Higher Vibration Modes in Railway Tracks at their Cutoff Frequencies

Markus R. Pfaffinger

PhD theses accepted on the recommendation of Prof. Dr. J. Dual (examiner) and Prof. Dr. P. Hagedorn (coexaminer)

Introduction

Forced vibrations of a railway track excited at the cutoff frequency of one of its wave modes have been examined theoretically, numerically and experimentally in the frequency range from 5 kHz to 50 kHz. The background of this work is the new idea to use the local vibration zone of the rail close to the excitation to detect passing train wheels.

Figure 1 shows the local vibration zone of mode 9 measured at 17 kHz.

On these web pages you will find:

• A short introduction to the behavior of higher vibration modes using a simple mechanical model including animations of the results.
• Experimental results showing measured mode shapes of a railway track. The results can also be viewed as animations.

For further information (damping measurements, numerical calculation of the mode shapes and cutoff frequencies,...) please download the online version (PDF, 7840 k, Acrobat Reader 4.0 required) of my thesis.