The use of metal matrix composites in railway wheel applications is explored in this paper. Static and dynamic analysis of railroad wheels made of metal matrix composites are made using the finite element method. The deflections, stresses, factor of safety and natural frequencies of these wheels are compared with those in steel as well as graphite/epoxy wheels. © 1993.

T. C. Ramesh

Natrajan Ganesan

Deflection (structures)

finite element method

Graphite fiber reinforced plastics

Mathematical models

Metallic matrix composites

RAILROAD ROLLING STOCK

Safety factor

Steel structures

stresses

Vibrations (mechanical)

GRAPHITE FIBER REINFORCED EPOXY

NATURAL VIBRATION FREQUENCIES

RAILROAD WHEELS

Wheels

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Studies on metal matrix composite railroad wheels

Computers and Structures

Based on a US patent, railroad wheels made of composite materials have been analyzed for static loads. The studies have been made using the finite element method. Comparison of results obtained from two elements based on a thin and a thick shell theory have been made. It is found that the stresses predicted by the thick shell theory are slightly higher than those predicted by the thin shell theory. However, significant differences are present in the case of displacements predicted by the two theories. Earlier studies have shown that thick shell theory predicts deflections better than thin shell theories; and as deflections are an important parameter in the case of railroad wheels, it is suggested that it is better to use the thick shell theory in the analysis of railroad wheels. Kevlar epoxy and graphite epoxy are the two materials used in the analysis and in each case, radial and circumferential orientations have been considered. © 1992.

Composite Structures

Comparison of shell theories in the analysis of railroad wheels

Composite materials have been finding increasing applications in the field of transportation. A U.S.A. patent suggesting the use of composite materials for railway wheels is the basis for this paper. In thispaper, the natural vibrations of railway wheels made of composite materials have been theoretically estimated by the finite element method and compared with those in wheels made of steel. A thick conical shell element with displacements in the axial, radial and circumferential directions has been used in the analysis. This element brings out the coupling between the different modes of vibration, and this aspect is important in the dynamic analysis of composite wheels. Three geometries of wheels and two materials (Kevlar-epoxy and graphite-epoxy) have been used in the study. For each of these materials, two fiber orientations (radial and circumferential) have been taken up and their natural frequencies determined. © 1992.

Journal of Sound and Vibration

Free vibration analysis of composite railway wheels

Thick shells made of composite materials have been analyzed by using a higher order shell theory. In this theory thickness normal strain and two transverse strains are included. A higher order three-noded isoparametric axisymmetric finite element is used to solve the problem. Numerical experiments with the present element indicate that this element yields accurate vibration results with very few elements. In the present study, the suitability of different theories used for vibration studies has been investigated. Three theories are compared, viz. Love's first approximation shell theory, an improved theory with shear deformation and rotatory inertia, and a shell theory with thickness normal strain and shear deformations. It is found that the shear deformations have an appreciable effect on the vibration characteristics of comparatively thick shells, especially composite shells. A parametric study has been conducted to study the effects of various geometric properties of shell on the free vibration characteristics of conical isotropic and composite shells. The effect of mass distribution on the natural frequencies is also studied in the present work. © 1992.

Vibration analysis of thick composite clamped conical shells of varying thickness

In this paper stresss and deflections in composite railroad wheels subjected to lateral and vertical loads have been predicted by using the finite element method. A thin conical shell element is used for the analysis which has advantages in terms of computer time and memory over the conventionally used triangular ring element. Two composite materials and two fiber orientations have been used in the studies. It is found that wheels with radially oriented fibers are better suited than circumferentially oriented ones from the strength point of view. It is also found that the thickness of the web in composite wheels would have to be nearly doubled in order to keep their lateral deflections of the same level as in steel wheels. © 1991.

Stress analysis of composite railroad wheels

Polymer International

Reference book for composites technology. vols 1 and 2. Edited by S. M. Lee, Technomic Publishing Co. Lancaster and Basle, 1989. pp. viii + 325 (Vol. 1), pp. vii + 197 (Vol. 2). price Vol. 1 SFr 165·00, Vol. 2 SFr 143·00. ISBN 087762 564 6 (Vol. 1) 0 87762 565 4 (Vol. 2)

Journal	Computers and Structures
ISSN	00457949
Open Access	No