PhD Research by Martin Hiensch
09/01/2014 - ongoing
Wear and RCF
M2i Materials innovation institute
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Railway switches, key elements in railway operation, are severely loaded by trains. Resulting damages lead to urgent and unplanned replacements, non-availability of track and high monitoring and replacement cost. The aim of this PhD study is to improve the structural performance of the switch panel (switch and stock rail) in terms of reliability, availability and maintainability, addressing the current industry needs. The research objective is to improve the understanding of the root causes of switch panel rail damage and potential mitigation measures and to develop improved engineering models to aid and design optimisation. June 2014 this PhD research started with a more in depth inventory of overall switch damage. Understanding the relationship between parallel research lines within the integrated project on switches at TUD a complementary research scope was defined. The research topic on vehicle-track interaction, identifying measures to decrease switch panel loading, was the first to be started, studying narrow curving behaviour. Investigating the optimisation of bogie rotation rigidity of trains by changing the suspension design between the wheelset and bogie frame, introducing suspension behaviour which depends on loading characteristics. Evaluating the potential of this design change to reduce wear and tear at the wheel-rail interface thus enhancing the so called ‘track friendliness’ of trains. Assessment of vehicle running behaviour was carried out by means of vehicle-track simulations within the VAMPIRE multi body simulation software. At the wheel-rail interface the impact of the suspension design modification is quantified in relation to the wear, rolling contact fatigue (RCF) damage, vehicle stability and passenger ride quality. Simulation results assessing classic curving behaviour clearly showed the potential the proposed measure through a significant reduce in wear and contact fatigue loading. From this first work fisrt full conference papers and a scientific article have been delivered. Preparation of a field test program regarding track friendliness has been carried out, together with setting-up further switch panel track models using the simulation software tool VAMPIRE to allow evaluation of switch panel vehicle negotiation. Furthermore foreseen in 2016 is to start researching on switch panel rail material optimisation. Dissimination of results through full conference papers and scientific articles.