Experimental validation of inspection intervals for railway axles accompanying the engineering process
In the paper an example of successful cooperation between an operator, a vehicle manufacturer, a wheel set supplier and a research institute is presented demonstrating the current state of a design procedure which aims at meeting wheelset specification requirements recently adopted by the Deutsche Bahn (DB). Different from the conventional praxis, these requirements incorporate the fracture mechanics approach for determining inspection intervals of railway axles. The procedure includes the wheelset dimensioning based on current railway standards, fracture mechanics considerations to assess subcritical crack propagation starting from a crack size just below the detection limit, and crack propagation tests on full-scale axles under load spectrum representative of in-service conditions. The paper describes different steps of the procedure, while mainly focusing on fracture mechanics - both computational and experimental issues.