Elektrik dağıtım direklerinde kullanılmak üzere lif takviyeli polimer kompozit köşebentlerden konsol geliştirilmesi

Glass fiber-reinforced polymer (GFRP) composites are increasingly used in critical infrastructure systems due to their high strength-to-weight ratio, corrosion resistance, and ease of installation. However, their anisotropic behavior and complex failure mechanisms make structural design more challenging compared with steel. In this study, a GFRP composite cross-arm was developed for 34.5 kV distribution towers using pultruded angle profiles. Critical loading conditions for the prototype tower were determined based on conductor properties, line configuration, and regulatory requirements. The composite angle sections were experimentally evaluated through single-bolted and multi-bolted connection tests, enabling the selection of an optimum section and connection layout. Full-scale loading tests were conducted on a four-member composite cross-arm under critical loading to assess its structural performance. A braced cross-arm configuration was also tested under multiple loading scenarios and evaluated according to relevant standards. Long-term performance was examined through a 3000-hour full-scale creep test, and a Findley Power Law model was developed to predict 50-year deformations. A simplified finite element model was developed and validated using connection-level experimental data, after which it was applied to the composite cross-arm for a comprehensive parametric study for load-carrying capacity and stiffness evaluations. Additionally, the electrical insulation performance, potential reductions in right-of-way and tower height, and both short- and long-term cost advantages were evaluated and compared with a conventional steel cross-arm. The results demonstrate that the GFRP composite cross-arm offers structural reliability, broad practical feasibility, and competitive economic performance compared with steel in modern distribution systems.