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Technical Paper

“U” Bolt Torque Influence over Leaf Springs

2014-05-07
2014-36-0024
”U” bolts are fixing elements and they are used to clamp an elastic joint. From the past, they still looking as an old design and unfortunately, suspension engineers are not specialists in fasteners and elastic joints. That is why we will show important assumptions and concepts to design and specifications this clamp element “U” bolt and its influence over leaf-springs. Currently, “U” bolt is used to clamp an elastic or elastic-plastic joint of heavy duty suspension, formed by leaf-spring, axle, spring pad, “U” bolt plate. This kind of suspension is typically used to trucks, buses and trailers. We are wondering, which one important assumption that an engineer must be careful when designs a new suspension changing from old designs to an updated technology. We provide a theoretical analysis and a FEA analysis to compare torque efficacy x leaf-spring reactions and what are effects this relationship can cause in a suspension.
Journal Article

“Sticky” Lining – the Phenomena, Mechanism and Prevention

2008-04-14
2008-01-0819
An unique bonding mechanism was studied after several instances, where the linings stuck to the brake drums on transit buses, were reported. Evidences suggested that the linings were “glued” to the brake drums surface after wear debris (dust) was turned into “adhesive paste” through complicated thermal and chemical changes. Factors such as the friction materials, environment and service conditions, which could activate and deactivate the lining bonding, were observed and discussed. The prevention measures are proposed.
Technical Paper

“Spacematic” Monitoring System

1998-09-15
982138
Pneumatic, manually operated, drilling machines are used to produce a significant proportion of all holes drilled during wing manufacture. Drilling machine design and the manual drilling process has not changed significantly in decades. By employing miniature, low power, electronics and interfacing techniques, a monitoring system has been developed. This system enables improved process control of the manual drilling operation. Machine calibration management, measurement of drill performance, jig drilling error control and asset management are some of the benefits attainable. This project will hopefully encourage others to discover the potential for improving historically established processes, by employing modern technological developments.
Technical Paper

“Smart sensing” of Oil Degradation and Oil Level Measurements in Gasoline Engines

2000-03-06
2000-01-1366
Proper lubrication of moving parts is a critical factor in internal combustion engine performance and longevity. Determination of ideal lubricant change intervals is a prerequisite to ensuring maximum engine efficiency and useful life. When oil change intervals are pushed too far, increased engine wear and even engine damage can result. On the other hand, premature oil changes are inconvenient, add to vehicle maintenance cost, and result in wasted natural resources. In order to determine the appropriate oil change interval, we have developed an oil condition sensor that measures the electrical properties of engine oil, and correlates these electrical properties to the physical and chemical properties of oil. This paper provides a brief background discussion of the oil degradation process, followed by a description of the sensor operational principles and the correlation of the sensor output with physical and chemical engine oil properties.
Technical Paper

“RoHS” Compliant Chrome - Free Conversion Coating for Aerospace Manufacturing

2006-09-12
2006-01-3130
This paper presents, chemistry, test data and processing procedures on a non toxic and environmentally friendly chrome-free conversion coating alternative with the same level of adhesion and secondary corrosion resistance as that found in chrome containing conversion coating systems. Test data from military and independent sources will be presented on secondary coating adhesion, electrical conductivity, filiform and neutral salt-spray corrosion resistance as compared to chromate based systems .on magnesium, aluminum and zinc and their respective alloys. The European “RoSH” initiative will not allow for the presence of any hexavalent chromium on imported electrical components as of July first of 2006. Trivalent chromium based systems generate hexavalent chromium due to the oxidation of the trivalent chromium and as such will not be allowed.
Technical Paper

“Projection-by-Projection” Approach: A Spectral Method for Multiaxial Random Fatigue

2014-04-01
2014-01-0924
This paper presents a fatigue criterion based on stress invariants for the frequency-based analysis of multiaxial random stresses. The criterion, named “Projection-by-Projection” (PbP) spectral method, is a frequency-based reformulation of its time-domain definition. In the time domain PbP method, a random stress path is first projected along the axes of a principal reference frame in the deviatoric space, thus defining a set of uniaxial random stress projections. In the frequency-domain approach, the damage of stress projections is estimated from the stress PSD matrix. Fatigue damage of the multiaxial stress is next calculated by summing up the fatigue damage of every stress projection. The criterion is calibrated on fatigue strength properties for axial and torsion loading. The calculated damage is shown to also depend on the relative ratio of hydrostatic to deviatoric stress components.
Technical Paper

“One-Side Aluminized Steel Sheet” Development and Properties of a New Anti-Corrosion Material

1983-02-01
830519
Nisshin Steel Co., Ltd. has developed a new process for the production of a “one-side aluminized steel sheet”. The process utilizes a double layer one-side “stop-off” coating to prevent the molten Al from adhering to the steel surface. The “Stop-off” coating is removed by simple mechanical brushing after hot dipping. The characteristics of this product by above mentioned process are: 1) The steel side was as clean as a conventional cold rolled surface and showed no trace of the “stop-off” layer. Thereby, phosphating and ED painting were performed. 2) In the salt spray test data was obtained from zinc and Al coated steel surfaces; the coatings on both surfaces being of equal thickness.
Technical Paper

“Motion in FEA”: An Innovative Approach for More Physical and More Accurate Vehicle Dynamics Simulation

2012-04-16
2012-01-0762
Vehicle dynamics is a discipline of mechanical engineering that benefited of significant improvements thanks to the progress of computational engineering. Vehicle dynamics engineers are using CAE for the development of a vehicle with MBS and FEA. The concurrent use of these two technologies is a standard in the automotive industry. However the current simulation process is not fully efficient because local geometrical and material nonlinearities are not accurately modeled in classical MBS software. This paper introduces a methodology for vehicle dynamics simulation integrating MBS capabilities in one single nonlinear FEA environment enabling an accurate modeling of nonlinearity in vehicles.
Technical Paper

“MONOGAL”: A New Anti-Corrosion Material for the Automotive Industry

1982-02-01
820335
MONOGAL is a coated steel developped to improve the corrosion resistance of exposed automotive body applications. Its process os based on the brittleness of the η zinc coating in a range of temperatures below the melting point of the zinc. MONOGAL is produced on a hot dip galvanizing line; at the exit of the pot the free zinc is brushed off the light side of the differentially coated sheet. Side 1 of MONOGAL presents a very thin and continuous layer of iron-zinc diffusion alloy with no free zinc. Side 2 is a standard G90 or G60 zinc coating. The iron-zinc alloy layer has excellent anti-galling properties which improve the formability of MONOGAL over two side hot dip galvanized steel with the same r value. MONOGAL also shows good weldability, paintability and corrosion resistance.
Technical Paper

“In-Car” Fatigue Data Acquisition

1969-02-01
690172
“In-car” measurement of vehicle loads and stresses is a basic step in solving fatigue design problems associated with passenger cars. The application includes measuring systems and techniques for evaluating fatigue design problems related to energy-absorbing steering columns and automotive gas turbines.
Technical Paper

“Fuel Flow Method2” for Estimating Aircraft Emissions

2006-08-30
2006-01-1987
In recent years there has been increasing interest in quantifying the emissions from aircraft in order to generate inventories of emissions for climate models, technology and scenario studies, and inventories of emissions for airline fleets typically presented in environmental reports. The preferred method for calculating aircraft engine emissions of NOx, HC, and CO is the proprietary “P3T3” method. This method relies on proprietary airplane and engine performance models along with proprietary engine emissions characterizations. In response and in order to provide a transparent method for calculating aircraft engine emissions non proprietary fuel flow based methods 1,2,3 have been developed. This paper presents derivation, updates, and clarifications of the fuel flow method methodology known as “Fuel Flow Method 2”.
Technical Paper

“Fatigue Behavior of Sheet Steels for Automotive Industry”

1992-11-01
921439
Carbon and rephosphorized pre-strained sheet steels for cold drawing forming operations were studied and the tensile, high cycle fatigue and fatigue crack propagation properties were determined. The fatigue limit was found to be higher for 20% than for 1% pre-strained condition. Threshold stress intensity factors (▵Ků) of 5.29 MPa. m1/2 for rephosphorized steel and 7.07 MPa. m1/2 for carbon steel. Critical crack lenghts were calculated by ▵Ků and fatigue limit data using the Lukas-Klesnil short-crack criterion. Through fractographic analysis it was possible to determine the general behavior of tested materials near threshold.
Technical Paper

“Derivation of Conduction Heat Transfer in Thin Shell Toroids”

2000-07-10
2000-01-2487
This paper presents the derivation of the equations for circumferential, longitudinal and radial heat transfer conductance for a thin shell toroid or a segment of the toroid. A thin shell toroid is one in which the radius to thickness ratio is greater than 10. The equations for the surface area of a toroid or of a toroidal segment will also be derived along with the equation to determine the location of the centroid. The surface area is needed to determine the radial conductance in the toroid or toroidal segment and the centroid is needed to determine the heat transfer center of the toroid or toroidal segment for circumferential and longitudinal conductance. These equations can be used to obtain more accurate results for conductive heat transfer in toroid which is a curved spacecraft components. A comparison will be made (1) using the equations derived in this paper which takes into account the curvature of the toroid (true geometry) and (2) using flat plates to simulate the toroid.
Technical Paper

“DELRIN” ACETAL RESIN —a new engineering material

1959-01-01
590033
“DELRIN” is a new thermoplastic which offers high strength, excellent thermal stability, good fatigue life, low creep, and excellent solvent resistance. This paper describes the physical and chemical properties of the material, and the range of possible uses. The material is easily fabricated into complex shapes by standard injection-molding techniques. Also, it can be easily joined to itself or to other materials. The authors think that the material offers advantages over metals in its good fric-tional properties, abrasion resistance, and corrosion resistance.
Technical Paper

“Cromard” Thin Wall Steel Liners and Hard Chrome Plated Liners for High Production Gasoline and Diesel Engines

1964-01-01
640361
This paper, confined to the application of hard chrome plated liners to high-speed four-stroke diesel and gasoline engines, illustrates the increase in their popularity in the United Kingdom, and the advanced production methods which make this economically possible. The need for balanced engine life has long been apparent and is even more important today, the growth of motor transport having outstripped repair facilities. Iron bore life has been surpassed by improvement in the life of other component parts in the modern diesel engine. The provision of hard chrome plated liners can restore the balance. Further development and turbocharging of diesel engines has shown the need for a bore material capable of preventing scuffing and galling at elevated temperatures. Hard chrome has already proved itself in four-stroke engines under these conditions.
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