Letters to the Editor Discussion of “dynamic Stability of Cables Subjected to an Axial Periodic Load”

In the referenced paper [ 11, the author examines the stability of the planar, linear response of a suspended cable subjected to harmonic axial loading. The study is motivated by a desire to understand the dynamic stability of cables employed in structures such as cablestayed bridges or guy-towers. In these applications, the harmonic axial load derives from the dynamic reaction of the structure at the connection with the cable. The problem of interest is illustrated in Figure 1, and consists of a uniform small-sag cable suspended in the vertical plane between two level supports separated by a distance 1. In the absence of any excitation, the cable hangs under gravity by an amount f and a static horizontal load H, develops at both supports. In the author’s paper, the cable is then driven by a harmonic “longitudinal” load H, cos f2t which, in the context of the cited applications, is applied to the cable at one (or perhaps both) supports.