Differential Displacement and Dynamic Conductor Strain

The results of recently reported experiments on vibrating conductors have shown a proportionality between dynamic flexural strain and differential displacement, or bending amplitude, for individual cables. A mathematical solution defining the relationship has been formulated. The analytic solution shows the relationship to be dependent upon conductor tension and flexural rigidity and is linear except for high frequencies when the loop lengths are short in relation to the deflection arm of the measuring instrument. Experimental data from three laboratories are in good agreement with the analytic solution. The nonlinearity of individual strain-displacement tests on stranded cables shows need to further investigate the flexural rigidity of multiwire construction.