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Viewing 31 to 60 of 1640
2017-03-28
Journal Article
2017-01-0052
Andre Kohn, Rolf Schneider, Antonio Vilela, Udo Dannebaum, Andreas Herkersdorf
Abstract A main challenge when developing next generation architectures for automated driving ECUs is to guarantee reliable functionality. Today’s fail safe systems will not be able to handle electronic failures due to the missing “mechanical” fallback or the intervening driver. This means, fail operational based on redundancy is an essential part for improving the functional safety, especially in safety-related braking and steering systems. The 2-out-of-2 Diagnostic Fail Safe (2oo2DFS) system is a promising approach to realize redundancy with manageable costs. In this contribution, we evaluate the reliability of this concept for a symmetric and an asymmetric Electronic Power Steering (EPS) ECU. For this, we use a Markov chain model as a typical method for analyzing the reliability and Mean Time To Failure (MTTF) in majority redundancy approaches. As a basis, the failure rates of the used components and the microcontroller are considered.
2017-03-28
Journal Article
2017-01-0495
Michael Christian Haverkamp
Abstract The vehicle interior constitutes the multi-sensory environment of driver and passengers. Beside overall design and execution, materials and its surfaces are of specific interest to the customer. They are not only needed to fulfil technical functions, but are in direct focus of the customer’s perception. The perceived quality is based on all sensory data collected by the human perceptual system. Surfaces express design intent and craftsmanship by their visual appearance. Haptic features supervene when materials are touched. And even smell has an influence on the perception of ambience. Although sound is generated nearly every time when fingers slide across a surface, touch-sounds have been disregarded so far. In various cases, these contact sounds are clearly audible. As essential sound responses to haptic activity, they can degrade perceived quality. A method has been developed for a standardized generation of touch-sounds.
2017-03-14
Journal Article
2016-01-9080
Yong-Yuan Ku, Jau-Huai Lu, Ko Wei Lin
Due to the rising price of crude oil, biofuel is being considered as a global alternative for fossil fuels to reduce the emission of greenhouse gases. Diesel blended with bio fuel is currently being widely adopted in many countries. The Taiwanese government has been enforcing the adoption of B2 since 2010. However, there have remained consistent concerns about engine durability related to the use of biofuel, especially regarding after-treatment systems. A selective catalytic reduction system (SCR) has been utilized recently to reduce NOX emission in order to meet the Euro IV and V emission standards. To evaluate the impact of biodiesel on the durability of engines equipped with the SCR system, a long-term testing program was organized for the purposes of this study. The results can be used as a reference for the development of marketing promotion strategies as well as government policies in Taiwan.
2017-01-10
Technical Paper
2017-26-0235
Vinaykumar Dhangar, Solairaj Perumal, Abhay Kumar, Dinesh Redkar, Arun Mahajan, Abhirup Chakraborty, T Ganesan
Abstract A tractor is vehicle specifically designed to deliver a high tractive effort at slow speeds for carrying out various agriculture operations like ploughing, rotavation etc. using implement. Hydraulic system is a key feature which connects these implements with the tractor. It controls the position and draft of the implement depending upon the type of crop, farming stage, implement type and soil conditions. These variations induces extreme range of load on the hydraulic system, thus making it challenging to design these components. Bell crank assembly is one of the main components of hydraulic system which controls the draft (thus, the loads experienced by tractor) through load sensing mechanism. Often bell crank assembly failures are reported from field due to uneven soil hardness and presence of rocks. This paper studies one of such bell crank assembly failures in the field. The failure was reported after half life cycle of usage during agriculture Operation.
2017-01-10
Technical Paper
2017-26-0309
Sathish Kumar Prasad, J Prakaash, P Dayalan
Abstract Automotive vehicles are subjected to a variety of loads caused by road undulations. The load history data measured from the roads are one of the vital input parameters for physical test as well as virtual durability simulation of vehicles. In general, the automotive vehicles are instrumented and subjected to a variety of driving conditions in diverse roads to obtain representative road load time histories. Acquired road load time history signals from various roads are exhaustive and repetitive in terms of both time length and data size. This results in more computation and virtual simulation processing. Hence it is imperative to reduce the input time signals without compromising on the representation of the actual operating conditions. Signal reduction of measured road load histories for virtual simulation assumes greater significance for durability prediction.
2017-01-10
Technical Paper
2017-26-0310
Vyankatesh Madane, Sameer Shivalkar, Chandrakant Patil, Sanjeev Annigeri
Abstract In rubber industry, different techniques are used to enhance durability. This paper gives complete design, development and testing methodology of rubber bush in which pre-compression of rubber is used to enhance rubber bush life. In bogie suspension, axle to torque rod join is critical as it has to transfer lateral and longitudinal load with flexibility. This makes challenging to design joint which need to carry more than 6 ton load and having flexibility of more than 10 degree articulation. In this torque rod to axle joint called as End bush, compressed rubber is used to carry high load with flexibility. Other possible material for bush can be brass bush which able to carry high load however not able to give high flexibility Design and finite element calculations are done to design pre-compression and rubber volume to get desired strength and stiffness to carry required load with flexibility.
2016-11-08
Technical Paper
2016-32-0020
Balasubramanian Thiruvallur Loganathan, Srivenkata Subramani Narasimhan, Lakshminarasimhan Varadha Iyengar, Ajith Kumar Sandur, Sudhagar Vediappan
Abstract Development of small air cooled motorcycles is ever challenging due to combination of customer expectation, regulatory requirements and cost factors. Achieving higher performance, emission standards means higher engine and parts operating temperature. Under these changes meeting durability targets at reasonable cost needs good understanding of material, surface treatment and tribological aspects. In this paper some of the surface and process improvements done to reduce wear in engine valves and interface systems is discussed in detail. Design of engine valves shall ensure meeting thermal, mechanical strength requirements, wear and durability targets. Surface treatments, coating, surface finish and also use of special materials in tip, valve stem, seat ensures higher durability; low wear in valve and interfacing parts. During new engine development process verification tests, wear observed in valve stem- guide, valve tip- screw interface.
2016-11-08
Journal Article
2016-32-0070
Toyofumi Tsuda, Kazuya Miura, Akio Hikasa, Keiji Hosoi, Fumikazu Kimata
Abstract An exhaust gas purifying catalyst must be durable, i.e., it must maintain a sufficient catalytic performance even after thermal degradation. Therefore, large amounts of platinum group metals (PGMs), such as Pt, Pd, and Rh, should be loaded onto the catalyst substrate. Exhaust gas heat deteriorates the catalyst by sintering the PGM particles, which decreases the active surface area. It is important to reduce the PGM load and many researchers have therefore attempted to carry out PGM load reduction while maintaining sufficient durability. We found that Pt ions could form Pt-hydroxide clusters in a hexahydroxyplatinate (IV) (Pt(OH)6·H2O) nitric acid solution. The Pt-hydroxide cluster size could be controlled by varying the Pt and nitric acid concentrations and solution temperature.
2016-10-28
Technical Paper
Quality, Reliability and Durability
2016-10-25
Technical Paper
2016-36-0226
Javier Gutierrez, Guido Tosolin, Alexandre Catala
Abstract The integration of IDIADA Spain virtual Proving Ground (ISVPG) within ADAMS/Car offers a new virtual scenario to carry out detailed analysis of durability as well as Comfort & Ride. Moreover, these high resolution roads (modeled as OpenCRG road format) support model development activities through better correlation with experimental tests. This approach helps to reduce the number of real tests and to shorten development process times. At the same time, this data would be prepared for performance testing to support driving simulator and active system development. The objective of this paper is to demonstrate the benefits to use FTire model for Ride and Comfort applications and the use of flexible bodies for better predictions. The availability of this information will depend on the status of the project and the level of maturity of the simulation input data. As a result, different levels of accuracy will be reached according to the existing input data.
2016-10-25
Technical Paper
2016-36-0503
Marcelo Lopes de Oliveira e Souza, Roberta de Cássia Ferreira Porto
Systems such as satellites, airplanes, cars and air traffic controls are becoming more and more complex and/or highly integrated. These systems integrate several technologies inside themselves, and must be able to work in very demanding environments, sometimes with few, or none, maintenance services, because of their severe conditions of work. To survive to such severe work conditions, the systems must present high levels of reliability, which are achieved through different approaches and processes. Therefore, it is necessary that the processes of decision analysis and making are progressively improved, taking into account experiences collected before by several technological communities, and then propose efficient modifications in the local processes. These experiences influence the proposition and improvement of several Reliability Standards Series taken by four different approaches and several technological communities.
2016-10-25
Technical Paper
2016-36-0169
Emilio C. Baraldi, Paulo Carlos Kaminski
Abstract The competition among automotive industries increases each year worldwide. Among their diverse needs, what can be highlighted are: market expansion, model diversification, competitive prices, customer-recognized quality, new products release in shorter time periods, among others. The occurrence of flaws that might compromise the health or safety of the product’s user is admittedly one of the largest issues for any manufacturer, especially if these flaws are identified after its commercialization (recall). In this work, a study on recall in the automotive industry in the Brazilian market will be presented, comprising the years of 2013 and 2014. Reasons and causes of recall are addressed, based on the sample of the aforementioned research, with special emphasis on flaws derived from the production process. The conclusion at the end of the work is that the final assembly in the automotive manufacturing process is what requires more attention from engineering area.
2016-10-25
Technical Paper
2016-36-0400
Carlos Abílio Passos Travaglia, Luiz Carlos Rolim Lopes
Abstract Great numbers of studies in sliding wear phenomena use the wear rate to quantify material losses. However, in more recent works, some authors have been tried to characterize the wear phenomena by means of the energy dissipation between the contact surfaces of the bodies. The aim of this work is to create an analytical model capable to relate the total energy dissipated by a friction material during a bench wear test and data collected directly in a vehicle brake, in order to predict the durability of this component in service life. To attain this aim, the concept of specific wear volume, SWV, is adopted. The specific wear volume is the relationship between the material wear volume and the energy dissipated during a sliding wear process. In addition, a method to calculate the energy dissipation on friction materials is presented.
2016-10-25
Technical Paper
2016-36-0430
Daniel Maretti de Carvalho, C. K. Takemori, D. W. da Silva, E. Baars
Abstract Operational modal analysis is when the modal properties are identified from measured responses only. The modal parameters are: mode shapes (the way the structure moves at a certain resonance frequency), natural frequencies and damping ratios. When modal identification is based on the measured response (output) only, things become more complicated: The excitation (input) is unknown and the measured response (output) is often noisy. In this study, the time domain Stochastic Subspace Identification - Unweighted Principal Components operational modal analysis was applied to the recorded dataset from the durability test conditions of a truck. Using the 40 minutes of road test accelerometer time history in three different road conditions, it was possible to identify the modal parameters and also compare with numerical modal analysis data. Both results presented good correlation.
2016-10-25
Technical Paper
2016-36-0432
A. C. Michelotti, A. L. F. Ferreira, L. F. Berto, C. K. Takemori, D. W. da Silva, E. Baars
Abstract This paper presents a numerical methodology to predict the dynamic behavior of the front end accessory drive (FEAD) and the overrunning alternator decoupler (OAD) pulley. The methodology uses the commercial code Altair Radioss, and is based on 3D Lagrangian formulation, finite element method and explicit time integration schemes. Contact between different parts were considered using penalty methods. The methodology is divided in two independent parts: 1) FEAD with rigid pulleys, and 2) OAD pulley alone with flexible components. In the first part it is possible to evaluate the vibration of relevant components like the belt and the tensioner pulley, and in the second part it is possible to analyze not only the vibration of the OAD pulley, but also the stresses on critical components to durability.
2016-10-17
Technical Paper
2016-01-2341
Arnab Ganguly, Vikas Kumar Agarwal, R Pradeepak
Abstract When a scooter is put on main stand, it keeps the vehicle from falling as it rests against the engine crankcase. As the main stand is operated it transmits a large amount of load to the crankcase, thus creating a necessity to check the durability of the later. Practical tests showed that continuous application of the main stand resulted in the failure of its pivot area on the crankcase. This raised questions not just on the feasibility of the crankcase design in terms of durability, but also on the main stand design in terms of a load transmitting member. However, as the project was at its later stage, crankcase design could not be altered; thus it asked for a main stand design optimization. The base main stand model was thus taken for MBD simulation and loads were generated for further FEA analysis. The meshed crankcase model was taken in a commercially available FEA code for checking its durability.
2016-09-27
Journal Article
2016-01-8011
Kevin Grove, Jon Atwood, Myra Blanco, Andrew Krum, Richard Hanowski
Abstract This study evaluated the performance of heavy vehicle crash avoidance systems (CASs) by collecting naturalistic driving data from 150 truck tractors equipped with Meritor WABCO OnGuardTM or Bendix® Wingman® AdvancedTM products. These CASs provide drivers with audio-visual alerts of potential conflicts, and can apply automatic braking to mitigate or prevent a potential collision. Each truck tractor participated for up to one year between 2013 and 2015. Videos of the forward roadway and drivers’ faces were collected along with vehicle network data while drivers performed their normal duties on revenue-producing routes. The study evaluated the performance of CAS activations by classifying them into three categories based on whether a valid object was being tracked and whether drivers needed to react immediately.
2016-09-20
Technical Paper
2016-01-1997
Wei Wu, Yeong-Ren Lin, Louis Chow, Edmund Gyasi, John P. Kizito, Quinn Leland
Abstract The aircraft electromechanical actuator (EMA) cooling fan is a critical component because an EMA failure caused by overheating could lead to a catastrophic failure in aircraft. Fault tree analysis (FTA) is used to access the failure probability of EMA fans with the goal of improving their mean time to failure (MTTF) from ∼O(5×104) to ∼ O(2.5×109) hours without incurring heavy weight penalty and high cost. The dual-winding and dual-bearing approaches are analyzed and a contra rotating dual-fan design is proposed. Fan motors are assumed to be brushless direct current (BLDC) motors. To have a full understanding of fan reliability, all possible failure mechanisms and failure modes are taken into account.
2016-09-18
Technical Paper
2016-01-1928
ByeongUk Jeong, Sang Do Kwak, Cheol Ki Kim
Abstract Recently, upon customer’s needs for noise-free brake, carmakers are increasingly widely installing damping kits in their braking systems. However, an installation of the damping kits may excessively increase softness in the brake system, by loosening stroke feeling of a brake pedal and increasing compressibility after durability. To find a solution to alleviate this problem, we first conducted experiments to measure compressibility of shims by varying parameters such as adhesive shims (e.g., bonding spec., steel and rubber thickness), piston’s shapes (e.g., different contact areas to the shims), and the numbers of durability. Next, we installed a brake feeling measurement system extended from a brake pedal to caliper. We then compared experimental parameters with brake feeling in a vehicle. Finally, we obtained an optimized level of brake feeling by utilizing the Design for Six Sigma (DFSS).
2016-09-02
Journal Article
2016-01-9111
Sebastian Brandes, Klaus-Dieter Hilf, Riccardo Möller, Tobias Melz
Abstract This paper makes a contribution toward a more efficient chassis durability process for the development of passenger cars, in which the simulation of relevant load data is a time-consuming part. This is especially due to the full vehicle model complexity which is usually determined by the demands of rough road simulations. However, for the load calculation on a racetrack, time saving model approaches that are more simplified might be sufficient. Our investigation comprises two levels of vehicle model complexity: one with all chassis parts modeled in a multibody system environment and one characteristic curve based model in an internal simulation environment. Both approaches consider an original chassis control system as a Software-in-the-Loop model. By the evaluation of real-world experiments the main influence factors in terms of durability are demonstrated. With the help of those highly sensitive durability criteria the measurement and simulation results are then compared.
2016-06-15
Journal Article
2016-01-1852
Ehsan Fatourehchi, Vishak Elisaus, Mahdi Mohammadpour, Stephanos Theodossiades, Homer Rahnejat
Abstract Efficiency and durability are key areas of research and development in modern racing drivetrains. Stringent regulations necessitate the need for components capable of operating under highly loaded conditions whilst being efficient and reliable. Downsizing, increasing the power-to-weight ratio and modification of gear teeth geometry to reduce friction are some of the actions undertaken to achieve these objectives. These approaches can however result in reduced structural integrity and component durability. Achieving a balance between system reliability and optimal efficiency requires detailed integrated multidisciplinary analyses, with the consideration of system dynamics, contact mechanics/tribology and stress analysis/structural integrity. This paper presents an analytical model to predict quasi-static contact power losses in lubricated spur gear sets operating under the Elastohydrodynamic regime of lubrication.
2016-05-11
Technical Paper
2016-36-0061
Juliana Negrini de Araújo, Leonardo Hoss, Alexandre Viecelli, Maicon Molon
Abstract The use of virtual and / or experimental test rigs applying random loading is becoming more relevant in the development and validation of new products. An application example is the analysis of components subject to vibrations, especially suspended components. For this type of application, product validation applying random loads and different frequencies becomes mandatory. This study developed a virtual test rig for suspended components validation and definition of experimental test rigs. The study was based on a standard component, using LMS Virtual.Lab Siemens software for the dynamic analysis and durability. The experimental data (extensometry and accelerometry) was collected on the special tracks of Randon Companies Proving Ground. From the virtual modeling and experimental data, the proper hydraulic actuators signals were defined to characterize the component behavior according to the field application.
2016-04-11
Journal Article
2016-01-9081
Sean A. McKelvey, Yung-Li Lee
Abstract Multiaxial loading on mechanical products is very common in the automotive industry, and how to design and analyze these products for durability becomes an important, urgent task for the engineering community. Due to the complex nature of the fatigue damage mechanism for a product under multiaxial state of stresses/strains which are dependent upon the modes of loading, materials, and life, modeling this behavior has always been a challenging task for fatigue scientists and engineers around the world. As a result, many multiaxial fatigue theories have been developed. Among all the theories, an existing equivalent stress theory is considered for use for the automotive components that are typically designed to prevent Case B cracks in the high cycle fatigue regime.
2016-04-05
Technical Paper
2016-01-0046
Markus Ernst, Mario Hirz, Jurgen Fabian
Abstract A steady increasing share and complexity of automotive software is a huge challenge for quality management during software development and in-use phases. In cases of faults occurring in customer’s use, warranty leads to product recalls which are typically associated with high costs. To avoid software faults efficiently, quality management and enhanced development processes have to be realized by the introduction of specific analysis methods and Key Process/Performance Indicators (KPIs) to enable objective quality evaluations as soon as possible during product development process. The paper introduces an application of specific analysis methods by using KPIs and discusses their potential for automotive software quality improvement. Target is to support quality evaluation and risk-analysis for the release process of automotive software.
2016-04-05
Technical Paper
2016-01-0053
Abhishek Sharma
Abstract Today open source software is widely used in different domains like Desktop systems, Consumer electronics (smart phones, TV, washing machines, camera, printers, smart watches), Automotive, Automation etc. With the increased involvement of the open source software in the different domains including the safety critical ones, there has been a requirement of the well-defined test strategy to test and verify such systems. Currently there are multiple open source tools and frameworks to choose from. The paper describes the various open source test strategies and tools available to qualify such systems, their features, maintenance, community support, advantages and disadvantages. Target audience would be the software engineers, program managers, using an open source stack for the product development.
2016-04-05
Technical Paper
2016-01-0657
T Sethuramalingam, Chandrakant Parmar, Sashikant Tiwari
Abstract DFSS is a disciplined problem prevention approach which helps in achieving the most optimum design solution and provides improved and cost effective quality products. This paper presents the implementation of DFSS method to design a distinctive cooling system where engine is mounted in the rear and radiator is mounted in the front of the car. In automobile design, a rear-engine design layout places the engine at the rear of the vehicle. This layout is mainly found in small, entry level cars and light commercial vehicles chosen for three reasons - packaging, traction, and ease of manufacturing. In conventional Passenger cars, a radiator is located close to the engine for simple packaging and efficient thermal management. This paper is about designing a distinctive cooling system of a car having rear mounted engine and front mounted radiator.
2016-04-05
Technical Paper
2016-01-0414
Nehal Sardar Rahim
Abstract The Aisin A465 6-Speed Diesel Hybrid powertrain started production in early 2012 and is available in the North American market in the Hino 195h DC COE truck. The suitability, and added fuel efficiency, of a Hybrid powertrain for Class 5 Box truck is very dependent on fleet usage conditions and duty cycle. Aisin has undertaken real-world, extended mileage, durability testing on public roads to determine the operational modes for which such a powertrain is most suitable, and for which a fleet owner can expect fuel savings that will result in a payback period justifying the higher cost of a hybrid system equipped commercial truck. Data collected on the same Aisin proprietary durability test routes with a Conventional Class 3-5 Cab Chassis truck provides insights into truck usage parameters that differ between Hybrid and Conventional Class 3-5 commercial trucks.
2016-04-05
Technical Paper
2016-01-0480
Weiguo Zhang, Mark Likich, Mac Lynch, John White
Abstract The noise radiated from the snorkel of an air induction system (AIS) can be a major noise source to the vehicle interior noise. This noise source is typically quantified as the snorkel volume velocity which is directly related to vehicle interior noise through the vehicle noise transfer function. It is important to predict the snorkel volume velocity robustly at the early design stage for the AIS development. Design For Six Sigma (DFSS) is an engineering approach that supports the new product development process. The IDDOV (Identify-Define-Develop-Optimize-Verify) method is a DFSS approach which can be used for creating innovative, low cost and trouble free products on significant short schedules. In this paper, an IDD project which is one type of DFSS project using IDDOV method is presented on developing a robust simulation process to predict the AIS snorkel volume velocity. First, the IDDOV method is overviewed and the innovative tools in each phase of IDDOV are introduced.
2016-04-05
Technical Paper
2016-01-0266
Greg K. Caswell, James McLeish
The use of Micro Electro-Mechanical Systems (MEMS) for measuring accelerations, pressure, gyroscopic yaw rate and humidity in engine controls, inflatable restraint, braking, stability and other safety critical vehicle systems is increasing. Their use in these safety critical systems in high stress automotive environments makes ensuring their reliability and durability essential tasks, especially as the Vehicle System Functional Safety requirements of ISO-26262 are being implemented across the industry. A Design for Reliability (DfR) approach that applies Physics of Failure methods to evaluate and eliminate or mitigate susceptibilities to failure modes of a device during the design of a product is the most effective and efficient way to achieve Functional Safety levels of reliability-durability. MEMS packages exhibit several failure modes that can be predicted as a device is designed using modern Computer Aided Engineering (CAE) software tools.
2016-04-05
Technical Paper
2016-01-0375
Sinan Eroglu, Ipek Duman, Ahmet Hamdi Guzel, Rifat Yilmaz
Abstract The exhaust manifold is one of the engine components which is used to collect the burned gases from the cylinder head and send it to the exhaust hot end aftertreatment system with low engine backpressure. The main purpose of the automotive exhaust manifolds are providing a smooth flow field and must be able to endure thermo-mechanical loadings. The present paper explains the CAE analysis method to assess the design of exhaust manifold of a heavy duty diesel engine. Coupled computational fluid dynamics (CFD) analyses were performed to solve the flow field within the exhaust system and surface convection loading prediction at fluid side and obtain temperature distribution at solid region of exhaust manifold domain. The metal temperature prediction provided by thermal model is used to carry out the durability analysis of the structure.
Viewing 31 to 60 of 1640