Experimental Study on Friction Coefficient and Stress Loss of Retard-bonded PC Steel Strand

Abstract A variable pressure damper (VPD) is used here to adjusted the friction force on the valve spring to investigate the relation between the friction force and the valve bouncing phenomenon. The friction force on the valve spring is found experimentally, and the corresponding friction coefficient is also determined. Dynamic valve displacements at different speeds with different friction forces are calibrated. Bouncing and floating of the valve are observed when the camshaft reaches high speed. From the measured valve displacement, the VPD is shown to have significant improvement in reducing valve bouncing distance and eliminating floating. However, experimental results indicate that the valve bouncing can not be eliminated completely when the camshaft speed is at 2985 rpm.

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Experimental study on friction performance of damaged interface in steel-concrete composite beam connected by high-strength bolt

Advances in Structural Engineering ◽

10.1177/1369433220947200 ◽

2020 ◽

pp. 136943322094720

Author(s):

Ying Xing ◽

Ya-ning Xu ◽

Qi Guo ◽

Jin-feng Jiao ◽

Qing-wei Chen

Keyword(s):

Experimental Study ◽

Friction Coefficient ◽

Composite Beam ◽

Structural Characteristics ◽

Concrete Strength ◽

Steel Structures ◽

High Strength ◽

Steel Strength ◽

Bare Steel ◽

Friction Performance

Although traditional steel-concrete composite beam has excellent structural characteristics, it cannot meet the requirement of quick disassembly and repair in the bridge. This article presents an experimental study on friction performance of damaged steel-concrete interface in recoverable composite beam connected by high-strength frictional bolts. A total of 21 specific split tests were carried out using different concrete strength, steel strength, and surface treatment of steel. The experimental results showed that the demountable high-strength frictional bolt used in composite beam has similar performance as in the bare steel structures. The initial friction coefficient and slip stiffness were measured to be 0.34–0.47 and 52.3–116.1 kN/mm, respectively. Friction performance of damaged interface was obtained, proving that friction coefficient and slip stiffness will not decrease after the first slip damage. It is also confirmed that shot blasted steel and concrete with higher strength were more suitable in the demountable composite beam.

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Calculation Model of Punch Force during Tube Extrusion

Materials Science Forum ◽

10.4028/www.scientific.net/msf.704-705.273 ◽

2011 ◽

Vol 704-705 ◽

pp. 273-276

Author(s):

Zhong Tang Wang ◽

Guang Xia Qi ◽

Fang Wang ◽

Shi Hong Zhang

Keyword(s):

Experimental Study ◽

Friction Coefficient ◽

Calculation Model ◽

Extrusion Force ◽

Calculation Formula ◽

Slab Method ◽

Punch Force ◽

Tube Extrusion ◽

Relative Errors ◽

Theoretical Results

] Theoretical calculation formula of punch force during tube extrusion has been proposed by means of slab method. On the basis of theoretical and experimental study, it is found that theoretical results of extrusion force given by the calculating formula approached to that of the experiment, and the relative errors are less than 20％. It is also found that the extrusion force is closely related to deformation temperature, lubricant and the ratio of extrusion. The calculating formula of extrusion force is given by considering the factors which are the conical angle of die, and the friction coefficient between the deformation zone and the extrusion container, and the friction coefficient between the undeformed zone and the mandrel. Key Words: Tube, Extrusion, Force, Physical model

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Experimental Study on Steel-Concrete Interface Skid Resistance Properties

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.163-167.3527 ◽

2010 ◽

Vol 163-167 ◽

pp. 3527-3531

Author(s):

Tian Lai Yu ◽

Xing Guo Liu ◽

Hong Xiang Zhang

Keyword(s):

Experimental Study ◽

Silicon Carbide ◽

Friction Coefficient ◽

Orthogonal Test ◽

Steel Plates ◽

Cohesive Force ◽

Skid Resistance ◽

Research Results ◽

External Prestressing ◽

Concrete Interface

Steel-concrete interface skid resistance properties have been studied by orthogonal test. Three factors are considered, including glue amount, silicon carbide mesh, and amount of silicon carbide. For each factor, five levels are selected. Through comparative analyses of the experiment results for each factor and the combinations of the levels of the factors, the combination with the optimal interface skid resistance was obtained. The friction coefficient with consideration of glue cohesive force was also determined. The research results provide references for structure strengthening using adhered steel plates and external prestressing.

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Experimental Study on Anti-Friction Property of Groove Textured Surface with Different Direction Angles

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.281.404 ◽

2013 ◽

Vol 281 ◽

pp. 404-408 ◽

Cited By ~ 1

Author(s):

Chen Bo Ma ◽

Jian Jun Sun ◽

Hua Zhu ◽

Jian Quan Li ◽

Fei Zhou

Keyword(s):

Experimental Study ◽

Friction Coefficient ◽

Smooth Surface ◽

Combined Effect ◽

Resistance Force ◽

Textured Surface ◽

Friction Property ◽

Friction Effect ◽

Direction Angle ◽

Design And Application

To investigate the influence of different direction angles on groove textured surface, tribology experiments for smooth surface and groove textured surface with angles of 0°, 30°, 45°, 60°, 90° were carried on under various loads and velocities. The results show that, the friction coefficient decreases first and then increases with the increase of groove direction angle. And the optimal anti-friction effect could be obtained when the groove textured surface with angle of 60°, because of its superior combined effect of resistance force and liquid squeeze force, which are introduced by the groove. The findings could provide a theoretical guide for the design and application of groove textured surface.

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Experimental Study on the Lubrication Behaviors of Seawater-Lubricated Thordon Bearings

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.500.297 ◽

2012 ◽

Vol 500 ◽

pp. 297-300

Author(s):

You Qiang Wang ◽

Wen Li Sun

Keyword(s):

Experimental Study ◽

Friction Coefficient ◽

Tribological Properties ◽

Experimental Studies ◽

Experimental Results ◽

Bearing Clearance ◽

Increasing Load

Seawater lubricated thordon bearing is one of the most appropriate bearings widely used in submerged pump for drainage. The apparatus for studying the lubrication behaviors of the seawater lubricated thordon bearings has been devised and established in the paper. The experimental studies on the tribological properties of the thordon bearings have been conducted under different load and velocity using the apparatus. Effects of load and velocity on friction coefficient of the thordon bearings have been estimated. The experimental results show that the friction coefficient decreases with increasing velocity; the friction coefficient decreases gradually at first and then decreases sharpy with increasing load; the friction coefficient increases sharply with the rising temperature. The experimental results also indicate that there is an appropriate bearing clearance for which the friction coefficient is up to minimum.

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An Experimental Study of Bearing and Thread Friction in Fasteners

Journal of Tribology ◽

10.1115/1.1843167 ◽

2005 ◽

Vol 127 (2) ◽

pp. 263-272 ◽

Cited By ~ 43

Author(s):

S. A. Nassar ◽

H. El-Khiamy ◽

G. C. Barber ◽

Q. Zou ◽

T. S. Sun

Keyword(s):

Experimental Study ◽

Friction Coefficient ◽

Experimental Model ◽

Contact Area ◽

Design Of Experiment ◽

Experimental Procedure ◽

Threaded Fasteners ◽

Thread Pitch ◽

Bearing Friction

An experimental procedure is proposed for studying the underhead and thread friction in fasteners. The effective bearing friction radius, the underhead friction coefficient, and the thread friction coefficient are experimentally determined for fasteners with standard hexagonal heads and for flanged head fasteners. Hence, greater accuracy has been achieved in determining the value of the torque components that are consumed in overcoming friction in threaded fasteners. This would lead to a more reliable torque-tension correlation and would enhance the safety and quality of bolted assemblies. A design of experiment procedure is presented in order to investigate the effect of fastener material class, the thread pitch, and the fastener size on thread friction coefficient. For the underhead bearing friction, an experimental model is presented in order to determine the effect of the radii ratio of the contact area on the bearing friction radius.

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Experimental Study on the Interface Characteristics of Geogrid-Reinforced Fly Ash

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.446-449.264 ◽

2012 ◽

Vol 446-449 ◽

pp. 264-268 ◽

Cited By ~ 1

Author(s):

Wei Shi ◽

Jin Han ◽

Yuan Hao Jiang ◽

Yong Bin Li

Keyword(s):

Experimental Study ◽

Fly Ash ◽

Friction Coefficient ◽

Reinforced Soil ◽

Paper Study ◽

Water Impact ◽

Interface Friction ◽

Pull Out ◽

Interface Characteristics ◽

Interface Parameters

The technology of Reinforced soil has been widely used in civil engineering, its theory has some development . However, there is nearly any study about the theory of Geogrid-reinforced fly ash .In this paper, study the interface characteristics between fly ash and geogrid through the pull-out test,reach the following conclusions:the size of normal stress and water impact the interface parameters between the geogrid and fly ash;the interface friction coefficient between Geogrid and fly ash is small,adding gravel to fly ash can improve the interface friction coefficient between geogrid and fly ash.

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