Fatigue behaviour of Vossloh SKL14 tension clamps

Abstract

In the paper the attention is paid to the flexible fastening system of the Vossloh W14 type with the use of SKL14 tension clamps. These clamps are often damaged by fatigue failures especially in the curves of small radii (R < 400 m). Within the research, fracture areas were identified and a detailed fractographic analysis was performed. The analysis proved a fatigue failure. Therefore, an estimation of the service life of the clamps was made. The evaluation was focused on a selected railway track where the fatigue-damaged clamps were found. Within the prediction of the fatigue life, static prestress was identified by means of experimental measurements (verified by FEM) and dynamic response to the operating loads. The strain gauges were placed directly on the clamps at critical points. The obtained values were confronted with the experimentally obtained fatigue curve. The fatigue curve was obtained on material samples taken from the new undamaged clamps. Finally, the service life of the clamps in the selected track was identified. The results of the lifetime estimation are remarkably consistent with the real lifetime.