Entwicklung einer Methode zur Einbringung von Druckeigenspannungen in Schienenfüße

Research output: ThesisMaster's Thesis

Organisational units

Abstract

The aim of this master thesis is to evaluate the state of the art regarding mechanical surface treatment methods on perlites for railroad applications. Furthermore, the state of the art regarding the introduction of residual compressive stresses into this material is to be extended. Since compressive residual stresses in the near-surface region can significantly reduce the rate of crack propagation, a possibility for application at the base surface of the rail is under investigation. By minimizing the crack growth, the fatigue lifetime can be increased. In this regard, the literature search showed only limited agreement regarding the properties of the materials already investigated and the base material used in the manufacture of rails for railways. Therefore, several treatment methods were evaluated and ranked with the help of a rating matrix in the process of a pre-selection. The most promising methods were shot peening, deep rolling, mechanical hammer peening and surface treatment by laser shock peening. After the test scale was transferred and the experimental investigations were completed, the residual stresses were measured using the borehole method. The analysis of the strains and evaluation of the residual stresses was performed by the software of the test system manufacturer SINT Technology. Subsequently, the determined residual stresses were processed graphically. The averaged curves of the applied compressive residual stresses are clearly presented, and the treatment methods are evaluated in terms of their efficiency. Finally, the methods are compared with an untreated reference specimen. The two best mechanical surface treatment methods were selected on the basis of the results obtained in this master thesis and, to complete the analysis, a possibility for integrating those methods into continuous operation was presented.

Details

Translated title of the contributionDevelopment of a method for introducing compressive residual stresses in rail feet
Original languageGerman
QualificationDipl.-Ing.
Awarding Institution
Supervisors/Advisors
Award date22 Oct 2021
Publication statusPublished - 2021