The effectiveness of conditioned aversion in wolves: Insights from experimental tests

ABSTRACTWhen an initially homogeneous binary mixture of granular media such as fine and coarse sand is poured near the closed edge of a “quasi-two-dimensional” Hele-Shaw cell consisting of two vertical transparent plates held a narrow distance apart, the mixture spontaneously forms alternating segregated layers. Experimental measurements of this stratification effect are reported in order to determine which model, one which suggests that segregation only occurs when the granular material contained within a metastable heap between the critical and maximum angle of repose avalanches down the free surface, or one for which the segregation results from smaller particles becoming trapped in the top surface and being removed from the moving layer during continuous flow. The result reported here indicate that the Metastable Wedge model provides a natural explanation for the initial mixed zone which precedes the formation of the layers, while the Continuous Flow model explains the observed upward moving kink of segregated material for higher granular flux rates, and that both mechansims are necessary in order to understand the observed pairing of segregated layersfor intermediate flow rates and cell separations.

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Automatic Tread Gaging Machine

Tire Science and Technology ◽

10.2346/1.2151011 ◽

1979 ◽

Vol 7 (1) ◽

pp. 31-39

Author(s):

G. S. Ludwig ◽

F. C. Brenner

Keyword(s):

Experimental Tests ◽

Automatic Machine ◽

Wear Rates ◽

Handling Device ◽

Straight Line ◽

Component Systems ◽

Before And After ◽

Good Repeatability ◽

The Difference ◽

Straight Lines

Abstract An automatic tread gaging machine has been developed. It consists of three component systems: (1) a laser gaging head, (2) a tire handling device, and (3) a computer that controls the movement of the tire handling machine, processes the data, and computes the least-squares straight line from which a wear rate may be estimated. Experimental tests show that the machine has good repeatability. In comparisons with measurements obtained by a hand gage, the automatic machine gives smaller average groove depths. The difference before and after a period of wear for both methods of measurement are the same. Wear rates estimated from the slopes of straight lines fitted to both sets of data are not significantly different.

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An Alternative Technique to Evaluate Crack Propagation Path in Hyperelastic Materials

Tire Science and Technology ◽

10.2346/1.3684484 ◽

2012 ◽

Vol 40 (1) ◽

pp. 42-58 ◽

Cited By ~ 6

Author(s):

R. R. M. Ozelo ◽

P. Sollero ◽

A. L. A. Costa

Keyword(s):

Constitutive Model ◽

Crack Propagation ◽

Experimental Tests ◽

Growth Direction ◽

Propagation Path ◽

J Integral ◽

Alternative Technique ◽

Crack Propagation Path ◽

Hyperelastic Materials ◽

Material Constitutive Model

Abstract REFERENCE: R. R. M. Ozelo, P. Sollero, and A. L. A. Costa, “An Alternative Technique to Evaluate Crack Propagation Path in Hyperelastic Materials,” Tire Science and Technology, TSTCA, Vol. 40, No. 1, January–March 2012, pp. 42–58. ABSTRACT: The analysis of crack propagation in tires aims to provide safety and reliable life prediction. Tire materials are usually nonlinear and present a hyperelastic behavior. Therefore, the use of nonlinear fracture mechanics theory and a hyperelastic material constitutive model are necessary. The material constitutive model used in this work is the Mooney–Rivlin. There are many techniques available to evaluate the crack propagation path in linear elastic materials and estimate the growth direction. However, most of these techniques are not applicable to hyperelastic materials. This paper presents an alternative technique for modeling crack propagation in hyperelastic materials, based in the J-Integral, to evaluate the crack path. The J-Integral is an energy-based parameter and is applicable to nonlinear materials. The technique was applied using abaqus software and compared to experimental tests.

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Modeling of Strain Energy Harvesting in Pneumatic Tires Using Piezoelectric Transducer

Tire Science and Technology ◽

10.2346/tire.14.420102 ◽

2014 ◽

Vol 42 (1) ◽

pp. 16-34 ◽

Cited By ~ 5

Author(s):

Ali E. Kubba ◽

Mohammad Behroozi ◽

Oluremi A. Olatunbosun ◽

Carl Anthony ◽

Kyle Jiang

Keyword(s):

Energy Harvesting ◽

Strain Energy ◽

Fiber Composite ◽

Experimental Tests ◽

Evaluation Study ◽

Monitoring Systems ◽

Monitoring Device ◽

Optimum Location ◽

Piezoelectric Fiber Composite ◽

Piezoelectric Fiber

ABSTRACT This paper presents an evaluation study of the feasibility of harvesting energy from rolling tire deformation and using it to supply a tire monitoring device installed within the tire cavity. The developed technique is simulated by using a flexible piezoelectric fiber composite transducer (PFC) adhered onto the tire inner liner acting as the energy harvesting element for tire monitoring systems. The PFC element generates electric charge when strain is applied to it. Tire cyclic deformation, particularly at the contact patch surface due to rolling conditions, can be exploited to harvest energy. Finite element simulations, using Abaqus package, were employed to estimate the available strain energy within the tire structure in order to select the optimum location for the PFC element. Experimental tests were carried out by using an evaluation kit for the energy harvesting element installed within the tire cavity to examine the PFC performance under controlled speed and loading conditions.

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