engleski

ENERGY BALANCE METHOD WITH USING EIGENFUNCTIONS IN THE ESTIMATION OF OVERHEAD TRANSMISSION LINE AEOLIAN VIBRATIONS

Wind-induced overhead transmission line Aeolian vibrations can cause the damage and breaking of the cable due to the material fatigue. Aeolian vibrations are in practice estimated by using the Energy Balance Method and the Modified Energy Balance Method with Using Eigenfunctions which enables determination of eigenvalues of a cable with line fittings, and therefore, the calculation of bending strains at any point in the span. Warning sphere is usually modelled as a particle having only a vertical rectilinear motion. This is a crude assumption because in this way any rotation of warning sphere cannot be taken into account. In this paper the warning sphere is modelled as a rigid body which perform plane motion. Bending strains at the critical points of the span, i. e. at the suspension clamps, at the points of damper attachments and at the points of warning sphere attachments are determined for considered two models of warning spheres. The results show significant differences of banding strains obtained with the model of a warning sphere as a particle (rectilinear motion of a particle) and with the model of a warning sphere as a rigid body (plane motion of a rigid body). In the considered example these results differ up to 57 %.

Aeolian vibrations; Energy Balance Method with Using Eigenfunctions; transmission line

nije evidentirano