Nonlinear static analysis and stability of a three-dimensional guyed truss tower considering the unilateral contact of the stays

Resumo

Guyed towers are widely used in various engineering applications, such as telecommunications, broadcasting, and power transmission, due to their slender geometry, favorable structural performance under service loads, and economic efficiency. However, numerous structural failures resulting in tower collapse are often associated with stay cable rupture or malfunction. In this context, the present work investigates the nonlinear static equilibrium and structural stability of a three-dimensional guyed truss tower, taking into account the hypothesis of unilateral contact in the stays. To achieve this, a positional formulation combined with the Euler–Lagrange equations is employed to derive a set of nonlinear second-order ordinary differential equations that describe the structural behavior of the guyed tower. This nonlinear system is then solved to obtain equilibrium paths and assess their stability under two practical loading scenarios: (i) the guyed tower subjected to vertical loads, and (ii) the guyed tower subjected to horizontal loads. Particular emphasis is placed on the influence of unilateral contact in the stays on the nonlinear equilibrium path, which reveals a complex bifurcation and stability scenario arising from this critical assumption regarding stay behavior.