Investigation on fatigue life of Rail-Wheel assembly using Finite Element Analysis
In recent years, the axle loads on railway cars is increasing due to increased transport of the goods and faster infrastructural growth. The rail wheels are subjected to high contact stresses of alternating magnitude due to rolling action of the wheels under these loads. The rail wheels should be able to sustain these variable loading for reasonably infinite life. Accidents due to fracture of rail wheels affects the safety of railway facility. Therefore more attention is paid to the quality of rail-wheel. The rail wheels are found to fail predominantly due to fatigue under these variable loadings whereas other modes of failure are damage to railway bogie, suspension failure and in some cases derailment of the vehicle. After all the advancements in design, materials and non-destructive inspection, the fatigue propagation and failure due to damage of railway components remains an important issue for safety engineering in railways. In this work, an attempt is made to investigate the occurrence of stresses in rail-wheel assembly due to high contact loads at the assembly points. The study involves the determination of equivalent stress (von-Mises), strain, safety factor using finite element method on ANSYS® 2016. An appropriate understanding of these mechanisms needs in depth knowledge of physical interactions between rail and wheel. The rail wheel assembly is assumed to operate under the designed load. The Goodman mean stress correction theory is used to obtain results. The results on the fatigue life are presented which are assumed to depend on these factors.
Analysis of wheel–rail interaction using FE software
Abstract In this article, research into the influence of interacting wheel and rail profiles on the distribution of contact zones and stresses is presented. The influence of contact forces on the deformation of rolling carload wheels and rails, and the influence of this deformation on the redistribution of the contact stresses is also investigated. The quasi-Hertz method as well as a finite element (FE) method were included as basis of mathematical simulation. With these tools, distributions of contact zones for different angles of attack of the wheelsets were defined. The problem was solved in three-dimensions. The offered technique to solve the contact problem has been used for the improvement of operating wheels.
Hobbes and the Reception of Leviathan
Although there has been much discussion of the reception of Hobbes’s work, Hobbes’s response to his own reception has rarely received much consideration. This article looks at Hobbes’s engagements with his critics. Far from being rearguard actions by a philosopher under siege, or disingenuous attempts to curry favour with those in power, they can be read as moments when Hobbes in fact sought to convert what he saw as the “truth of speculation into the utility of practice.”