Strain Measurements on ACSR Conductors During Fatigue Tests III—Strains Related to Support Geometry

A simple conductor bending model taking into account the geometry of the suspension clamp has been used to interpret the strains measured on top and bottom wires of two ACSR conductors outer layer. Taut Drake and Bersfort ACSR conductor specimens were fitted with a short commercial metallic suspension clamp and forced to vibrate at one of their normal modes. On each gauged wire, five equally-spaced cross-sections were monitored near the last point of contact of the conductor with the bed of the clamp or with the bolted keeper. Three strain gauges were used at each selected wire cross-section making it possible to obtain the wire traction strain as well as the binormal and normal bending strains. This more complex conductor-clamp model was found to yield theoretical strain values closer to measured values than the usual models where clamp geometry is ignored. Hence, this could be a step to a more precise estimate of a given conductor-clamp fatigue limit when undergoing Aeolian vibrations.