Experimental Determination of the Effect of the Surface Curvature on Rolling Resistance Measurements4

2009 ◽  
Vol 37 (4) ◽  
pp. 254-278 ◽  
Author(s):  
T. Freudenmann ◽  
H.-J. Unrau ◽  
M. El-Haji
Keyword(s):  
Experimental Determination ◽  
Test Bench ◽  
Measurement Data ◽  
Rolling Resistance ◽  
Surface Curvature ◽  
Operational Parameters ◽  
Combined Test ◽  
Modified Formula ◽  
New Formula

Abstract REFERENCE: Freudenmann, T., Unrau, H.-J., and El-Haji, M., "Experimental Determination of the Effect of the Surface Curvature on Rolling Resistance Measurements," Tire Science and Technology, TSTCA, Vol. 37, No. 4, October - December 2009, pp. 254-278. Vehicle and tire manufacturers usually perform rolling resistance measurements on external drums with diameters of 1.71 or 2.0 m. The rolling resistance measured on these test benches is higher than the actual rolling resistance measured on a flat surface. This deviation is caused by the drums’ curvature. In 1979, S. K. Clark aimed to solve this problem by developing a formula, which converts the rolling resistance of a tire measured on a curved surface into the corresponding rolling resistance on a plane. This formula is still used today in ISO and SAE standards. To verify Clark’s universally accepted formula, a research project was initiated at the Universität Karlsruhe. A combined test bench that allows measurements on two external drums of different diameter and a continuous flat track with the same wheel suspension was built up and came into operation. The rolling resistances of six different tires on the three surfaces were measured under variation in operational parameters, such as tire load and inflation pressure. Comparison of converted values from measurements on external drums with flat track measurements showed the necessity for an upgrade of the existing formula. By conducting a multiple regression analysis, which took various tire properties and operational parameters into account, a modified formula was derived. Application of this new formula on the measurement data of the six tires as well as on further measurements showed excellent results.

scholarly journals The determination of the rolling resistance coefficient of a passenger vehicle with the use of roller test bench method

2019 ◽  
Vol 254 ◽  
pp. 04007 ◽  
Author(s):  
Bartłomiej Pałasz ◽  
Konrad J. Waluś ◽  
Łukasz Warguła
Keyword(s):  
Energy Consumption ◽  
Experimental Research ◽  
Research Method ◽  
Test Bench ◽  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Laboratory Method ◽  
Passenger Vehicle ◽  
Rolling Resistance Coefficient

Contemporary vehicle are designer to be eco-friendly. One of the factors limiting the energy consumption of driving processes is a low value of the rolling resistance coefficient. The rolling resistance depends on the construction features of a tire, exploitation conditions and the type of surface the car moves on. This article presents the results of experimental research of determining the rolling resistance coefficient with the use of laboratory method of roller test bench. The results presented here are a part of a wider research of determining the rolling resistance coefficient and the influence of research method on its value.

scholarly journals Experimental study of reclining the cultivator’s paws on spring racks

2018 ◽  
Vol 226 ◽  
pp. 01029
Author(s):  
Alexey I. Buryanov ◽  
Vitaliy I. Ignatenko ◽  
Ivan V. Ignatenko ◽  
Ivan L. Vyalikov
Keyword(s):  
Experimental Study ◽  
Experimental Determination ◽  
Test Bench ◽  
Non Linear ◽  
Light Medium

The article describes the results of experimental determination of the trajectories of the toe of cultivator paws on spring racks of three types: light, medium and heavy. The trajectory was determined by loading on the test bench. It is established that the trajectories are non-linear in nature, and elastic displacements lead to the deepening of the toe of the paw, which violates the established depth of stroke. The loading ranges of the racks are defined, under which the deepening does not exceed the limits of agroadmission. The greatest recession was noted in middle racks, the smallest in heavy racks. It was concluded that it is necessary to monitor the recess of the toe of the feet mounted on the spring post.

Experimental Determination of Axial Viscoelasticity of Braided Steel Cables Through the Design of a Special Purpose Machine

2019 ◽  
Author(s):  
Diego A. Zamora-Garcia ◽  
Luis Miguel Acosta-Carrion ◽  
Ma. Pilar Corona-Lira ◽  
Alejandro C. Ramirez-Reivich
Keyword(s):  
Free Vibration ◽  
Experimental Determination ◽  
Test Bench ◽  
Viscoelastic Behavior ◽  
Axial Direction ◽  
The Other ◽  
Effective Length ◽  
Essential Idea ◽  
Steel Cables

Abstract Braided steel cables have the potential for improving the mechanisms providing them several advantages in comparison with rigid elements. Nevertheless, a limitation in the use of cable mechanism is that due to the inherent flexibility, the problem of vibration arises. In this research, we investigate the axial viscoelastic behavior of 1/32″ braided steel cables. The essential idea is to determine the parameters of elasticity (k) and viscosity (b) as a function of the length of the cable in its axial direction. It was achieved through the design and construction of a test bench and the design of an experiment. The test bench is a free vibration particular design machine. One end of the cable is fixed to the structure, and in the other end, a load is attached. Then, the load is released, and the free vibration of the cable in the axial direction is registered. The factor of the experiment is the length of the cable. There are six levels, and these were repeated four times. We demonstrated that the braided steel cables have a viscoelastic behavior like a Kelvin-Voigt. Also, we found a relation between the effective length of the cables and the parameters of elasticity and viscosity.

Experimental determination of a state equation for dissipative granular gases

1999 ◽  
Vol 96 (6) ◽  
pp. 1111-1116 ◽  
Author(s):  
E. Falcon ◽  
S. Fauve ◽  
C. Laroche
Keyword(s):  
Experimental Determination ◽  
State Equation ◽  
Granular Gases
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