Deicing of The Contact Lines of the High-Speed Electric Railways: Deicing Configurations. Experimental Test Results

In this study, the co-effects of steel fibers and FRP confinement on the concrete behavior under the axial compression load are investigated. Thus, the experimental tests were conducted on 18 steel fiber-reinforced concrete (SFRC) specimens confined by FRP. Moreover, 24 existing experimental test results of FRP-conﬁned specimens tested under axial compression are gathered to compile a reliable database for developing a mathematical model. In the conducted experimental tests, the concrete strength was varied as 26 MPa and 32.5 MPa and the steel fiber content was varied as 0.0%, 1.5%, and 3%. The specimens were confined with one and two layers of glass fiber reinforced polymer (GFRP) sheet. The experimental test results show that simultaneously using the steel fibers and FRP confinement in concrete not only significantly increases the peak strength and ultimate strain of concrete but also solves the issue of sudden failure in the FRP-confined concrete. The simulations confirm that the results of the proposed model are in good agreement with those of experimental tests.

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Measurement and Analysis on Transient Thermal Characteristics of High Speed Motorized Spindle

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.52-54.2021 ◽

2011 ◽

Vol 52-54 ◽

pp. 2021-2026

Author(s):

Gui Ling Deng ◽

Can Zhou

Keyword(s):

High Speed ◽

Thermal Deformation ◽

Thermal Characteristics ◽

Measuring System ◽

Test Results ◽

Motorized Spindle ◽

Measurement And Analysis ◽

Turning Center ◽

Transient Thermal ◽

Deformation Compensation

Thermal deformation is an important factor to affect the accuracy of the motorized spindle, the core component of high-speed machine tool. To understand the spindle system transient thermal characteristics of the high-speed turning center CH7516GS, some high-precision sensors and high-frequency data acquisition system is used to establish the temperature and displacement measuring system. The thermal deformation compensation model is established on the basis of the experimental test results.

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A 25 Gbps VCSEL driving ASIC: an attempt for ultra-high-speed front-end readout applications

Journal of Instrumentation ◽

10.1088/1748-0221/17/01/c01040 ◽

2022 ◽

Vol 17 (01) ◽

pp. C01040

Author(s):

C. Zhao ◽

D. Guo ◽

Q. Chen ◽

N. Fang ◽

Y. Gan ◽

...

Keyword(s):

High Speed ◽

Cmos Technology ◽

Test Results ◽

Eye Diagram ◽

Optical Links ◽

Optical Module ◽

Active Feedback ◽

High Bandwidth ◽

Output Driver ◽

Very High

Abstract This paper presents the design and the test results of a 25 Gbps VCSEL driving ASIC fabricated in a 55 nm CMOS technology as an attempt for the future very high-speed optical links. The VCSEL driving ASIC is composed of an input equalizer stage, a pre-driver stage and a novel output driver stage. To achieve high bandwidth, the pre-driver stage combines the inductor-shared peaking structure and the active-feedback technique. A novel output driver stage uses the pseudo differential CML driver structure and the adjustable FFE pre-emphasis technique to improve the bandwidth. This VCSEL driver has been integrated in a customized optical module with a VCSEL array. Both the electrical function and optical performance have been fully evaluated. The output optical eye diagram has passed the eye mask test at the data rate of 25 Gbps. The peak-to-peak jitter of 25 Gbps optical eye is 19.5 ps and the RMS jitter is 2.9 ps.

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Experimental Test Results for Four High-Speed, High-Pressure, Orifice-Compensated Hybrid Bearings

Journal of Tribology ◽

10.1115/1.2927031 ◽

1994 ◽

Vol 116 (1) ◽

pp. 147-153 ◽

Cited By ~ 37

Author(s):

N. M. Franchek ◽

D. W. Childs

Keyword(s):

High Speed ◽

Load Capacity ◽

Pressure Ratio ◽

Reynolds Numbers ◽

Orifice Diameter ◽

Test Results ◽

Rotordynamic Coefficients ◽

Geometric Configurations ◽

Overall Performance ◽

Mass Terms

In this study, four hybrid bearings having different geometric configurations were experimentally tested for their static and dynamic characteristics, including flowrate, load capacity, rotordynamic coefficients, and whirl frequency ratio. The four bearings included a square-recess, smooth-land, radial-orifice bearing (baseline), a circular-recess bearing, a triangular-recess bearing, and an angled-orifice bearing. Each bearing had the same orifice diameter rather than the same pressure ratio. Unique to these test results is the measurement of the added mass terms, which became significant in the present tests because of high operating Reynolds numbers. Comparisons of the results were made between bearings to determine which bearing had the best performance. Based on the parameters of interest, the angled-orifice bearing has the most favorable overall performance.

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Plasma Surface Alloying W-Mo Low-Alloy HSS

Materials Science Forum ◽

10.4028/www.scientific.net/msf.475-479.3955 ◽

2005 ◽

Vol 475-479 ◽

pp. 3955-3958

Author(s):

Jin Yong Xu ◽

Yan Ping Liu ◽

Yuan Gao ◽

Zhong Xu

Keyword(s):

High Speed ◽

Surface Hardness ◽

High Speed Steel ◽

Alloying Elements ◽

Work Piece ◽

Test Results ◽

Surface Alloying ◽

Plasma Surface ◽

The Common ◽

Plasma Surface Alloying

The plasma surface alloying low-alloy high speed steel (HSS) is carried out in vacuum chamber where a source electrode (W-Mo) and a work piece are properly placed. By using the sputter of glow-discharge, under the common function of electric field and temperature field, ?????? the desired alloying elements (W- Mo) are sputtered from the source cathode, traveling toward the substrate. Subsequently the alloying elements deposit onto the surface of the substrate, forming alloy diffusion layer which the depth may vary from several micron to several hundreds micron. In the end a surface low-alloy HSS steel would be produced after ultra-saturation ion carbonization. The composition of the alloyed layer is equal or similar with it of low-alloy HSS. The carbonized layer, without coarse eutectic ledeburite structure, possesses high density of finely and dispersed alloy carbides with tungsten equivalent 10% above and a significant improvement in surface hardness and wear resistance. The principle of plasma surface alloying and its test results and commercial products application are introduced in this paper.

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Model Test Results for a 55 Knot High Speed Sealift Trimaran

10.3940/rina.tri.2004.24 ◽

2004 ◽

Author(s):

C Kennell ◽

Keyword(s):

Model Test ◽

High Speed ◽

Test Results

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Simulation of hot high-speed yielding of intermetallic titanium alloy VTI-4 under conditions of high-speed loading

Materials Science ◽

10.31044/1684-579x-2020-0-12-10-16 ◽

2020 ◽

Vol 0 (12) ◽

pp. 10-16

Author(s):

V.V. Avtaev ◽

◽

D. V. Grinevich ◽

A. V. Zavodov

Keyword(s):

Finite Element ◽

Titanium Alloy ◽

Strain Rate ◽

Finite Element Simulation ◽

Modulus Of Elasticity ◽

High Speed ◽

Residual Deformation ◽

Test Results ◽

Element Simulation ◽

The Relationship

Yielding tests of VTI-4 alloy specimens have been carried out at temperature 1010 °C under conditions of high-speed loading. Based on the test results the modulus of elasticity as well as axial and radial residual deformation values in the end and central zones for each loading stage were determined. Fitting criteria for finite element simulation and the experiment are proposed with tracing VTI-4 alloy diagram deformation at temperature 1010 °C and strain rate of 2.5 sec–1. As a result of finite element simulation the relationship between the material structures obtained during high-speed yielding and the deflected modes in different zones was determined.

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Acoustical behavior of loss-optimized involute gears

INTER-NOISE and NOISE-CON Congress and Conference Proceedings ◽

10.3397/in-2021-1876 ◽

2021 ◽

Vol 263 (5) ◽

pp. 1574-1585

Author(s):

Sebastian Sepp ◽

Joshua Goetz ◽

Karsten Stahl

Keyword(s):

High Speed ◽

Low Noise ◽

Test Results ◽

Motor Speed ◽

Power Train ◽

Higher Power ◽

Involute Gears ◽

Gear Geometry ◽

Drive Systems ◽

Design Calculations

The progressing electrification of vehicle drive systems focuses more and more on efficient high-speed concepts. Increasing the motor speed leads to a higher power density of the electrified power train and thereby to an increased range for battery electric vehicles. The high rotational speeds cause new challenges in designing gearboxes regarding the efficiency and the acoustical behavior. Most present gearings in conventional vehicles are designed with high tooth depths to ensure low noise excitation behavior combined with the best possible efficiency. By changing the gear geometry to smaller tooth depths with higher pressure angles, it is possible to further decrease gear losses. However, the loss-optimized gear geometry must not jeopardize the beneficial acoustical behavior. In theoretical studies, the acoustical behavior of loss-optimized gears are investigated and compared to gearings designed according to the state of the art. Design calculations of the excitations of all ideal gears without deviations are on similar levels. However, application of such gear geometries faces severe challenges because the sensitivity to manufacturing deviations may be high. In this paper, simulation results and test results between low-NVH gears and loss-optimized gears are documented and analyzed.

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