Static Bending Strain in Stranded Conductor

The analytic solution for static bending in stranded conductors is derived for the following cases of conductor supports: (1) Conductors with and without armor rod reinforcement; (2) conventional suspension clamps with bell mouths; and (3) unequal sag angles on either side. Rigorous solutions are reduced to simplified forms for ease of computation. Over a wide range of test conditions, calculated static bending strains are in good agreement with those determined experimentally. Overhead power conductors and other taut cables exposed to wind-induced transverse vibration are susceptible to fatigue failures, particularly at supports. The vibration fatigue life of such cables decreases as the static strain level is increased. The static strain level at a cable support includes three major components: Tension, radial compression; and bending.