The fretting fatigue analysis between strands of ACSR
In this paper, self-made fretting fatigue wear test bed was used to investigate fretting fatigue and wear properties of overhead transmission line between the strands, and then the fretting fatigue fracture life and the fracture surface microscopic morphology of ACSR in different testing conditions was analysed. The results show that under larger included angle, larger ACSR tensile force and larger fretting amplitude, the fretting fatigue life of the wire was reduced. The crack initiation and propagation occurs in the contact edge, and the angle is 45° between fracture surface and the wire axis. Fretting fatigue fracture can be divided into three areas: micro-crack nucleation area, fatigue crack propagation area, crack area, and the three regions have different fatigue properties.
Dynamic wear evolution and crack propagation behaviors of steel wires during fretting-fatigue
Abstract Dynamic wear evolution and crack propagation behaviors of steel wires during fretting-fatigue were investigated in this study. Wear scar and wear depth profiles of steel wires were quantitatively analyzed employing a three-dimensional white light interferometer. Theoretical models of maximum wear depth and wear coefficient of parabolic wear scars were established. Three-dimensional crack propagation characteristics of steel wires were presented using X-ray computed tomography. The results show that larger fatigue cycles induce decreased increase rates of elliptical wear scar area and parabolic wear depth of steel wires. An increase of relative displacement induces reduced damage and thereby better anti-wear properties of wires. The central zone of wear scar exhibits larger crack depth and faster crack propagation as compared to edge zones.
Dynamic Analysis of the Transmission Line Crossing 'Lago de Maracaibo'
Abstract This paper is concerned with the dynamic design of an important transmission line overhead crossing. It presents the different problems which have to be taken into account to assess the correct and safe design of towers, damping devices, insulator suspension and tension sets. Analytical tools used to simulate these problems (wind excitation and exceptional events such as phase failure) are also presented, together with some results relevant to this application.