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Viewing 1 to 30 of 501
2011-04-12
Technical Paper
2011-01-0399
Andre Ferrarese, Jason Bieneman, David J. Domanchuk, Thomas Smith, Thomas Stong, Peter Einberger
Changing emission legislation limits are challenging the engine developers in many aspects. Requirement to improve combustion and engine efficiency have resulted in increased loads and higher levels of abrasive particles within the engine environment. Concerning piston rings and piston ring grooves, such engine modifications are leading to critical tribological conditions and side wear is becoming a key issue in the design of these components. Historically one of the most common forms of side wear protection on piston rings has been chromium plate. This solution has limitations on durability (low thickness) and on topography (rough surfaces). In response to these limitations, nitrided stainless steel top rings have been used to improve the side protection; it is harder and typically has a smoother surface finish when compared to chromium coating.
2014-01-15
Journal Article
2013-01-9091
Dongfang Jiang
To get a sequence retainable rainflow cycle counting algorithm for fatigue analysis, an alternate equivalent explanation to rainflow cycle counting is introduced, based on which an iterative rainflow counting algorithm is proposed. The algorithm decomposes any given load-time history with more than one crest into three sub-histories by two troughs; each sub-history with more than one crest is iteratively decomposed into three shorter sub-histories, till each sub-history obtained contains only one single or no crest. Every sub-history that contains a single crest corresponds to a local closed (full) cycle. The mean load and alternate load component of the local cycle are calculated in parallel with the iterative procedure.
2013-09-24
Technical Paper
2013-01-2378
Manimaran Krishnamoorthy, Mathew Sam Paul Albert
In this work, durability of the bus structure is evaluated with a Virtual Test Model (VTM).Full vehicle Multi Body Dynamics (MBD) model of the bus is built, with inclusion of flexibility of the bus structure to capture structural modes. Component mode synthesis method is used for creation of flexible model for use in MBD. Load extraction is done by performing MBD analysis with measured wheel inputs. Modal Superposition Method (MSM) is employed in FE along with these extracted loads for calculation of modal transient dynamic stress response of the structure. e-N based fatigue life is estimated. The estimated fatigue life from the modal superposition method show good correlation with the physical test results done in 6-poster test rig.
2013-09-24
Technical Paper
2013-01-2350
Matt Kero
The commercial vehicle industry has seen regulations create new requirements over the last few years. Reductions to stopping distance, improvements to vehicle emissions, and the overall need for lighter weight vehicles has caused the commercial vehicle industry to look for new solutions to meet these needs. One such solution is light-weight aluminum metal matrix composite (MMC) brake drums. Aluminum MMC brake drums create the opportunity to reduce weight, lower brake temperatures, improve brake life cycle, and improve brake performance. During the evaluation of these aluminum MMC components it has been seen that existing procedures do not create accurate comparisons for this new material. Current procedures were designed and implemented for cast iron braking solutions. This paper will outline two procedures; FMVSS121 dynamometer burnishing and SAE J2115 wear performance testing, that do not allow direct comparisons from brake system to brake system to be made.
2004-10-26
Technical Paper
2004-01-2739
Saveliy M. Gugel
This article describes the experience of Sanova-Polytech, Inc. (SPI) in the creation, testing, and usage of new Liquid Induction Thermochemical Processes (LINTERPROCESS™) and Liquid Induction Heat Treatment (LINHEAT™) technologies, and in the designing, manufacturing, and employment of new automatic computerized production equipment, which can be of significant advantage to manufacturers of commercial vehicles. Heat treatment and thermochemical processing of various metals play an important role in the global effort to produce stronger, lighter, and more durable machine parts at lower costs. They are widely used in the manufacturing of cars and buses, and farm, construction, industrial, and other machinery.
2013-01-09
Technical Paper
2013-26-0139
Sathish Kumar P, Vikram Suryavanshi, Manikandan M, Bollishetty Sreedhar
Evaluation of vehicle structural durability is one of the key requirements in design and development of today's automobiles. Computer simulations are used to estimate vehicle durability to save the cost and time required for building and testing the prototype vehicles. The objective of this work was to find the service life of automotive structures like passenger commercial vehicle (bus) and truck's cabin by calculating cumulative fatigue life for operation under actual road conditions. Stresses in the bus and cabin are derived by means of performing finite element analysis using inertia relief method. Multi body dynamics simulation software ADAMS was used to obtain the load history at the bus and cabin mount locations - using measured load data as input. Strain based fatigue life analysis was carried out in MSC-Fatigue using static stresses from Nastran and extracted force histories from ADAMS. The estimated fatigue life was compared with the physical test results.
2013-10-07
Technical Paper
2013-36-0359
C.C. Scozzafave, L.G.S Ericsson, U. Wildmann, D.M. Spinelli
The aim of this paper is to present a methodology for approval of component that is applied when the first version is tested on a durability track with closed circuit and fails without meeting the approval criteria previously established. This approach was applied in suspension support on commercial vehicles. The full commercial vehicle was modeled in finite element for stress analysis in frame torsional loading. By presenting stress regions near the material's limit, tests were made on durability track with deformation measurement at the main critical spots. The component has failed in one of the measured spot without reaching the established number of laps for component approval on track. With the deformation measurement signal for one lap at the failure spot, a fatigue analysis using the software FEMFAT strain ® has been made, correlating the obtained damage with the number of laps on track until component failure.
2013-10-07
Technical Paper
2013-36-0471
José Eduardo D'Elboux, Marcus Kliewer, Camilo A. Adas, Fernando C. Dusi, Marco A. Fogaça Accurso, Eraldo de J. Soares, Alan M. Oliva
Due to the growing necessity to reduce time for new products development, or even to evaluate the reliability of them, a rationalization tendency of the tests has been observed in the field through more and more representative bench tests in a shorter time and with smaller costs. In the automotive industry, the amount of simulated parameters is always increasing; therefore it is necessary to collect a great number of sign measurements in suspension systems (accelerations, temperatures, strokes and deformations), using prototype vehicles. In the present paper we will present the measurements made in a representative track, where it was possible to analyze the measured signs. In a second step they were compiled and compacted, and finally applied in a one-axial bench test. This procedure permits to get a correlation between field and laboratory results.
2011-04-12
Technical Paper
2011-01-1207
Wim Van Dam, Mark W. Cooper, Kenneth Oxorn, Scott Richards
Since the invention of the internal combustion engine, the contact between piston ring and cylinder liner has been a major concern for engine builders. The quality and durability of this contact has been linked to the life of the engine, its maintenance, and its exhaust gas and blowby emissions, but also to its factional properties and therefore fuel economy. While the basic design has not changed, many factors that affect the performance of the ring/liner contact have evolved and are still evolving. This paper provides an overview of observations related to the lubrication of the ring/liner contact.
2011-09-13
Journal Article
2011-01-2306
Xin Lei, Antoun Calash, John Cagney
A cyclically pressurized hydraulic component made of compacted graphite iron (CGI) is examined in fatigue design. This CGI component has a notch, formed at the intersection of two drilling channels. This notch causes the stress to be locally elevated and may potentially serve as a fatigue initiation site. Traditional fatigue design approaches calculate the maximum stress/strain range acting at the notch and apply the Neuber correction when calculating fatigue life. It is, however, found that the fatigue life is dramatically underestimated by this method. This prompts the use of the critical distance method because the stresses are concentrated in a relatively small volume. When using the critical distance method, the fatigue life is correctly predicted. Finally, a fracture mechanics model of the crack check the reasonableness of the critical distance method results.
2011-08-30
Journal Article
2011-01-2114
Jai G. Bansal, Patrick Colby, Maryann Devine, Jack Emert, Kaustav Sinha
This paper is first in a series of papers designed to investigate wear processes in modern heavy duty diesel engines. The objective of the series is to discuss the effects that engine drive cycle, lubricant formulations and in-service ageing of lubricants have on wear of critical engine components. In this paper, the Radioactive Tracer Technology technique was used to study the steady state wear behavior of a number of contacting surfaces in a Caterpillar 1P engine, as a function of the drive cycle. A test protocol consisting of 7 modes or stages was used to simulate a variety of drive cycles. The results from this work provide useful insights into the wear behavior of these surfaces under a variety of speed and load conditions.
2011-08-30
Technical Paper
2011-01-2113
Masataka Hashimoto, Tadanori Azuma, Morio Sumimoto, Kanji Mitsuda
A new type of lube oil cleaning system is successfully developed for semi-permanent use of oil by always keeping oil clean with the result of no oil change and no waste oil. It is in practical use in many marine diesel engines and in some other fields. In recent years, possibility of semi-permanent use of engines themselves has been expected based on the field data. A ship test for 7 years has verified the expected semi-permanent use of engines with almost no wear and constant thermal efficiency during the test. We present the characteristics of the oil cleaning system and the result of the test. Also, a new type of fuel oil cleaning system is presented which is useful for cleaning low quality fuel oil. As a whole, this test is the beginning of the new stage of our work following the semi-permanent use of lube oil, which has been verified and established in many diesel engines since the 1980s.
1999-12-01
Technical Paper
1999-01-3034
Márcio G. Pinto, Felipe Nogueira, Leandro P. de Siqueira
A platform communization is being conducted at VW Truck and Bus aiming at cost reductions. This opportunity is also being used in order to improve the NVH characteristics of the VW commercial vehicles by optimizing engine mounts and other parts. This paper summarizes the procedure followed while optimizing engine mounts and its effect on NVH.
2011-10-04
Technical Paper
2011-36-0257
Ricardo Victorino Coelho, Túlio Gustavo Lima Rabelo
Extra heavy vehicles, depending on their application and configuration, demand higher torque, longer drive-off time, many gear shifts, more complex and unusual maneuvers. These situations lead to a high thermal energy applied on the clutch, increasing clutch wear and, in extreme conditions, leading to a thermal destruction. These events demand a technically and economically viable solution as well as a compact layout for easy implementation to increase the clutch performance and life. Since the problem is of thermal nature, without the possibility of forced cooling or the use of a larger clutch assembly to faster dissipate the energy, the proposed improvement has been focused on faster energy absorption in order to minimize peak temperature, both in occurrences and in magnitude.
2012-10-02
Technical Paper
2012-36-0520
Sandro Victor Polanco Espezua, Carlos Antonio Reis Pereira Baptista, Denise Ferreira Laurito, Ana Marcia Barbosa da Silva
Due to their favorable properties, among them the excellent strength-to-weight ratio, aluminum alloys are applied in transport vehicles, like trucks and buses. With respect to their mechanical behavior, fatigue is a process that alters the life of a structural component producing local stresses and floating strains and consequently giving rise to crack nucleation and the fracture of the material. In this work it is shown the influence of microstructure and intermetallic particles in aluminum alloy AA6005-T6, AA6063-T6 and AA6351-T6 that were tested for tension and fatigue. The microconstituents and the crack path on the fracture surfaces were analyzed by optical microscopy and scanning electron microscopy (SEM). The variation of the geometry of the precipitated particles of Mg₂Si, intermetallics (Fe,Mn)₃SiAl₁₂ and irregular distribution of particles in the matrix of the alloys were observed.
2013-04-08
Journal Article
2013-01-0331
Phil Carden, Carl Pisani, Jon Andersson, Ian Field, Emmanuel Lainé, Jai Bansal, Maryann Devine
This paper describes the results of a series of tests on a heavy-duty truck diesel engine using conventional and low viscosity lubricants. The objectives were to explore the impact of reducing lubricant viscosity on wear, friction and fuel consumption. The radiotracing Thin Layer Activation method was used to make on-line measurements of wear at the cylinder liner, top piston ring, connecting rod small end bush and intake cam lobe. The engine was operated under a wide range of conditions (load, speed and temperature) and with lubricants of several different viscosity grades. Results indicate the relationship between lubricant viscosity and wear at four critical locations. Wear at other locations was assessed by analysis of wear metals and post test inspection. The fuel consumption was then measured on the same engine with the same lubricants. Results indicate the relationship between oil viscosity and fuel consumption under a wide range of operating conditions.
2012-10-02
Technical Paper
2012-36-0457
Thiago Barao Negretti, Helio Kitagawa, Antonio Augusto Couto, Carlos Miletovic, Alex Petruk
The study is carried out through numerical and experimental methods. The finite element method is used to simulate the support mechanical behavior via modal analysis, and for the evaluation of stress concentration regions through pressure and thermoelastic static analyses, and dynamic analysis. The fatigue life is calculated for the presented stresses. Stress, acceleration and temperature data were obtained through dynamic test. For material evaluation, chemical analysis, hardness and metallographic analysis were carried out. For thoroughness, a failed support fractography will be presented. The objective of this study is to correlate the data obtained by numerical method with experimental data, and as a result, the support failure mechanism was identified. A modified support is presented to avoid the failure for the determined loads. The support within the proposed modifications reduces the current maximum stress in 41% and improved the fatigue life in 4.99e5 cycles.
2012-09-24
Technical Paper
2012-01-1991
Amir Ghasemi
Cyclic firing loading conditions coupled with high thermal loads are the main causes for failure of the cylinder head. A complete thermo-mechanical fatigue analysis of a cast aluminum cylinder head should include both high and low cycle fatigue. Reliable nonlinear material behavior, accurate thermo-mechanical stress analysis, and dependable failure criterion are the keys to successful life prediction. The low cycle fatigue is primarily due to thermal stress resulted from repeated start-up and shut-down cycle of the engines. The high cycle fatigue is mainly due to the firing loads, as amplitude stress, accumulated to the mean stress due to the thermal load. In this paper the required CAE simulations for high/low cycle fatigue of cylinder head will be discussed.
2012-09-24
Technical Paper
2012-01-1922
Matt Kero, Thomas Hewer, Jeremy Zills
The use of Aluminum Metal Matrix Composites (MMC's) is becoming a viable solution to help meet the new regulations of the medium to heavy-duty truck markets. The objective of this paper is to present both analytical and dynamometer data that demonstrate the damage tolerance of a selectively reinforced Aluminum MMC brake drum. In particular, dissimilar coefficients of thermal expansion (CTEs) between the MMC and Aluminum portion of the drum results in favorable compressive stresses in the Aluminum. This state of stress facilitates the slowing of crack growth for flaws whose depth reaches the boundary between MMC and Aluminum. This paper will present an analytical study utilizing finite-element models to predict stress levels in a drum subject to thermal and mechanical loading. Examination of the stress-fields for braking events at room temperature and elevated temperature provides evidence of the aforementioned compressive stresses in the Aluminum portion of the drum.
2012-09-24
Technical Paper
2012-01-1910
Michael Karge
By the fatigue assessment of large welded steel structures such as construction machines structures, the calculation engineer is confronted with a difficulty: the local stress approaches with fictitious notch radius that are very accurate cannot be used on the global structure because of the current computer limitations. Only a nominal stress can be estimated on the whole structure. The accuracy of the current commercial code methods that are using the nominal stress approach is not satisfying for most of the cases. The major problems are the following: only one SN-Curve (FAT-class) can be chosen for a weld the stress used for the calculation is based on the critical plane concept, not taking into account the direction of the weld (anisotropy of notch effects) and the geometrical weld parameters (e.g. weld throat thickness and penetration) choice of the FAT-class when the structural detail is not available in the IIW guideline.
2012-09-24
Technical Paper
2012-01-1909
Saurabh Kumar Singh, Vijay Hiremath, Vijay Kumar Ojha, Narayan Jadhav
Subject paper focuses primarily on non uniform tire wear problem of front steered wheels in a pickup model. Cause and effect analysis complemented with field vehicle investigations helped to identify some of the critical design areas. Investigation revealed that steering geometry of the vehicle is undergoing huge variations in dynamic condition as compared to initial static setting. Factors contributing to this behavior are identified and subsequently worked upon followed by a detailed simulation study in order to reproduce the field failures on test vehicles. Similar evaluation with modified steering design package is conducted and results are compared for assessing the improvements achieved. In usual practice, it is considered enough if Steering Geometry parameters are set in static condition and ensured to lie within design specifications.
2012-09-24
Technical Paper
2012-01-1963
Dimitrios Dardalis, Ronald D. Matthews, Alan O. Lebeck
The Rotating Liner Engine (RLE) is an engine design concept where the cylinder liner rotates in order to reduce piston assembly friction and liner/ring wear. The reduction is achieved by the elimination of the mixed and boundary lubrication regimes that occur near TDC. Prior engines for aircraft developed during WW2 with partly rotating liners (Sleeve Valve Engines or SVE) have exhibited reduction of bore wear by factor of 10 for high BMEP operation, which supports the elimination of mixed lubrication near the TDC area via liner rotation. Our prior research on rotating liner engines experimentally proved that the boundary/mixed components near TDC are indeed eliminated, and a high friction reduction was quantified compared to a baseline engine. The added friction required to rotate the liner is hydrodynamic via a modest sliding speed, and is thus much smaller than the mixed and boundary friction that is eliminated.
2016-04-05
Technical Paper
2016-01-1575
Federico Ballo, Roberto Frizzi, Gianpiero Mastinu, Donato Mastroberti, Giorgio Previati, Claudio Sorlini
Abstract In this paper the lightweight design and construction of road vehicle aluminum wheels is dealt with, referring particularly to safety. Dedicated experimental tests aimed at assessing the fatigue life behavior of aluminum alloy A356 - T6 have been performed. Cylindrical specimens have been extracted from three different locations in the wheel. Fully reversed strain-controlled and load-controlled fatigue tests have been performed and the stress/strain-life curves on the three areas of the wheel have been computed and compared. The constant amplitude rotary bending fatigue test of the wheel has been simulated by means of Finite Element method. The FE model has been validated by measuring the strain at several points of the wheel during the actual test. From the FE model, the stress tensor time history on the whole wheel over a loading cycle has been extracted.
2016-09-27
Technical Paper
2016-01-8044
Guoyu Feng, Wenku Shi, Henghai Zhang, Qinghua Zu
Abstract In order to predict the fatigue life of thrust rod heavy duty commercial vehicle balanced suspension, based on the continuum mechanics theory, the fatigue life prediction model of rubber with equivalent effect as damage parameter is established. Based on the equivalent stress and fatigue cumulative damage theory, the fatigue damage evolution equation of rubber material expressed by stress is derived by using the strain energy function. The general fatigue life model is established by using the maximum logarithmic principal strain as the damage parameter. The finite element model of the thrust rod is established, and the stress distribution of the spherical hinge rubber layer and the easy damage area are analyzed. Based on the equivalent stress calculation results and the axial tension stress and strain data of the rubber material, the accuracy of the results of the finite element calculation is verified.
2016-09-27
Technical Paper
2016-01-8027
Stefan Steidel, Thomas Halfmann, Manfred Baecker, Axel Gallrein
Abstract Rolling resistance and tread wear of tires do particularly influence the maintenance costs of commercial vehicles. Although tire labeling is established in Europe, it is meanwhile well-known that, due to the respective test procedures, these labels do not hold in realistic application scenarios in the field. This circumstance arises from the development phase of tires, where the respective performance properties are mainly evaluated in tire/wheel standalone scenarios in which the wide range of usage variability of commercial vehicles cannot be considered adequately. Within this article we address a method to predict indicators for rolling resistance and tread wear of tires in realistic application scenarios considering application-based factors of influence like specific customers, operation circumstances, regional dependencies, fleet specific characteristics etc.
2015-04-14
Technical Paper
2015-01-0517
Masaaki Kawahara, Noriaki Katori, Tatsuya Koyama
Abstract The friction pattern on the chamfers of sleeves and dog gears is a combination of peeling and adhesive wear caused by the formation and propagation of fine cracks. The effect of additional elements on wear were checked by making a test apparatus capable of performing evaluations on test pieces equivalent to those using actual parts. The results showed that the addition of B, Ti-Nb helped improve wear resistance. This is attributed to enhanced toughness and reduced peeling due to the formation of a texture. A 45% reduction in wear was achieved in actual parts tests on steel with added B, Ti-Nb.
2014-05-07
Technical Paper
2014-36-0038
Fabio Augusto Schuh, Leandro Luís Corso, Leonardo Hoss
Abstract Applying knowledge available at technical literature for cycle counting, damage caused by each load cycle through S-N curve, and fatigue damage accumulation by Palmgren-Miner rule, durability prediction is performed for a leafspring of a commercial vehicle with 6×4 suspension system. Max principal tension is measured by means of strain gages in the most representative points for fatigue life of the leafspring, determined with FEA, while vehicle runs over off-road track in a proving ground. Load and tension are also measured in a laboratory bench test for this component. Correlation between off-road track and bench test is then performed. Finally, representative samples of the component are tested with dynamic loading until fatigue fracture in bench test, and using data from these tests, statistical analysis is performed with application of Weibull distribution, allowing life prediction in statistical terms.
2016-04-05
Technical Paper
2016-01-0412
Mathialgan Balaji, B. Jaiganesh, Selvakumar Palani, K. Somasundaram, Srinivasa Rao
Abstract Tractors are the self-propelled vehicle which finds its major application in agriculture, haulage and construction equipment. The product development cycle time of a tractor is more as compared to automobiles since it has to undergo rigorous field testing. Bringing more realistic component and system level validation in the test lab will drastically reduce the product development cycle time. Non-availability of standard usage pattern and customer-correlated proving ground pose a bigger challenge for bringing the field conditions to the lab. As a result, the tractor has to be instrumented with sensors and load-time history needs to be acquired as per real world usage pattern. Raw data from the field cannot be used directly for lab testing since the number of load cycles will be very high. Raw data have to be edited based on damage calculation and fatigue sensitivity analysis technique.
2015-05-13
Technical Paper
2015-36-0009
Evandro Benincá, Mauricio da Silva, Ruy Alberto Bueno Jr., Vagner do Nascimento
Abstract One effect which is present in drum and disc brakes is the temperature. This effect significantly changes the vehicle and semi-trailer combinations performance, mainly in drum brakes that is more susceptible to this factor. High temperatures mean loss of efficiency, higher lining wear, brakes and rolling systems components life reduction and could be caused by many factors, which can be mentioned, overload, error in design and choice of brake system, speeding, over adjustment (dragging) and environment heat exchange. The challenge is to comprehend the relation between different brake configuration and how these configurations affects the temperatures generation on brake system, allowing that this factors can be evaluated during the project design. This paper aims to show a case study for a new brake family to be used in city bus application where the fleets are looking for better, safety, performance and low lining wear reduce the to increase the maintenance time.
2015-09-01
Technical Paper
2015-01-2033
Takashi Honda, Satoshi Ogano
Increased attention has been focused on fuel economy (FE) of passenger vehicle lubricants. For diesel engine oils, FE is significantly lost in service due to soot loading in oils which inhibits adsorption of friction modifier (FM) on rubbing metal surfaces. On the other hand, soot may have a positive aspect because this has a similar molecular structure to graphite which may have a possibility to work well as a solid lubricant, i.e., FM in oils. This suggests that management of soot in diesel engine oils could achieve lower frictional performance, and thus enhance further improvement of fuel economy. The impact of soot properties on friction coefficient by physical and chemical characterization of soot accumulated in diesel engine oils have been firstly discussed in our previous paper. In this paper, the frictional response was investigated in the presence of soot at various test conditions and surface roughness.
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