The Development of a Damage Tolerance Concept for Railway Components and its Demonstration for a Railway Axle

Abstract

Various fracture control concepts such as safe-life, fail-safe and damage tolerance are briefly discussed with respect to railway application. A detailed discussion is provided on damage tolerance along with various aspects of a draft procedure for fracture mechanics application to railway components prepared for DB (Deutsche Bahn). This scheme is based on the recently developed European flaw assessment procedure SINTAP and other documents such as the R6 Routine of British Energy Ltd., the British standard BS 7910 and the GKSS method EFAM. With respect to fatigue crack extension essential parts have been taken over from the NASGRO/ESACRACK procedure which is common now in the aerospace sector. The use of the draft procedure is demonstrated by a case study on a railway axle the result of which is a sub-critical crack size which has to be detected in non-destructive inspection if the inspection interval is fixed by an existing maintenance scheme. The resulting numbers are aimed at illustrating the method and cannot be taken over unmodified for industrial implementation.