Dynamic Parameter Investigation of a Full Scale Laboratory Overhead Contact Line Section Model

Abstract

In the dynamic parameter investigation of a full scale laboratory section model of a overhead contact line, the effects of tension force and the effect of removing a dropper is of interest. The thesis present the results of multiple tests done on a lab model regarding frequency and damping. The study show that determining damping based on the principle of logarithmic decrement is not very accurate. The natural frequency show a clear trend throughout the measurements. Whit increment in the tension force, follows the natural frequency. This is applicable for both the first and the second mode shape. The fact that an increment in the tensile forces also lead to an increment in the natural frequencies is also backed up by the literature. This is however a simplification, not taken into account the fact that there might be different tensioning forces in the contact wire (CW) and messenger wire (MW). When the wires are tensioned with different force, this affects the frequency different than simplified theory presented in literature. Removing a dropper will have a greater impact on the first mode shape than on the second.