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Fuel and Additive Effects on Engine Systems, 2017

2017-03-28
Topics include the effects of fuel and additives on deposit formation, intake system cleanliness, friction, wear, corrosion, and elastomer compatibility. Also covered are effects of fuel specification on drivability, on evaporative emissions, and on the relationship between emissions and drive cycle.
Collection

Fatigue Modeling/Testing & CAE Durability Analysis, 2017

2017-03-28
This collection of papers focus on state-of-the-art fatigue theory and advanced development in fatigue testing, material behavior under cyclic loading, and fatigue analysis methodology & research in the ground vehicle industry. Studies and discussions on innovative and improved fatigue theory/methods in will be discussed along with and engineering applications of CAE durability analysis.
Video

5000 Hours Aging of THERBAN® (HNBR) Elastomers in an Aggressive Biodiesel Blend

2012-05-23
TERBAN® hydrogenated nitrile rubber (HNBR) is a specialty elastomer used in demanding engineering applications such as the automotive, heavy duty, and industrial markets. It has excellent combination of heat, oil and abrasion resistance in addition to its high mechanical strength, very good dynamic and sealing properties. This paper will present data on aging HNBR for five thousand hours in an aggressive and un-stabilized B30A biodiesel fuel blend (70% ULSD, 30% SME, and an aggressive additive package) and explore the effect of HNBR polymer properties and vulcanizate composition on the performance in such fuel blends. Presenter Victor Nasreddine
Video

Polycarbonate Glazing - Accelerated Wiper Testing, Surface Characterization and Comparison with On-Road Fleet Data

2012-05-23
Exatec� PC glazing technology team, has developed advanced weathering and abrasion resistant coatings technology that can be applied to protect polycarbonate. It is of particular interest to quantify and understand the factors that determine the surface abrasion performance of coated PC in rear window and backlight applications that have a wiper system. In the present study we describe Exatec's lab scale wiper testing equipment and test protocols. We also describe adaptation of optical imaging system to measure contrast and nano-profiling using nano-indenter, as post wiper surface characterization methods. These methods are more sensitive to fine scratches on glazing surface than standard haze measurement and mechanical profilometry. Three coating systems were investigated; Siloxane wetcoat (A), Siloxane wetcoat (B), and Siloxane wetcoat (B) plus plasma coat (Exatec� E900 coating). The performance comparisons were made using all these surface characterization methods.
Video

Ionic Liquids as Novel Lubricants or Lubricant Additives

2012-05-10
For internal combustion engines and industrial machinery, it is well recognized that the most cost-effective way of reducing energy consumption and extending service life is through lubricant development. This presentation summarizes our recent R&D achievements on developing a new class of candidate lubricants or oil additives ionic liquids (ILs). Features of ILs making them attractive for lubrication include high thermal stability, low vapor pressure, non-flammability, and intrinsic high polarity. When used as neat lubricants, selected ILs demonstrated lower friction under elastohydrodynamic lubrication and less wear at boundary lubrication benchmarked against fully-formulated engine oils in our bench tests. More encouragingly, a group of non-corrosive, oil-miscible ILs has recently been developed and demonstrated multiple additive functionalities including anti-wear and friction modifier when blended into hydrocarbon base oils.
Video

Monitoring the Progression of Micro-Pitting in Spur Geared Transmission Systems Using Online Health Monitoring Techniques

2012-03-16
Micro-pitting is a fatigue effect that occurs in geared transmission systems due to high contact stress, and monitoring its progression is vital to prevent the eventual failure of the tooth flank. Parameter signature analysis has been successfully used to monitor bending fatigue failure and advanced phases of gear surface fatigue failure such as macro-pitting and scuffing. However, due to modern improvements in steel production the main cause of gear contact fatigue failure can be attributed to surface micro-pitting rather than sub-surface phenomena. Responding to the consequent demand to detect and monitor the progression of micro-pitting, this study experimentally evaluated the development of micro-pitting in spur gears using vibration and oil debris analysis. The paper presents the development of an online health monitoring system for use with back-to-back gear test rigs.
Video

Study of Exit Burr Formation and Exit Burr Reduction in Automated Drilling of Titanium Stacked With Carbon Fiber Composite

2012-03-16
With the growing use of carbon fiber composite structure in Aircraft Manufacturing, the challenge of drilling carbon fiber stacked with Titanium has become a focus point. Due to the abrasive nature of the carbon fiber (CF), cutting tool life is relatively short when drilling carbon fiber stalked with Titanium. A common drill wear indicator is exit burr formation in the Titanium. As drilling tools wear due to the abrasive nature of the CF, the exit burr in the in the Titanium increases. This study seeks to understand the factors that lead to tool wear and exit burr formation. A correlation may be made relating drilling thrust forces with exit burr formation. Different cutting tools geometries and materials are studied using a high speed camera to attempt to understand the factors influencing exit burr formation. Findings are optimized and tested. Decreasing exit burr in the drilling of CF and Titanium may increase tool life thereby reducing tool costs to airframe manufacturers.
Standard

Traction Coefficient Measurement

2013-02-12
WIP
ARP6243
Aviation oils provide thin lubricating films between highly stressed bearing, gear and other lubricated contacts. The stresses and shear rates cause rapid rheological changes in the oil which affect the traction (friction) between the surfaces. Thin film dynamic forces are associated with the molecular structure of the oil provided by the oil supplier. Traction force divided by the normal load (i.e. traction coefficient) can be viewed as a fundamental property of aviation oil. Its value is a function of stress, temperature and shear rate. Appropriate measurements are made under dynamic conditions to characterize aviation oil products for engineering design purposes and service performance prediction.
Training / Education

Performance and Use of Polymer Plan Bearings in Transmission Design Web Seminar RePlay

Anytime
As part of a broad transmission design philosophy, the understanding and application of tribological systems is critical. The number of interacting surfaces within a modern automotive transmission continues to increase, while the demands on the system continue to press the limits of traditional technologies. The understanding of each surface interaction within the greater system becomes increasingly important as each component is asked to do more to benefit the overall system. This short course will present the tribological performance of polymeric plain bearings as related to transmission applications.
Training / Education

Introduction to Materials Bundle

Anytime
The following six on-demand courses are included in the Introduction to Materials bundle. Each course is approximately one-hour in duration. See Topics/Outline for additional details. Introduction to Physical Properties This course provides an an overview of manufacturing materials and their physical properties, including thermal, electrical, and magnetic properties and introduces volumetric characteristics, such as mass, weight, and density.
Technical Paper

Innovative Material Characterisation Methodology for Tyre Static and Dynamic Analyses

2020-09-30
2020-01-1519
Tyre structures are based on composite materials that constitute numerous layers, each providing specific properties to the tyre mechanic and dynamic behaviour. In principle, the understanding of the partial contributions of the individual layers requires knowledge of its mechanical properties. In case of non-availability of such critical information, it is difficult to perform tyre FE analyses. In the current work, a methodology is proposed to study the tyre static and dynamic behaviour to estimate its constituents properties based on the measured quasi-static responses of the tyre for certain specific loads. As a first step, a simplified tyre numerical model with standard rubber material properties is modeled that can substantively predict the necessary tyre static responses, i.e. radial, longitudinal and lateral stiffness. These responses are correlated with the physical tyre response that are measured using a kinematic and compliance (K&C) test rig in the laboratory.
Technical Paper

On Prediction of Automotive Clutch Torsional Vibrations

2020-09-30
2020-01-1508
Automotive clutches are prone to rigid body torsional vibrations during engagement, a phenomenon referred to as take-up judder. This is also accompanied by fore and aft vehicle motions. Aside from driver behaviour in sudden release of clutch pedal (resulting in loss of clamp load), and type and state of friction lining material, the interfacial slip speed and contact temperature can significantly affect the propensity of clutch to judder. The ability to accurately predict the judder phenomenon relies significantly on the determination of operational frictional characteristics of the clutch lining material. This is dependent upon contact pressure, temperature and interfacial slip speed. The current study investigates the ability to predict clutch judder vibration with the degree of complexity of the torsional dynamics model. For this purpose, the results from a four and nine degrees of freedom dynamics models are compared and discussed.
Technical Paper

Numerical Analysis of the Influences of Wear on the Vibrations of Power Units

2020-09-30
2020-01-1506
Numerical Analysis of the Influences of Wear on the Vibrations of Power Units Yashwant Kolluru, Rolando Doelling eBike Department Robert Bosch GmbH Kusterdingen, Germany yashwant.kolluru@de.bosch.com rolando.doelling@de.bosch.com Lars Hedrich Institute of Informatics Goethe University Frankfurt Frankfurt, Germany hedrich@em.informatik.uni-frankfurt.de The prime factor, which influences vibrations of electro-mechanical drives, is wear at the components. This paper discusses the numerical methods developed for abrasion, vibration calculations and the coupling between wear and NVH models of drive unit. Wear is a complex process and understanding it is essential for vibro-acoustics. The paper initially depicts finite element static model used for wear calculations. The special subroutines developed, aids in coupling the wear equations, various contact and friction formulations to the numerical model.
Technical Paper

Resabtors - Advanced Multi-Material Muffler Designs for Clean Air Applications

2020-09-30
2020-01-1554
The development and production of resonators on the charged air side of combustion engines require profound base of knowledge in designing, simulating and the production of such parts in different materials (aluminum, copper, stainless steel and technical plastic). As combustion engines are under constant discussion, this existing knowledge base should be used for other applications within and outside the automotive industry. Very quickly it became apparent that new challenges often require completely new solutions, designs and materials to meet the requirements of flow noise reducing parts. For example, for clean air applications mufflers based on “special treated foams” and “meta-materials” can be introduced. These materials offer new potentials for tuning of the frequency range and allow improved broad banded flow noise attenuation. Such parts are named “Resabtors” in order to take respect of the different flow noise attenuation principles resonation and absorbing.
Technical Paper

Optimization Of Vehicle Damping Sheets Position Based On Energy Calculation

2020-09-30
2020-01-1528
As a common means for reducing vibration and noise for automobiles, damping material is usually employed in the vehicle body, typically on the floor, the dashboard, and the top roof. With the growing demand of fuel economy, light weighting, as well as NVH comfort, the optimization of the damping pads has become a topic of increasing importance. In numerical simulation, the traditional methods generally make use of the modal strain energy of the metal sheet as the main indicator for making layout choice for the damping pads. The optimization is not performed according the vehicle’s real working condition. Furthermore, the traditional methods do not depend on the accurate properties of the damping material. In this paper, a novel optimization method based on energy analysis is presented.
Technical Paper

Inverse Vibration Problem Used for the Characterization of the Damping Added by a Trim Foam on a Plate

2020-09-30
2020-01-1580
Many solutions exist to insure the NVH comfort of ground and air vehicles, like heavy mass (bitumen pads), viscoelastic treatments and absorbing foams. The trim foam is an alternative to heavy solutions. To know the potential of the foam, a study of its capacity to damp vibration is done. A system, composed by a suspended plate, with a foam on it, is characterized in different cases of contact at the foam-plate interface (glued or not) and with different types of foam. An experimental test facility is developed to identify the global damping of the structure: a laser vibrometer measures the displacement field of the foam-plate structure, an inverse method is used to determine the structural parameters. By changing the contact at the interface, it is possible to identify the contribution of the friction forces to the global damping of the structure. Another type of damping is the viscoelastic damping due to the intrinsic characteristics of the trim foam.
Technical Paper

Coarse Mesh RIFF Method to Identify the Homogenized Flexural and Shear Complex Moduli of Composite Beams

2020-09-30
2020-01-1579
Facing the increasing use of composite materials regarding their stiffness to mass ratio, industries need to design complex structures. Hence specific methods must developed to predict the vibratory behavior of such materials but also to check their performances in-situ, analyse the presence of flaws or quantify degradation of properties throughout time. This paper describes a method to estimate the flexural and shear complex moduli of composite beams, based on a simple measurement of the transverse displacement on a coarse mesh using a hammer and an accelerometer. The herein depicted approach consists in an adaptation of the corrected finite difference scheme (Leclere et al. 2012) applied to an inverse vibratory method developed by the authors in previous works (Wassereau et al. 2017). The Timoshenko’s equation of motion and the corrected finite difference scheme are the two major key points of the method.
Training / Education

FEA Beyond Basics: Nonlinear Analysis Web Seminar RePlay

Anytime
Finite Element Analysis (FEA) has been an indispensable tool for design simulation for several decades but this wide spread use has been limited to simple types of analyses. Relatively recently, more advanced analyses have given easy-to-use interfaces enabling design engineers to simulate problems formerly reserved for analysts. FEA Beyond Basics targets the FEA users who wish to explore those advanced analysis capabilities. It will demonstrate how to move past the ubiquitous linear structural analysis and solve structural nonlinear problems characterized by nonlinear material, large displacements, buckling or nonlinear connectors.
Training / Education

Metallurgy of Steel: Principles

Anytime
This online course teaches the phases and microstructures that form in steels, their effects on steel properties, the microstructure changes that occur when steel is heated and cooled, the effects of carbon content and cooling rate on the microstructures that form. Also, how to read the iron-carbon phase diagram will be discussed. All this information is applicable to understanding the effects of steel heat treating processes and heat treating process parameters on the microstructure and properties of heat treated plain carbon, low-alloy, and tools steels. The course is divided into six modules followed by a quiz.
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