The influence of the first integrals and the rolling resistance model on tippe top inversion

Rolling resistance model, developed based on rigid body assumption, is further analyzed in this paper using a simplified analytical model and experimental results. The analysis leads to the conclusion that the effect of the reaction forces is equivalent to a resultant having the point of contact located outside the zone of contact.

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Effect of Particle Size Distributions and Shapes on the Failure Behavior of Dry Coke Aggregates

Materials ◽

10.3390/ma14195558 ◽

2021 ◽

Vol 14 (19) ◽

pp. 5558

Author(s):

Alireza Sadeghi-Chahardeh ◽

Roozbeh Mollaabbasi ◽

Donald Picard ◽

Seyed Mohammad Taghavi ◽

Houshang Alamdari

Keyword(s):

Particle Size ◽

Fine Particles ◽

Rolling Resistance ◽

Structural Defects ◽

Failure Behavior ◽

Size Distributions ◽

Particle Size Distributions ◽

Resistance Model ◽

The Stability ◽

Carbon Anodes

Carbon anodes participate in chemical reactions to reduce alumina in the Hall–Héroult process, of which coke aggregates make up a major part. The failure analysis of coke aggregates not only leads to a better understanding of the deformation mechanisms of anode paste under compressive loading but also can identify potential causes of structural defects in carbon anodes, such as horizontal cracks. The coke aggregates are composed of particles with different size distributions and shapes, which may strongly affect the failure behavior of the anode during compaction. In this paper, the effects of particle size distributions and shapes on the mechanical behavior and the failure of coke aggregates are investigated using the discrete element method modeling technique. The numerical results reveal that, although the mechanical behavior of coke mixtures is generally dependent on larger particles, the presence of fine particles in the coke aggregates reduces fluctuations in the stress–strain diagram. In addition, the rolling resistance model is employed as a parameter representing the effect of particle shape. It is shown that the rolling resistance model can be an alternative to the overlapped spheres model, which has a higher computational cost than the rolling resistance model. The second-order work criterion is used to evaluate the stability of the coke aggregates, the results of which indicate that the addition of fine particles as well as increasing the rolling resistance between the particles increases the stability range of the coke aggregates. Moreover, by using the analysis of micro-strain contour evaluations during the compaction process, it is shown that, both by adding fine particles to the coke mixture and by increasing the rolling resistance between the particles, the possibility of creating a compression band in the coke aggregates is reduced. Since the presence of the compaction bands in the anode paste creates an area prone to horizontal crack generations, the results of this study could lead to the production of carbon anodes with fewer structural defects.

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Tire Temperature Measurements for Validation of a New Rolling Resistance Model

IFAC Proceedings Volumes ◽

10.1016/s1474-6670(17)30407-x ◽

2004 ◽

Vol 37 (22) ◽

pp. 589-594

Author(s):

Tony Sandberg ◽

Christer Ramdén ◽

Magnus Gamberg

Keyword(s):

Rolling Resistance ◽

Temperature Measurements ◽

Resistance Model

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Suitable rolling resistance model for quasi-static shear tests of non-spherical particles via discrete element method

Granular Matter ◽

10.1007/s10035-018-0837-7 ◽

2018 ◽

Vol 20 (4) ◽

Author(s):

Chuang Zhao ◽

Yinghao Luo ◽

Lin Hu ◽

Chengbo Li

Keyword(s):

Discrete Element Method ◽

Rolling Resistance ◽

Discrete Element ◽

Spherical Particles ◽

Shear Tests ◽

Resistance Model ◽

Static Shear ◽

Element Method

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Extraction and identification of fillers and pigments from pyrolyzed rubber and tire samples

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100163332 ◽

1996 ◽

Vol 54 ◽

pp. 174-175

Author(s):

P. Sadhukhan ◽

J. B. Zimmerman

Keyword(s):

Zinc Oxide ◽

Electron Microscope ◽

Carbon Black ◽

Natural Rubber ◽

Transmission Electron Microscope ◽

Rolling Resistance ◽

Synthetic Polymers ◽

Nitrogen Atmosphere ◽

Transmission Electron ◽

Curing Agents

Rubber stocks, specially tires, are composed of natural rubber and synthetic polymers and also of several compounding ingredients, such as carbon black, silica, zinc oxide etc. These are generally mixed and vulcanized with additional curing agents, mainly organic in nature, to achieve certain “designing properties” including wear, traction, rolling resistance and handling of tires. Considerable importance is, therefore, attached both by the manufacturers and their competitors to be able to extract, identify and characterize various types of fillers and pigments. Several analytical procedures have been in use to extract, preferentially, these fillers and pigments and subsequently identify and characterize them under a transmission electron microscope.Rubber stocks and tire sections are subjected to heat under nitrogen atmosphere to 550°C for one hour and then cooled under nitrogen to remove polymers, leaving behind carbon black, silica and zinc oxide and 650°C to eliminate carbon blacks, leaving only silica and zinc oxide.

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Method of first integrals and interface, surface waves

Vietnam Journal of Mechanics ◽

10.15625/0866-7136/32/2/310 ◽

2010 ◽

Vol 32 (2) ◽

pp. 107-120

Author(s):

Pham Chi Vinh ◽

Trinh Thi Thanh Hue ◽

Dinh Van Quang ◽

Nguyen Thi Khanh Linh ◽

Nguyen Thi Nam

Keyword(s):

Rayleigh Waves ◽

Displacement Vector ◽

Attenuation Factor ◽

Electrical Potential ◽

Polarization Vector ◽

First Integrals ◽

Dispersion Equations ◽

Interface Surface ◽

Electric Induction ◽

The One

The method of first integrals (MFI) based on the equation of motion for the displacement vector, or based on the one for the traction vector was introduced recently in order to find explicit secular equations of Rayleigh waves whose characteristic equations (i.e the equations determining the attenuation factor) are fully quartic or are of higher order (then the classical approach is not applicable). In this paper it is shown that, not only to Rayleigh waves, the MFI can be applicable also to other waves by running it on the equations for mixed vectors. In particular: (i) By applying the MFI to the equations for the displacement-traction vector we get the explicit dispersion equations of Stoneley waves in twinned crystals (ii) Running the MFI on the equations for the traction-electric induction vector and the traction-electrical potential vector provides the explicit dispersion equations of SH-waves in piezoelastic materials. The obtained dispersion equations are identical with the ones previously derived using the method of polarization vector, but the procedure of driving them is more simple.

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Tire-Road Interactions — Harmony or Conflict?

Tire Science and Technology ◽

10.2346/1.2141676 ◽

1989 ◽

Vol 17 (1) ◽

pp. 66-84

Author(s):

A. R. Williams

Keyword(s):

Rolling Resistance ◽

Major Effect ◽

Road Surface ◽

Interactive Effects ◽

Central Theme ◽

Water Drainage ◽

The Road ◽

Truck Tires ◽

Road Surfaces ◽

Tire Wear

Abstract This is a summary of work by the author and his colleagues, as well as by others reported in the literature, that demonstrate a need for considering a vehicle, its tires, and the road surface as a system. The central theme is interaction at the footprint, especially that of truck tires. Individual and interactive effects of road and tires are considered under the major topics of road aggregate (macroscopic and microscopic properties), development of a novel road surface, safety, noise, rolling resistance, riding comfort, water drainage by both road and tire, development of tire tread compounds and a proving ground, and influence of tire wear on wet traction. A general conclusion is that road surfaces have both the major effect and the greater potential for improvement.

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Tread Depth Effects on Tire Rolling Resistance

Tire Science and Technology ◽

10.2346/1.2135235 ◽

2001 ◽

Vol 29 (3) ◽

pp. 134-154 ◽

Cited By ~ 5

Author(s):

J. R. Luchini ◽

M. M. Motil ◽

W. V. Mars

Keyword(s):

Finite Element Analysis ◽

Common Knowledge ◽

Rolling Resistance ◽

Test Method ◽

Tire Model ◽

Element Analysis ◽

Truck Tires ◽

The Finite Element Analysis ◽

Equilibrium Test ◽

Depth Effects

Abstract This paper discusses the measurement and modeling of tire rolling resistance for a group of radial medium truck tires. The tires were subjected to tread depth modifications by “buffing” the tread surface. The experimental work used the equilibrium test method of SAE J-1269. The finite element analysis (FEA) tire model for tire rolling resistance has been previously presented. The results of the testing showed changes in rolling resistance as a function of tread depth that were inconsistent between tires. Several observations were also inconsistent with published information and common knowledge. Several mechanisms were proposed to explain the results. Additional experiments and models were used to evaluate the mechanisms. Mechanisms that were examined included tire age, surface texture, and tire shape. An explanation based on buffed tread radius, and the resulting changes in footprint stresses, is proposed that explains the observed experimental changes in rolling resistance with tread depth.

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