Traction Characteristics Research Articles

Transient Traction Characteristics Between Rail and Wheel under Low Velocity and Low Slip Ratio (An Experimental Study Under Dry Condition)

Transient Traction Characteristics Between Rail and Wheel under Low Velocity and Low Slip Ratio (An Experimental Study Under Dry Condition)

2408 レール/車輪間の過渡的トラクション特性と表面性状との関係(OS9 接触問題とトライボロジ,OS9 接触問題とトライボロジ,TRANSLOG 2006)

This paper describes an experimental investigation on relationships between transient traction characteristics and hardness distribution in the direction of the depth of roll-slide surface of twin discs. Hardness was measured using a nanoindentation tester as well as a micro Vickers hardness tester to cover wide range of indent depth. The experimental results show that hardness of worn surface under dry condition was higher than that of virgin surface. Hardness of worn surface under wet condition, however, changed little.

Effect of surface roughness on elastohydrodynamic traction. Part 2

To investigate the performance of a traction-drive toroidal continuously variable transmission, the traction characteristics under partial elastohydrodynamic lubrication contact were calculated theoretically based on roller test results. A calculation model was constructed for considering the effects of surface roughness on performance. The model incorporated a viscoelastic and elastic-plastic model using a nonlinear Maxwell model to represent the rheological behaviour of the traction fluid. The validity of the model was confirmed by its good agreement with the experimental results described in Part 1 of this paper. Various calculations were made to investigate the effect of surface roughness on traction under the operating conditions of an actual traction drive. The results indicated that the effect of surface roughness on durability could not be ignored.

Bulk Modulus of Lubricating Oils as Predominant Factor Affecting Tractional Behavior in High-Pressure Elastohydrodynamic Contacts

The phase diagrams corresponding to transition from liquid to viscoelastic solid and that from viscoelastic solid to elastic-plastic solid of Santotrac100 (SN100), mineral oil, synthetic naphthenic oil, polybutene, and tetradecane were first made up by high-pressure density measurements and others. The bulk modulus of lubricating oils under a quasi-static condition was evaluated using a phase diagram. The results indicated that the bulk modulus of lubricating oils is closely related to the oil molecular packing parameter T VE −T (where T VE is the viscoelastic solid transition temperature at pressure p, and T is the oil temperature). The constant values of the bulk modulus in the elastic-plastic range are different depending on the molecular structures of the oils. It has also been shown that SN100, mineral oil, synthetic naphthenic oil, and polybutene converted to amorphous solids at high pressures and tetradecane converted to molecular crystal. Next, the elastohydrodynamic lubrication tractions were measured by a ball-on-disk machine. The results indicated that the maximum traction coefficient is closely related to T VE −T. As a result, the importance of the bulk modulus as a predominant factor for traction characteristics of lubricating oil was pointed out.

1202 ウェブ搬送時のしわ発生予測モデル : 第1報,実験(要旨講演,柔軟媒体ハンドリング/画像形成機器)

In the transportation system for continuous flexible materials such as paper, plastic film, metal foil, textile, most webs are very thin and consequently easy to buckle or wrinkle. Especially, in the case of paper-web, the creation of wrinkles is more often as compared with the case of plastic film or metal foil. The web wrinkling affects significantly the product quality and sometimes it leads to less profitability in the manufacturing operation. The paper-web wrinkles treated in this paper are caused by the roller misalignment and traction characteristics between web and roller in the transportation systems. The prediction model of paper-web wrinkles is formulated and some numerical calculation results are shown with experimental verifications for coated and uncoated paper-webs. Moreover, the idea of "web defect map" is presented for designing and safety operating the web transportation system.

1204 ウェブ搬送時のしわ発生予測モデル : 第3報,ウェブ損傷図(要旨講演,柔軟媒体ハンドリング/画像形成機器)

In the transportation system for continuous flexible materials such as paper, plastic film, metal foil, textile, most webs are very thin and consequently easy to buckle or wrinkle. Especially, in the case of paper-web, the creation of wrinkles is more often as compared with the case of plastic film or metal foil. The web wrinkling affects significantly the product quality and sometimes it leads to less profitability in the manufacturing operation. The paper-web wrinkles treated in this paper are caused by the roller misalignment and traction characteristics between web and roller in the transportation systems. The prediction model of paper-web wrinkles is formulated and some numerical calculation results are shown with experimental verifications for coated and uncoated paper-webs. Moreover, the idea of "web defect map" is presented for designing and safety operating the web transportation system.

Методика расчета тяговых и прочностных характеристик сортиментных плотов для условий Онежского озера

Методика расчета тяговых и прочностных характеристик сортиментных плотов для условий Онежского озера

20902 パラフィン系基油のEHL油膜の粘性挙動の解析(OS4 機構デバイスとトライボロジー)

Traction characteristics of some paraffinic oils were determined with an EHD tester under full EHL conditions. Comparison of the results calculated by the simplified Newtonian solution with the measurements showed that a limit of Newtonian lied in the range below the product of viscosity-pressure and pressure of 4. In the non-Newtonian region, the theoretical traction curves based on an Eyring model described well the experimental traction curves in comparison with the other plastic models.

20905 弾塑性モデルによるトラクション特性の計算(OS4 機構デバイスとトライボロジー)

Effective shear modulus was derived from the traction measurements based on spin and side-slip was an order of 0.1GPa at 30℃, which slightly decreased as the contact pressure was increased. Then, traction characteristics of synthetic naphthene were determined with a disk-on-roller machine under the full EHD conditions. In the traction curve, the coefficient of traction linearly increased, and then decreased after reaching a maximum. The results calculated by the thermal elastic-plastic solution showed a good agreement with the experimental results, where the limiting shear stress was expressed as a function of pressure and temperature based on the data reported by Bair and Winer.

Experimental analysis of soil deformation below a rolling rigid cylinder

In the paper the compaction process of cohesive soil was investigated. Laboratory tests were carried out using a computer controlled stand simulating a single static cylinder under plane strain conditions. The results of experiments using driven and towed rigid cylinders are presented. The influence of the slip value, number of passes, friction coefficient between soil and cylinder surface and the weight of the cylinder on the generated drawbar-pull and final density is discussed. The differences in resulting deformation fields and soil particle paths for the driven and the towed cylinders are presented. The obtained traction characteristics turned out to be essential for proper understanding and further simulation of the working process of the two drum static roller. The variation of the final density, the structure of the compacted soil and the developed drawbar-pull was observed depending whether the driven or the towed cylinder was used.

Experimental analysis of soil deformation below a rolling rigid cylinder

In the paper the compaction process of cohesive soil was investigated. Laboratory tests were carried out using a computer controlled stand simulating a single static cylinder under plane strain conditions. The results of experiments using driven and towed rigid cylinders are presented. The influence of the slip value, number of passes, friction coefficient between soil and cylinder surface and the weight of the cylinder on the generated drawbar-pull and final density is discussed. The differences in resulting deformation fields and soil particle paths for the driven and the towed cylinders are presented. The obtained traction characteristics turned out to be essential for proper understanding and further simulation of the working process of the two drum static roller. The variation of the final density, the structure of the compacted soil and the developed drawbar-pull was observed depending whether the driven or the towed cylinder was used.

部分EHL下におけるポリマー添加油のトラクション特性(OS.18 機械要素のトライボロジー)

Traction characteristics of polymer solutions were determined at a constant rolling speed of 0.05m/s over a range of temperature with a disk on ball type EHL tester using steel disk. As the temperature is raised, the traction curves of base oil as well as conventional polymethacrylate containing oil increase, while those of dispersant type polymethacrylate containing oil remains constant. Such a tendency was more significant for hydro cracked oils than solvent refined oils. The measured oil film of dispersant type polymethacrylate containing oil showed much thicker than polymethacrylate containing oil. It was inferred that dispersant group of DPMA contributed to the friction reduction due to thick film formation in EHL contact.

Designing documents for train operators

This paper addresses the issue of redesigning a train list. The train list is a paper document of few pages that provides train operators of the Italian railway company with basic information about the features of the railway line they are moving along, the means of traction and engine characteristics. Methodologies borrowed from the fields of document design and human–computer interaction were applied to the analysis, redesign, and evaluation of a new train list following a first prototype developed by the railway company. In all phases (analysis, redesign, evaluation) the study was guided by the theoretical framework of cultural-historical psychology, according to which artifacts historically shaped by human practice always mediate human cognition. The results of the evaluation provide empirical evidence to support the added value of combining document design techniques with the heuristic role of the historical analysis of an artifact, especially in a safety-critical context, so as to properly improve tools and instruments used in human activity and thus reduce the risk of breakdowns.

Monitoring system design for estimating the lateral tyre force

Longitudinal and lateral forces acting on tyres are known to be closely related to tractive ability, braking characteristics, handling stability and manoeuvrability of ground vehicles. However, it is not feasible in the operating vehicles to measure the tyre forces directly because of the high cost of sensors, the limitations in sensor technology, interference with tyre rotation and the harsh environment. Another approach is the indirect monitoring technique that can estimate the tyre forces based on remote sensor outputs and vehicle dynamics models. In this paper, in order to develop tyre force-monitoring systems, a monitoring model is proposed utilizing not only the yawing motion but also the roll motion. Based on the monitoring model, a monitoring system is designed to estimate the lateral tyre force acting on each tyre. The monitoring system is constructed on the basis of a new scaled Kalman filter with model error compensator (SKFMEC) technique that is developed in this study to improve the robustness performance of Kalman filter methods. The SKFMEC technique adopts both the well-conditioned observer and the model error compensator concepts. Tyre force estimation performance of the monitoring system is evaluated in the MATLAB simulations where true tyre force data are generated from a 14-degree-of-freedom vehicle model with the combined-slip ‘magic formula’ tyre model.

2512 自動車用トロイダル CVT のトラクション特性研究(第 3 報、実機トラクション特性)

It is essential to ascertain traction characteristics under actual operating conditions in order to apply a toroidal CVT incorporating a traction drive system to automobiles. This paper first describes the traction characteristics obtained quantitatively over a wide range of conditions by using an actual variator. The resulting characteristics showed the large influence of spin. Furthermore, an attempt was made to obtain the calculated prediction of an actual variator by using a viscoelastic-plastic model with a measured temperature of variator. A comparison was made between the calculated results and the actual variator test results. It was found that an accurate prediction of traction characteristics requires the surface temperature of variator.

2621 EHL 状態下におけるトラクション特性に及ぼすトラクションオイルの影響

In this research, investigation was made on the traction characteristics under wide-ranging mean Hertzian pressure from 0.7GPa to 2.3GPa with using various axial direction curvature steel specimens. And then, same tests were carried out under test conditions for several types of traction oil. As a result, in the case of the Santotrac40 and KTF1,it was shown that the maximum traction coefficient increased slowly with the increase of mean Hertzian pressure at the first stage of that traction coefficient curve. After then, that traction coefficient curve gradually decreased. And, the numerical calculation was carried out by the Tevaarwerk's elastoplasticity shearing model with some oil film properties in EHL state reported by another researches.

602 非定常 EHL 試験機の試作 : 定常状態におけるトラクション特性

602 非定常 EHL 試験機の試作 : 定常状態におけるトラクション特性

603 非定常 EHL 条件下のトラクション特性

Traction characteristics under the non-steady state conditions were studied with a ball-on-disk type EHL tester, in which the experiments were conducted by moving the disk toward the rolling direction to the predetermined position. When giving the rapid change in the rolling speed of the disk under keeping the constant rolling speed of the ball, a delay of change in traction was appreciably observed.

601 トラクション特性に与えるスピンの影響

601 トラクション特性に与えるスピンの影響

30S ランニング・シューズの使用によるソールの摩耗とトラクション性との相関

The purpose of this study is to investigate correlations between the deterioration of the traction characteristics of running shoes due to the wear and the sensory evaluations by runners. The sample shoes were worn by running continually. The amount of wear was detected by comparing the measurements for the cross-sectional shapes of shoe soles with wear and without wear respectively. As a result, it is found that runners' evaluations seem to be affected not only by the amount of wear but also by the cross-sectional shape of medial parts in fore sole, especially around the articulations metatarsophalangeae.