Structural Design of Safety Steel Device of Railway Vehicles Through Analytical and Experimental Investigations

The subject of this paper is the structural design of a safety steel device that is located between the standard wagon buffer and the collision energy absorber. The safety steel device is a sacrifical part able to withstand normal operating loads from the buffer across the absorber to the vehicle bearing structure without any permanent deformation, but experiences fully controlled fracture when the load exceeds the defined threshold. Following fracture, the load path is through the energy absorber. The sacrificial part is a ring made from quenched and tempered low alloyed steel with precisely defined heat treatment and material properties. Experimental investigations of scaled samples were performed to get mechanical characteristics of the material and geometry. A full-scale prototype of the safety device was produced, and final quasi-static and dynamic experiments were conducted. The results validate the anaytical predictions, and thus validate the design method used here for dimensioning the safety steel device.