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Viewing 211 to 240 of 6755
2016-04-05
Technical Paper
2016-01-1349
Siddharth Bhupendra Unadkat, Suhas Kangde, Mahalingesh Burkul, Mahesh Badireddy
Abstract In the current scenario, the major thrust is to simulate the customer usage pattern and lab test using virtual simulation methods. Going ahead, prime importance will be to reduce the number of soft tool prototype for all tests which can be predicted in CAE. Automotive door slam test is significantly complex in terms of prediction through simulation. Current work focuses on simulating the slam event and deriving load histories at different mounting locations through dynamic analysis using LSDyna. These extracted load histories are applied to trimmed door Nastran model and modal transient analysis is performed to find the transient stress history. This approach has a significant advantage of less computation time and stress-convergence with Nastran for performing multiple design iterations compared to LSDyna. Good failure correlation is achieved with the test using this approach.
2016-04-05
Technical Paper
2016-01-0391
Tanmay Sushant Santra, Vikas Kumar Agarwal, Mihir Bhambri
This paper depict the difference in the endurance factor of safety with usage of static and quasi static FE analysis and corrective measures take to solve the problem. The importance of the dynamic loading and subsequent effect of it on the multi axial fatigue analysis. Considering the modern trend prevailing among the vehicle manufacturers and specifically talking about two wheeler industry, it is clear that while the engine remains the same but the frame is changed to cater the market with new models to cut down on the development time. Initially the crankcase was designed for a double cradle frame where the crankcase was mounted on the frame. Later, the frame design was changed to single cradle where engine acts as a stress member link. This kind of arrangement makes the crankcase mountings participate in the chassis loads. Therefore, the crankcase mounting experiences road loads when the vehicle encounter the road irregularities.
2016-04-05
Journal Article
2016-01-0261
Lili Feng, Predrag Hrnjak
Abstract This paper presents a simulation model for a reversible air conditioning and heat pump system for electric vehicles. The system contains a variable speed compressor, three microchannel heat exchangers, an accumulator, and two electronic expansion valves. Heat exchangers are solved by discretizing into cells. Compressor and accumulator models are developed by fitting data with physical insights. Expansion valves are modeled by isenthalpic processes. System performance is calculated by connecting all parts in the same way as the physical system and solved iteratively. The model is reasonably validated against experimental data from a separate experimental study. Future improvement is needed to take into account maldistribution in outdoor heat exchanger working as an evaporator in HP mode. Charge retention in components also requires further study.
2016-04-05
Technical Paper
2016-01-0257
Lili Feng, Predrag Hrnjak
Abstract This paper presents the experimentally obtained performance characteristics of an air conditioning-heat pump system that uses heat exchangers from a commercially available Nissan Leaf EV. It was found that refrigerant charge needed for cooling operation was larger than that for heating function with the test setup. The effects of: a). indoor air flow rate, b). outdoor air flow rate, and c). compressor speed on heating capacity and energy efficiency were explored and presented. Appropriate opening size of expansion valve that controlled subcooling for better energy efficiency was discussed and results were presented. Expansion valve opening size also strongly affected charge migration. Warm-up tests at different ambient conditions showed the necessity of a secondary heater to be reserved for very low ambient temperature.
2016-04-05
Technical Paper
2016-01-0011
Salah Alhasia, Sharif Gindy, Badih Jawad, Chris Riedel, Selin Arslan
Abstract Bearings are a major component in any rotating system. With continually increasing speeds, bearing failure modes take new unconventional forms that often are not understood. In high speed applications, rolling element forces and gyroscopic moments can be significantly high compared to the applied forces acting on a bearing. Such moments create a “driving” torque causing outer race to creep. In this paper a mathematical model for the dynamics of a rolling element in a high speed bearing is derived. Preload values counterbalancing the torque driving the outer race to rotate can be predicted from this model. An attempt to experimentally measure this torque using a specially designed apparatus with integrated strain gauge torque sensor is also described. Both model and experimental measurements are aimed at understanding, and therefore preventing bearing failures due to outer race (creep) rotations.
2016-04-05
Journal Article
2016-01-1597
Christopher Collin, Steffen Mack, Thomas Indinger, Joerg Mueller
Abstract The open jet wind tunnel is a widespread test section configuration for developing full scale passenger cars in the automotive industry. However, using a realizable nozzle cross section for cost effective aerodynamic development is always connected to the presence of wind tunnel effects. Wind tunnel wall interferences which are not present under open road conditions, can affect the measurement of aerodynamic forces. Thus, wind tunnel corrections may be required. This work contains the results of a CFD (Computational Fluid Dynamics) approach using unsteady Delayed Detached Eddy Simulations (DDES) to evaluate wind tunnel interferences for open jet test sections. The Full Scale DrivAer reference geometry of the Technical University of Munich (TUM) using different rear end shapes has been selected for these investigations.
2016-04-05
Journal Article
2016-01-1560
Bo Lin, Chinedum E. Okwudire
Abstract Ball nut assemblies (BNAs) are used in a variety of applications, e.g., automotive, aerospace and manufacturing, for converting rotary motion to linear motion (or vice versa). In these application areas, accurate characterization of the dynamics of BNAs using low-order models is very useful for performance simulation and analyses. Existing low-order contact load models of BNAs are inadequate, partly because they only consider the axial deformations of the screw and nut. This paper presents a low-order load distribution model for BNAs which considers the axial, torsional and lateral deformations of the screw and nut. The screw and nut are modeled as finite element beams, while Hertzian Contact Theory is used to model the contact condition between the balls and raceways of the screw and nut. The interactions between the forces and displacements of the screw and nut and those at the ball-raceway contact points are established using transformation matrices.
2016-04-05
Technical Paper
2016-01-1397
Charles Yuan, Erik Kane, Abid Rahman
Abstract New seal cross-section development is a very tedious and time consuming process if conventional analysis methods are used, as it is very difficult to predict the dimensions of the seal that will satisfy the sealing performance targets. In this study, a generic cross-section is defined and the design constraints are specified. Isight then runs the FEA model, utilizing a custom python script for post-processing. Isight then updates the dimensions of the seal and continues running analyses. Isight was run using two different design exploration techniques. The first was a design of experiments (DOE) to discover how the seal’s response varies with its dimensions. Then, after the analyst examined the results, Isight was run in optimization mode focusing on feasible design areas as determined from the DOE.
2016-04-05
Technical Paper
2016-01-0393
Kevin P. Barbash, William V. Mars
Abstract We demonstrate here an accounting of damage accrual under road loads for a filled natural rubber bushing. The accounting is useful to developers who wish to avoid the typical risks in development programs: either the risk of premature failure, or of costly overdesign. The accounting begins with characterization of the elastomer to quantify governing behaviors: stress-strain response, fatigue crack growth rate, crack precursor size, and strain crystallization. Finite Element Analysis is used to construct a nonlinear mapping between loads and strain components within each element. Multiaxial, variable amplitude strain histories are computed from road loads. Damage accrues in this reckoning via the growth of cracks. Crack growth is calculated via integration of a rate law from an initial size to a size marking end-of-life.
2016-04-05
Technical Paper
2016-01-1387
Subash Sudalaimuthu, Barry (Baizhong) Lin, Mohamed Sithik, Rajeev Sakunthala Rajendran
Abstract The advanced Optimization techniques help us in exploring the light weight architecture. This paper explains the process of designing a lightweight track bar bracket, which satisfies all durability performance targets. The mounting locations and load paths are critical factors that define the performance and help in the development of weight efficient structure. The process is to identify the appropriate bolt location through Design of Experiment (DOE) and topology based studies; followed by section and shape optimization that help to distribute material in a weight efficient manner across the structure. Load path study using topology optimization is performed to identify the load path for durability load cases. Further shape optimization is done using hyper study to determine the exact thickness of the webs and ribs. A significant weight reduction from the baseline structure is observed. This process may be applicable for all casting components.
2016-02-01
Technical Paper
2016-28-0175
Siddharth Dahiya, Adithya Asok Sharma, Rahul Srinivasan, Ritesh Tekriwal, Kamalkishore Vora, B Ashok, C Kavitha
Abstract This paper describes the design methodology and algorithm development towards the design of an automatic external gear-shifting and clutch-actuation system for a sequential gearbox with the aim of providing the drivers with easier and an efficient means of shifting gears. Automatically actuated manual transmission system bridges the gap between automatic and manual transmissions which provides the advantages of both type of transmissions. This would ideally leads to faster shifting time and provide significant benefits in the form of electronic-aids like launch control and traction control. Removal of mechanical clutching would reduce fatigue and lead to ergonomic benefit. Based on the benchmarking performed on an easily available ready-to-install aftermarket alternative, options will be considered for the actuating mechanism and the most feasible will be used to develop a shifting system.
2016-02-01
Technical Paper
2016-28-0224
Akshay Ramesh Karjol, Ajay Virmalwar
Abstract Reducing overall weight of the vehicle is one of the main areas of research in automotive industries. Current trend, CO2 reduction, is a major incentive for this process. For this, engineers are finding out various ways to reduce weight to strength ratio of the different components. The immediate pay-off of such developments is lower fuel consumption, which is followed by lower CO2 emissions. For this engineers opt for, use of low-density and high-strength materials, along with optimization of the geometry of the components. One of the solutions is to convert metal parts to plastics which have desired properties. The main focus of this paper is to convert the sheet metal brackets to plastic brackets which will ultimately reduce weight and production cost associated with automobile. In this paper, an optimum process, using Topology optimization and Mold Flow Analysis, is developed to convert sheet metal bracket to plastic bracket.
2016-02-01
Technical Paper
2016-28-0251
Kantilal Patil, Siva Reddy, Nadeem Zafar
Abstract In the event of a frontal car crash, occupant sitting in a car meets various types of injuries like Head injury, Chest compression, Neck injury etc. These injuries may lead to the death of an occupant if exceeded beyond biomechanical limits. Seat belt is a primary restraint system, which when worn controls the motion of occupant sitting inside the car during the event of a car crash. An Anchorage location of three point seat belt system has significant effect on occupant injuries during the crash event. By changing the mount locations of a seat belt anchor points i.e. D-ring, Anchor & Buckle, performance of seatbelt system can be enhanced further thereby reducing occupant injuries to certain extent. As per regulation AIS015, locations of safety belt anchorage points should be within prescribed zone.
2016-02-01
Technical Paper
2016-28-0001
Akhilendra Pratap Singh, Suresh Gadekar, Avinash Kumar Agarwal
Abstract Fuel-air mixing is the main parameter, which affects formation of NOx and PM during CI combustion. Hence better understanding of air-flow characteristics inside the combustion chamber of a diesel engine became very important. In this study, in-cylinder air-flow characteristics of four-valve diesel engine were investigated using time-resolved high-speed tomographic Particle Imaging Velocimetry (PIV). For visualization of air-flow pattern, fine graphite particles were used for flow seeding. To investigate the effect of different operating parameters, experiments were performed at different engine speeds (1200 rpm and 1500 rpm), intake air temperatures (room temperature and 50°C) and intake port configurations (swirl port, tangential port and combined port). Intake air temperature was controlled by a closed loop temperature controller and intake ports were deactivated by using a customized aluminum gasket.
2016-02-01
Technical Paper
2016-28-0082
Venu Ganti, Yogesh Kumar Dewangan, Ganesan Subramanian
Abstract In an automotive transmission system, gear mesh misalignment implies the shift in the position of the meshing surfaces. Misalignment at the mesh results in non-uniform load distribution leading to gear failure, increased noise and thus affects the transmission performance. In general, misalignment along the line of action (MLOA) of 0-5 mrad is common in the gear meshes of automotive transmissions. Major factors contributing to mesh misalignment are deflections of various elastic components in the transmission like shaft, gear web, bearing, housing etc. Contribution from other factors include clearance between the components, temperature gradient and manufacturing process limitations. Different approaches for compensating gear mesh misalignment involves control over the above factors at design and manufacturing stages. This paper focuses on three different approaches for compensating MLOA in the design stage.
2016-02-01
Technical Paper
2016-28-0118
J. Sureshkumar, K. Vijayakumar, R. Elayaraja
Abstract The main challenge in today's modern engines is to design the parts, which should withstand higher temperatures. To achieve this, selection of materials and process tolerances are very important factors. The product identified in this study is a conventional oil pump, which is an engine auxiliary component. The function of the oil pump is to supply oil to different parts of the engine to lubricate and reduce the overall engine friction. The different speed and load conditions for which the engine is subjected, pose a challenge to the oil pump, to supply the necessary quantity of oil at the required pressure and temperature. Normally, the oil pump is subjected to a temperature of 120°C at higher speeds. However, the peak oil temperature in modern diesel engines can be as high as 140°C to 150°C for a short period of time. For this study, two engine grade oils were selected. Numerical analysis was performed to predict the oil flow rate for these oil grades.
2016-02-01
Technical Paper
2016-28-0113
Anurag Kamal, Kaarthic Kaundabalaraman, Hemantkumar Rathi, Alok Muley
Abstract This work is an effort to find the parallelism between the volumetric efficiency of a Gerotor, and its inherent design parameters: number of teeth, tooth profile, outer dimensions of diameter and thickness, and the input power (torque and speed). The preliminary relations are derived from the software simulation of a range of Gerotor models with varying aforementioned parameters. These results are augmented by a previously proposed method of theoretically estimating the displacement of a Gerotor. Then, these results are validated and revised by practical results from three different Gerotors with epitrochoidal and its conjugate profiles, which are used in automotive applications like engines and transmissions. These relations can be used for choosing parameters yielding the maximum efficiency in specific environments: the packaging space, the input available, and the output required.
2016-02-01
Technical Paper
2016-28-0172
Praharsh Srivastava, Kamal Sharma, Raushan Jha
Abstract Rapid advent of mobile air conditioning industry has witnessed a wide use of fixed displacement swash plate compressor due to its small size, compact structure and light weight. An accurate prediction of volumetric efficiency and power of compressor at early stages of design serves as a very useful information for designer. No work regarding the power and volumetric efficiency prediction for double headed fixed displacement swash plate compressor is reported in the existing literature. This paper presents a mathematical model for a double acting fixed displacement swash plate compressor with the objective of evaluating the shaft torque and volumetric efficiency of compressor. Shaft torque, in turn is a measure of compressor power. The geometrical description of swash plate yields a kinematic model to obtain the piston displacement as an explicit function of angle of rotation of shaft.
2016-01-01
Journal Article
2015-01-9085
Vinod Upadhyay, Xiaoning Qi, Nick Wilson, Dante Battocchi, Gordon Bierwagen, Joy Forsmark, Robert McCune
Abstract This work reports on measurement and analysis of the galvanic interaction between steel self-piercing rivets (SPRs) having several different surface conditions and magnesium alloy substrates under consideration for use in automotive structural assemblies. Rivet surface conditions included uncoated steel, conventional Zn-Sn barrel plating and variations of commercial aluminizing processes, including supplemental layers and sealants. Coating characteristics were assessed using open circuit potential (OCP) measurement, potentiodynamic polarization scanning (PDS), and electrochemical impedance spectroscopy (EIS). The degree of galvanic coupling was determined using zero-resistance ammeter (ZRA) and the scanning vibrating electrode technique (SVET), which also permitted characterization of galvanic current flows in situ.
2015-11-17
Technical Paper
2015-32-0742
Kenta Goto, Shinji Noda, Kohei Nakashima, Yoshio Murakami
To improve engine torque and specific fuel consumption in a supermilage vehicle, we experimentally adjusted the valve lift and opening period in rocker arms, testing various follower configurations and adjust screws. Using the follower configuration in a commercially-available rocker arm, we compared 4 different levels of valve lift and opening period in the intake, and 4 different levels in the exhaust, making 16 combinations. Then, utilizing 5 kinds of modified follower configurations of the rocker arms in the intake, and 3 in the exhaust, we also compared 24 combinations (including the commercially-available follower configurations). We tested our experimental supermilage engine under full-load at 2000 to 4500rpm, simulating powering a supermilage vehicle.
2015-11-17
Journal Article
2015-32-0743
Hiroyuki Yoshida, Hiroshi Hirayama, Shinsuke Mochizuki, Manabu Inoue, Yasuhiro Kato, Toshiki Inomata
A black surface treatment without using hexavalent chromium and applicable to bolts of motorcycles has been developed. The surface treatment also satisfies the requirements of bolts for motorcycles such as fastening performance, corrosion resistance, weather resistance and appearance of outer finish. There is a method of coating a black chemical conversion film using trivalent chromium on the zinc-plated surface as one of the surface treatments that do not use the hexavalent chromium. Such a black film, however, is thinner than the film using hexavalent chromium, and unable to ensure satisfactory black appearance. Meanwhile, although the dip-coating using a black paint can provide a sufficient black color, it is necessary to apply coating two times to eliminate an irregular color. As a result, thick paint films are formed on the roots of thread, making it difficult to fit into the internal thread. To simultaneously solve the above-mentioned two issues, two measures were executed.
2015-11-17
Technical Paper
2015-32-0701
Takayuki Sugita
An existing 4 stroke-cycle gasoline engine has been partially modified without dynamically changing its mechanism for the purpose to utilize the compressed air as an alternative energy source. The principle is to mechanically control the compressed air flow through the intake and exhaust valve every revolution of a crankshaft by modifying the camshaft cam's lobes, which changes the engine operation from 4 strokes to 2 strokes cycle mode. In the previous investigation the principle was verified with a current 50 cc motorcycle modified engine and the pressure behavior inside the cylinder of the compressed air engine was evaluated. It turned out as a most promising result that the back pressure, which is defined as the positive pressure left in an expansion chamber while a piston is moving back from BDC to TDC, has a high influence on the performance of the compressed air reciprocating engine.
2015-09-29
Technical Paper
2015-01-2791
Srinivas Anantharaman, Manoj Baskaran
Abstract Nozzles tip Temperature (NTT) of an injector is a critical parameter for an engine as far as reliability of engine is concerned. It is required to ensure that the injectors operate under its operational limit because higher operating temperatures would result in enlargement of the nozzle spray tip, resulting in higher through flow, producing more undesirable power. This could result in failure of other components in the engine. In this paper we identify the various parameters that are critical for NTT and thereby predict the NTT by having the known input parameters. Response surface methodology and artificial neural network are used to identify the parameters, estimate the significance of each parameter and predict the NTT. Based on this analysis, even without the use of an instrumented injector NTT can be predicted at various working conditions of the vehicle on different terrains.
2015-09-29
Technical Paper
2015-01-2730
Prasad S. Warwandkar, Naveen Sukumar, Preeti Gupta
Abstract Ever-increasing operational cost, reducing profit margins & increase in competition, it is of upmost significance for fleet owners & drivers to opt for a vehicle having maximum uptime. OEM's are under immense pressure to design & develop vehicles/subsystems which are reliable enough to minimize downtime & withstand heavy overloading plus extreme operating conditions especially tippers. Vehicle systems like Wheel end (hub, bearing, and grease) which are designed & packaged according to a very stringent envelop & operate as a closed system facing all the extremities of operating conditions. This undoubtly make them prone to no. of failure modes which are resulting in vehicle unplanned stoppages, so any failure mode related to the same must be taken care with utmost importance. In commercial vehicles the bearing outer cup is in interference fit with the hub. These bearings of wheel hub have to be maintained at the wheel end play of few microns.
2015-09-29
Technical Paper
2015-01-2720
Sundarram Arunachalam, Ramprabhu Kannan, Jayaramareddy Sekar
Abstract Steering gear box function is one of the important requirements in heavy vehicles in order to reduce driver fatigue. Improper functioning of steering gear box not only increases the driver fatigue, also concerns the safety of the vehicle. In this present investigation, the engine oil mixing up with steering oil has been identified and steering gear box failure has been observed in the customer vehicle. The root cause of failure has been analyzed. Based on the investigations, in particular design of steering pump has been failed at customer end. The same design of steering pump were segregated and analyzed. Initial pressure mapping study has been conducted. The pressure mapping results revealed that the cavity pressure obstructs the flow of suction pressure. It indicates that obstacle at suction port due to the existence of internal leakage that causes back pressure in the internal cavity of steering pump which sucks engine oil.
2015-09-29
Technical Paper
2015-01-2725
Amine Nhila, Daniel E. Williams
Abstract Today's hydraulic steering systems suffer from poor efficiency due to their use of throttling valves to build pressure inside the steering gear. In this work, we propose a novel way to build and control pressure by controlling the flow from the pump and without throttling. As a result, such a system will be more energy efficient. Moreover, the ability to control pressure inside a steering gear, and thus assistance torque, allows the steering system to become an active closed-loop system rather than a passive open-loop system. Specifically, by controlling pressure, one can closely control the hand wheel torque the operator feels. Consequently, the new pressure control concept has the potential to not only significantly improve the efficiency of steering systems, but also offers the numerous benefits of torque overlay without the use of an electric motor.
2015-09-29
Technical Paper
2015-01-2761
Boris Belousov, Tatiana I. Ksenevich, Sergei Naumov, Vitalii Stepnov, Anna Klimachkova
An electro-hydraulic servo system makes the basis for a mechatronic locomotion module (LM) and for a complex comprising an LM and an undercarriage of a vehicle. The servo system of the wheel module/LM complex is a combination of the information and power channels of the electro-hydraulic wheel drive within the steering system. A combination of the servo systems makes up a complex of servo systems of the steering system of the multi axis wheel mover of the vehicle. Theoretical and experimental studies of the functioning all-wheel steering were aimed on substantiation the rational algorithmic maintenance of the automatic control system. The results of the study allowed formulating the basic principles of designing and calculating the functionality algorithms for the steering system of the complex of mechatronic modules of the multi-axis vehicle.
2015-09-29
Technical Paper
2015-01-2765
Shannon K. Sweeney
Abstract This paper presents simple but comprehensive modeling of the loads on the rubber sandwich-type mounts that often suspend the drum(s) in vibratory compactors or asphalt rollers. The goal of the modeling is to predict the overall performance of the rubber mount system. The modeling includes calculations to 1) identify and quantify all predictable low-frequency loads on the rubber mounts during normal vehicle operations, 2) predict the steady-state high-frequency vibration response of the drum, rubber mounts, and vehicle frame during compaction operations, 3) predict the heat generation in the rubber mounts from their hysteretic damping, and 4) predict the fatigue life and life distribution of the rubber mounts. Some typical results of the modeling are provided along with some brief criteria to assess suspension performance. Other, unpredictable suspension loads are discussed but not modeled.
2015-09-29
Technical Paper
2015-01-2855
Massimiliano Ruggeri, Giorgio Massarotti, Pietro Marani, Carlo Ferraresi
Abstract Losses reduction and oil flow optimization management in construction machines and, in general, in heavy duty vehicles are two of the most challenging missions of today fluid power research. One of the most promising ideas is to implement multiple hydraulic power sources but this requires a flexible pump switch system; in fact, depending on flow request and machine mode, one or more pumps can be switched to serve each actuator. To put into practice these concepts it is necessary to in-depth design the distribution system, through which hydrostatic transmissions supply the different loads. The new component here presented realizes the pump switch management, creating a matrix framework of the hydraulic flow connections. Putting this concept it into practice the new architecture is able to connect alternatively a pump to one actuator at a time providing also for cross connections, enabling different sources flow summation.
2015-09-27
Journal Article
2015-01-2672
Aihong Meng, Jian Song
Abstract High speed on-off valve is applied widely in vehicle control systems. When high speed on-off valve is controlled by Pulse Width Modulation (PWM) of high frequency, the valve core can float at a certain position which is adjusted by changing the duty ratio within a certain effective range. Then the high speed on-off valve can control the flow and pressure linearly like proportional valve. Thus it is essential to extend the effective range of duty ratio to improve the linear control performance of high speed on-off valve. In this paper, the high speed on-off valve of the automotive Electronic Stability Program (ESP) is the focus, and its flow force is analyzed in detail to get the effects of hydraulic parameters on the valve performance. The mathematic model of the high speed on-off valve is derived. Then the valve structural parameters are optimized according to the Genetic Algorithm(GA), offering the theoretical references for extending the effective duty ratio of PWM.
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