Experimental Analysis of Frictional Characteristics of the Interface between Gantry Crane Wheels and Rails under Dry Conditions - Effects of Wheel Load and Sliding Velocity on the Characteristics

ABSTRACT The potential of a race tire strongly depends on its thermal condition, the load distribution in its contact patch, and the variation of wheel load. The approach described in this paper uses a modular structure consisting of elementary blocks for thermodynamics, transient excitation, and load distribution in the contact patch. The model provides conclusive tire characteristics by adopting the fundamental parameters of a simple mathematical force description. This then allows an isolated parameterization and examination of each block in order to subsequently analyze particular influences on the full model. For the characterization of the load distribution in the contact patch depending on inflation pressure, camber, and the present force state, a mathematical description of measured pressure distribution is used. This affects the tire's grip as well as the heat input to its surface and its casing. In order to determine the thermal condition, one-dimensional partial differential equations at discrete rings over the tire width solve the balance of energy. The resulting surface and rubber temperatures are used to determine the friction coefficient and stiffness of the rubber. The tire's transient behavior is modeled by a state selective filtering, which distinguishes between the dynamics of wheel load and slip. Simulation results for the range of occurring states at dry conditions show a sufficient correlation between the tire model's output and measured tire forces while requiring only a simplified and descriptive set of parameters.

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Experimental Analysis of Frictional Characteristics of the Interface between Gantry Crane Wheels and Rails under Submerged Rail Conditions

Marine Engineering ◽

10.5988/jime.56.144 ◽

2021 ◽

Vol 56 (1) ◽

pp. 144-154

Author(s):

Kengo Takahashi ◽

Masajiro Abe ◽

Seiya Norimoto ◽

Toshikazu Fujino

Keyword(s):

Experimental Analysis ◽

Gantry Crane

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Tribological Characteristics of Deformed Magnesium Alloy AZ61 Under Dry Conditions

Journal of Tribology ◽

10.1115/1.4004761 ◽

2011 ◽

Vol 133 (4) ◽

Cited By ~ 3

Author(s):

Abdel-Wahab El-Morsy ◽

A. Abouel-Kasem

Keyword(s):

Magnesium Alloy ◽

Wear Rate ◽

Deformation Process ◽

Wear Behavior ◽

Sliding Velocity ◽

Wear Rates ◽

Power Spectral ◽

Dry Conditions ◽

The Relationship ◽

Applied Stresses

The wear behavior of deformed magnesium alloy AZ61 under dry conditions was evaluated. Two types of AZ61 alloy were used, extruded and rolled samples, to investigate the effect of deformation process on the wear behavior. The experiments were performed using a pin-on-ring type wear apparatus against a stainless-steel counterface under applied stresses in the range of 3–7 MPa, and within a sliding velocity range of 0.2–1.8 m/s. The topographical images of the eroded surfaces at different sliding velocity for extruded and rolled samples were quantified using fractal analysis. The results revealed that for all applied stress, the wear rates increased with increasing the sliding velocity of both samples. The wear rate of the rolled samples is greater than that of the extruded samples at the stress range from 3 to 5 MPa. However, when the stress is increased to 7 MPa the wear rate of the rolled samples is lower than that of the extruded samples. The variation of fractal value of slope of linearized power spectral density (PSD) with the sliding velocity is largely similar to the relationship between the wear rate and the sliding velocity.

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Modeling Sliding Friction of a Multiscale Wavy Surface over a Viscoelastic Foundation Taking into Account Adhesion

Lubricants ◽

10.3390/lubricants7020013 ◽

2019 ◽

Vol 7 (2) ◽

pp. 13 ◽

Cited By ~ 2

Author(s):

Yulia Makhovskaya

Keyword(s):

Contact Problem ◽

Friction Force ◽

Contact Surface ◽

Sliding Friction ◽

Adhesion Force ◽

Wavy Surface ◽

Viscoelastic Foundation ◽

Sliding Velocity ◽

Scale Level ◽

Dry Conditions

A model for calculating the hysteretic friction force for a multilevel wavy surface sliding in dry conditions over the surface of a viscoelastic foundation is suggested, taking into account adhesion force acting in the direction normal to the contact surface. At each scale level, the contact problem for a 3D periodic wavy indenter is solved by using the strip method to reduce the problem to 2D formulation in a strip. Different regimes of contact and adhesion interaction are possible in each strip, including partial and saturated contact. The friction force is calculated as a sum of two terms. The first term is due to hysteretic losses occurring when asperities of this scale level cyclically deform the viscoelastic foundation during sliding. The second term is the law of friction determined from the solution of the contact problem at the inferior scale level. For the case of a two-level wavy surface, the contribution of both levels into the total friction force is calculated and analyzed depending on the sliding velocity and specific energy of adhesion of the contacting surfaces.

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Pristine and hydrated fluoroapatite (0001)

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520619010412 ◽

2019 ◽

Vol 75 (5) ◽

pp. 830-838

Author(s):

Xavier Torrelles ◽

Immad M. Nadeem ◽

Anna Kupka ◽

Adrián Crespo-Villanueva ◽

Sandrina Meis ◽

...

Keyword(s):

Water Molecule ◽

Experimental Analysis ◽

Surface Coverage ◽

Adsorbed Water ◽

Water Molecules ◽

X Ray Diffraction ◽

X Ray ◽

Crystal Truncation Rod ◽

Before And After ◽

Dry Conditions

The surface structure of fluoroapatite (0001) (FAp0001) under quasi-dry and humid conditions has been probed with surface X-ray diffraction (SXRD). Lateral and perpendicular atomic relaxations corresponding to the FAp0001 termination before and after H2O exposure and the location of the adsorbed water molecules have been determined from experimental analysis of the crystal truncation rod (CTR) intensities. The surface under dry conditions exhibits a bulk termination with relaxations in the outermost atomic layers. The hydrated surface is formed by a disordered partially occupied H2O layer containing one water molecule (33% surface coverage) adsorbed at each of the three surface Ca atoms, and is coupled with one OH group randomly bonded to each of the three topmost P atoms with a 33% surface coverage.

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FRICTION AND WEAR RESPONSE OF TiB2-B4C CERAMICS

International Journal Sustainable Construction & Design ◽

10.21825/scad.v4i2.1044 ◽

2013 ◽

Vol 4 (2) ◽

Author(s):

Yeczain Perez ◽

Koen Bonny ◽

Patrick De Baets ◽

M. H. Staia ◽

P.D. Neis ◽

...

Keyword(s):

Friction Coefficient ◽

Wear Rate ◽

Wear Debris ◽

Sliding Wear ◽

Friction And Wear ◽

Room Temperature ◽

Hertzian Contact ◽

Sliding Velocity ◽

Dry Conditions ◽

Wear Response

Rotating sliding wear experiments on TiB2-B4C have been conducted at room temperature (25 °C) in dry conditions according to the ASTMG99-95a standard. SiC balls were used as static counterpart. The disk specimens were surface finished by polishing. The tests were performed using different rotating sliding speeds from 0.1 up to 1.5 m/s with a mean Hertzian contact pressure of 1.2 GPa. Balls and disk specimens were analyzed by 2-D and 3-D surface topography, SEM and optical microscopy. The experimental results demonstrated that the sliding velocity influences both friction coefficient and wear rate values of TiB2-B4C ceramics. It was shown, that the wear rate varied between 3.64E-7 to 8.43E-7 mm3/Nm. Wear mechanisms such as polishing, abrasion and wear debris formation have been identified by means of SEM and EDX technique.

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