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.
Fretting fatigue of 6201 aluminum alloy wires of overhead conductors
Abstract Fretting fatigue tests were conducted on 6201-T81 aluminum alloy wires of an AAAC 900 MCM conductor. A finite element-based cont7act model combined with a nonlocal Smith–Watson–Topper criterion was used to estimate fatigue life. To account for the stress gradients beneath the contact, an average stress over a fatigue damage zone was adopted. A procedure for determining the size of the damage zone from V-notched wire test data is presented. Fatigue lives estimated using stresses from a linear elastic contact model were overly conservative, while the use of an elastic-plastic contact model significantly improved the estimates.
Experimental observation of a strange nonchaotic attractor.
Evidence is presented for the existence of a strange nonchaotic attractor in a two-frequency quasi-periodically driven, buckled, magnetoelastic ribbon experiment. Scaling behavior in the Fourier amplitude spectrum is observed in agreement with predicted scaling behavior for strange nonchaotic attractors. Dimension measurements also support the existence of a strange nonchaotic attractor