The stress-endurance (S-N) method has been widely used in metal fatigue in the railway industry over many years. However, when this method is applied to rubber-like materials, it seems not as successful as when it is applied to metallic materials. Recently, an integrated fatigue evaluation programme has been carried out with the aim of improving the design of antivibration components in response to the increasing demands of the rail operating environment. This programme will also make simulations more reliable and relevant to industrial applications, especially for the fatigue design of rubber springs used in rail vehicle suspensions. The continuum mechanics (total life) approach has been used to characterize the fatigue life in terms of the cyclic stress range (S-N curve). It is suggested that the effective stress, s f , can be used as a parameter (taking three principal stress ranges into consideration) to evaluate fatigue failure. The initial verification of this approach has been carried out on two types of rubber spring. The results have shown good agreement between the fatigue test of the components and the simulation based on this approach.
Rubber-to-metal bonded springs are vital antivibration components for rail vehicles. Metacone rubber springs are widely used as a primary spring on a rail vehicle ®tted at the wheel axle box. Nowadays the more demanding operating environment has made the design of such components more challenging than ever before. By using an integrated design±simulation±testing procedure it is possible to achieve the maximum fatigue capacity of the suspension components under a very tight space envelope. This note illustrates the procedure to achieve the high performance and the fatigue service life requirements for the suspension components.
The offset sandwich mount design is often considered for application on rail vehicles. This paper reviews several different aspects of the product. These include the more commonly evaluated benefits of higher order material properties, the product design and its associated geometry optimisation. It is shown that a large error occurs when calculating the rubber shrinkage using a constant coefficient in the moulding process. Hence a postulation is made to link the compressibility with temperature change, which leads to the accuracy increased by fivefold against the measurement. A design concept, balancing the internal moments in different layers of the component, is proposed for this type of the product. Finally the paper suggests an effective stress criterion which takes into account all stress components when considering the complications associated with multiaxial loadings. The objective is to identify which can be considered the best approach for crack initiation evaluation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.