of Process Flow Diagrams (PFDs), Process Failure Mode and Effects Analysis (PFMEA) and Control Plans throughout the life cycle of a product. This standard aligns and collaborates with the requirements of AS9100, AS9102, AS9103, and AS9145. The requirements specified in this standard apply in conjunction with and are not alternative to contractual and applicable statutory and regulatory requirements. In case of conflict between the requirements of this standard and applicable statutory or regulatory requirements, the latter shall take precedence.
G-22 Aerospace Engine Supplier Quality (AESQ) Committee
Geared automotive and aerospace transmissions are one of the most critical systems regarding wear. Limiting wear is of paramount importance to improve sustainability by reducing replacements that lead to increased waste and energy consumption for re-manufacturing. Simulation of gears including the wear effect can be very useful for the design of new more efficient and compact gears. Thermal effects may play a decisive role in the wear phenomena and should be included in the models used for simulations. In this study, some tests are conducted on a pin-on-disk apparatus under varying temperatures to assess its influence on steel-to-steel wear rate. A modified Archard law is used for wear estimation which includes the experimentally derived parameters accounting for thermal effects. This model is then coupled with a loaded tooth contact analysis (LTCA) tool to obtain accurate predictions of the contact pattern, as well as the instantaneous load shared by the mating teeth pairs during the
Grabovic, EugeniuCiulli, EnricoArtoni, AlessioGabiccini, Marco
Rolling bearings play a critical role in rotating machinery, with their fatigue life directly impacting equipment’s operational reliability. This underscores the significant engineering application value of “fault diagnosis” (FD) technology for rolling bearings in mechanical, automation, and aerospace domains. Literature reviews highlight that a substantial portion of failures in machinery such as jet turbine engines, wind turbines, gear reducers, and induction machines are attributable to bearing issues. Early fault detection and preventive maintenance are therefore imperative for ensuring the smooth operation of rotating machinery. This paper focuses on rolling bearings, delving deep into FD technology using machine learning principles. It analyses the structure and common failure modes of rolling bearings, discussing an FD method based on machine learning. Specifically, the SE-DRN (“squeeze-exclusion deep residual network”) approach is employed, leveraging “variational modal
Muin, Abdullah-AlKhan, ShahrukhMiah, Md Helal
With the increasing demand of human–machine interaction under a scenario of the novel Maintenance Strategy 5.0, it sparks off a growing requisition of reliable maintenance strategies to maintain operations in good order. In this study, a novel hierarchical maintenance strategy model based on multi-criteria decision analysis (MCDA) is proposed to pledge scientific maintenance. First, failure mode and effects analysis (FMEA) based on negative information and Deng entropy is introduced to assess the equipment maintenance requirement level. Subsequently, the improved average rank method is selected to fit the Weibull distribution function, which is able to better qualify the characteristics lifespan of target equipment. Moreover, hybrid effect with multi-criteria decision-making, in aspects of risk priority, expert assessment as well as human interference of failure are deduced, which highlights the scientific significance and credibility of the recommended maintenance levels and times
Wei, MingxinPan, ZheshengWang, ChengxiangMa, ZexinLi, GuoxiangZhao, FeiyangYu, WenbinZhu, Sipeng
Verification and validation (V&V) is the cornerstone of safety in the automotive industry. The V&V process ensures that every component in a vehicle functions according to its specifications. Automated driving functionality poses considerable challenges to the V&V process, especially when data-driven AI components are present in the system. The aim of this work is to outline a methodology for V&V of AI-based systems. The backbone of this methodology is bridging the semantic gap between the symbolic level at which the operational design domain and requirements are typically specified, and the sub-symbolic, statistical level at which data-driven AI components function. This is accomplished by combining a probabilistic model of the operational design domain and an FMEA of AI with a fitness-for-purpose model of the system itself. The fitness-for-purpose model allows for reasoning about the behavior of the system in its environment, which we argue is essential to determine whether the
Paardekooper, Jan-PieterBorth, Michael
The modern automotive industry is facing challenges of ever-increasing complexity in the electrified powertrain era. On-board diagnostic (OBD) systems must be thoroughly calibrated and validated through many iterations to function effectively and meet the regulation standards. Their development and design process are more complex when prototype hardware is not available and therefore virtual testing is a prominent solution, including Model-in-the-loop (MIL), Software-in-the-loop (SIL) and Hardware-in-the-loop (HIL) simulations. Virtual prototype testing relying on real-time simulation models is necessary to design and test new era’s OBD systems quickly and in scale. The new fuel cell powertrain involves new and previously unexplored fail modes. To make the system robust, simulations are required to be carried out to identify different fails. Thus, it is imminent to build simulation models which can reliably reproduce failures of components like the compressor, recirculation pump
Pandit, Harshad RajendraDimitrakopoulos, PantelisShenoy, ManishAltenhofen, Christian
The Aerospace Industry's drive towards zero defects has seen a significant shift to prevent defects and improve product quality during the design phase, instead of waiting until post-production inspection to discover and troubleshoot problems. Trying to ensure zero defects during the post-production inspection phase is too late in the product life cycle because it can lead to substantial costs. Aerospace Engine Supplier Quality (AESQ) introduced the Advanced Product Quality Planning (APQP) [2] process to realize zero defects. In APQP Phase 2 [2], Product and Design Development, a key output is performing a Design Failure Modes and Effects Analysis (DFMEA). Moog has effectively implemented a DFMEA process that adeptly identifies and mitigates design risks. This work showcases Moog's successful deployment of DFMEA, exemplifying the industry best practices. This work also presents simplified and innovative interpretations of DFMEA definitions and approaches. By addressing defects during
Shah, AchintShea, RachelleSiskowski, Bruce
Thermo-mechanical fatigue and natural aging due to environmental conditions are challenging to simulate in an actual test with advanced fiber-reinforced composites, where their fatigue and aging behavior are little understood. Predictive modeling of these processes is challenging. Thermal cyclic tests take a prohibitively long time, although the strain rate effect can be scaled well for accelerating the mechanical stress cycles. Glass fabric composites have important applications in pipes, aircraft, and spacecraft structures, including microwave transparent structures, impact-resistant parts of the wing, fuselage deck and many other load-bearing structures. Often additional additively manufactured features and coatings on glass fabric composites are employed for thermal and anti-corrosion insulations. In this paper, we employ a thermo-mechanical fatigue model based on an accelerated fatigue test and life prediction under hot-to-cold cycles. Thermo-mechanical strain-controlled stress
Kancherla, Kishore BabuB S, DakshayiniRaju, BenjaminRoy Mahapatra, Debiprosad
Hydraulic systems in aircraft largely comprise of metallic components with high strength to weight ratios. Some examples of such material include Aluminum and Titanium alloys which are typically chosen for low and high-pressure applications respectively. For aircraft fluid conveyance products, hydraulic conduits are fabricated by axisymmetric turning to support flow conditions. The hydraulic conduits can have grooved interfaced design within for placement of elastomeric sealing components. This article presents a systematic study carried out on common loads experienced by fluid carrying conduits and the failure modes induced. Firstly, a static structural analysis was carried out on each of the geometries of the test articles to identify the locations having areas of high stress concentration. Test articles of various wall thicknesses and internal diameters were pressure impulse tested at different conditions of side loads to identify cycle numbers till failure and failure locations. On
Paidimarri, VishalJacob, KrupaHarish, UppuHovis, David
With globalization, vehicles are sold across the world throughout different markets and their automotive brake systems must function across a range of environmental conditions. Currently, there is no current standardized test that analyzes brake pads’ robustness against severe cold and humid environmental conditions. The purpose of this proposed test method is to validate brake system performance under severe cold conditions, comparing the results with ambient conditions to evaluate varying lining materials’ functional robustness. The goal of this paper is to aid in setting a standardized process and procedure for the testing of automotive brakes’ environmental robustness. Seven candidate friction materials were selected for analysis. The friction materials are kept confidential. Design of experiment (DOE) techniques were used to create a full-factorial test plan that covered all combinations of parameters. The test script involves brake applications at 5, 10, 15, and 20 bar, at both
Passador, Stephen Daniel AustinBoudreau, Douglas BarretCapacchione, Christopher James
The qualification requirements of automakers derive from track testing in which road load and moment inputs to a part in x, y and z directions are recorded over a set of driving conditions selected to represent typical operation. Because recorded histories are lengthy, often comprising many millions of time steps, past industry practice has been to specify simplified block cycle schedules for purposes of durability testing or analysis. Simplification, however, depends on imprecise human judgement, and risks fidelity of the inferred life and failure mode relative to actual. Fortunately, virtual methods for fatigue life prediction are available that are capable of processing full, real-time, multiaxial road load histories. Two examples of filled natural rubber ride bushings are considered here to demonstrate. Each bushing is subject to a schedule of 11 distinct recorded track events. Endurica EIETM map building procedures are first used together with a finite element solution to map the
Mars, WilliamBarbash, KevinWieczorek, MatthewBraddock, ScottGoossens, JoshuaSteiner, Ethan
The modern luxurious electric vehicle (EV) demands high torque and high-speed requirements with increased range. Fulfilling these requirements gives rise to the need for increased efficiency and power density of the motors in the Electric Drive Unit (EDU). Internal Permanent Magnet (IPM) motor is one of the best suited options in such scenarios because of its primary advantages of higher efficiency and precise control over torque and speed. In the IPM motor, permanent magnets are mounted within the rotor body to produce a resultant rotating magnetic field with the 3-phase AC current supply in the stator. IPM configuration provides structural integrity and high dynamic performance as the magnets are inserted within the rotor body. Adhesive glue is used to install the magnets within the laminated stack of rotor. High rotational speed of rotor introduces centrifugal loading on the magnets which can result in multiple failure modes such as the debonding of the magnet, and high radial
Karmakar, NilankanP, PraveenGoel, Ashish
The paper introduces two methods for controlling motor voltage. One method requires the implementation of boost hardware, while the other allows for voltage control in battery failure mode without any additional hardware requirements. The boost voltage strategy for the hybrid system is based on managing boost modes, determining target voltages, and implementing PI control. The boost mode control includes different modes such as initial mode, normal mode, shutdown mode, and fault mode. Determining the boost target voltage involves regulating the boost converter with variable voltages depending on the operating states of the motor and generator. The second voltage control method without boost hardware is proposed in order to ensure that the vehicle can still function like a traditional car even under abnormal conditions of high-voltage battery failure in micro-mixing systems. In this mode, instead of conventional torque control, the generator operates in a voltage control mode where
Jing, JunchaoSun, XudongLiu, YiqiangHuang, Weishan
Validation of powertrain systems is nowadays performed with specific durability relevant load cycles, which represent the lifetime requirement of individual powertrain components. The definition of such durability relevant load cycles, which are used for vehicle testing should ideally be based on the actual vehicle's usage. Recording driving cycles within a vehicle is one of the most typical ways of collecting vehicle usage and relevant end customer behavior, but the generation of such measured vehicle data can be time consuming. In addition, this method of capturing on-road measurements has limitations in the variation of vehicle loadings (e.g., number of passengers, luggage, trailer usage etc.). Especially for new applications, entering new target markets, these kinds of in-vehicle measurements are not possible in early development stages, as the required vehicle or powertrain configuration is not available in hardware or incapable of measurements. This paper shows a method to
Haspl, AndreasUnterweger, MichaelaKuruc, JanPlettenberg, MirkoAkasapu, Uday Venkateswar
Complex chassis systems operate in various environments such as low-mu surfaces and highly dynamic maneuvers. The existing metrics for lateral motion hazard by Neukum [13] and Amberkar [17] have been developed and correlated to driver behavior against disturbances on straight line driving on a dry surface, but do not cover low-mu surfaces and dynamic driving scenarios which include both linear and nonlinear region of vehicle operation. As a result, an improved methodology for evaluating vehicle yaw dynamics is needed for safety analysis. Vehicle yaw dynamics safety analysis is a methodical evaluation of the overall vehicle controllability with respect to its yaw motion and change of handling characteristic. The yaw dynamics safety analysis is crucial for understanding how a driver-vehicle system responds to disturbances (external forces such as failure modes) in various driving scenarios and maneuvers., and it plays a significant role in evaluating the overall safety and performance of
paik, ScottAlmasri, HossamRao Medidha, NeelakantaCapobianco, AnthonyEvans, AndrewSevillano, Yvette
Lithium-ion batteries serve as the main power source for contemporary electric vehicles. Safeguarding these batteries against damage is paramount, as it can trigger accelerated performance deterioration, potential fire hazards, environmental threats, and more. This study explores damage progression of a commercial vehicle lithium-ion battery module containing prismatic cells under indentation crush loading. We employed computational simulations of mechanical loading tests to investigate this behavior. Physical tests involved subjecting modules to low-speed (0.05 m/s) indentations using a V-shaped stainless-steel wedge, under six unique loading conditions. During the tests, force, and voltage change with wedge displacement were monitored. Utilizing experimental insights, we constructed a finite element model, which included key components of the battery module, such as the prismatic cells, steel frames, and various plastic parts. The finite element model reproduced failure modes
Zhu, FengLogakannan, KrishnaXu, SidaSypeck, David
Steer-By-Wire (SBW) system directly transmits the driver's steering input to the wheels through electrical signals. However, the reliability of electronic equipment is significantly lower than that of mechanical structures, and the risk of failure increases, so it is important to conduct functional safety studies on SBW systems. This paper develops the functional safety of the SBW system according to the requirements of the international standard ISO26262, and first defines the relevant items and application scope of SBW system. Secondly, the Hazard and Operability (HAZOP) method was used to combine scenarios and possible dangerous events to carry out Hazard Analysis and Risk Assessment (HARA), and the Automotive Safety Integrity Level (ASIL) was obtained according to the three evaluation indicators of Exposure, Severity and Controlabillity, and then the corresponding safety objectives were established and Fault Tolerant Time Interval (FTTI) was set. Finally, the safety analysis of the
Li, AohanKaku, ChuyoWang, ZhenhuaZheng, Hongyu
The global electric and hybrid aircraft market utilizing lithium-ion Energy Storage Systems (ESS) as a means of propulsion, is experiencing a period of extraordinary growth. We are witnessing the development of some of the most cutting-edge technology, and with that, some of the most complex challenges that we as an industry have ever faced. The primary challenge, and the most critical cause of concern, is a phenomenon known as a “Thermal Runaway”, in which the lithium-ion cell enters an uncontrollable, self-heating state, that if not contained, can propagate into a catastrophic fire in the aircraft. A Thermal Runaway (TR) can be caused by internal defects, damage, and/or abuse caused by an exceedance of its operational specifications, and it is a chemical reaction that cannot be stopped once the cell has reached its trigger temperature. There are many technical papers that explore the characteristics of battery cells and the TR as a failure mode, but the failure mechanism(s) are still
Hanna, MichaelWalker, Cherizar
In the aerospace industry, large aircrafts employ composite materials for making complex structures which not only reduces weight and cost but also reduces the number of joints. Irrespective of that joining of structures cannot be avoided and for that mechanical fasteners such as rivets and bolts are employed along with adhesive bonding. Further, in recent years natural fibers have been studied extensively for their numerous advantages and have already been made into several automotive applications. Keeping these current trends in mind an attempt is made to investigate the joining behavior of natural fiber composites experimentally. So in this study, the ultimate failure load, bearing strength and the dominating failure mode of jute-hemp fabric-reinforced polymeric composites joined using single and double-bolted configurations are studied. The polymeric composite laminates were successfully fabricated using resin infusion technique and test specimens were fabricated following ASTM
Koppad, PraveennathChinnakurli Suryanarayana, RameshReddy, NagarajaSethuram, D
Airworthiness Directives (ADs) serve as a medium through which commercial and military regulators improve the system’s performance by responding to the failure of the airplanes. The Federal Aviation Administration (FAA) and United States Air Force (USAF) provide ADs that detail overall cost on operators. The dataset derived from the Boeing 767 (B767) and its military derivatives, USAF’s KC-46A gives ideas into sensor solutions and maintenance approaches that may reduce these costs. Given the ADs significant costs for Boeing 767 operations, an analytical failure framework that determines the failure modes and failure mechanisms is introduced. For example, a huge portion of severe impairment (e.g., cracking, corrosion, and chafing) constitutes 27% of failure mechanisms in these systems. To reduce future B767 ADs for commercial and military operators, sensor solution and maintenance strategies using performance metric and genetic algorithm are assessed. As a result, maintenance downtimes
Rasaq, LukmonFerguson, KorbinYadav, OmKyle, BlondSiddula, Madhuri
Aluminium composites are remarkably used in automotive, aerospace, and agricultural sectors because of their lightweight with definable mechanical properties. The stir casting route was followed to fabricate cylindrical samples with base aluminium alloy LM4, LM4/SiC, LM4/Al2O3, and LM4/SiC/Al2O3. The tensile strength, compressive strength, hardness, and micro-structural analysis were performed on samples and Finite element analysis (FEA) was adopted to predict the failure modes of composites. The composites experimental results were found to be in line with the FEA results, however, the LM4/SiC/Al2O3 revealed better results on the mechanical properties when compared with other composite configurations. The mechanical properties improvement like hardness 5%-11%, tensile strength 10.26%-20.67%, compressive strength 15.19% - 32.58% and 71.52 - 82.1% reduction in dimension have been achieved in LM4/SiC/Al2O3 composite comparing to base metal.
Rajeswari, B.Manikandan, C.Rajeshkumar, L.Aravind, R.M.
Construction equipment off highway vehicles are heavy industry vehicles that run on diesel engines. To meet the emission norms, these engines have the Exhaust After Treatment System (EATS) which includes two primary subassemblies, i.e., a Diesel Oxidation Catalyst (DOC) subassembly to reduce the HC and CO emissions and a Selective catalytic Reduction (SCR) subassembly to reduce NOx emissions. Because of the excessive vibrations in the engine and continuous heavy-duty usage of the Construction equipment, any failures in the EATS system leading to escape of exhaust gas is a statuary non-compliance. Hence, understanding the effect of engine vibrations and proposing a cost-effective solution is paramount in designing the EATS system including the SCR assembly. A field-testing failure of an SCR assembly has been taken in consideration for this study. Several use-cases were simulated for the baseline design using real world acceleration data and Frequency Response Function (FRF) Analysis was
Rahman, ShahzerChakraborty, AbhirupPerumal, SolairajRedkar, DineshUsulamarthi, RamwarunSingh, Rajendra
The stress concentration at welded joints and small crack propagation from some pre-existing discontinuities at notched regions control the fatigue life of typical welded structures. There are numerous FEM stress-based weld fatigue assessment approaches available commercially which unify FEM stresses with various fatigue software codes embedded with international weld standards. However, FEM stress-based approaches predict extensively conservative results. Considerable efforts & subjective decision making is required to arrive at desired level of weld life correlation with physical test results, in terms of weld life and failure location. This is majorly because of inconsistency & inaccuracy in capturing the hot spot stress results due to stress singularities occurring at the notched regions owing to the mesh sensitivity, modeling complexity. Hence to address these concerns, a force based equivalent structural stress solid weld approach in commercial weld fatigue code fe-safe VERITY
Pendse, AmeyaBabar, RanjitPatil, Sanjay
Diesel Exhaust Fluid (DEF) concentration monitoring is done to detect the concentration at which the emission thresholds are exceeded in BSVI engines [1]. This paper introduces a novel method to model the fault monitoring system with enable conditions designed to detect deterioration in DEF concentration, while reducing misdetection. This eliminates the need for dedicated sensor, reduces complexity, cost, and potential sensor-related failure modes. Traditionally, Diesel Exhaust Fluid quality sensors have been employed to measure the absolute concentration of Diesel Exhaust Fluid in the aqueous solution of urea [2]. This information is used to detect usage of poor quality DEF which results in increase in NOx emission beyond legal limits. The proposed method leverages the strong relationship between catalyst conversion efficiency and Diesel Exhaust Fluid concentration for modelling a fault monitoring system which also takes inputs from various other sensors, to make the system fault
Venkat, HarishKumar, Gokul ElumalaiKumar, KosalaramanG, Vijayakumar
In the realm of modern powertrains, the paramount objectives of weight reduction, cost efficiency, and friction optimization drive innovation. By streamlining drive trains through component minimization, the paper introduces a groundbreaking approach: the integration of fuel pump and vacuum pump drive systems into the main camshaft of a two-valve-per-cylinder push-rod actuated 4-cylinder diesel engine. This innovation is poised to concurrently reduce overall weight, lower costs, and minimize drive losses. The proposed integration entails the extension of the camshaft with a tailored slot, accommodating a three-lobed cam composed of advanced materials. This novel camshaft configuration enables the unified propulsion of the oil pump, vacuum pump, fuel pump, and valve train, effectively consolidating functions and components. The integrated camshaft design is subject to meticulous evaluation, ensuring its capacity to manage higher power transmission and accommodate multiple connected
John, Shijino ShajiSasikumar, K
In the automotive industry, silicon adhesive has become increasingly popular due to its benefits in ease of assembly and cost savings associated with material and manufacturing processes. To meet the imperative of minimizing both time and expenses during the project's development phase, it becomes essential to select the appropriate gasket material and an optimal flange design at the outset of the design process. In order to achieve stringent emission standards such as Real Driving Emission (RDE) and Corporate Average Fuel Economy (CAFE) norms, a better sealing performance is an essential parameter. Various types of liquid gaskets such as silicon rubber based Room Temperature Vulcanizing (RTV) sealants and thermoset plastic based Anaerobic sealants are widely used in an Internal Combustion engine. They are commonly used for the components such as oil sump, bedplate, and gearbox housings, etc. Traditional simulation methods could not capture the exact failure modes of the liquid
Kumbhar, Dipak MadhukarBabar, RanjitPatil, SanjayBagane, Shivraj
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