Fretting fatigue of the drake acsr electrical conductor under cyclic bending a t a suspension clamp

摘要

Under wind excitation, overhead electrical conductors undergo very small amplitude bending vibrations. However, these vibrations can be very damaging for conductor because of fretting fatigue. Such damage occurs wherever therre is contact with some device, most notably at suspension clamps where a conductor is hanging from a transmission tower. Thus, conductor fatigue strength is an important parameter in overhead power line design. Such fatigue strength chanracterization may be carried out case by case or, instead, by performing a detailed analysis of a typical conductor under a wiede range of parameters. The present study is based on a based on a typical Aluminum COnductor Steel Reinforced (ACSR), the so-called Drake ACSR conductor, a two-layer EC-H19 aluminum conductor with a steel core. Bending fatigue tests have been performed on this conductor. New results are presented for a wide range of amplitude parameters. Basic fretting considerations, in which local contact conditions are taken into account, are examined. It is shown that fetting parameters can be estimated and compared quantitatively with global conductor endurance limit.