Three-dimensional analysis of the seismic response of guyed masts

The response of a 120 m-tall guyed mast to three-dimensional seismic excitation is analyzed using the finite-element program ABAQUS. The Northridge earthquake and an amplified El Centro earthquake are applied. The mast is pinned at its base, and guy cables are attached at four equally spaced points along its height. The dynamic tension in the guys is modeled by a nonlinear function based on tests, and periods of slackness in the guys during motion of the system lead to snap tension loads and affect the response. The mast is represented by three-dimensional beam elements. Displacements, bending moments, and base shears are computed for the mast, along with guy tensions. The effects of guy stiffness and pre-tension, mast weight, and directionality of the ground motion are investigated.