Fiber Trajectories on Shells of Revolution—An Engineering Approach

2011 ◽  
pp. 49-64
Author(s):  
Sotiris Koussios
Keyword(s):  
Coefficient Of Friction ◽  
Shell Of Revolution ◽  
Shells Of Revolution ◽  
Engineering Approach

Abstract This chapter outlines a method for mathematically describing fiber trajectories on a shell of revolution. After a short outline of the basic geometry of shells of revolution, the focus shifts to fiber trajectories and their characteristic metrics, angles, and vectors. Next, the chapter focuses on the determination of various kinds of curvatures that eventually lead to the derivation of (non-) geodesic fiber trajectories according to a predetermined coefficient of friction. It concludes with the analysis of nongeodesics on conical segments, annuli, and cylinders.

Designing of Outriggers for the Needs of the Vehicles Stability Testing

2018 ◽  
Vol 875 ◽  
pp. 71-76
Author(s):  
Victor Kryaskov ◽  
Andrey Vashurin ◽  
Anton Tumasov ◽  
Alexey Vasiliev
Keyword(s):  
Coefficient Of Friction ◽  
Computer Aided Design ◽  
Strength Analysis ◽  
Direct Impact ◽  
Stability Testing ◽  
Supporting Surface ◽  
Stability Tests ◽  
Computer Aided ◽  
Aided Design

This paper is dedicated to the issues of designing of outriggers for avoidance of vehicle tilting during its stability tests. An analysis of existing types of outriggers was done by authors as well as legislative requirements on them. The reliable and well-timed operation of outriggers largely depends on the height of their positioning on a vehicle. In order to determine this important parameter a special methodic of determining the tipping angle of the vehicle with the use of computer-aided design (CAD) was composed by authors. The article also contains some main principles of strength analysis of the structure a very important part of which became the necessity of determination of coefficient of friction between the outrigger sliders and the supporting surface. This coefficient has a direct impact on the value of transverse forces appearing at the ends of outrigger beams.

Determination of coefficient of friction between the equine foot and different ground surfaces: an in vitro study

2006 ◽  
Vol 3 (4) ◽  
pp. 191-198 ◽  
Author(s):  
Nicolas J Vos ◽  
Dirk J Riemersma
Keyword(s):  
Coefficient Of Friction ◽  
Force Plate ◽  
Ground Surface ◽  
In Vitro Study ◽  
Gravity Force ◽  
Uniform Motion ◽  
The Coefficient Of Friction ◽  
Equine Industry

AbstractSlippery surfaces are a continuous concern in equine veterinary practice during both treatment and orthopaedic work-ups, especially when horses have to trot on circles. Sliding of the equine foot on the ground with the potential of injury is prevented if the horizontally acting accelerating or decelerating forces on the foot do not exceed maximal friction. Friction can be calculated and therefore anticipated if the coefficient of friction (μ) between the foot of the horse and the particular ground surface is known. Friction between shod and unshod cadaver equine hooves and different ground surfaces (concrete, tarmac and rubber) was determined by pulling the hooves horizontally in a uniform motion. Horizontal forces (Fh) were measured on a force plate and with a portable digital electronic force meter. The coefficient of friction (μ) was calculated as the quotient between Fh and the gravity force (N) of the object, hence: μ = Fh /N. This study has shown that the coefficient of friction between equine hooves and a specific ground surface can be determined using a portable digital force meter or a force plate. Friction significantly depended not only on the type of surface but also on shoeing of the equine foot. Bare feet showed more friction with the hard surfaces (bricks and tarmac), the shod feet showing more friction with the rubber surfaces. Coefficients of friction could be used to estimate the possibility of injuries occurring in the equine industry during exercise and/or lameness or pre-purchase examinations.

scholarly journals Determination of the coefficient of friction using spinning motion

2016 ◽  
Vol 147 ◽  
pp. 012024
Author(s):  
S Alaci ◽  
F C Ciornei ◽  
C Filote ◽  
I C Romanu ◽  
C P Nastaca
Keyword(s):  
Coefficient Of Friction ◽  
The Coefficient Of Friction

AN ANALYSYS OF WEAR AND MECHANICAL AND TRIBOLOGICAL PROPERTIES OF HIGH-MANGANESE CAST STEEL HARDENED BY DIFFERENT METHODS

Tribologia ◽  
2018 ◽  
Vol 280 (4) ◽  
pp. 137-142
Author(s):  
Dagmara TRYBA ◽  
Marcin KOT ◽  
Anna ANTOSZ
Keyword(s):  
Wear Resistance ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Cast Steel ◽  
Base Material ◽  
High Manganese ◽  
Dynamic Impact ◽  
Mechanical And Tribological Properties ◽  
Alternative Method

Properties of high manganese austenitic cast steel are not satisfactory; therefore, this material should be hardened. Currently, the commonly used method of hardening does not allow eliminating problems related to premature wear of railway frogs. Therefore, many studies have been carried out to find an alternative method to obtain improved wear resistance of such elements. The article presents an analysis of the mechanical and tribological properties of base and hardened, by different methods, high-manganese cast steel applied for turnouts. Tests were performed for three hardening methods: explosive, pressure-rolling, and dynamic impact. The results were compared with the properties of base material after saturation treatment. The conducted tests allowed the determination of hardness profiles of hardened surfaces, as well as the wear resistance and coefficient of friction, and the obtained results are very promising. Hardening by dynamic impact provided much better results in relation to presently used explosive hardening technology.

A Method for the Calculation of Natural Frequencies of Orthotropic Axisymmetrically Loaded Shells of Revolution

1994 ◽  
Vol 116 (1) ◽  
pp. 16-25 ◽  
Author(s):  
A. Kayran ◽  
J. R. Vinson ◽  
E. Selcuk Ardic
Keyword(s):  
Numerical Integration ◽  
Transfer Matrix ◽  
Transfer Matrix Method ◽  
Matrix Method ◽  
Natural Frequencies ◽  
Shell Of Revolution ◽  
Initial Stresses ◽  
Integration Technique ◽  
Shells Of Revolution ◽  
Axisymmetric Loading

A methodology is presented for the calculation of the natural frequencies of orthotropic axisymmetrically loaded shells of revolution including the effect of transverse shear deformation. The fundamental system of equations governing the free vibration of the stress-free shells of revolution are modified such that the initial stresses due to the axisymmetric loading are incorporated into the analysis. The linear equations on the vibration about the deformed state are solved by using the transfer matrix method which makes use of the multisegment numerical integration technique. This method is commonly known as frequency trial method. The solution for the initial stresses due to axisymmetric loading is omitted; since the application of the transfer matrix method, making use of multisegment numerical integration technique for both linear and nonlinear equations are available in the literature. The method is verified by applying it to the solution of the natural frequencies of spinning disks, for which exact solutions exist in the literature, and a deep paraboloid for which approximate solutions exist. The governing equations for a shell of revolution are used to approximate circular disks by decreasing the curvature of the shell of revolution to very low values, and good agreement is seen between the results of the present method and the exact solution for spinning disks and the approximate solution for a deep paraboloid.

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