A Mathematical Model of Flexural-Creep Behaviour for Future Service Expectancy of a GFRP Composite Cross-Arm with the Influence of Outdoor Temperature

• Main Authors: Alhayek A., Syamsir A., Supian A.B.M., Usman F., Najeeb M.I., Asyraf M.R.M.
• Other Authors: 57221437286
• Format: Article
• Published: Korean Fiber Society 2024
• Subjects: Elevated temperature; Flexural creep behaviour; GFRP composite cross-arm; Mathematical model; Pultrusion; Brittleness; Creep; Data; Mathematical Models; Samples; Service Life; Stresses; Temperature; Bending tests; Brittle fracture; Fiber reinforced plastics; Creep behaviors; Cross arm; Flexural creep behavior; GFRP composites; GFRP laminates; Glassfiber reinforced polymers (GFRP); S models; Stress levels

Exposure to high temperatures can damage GFRP laminates� mechanical properties and, as a result, degrade their long-term performance, leading to rupture during their service life. Therefore, this study investigated the flexural-creep behaviour of pultruded glass fibre-reinforced polymer (pGFRP) when subjected to elevated temperatures and utilised two mathematical models to evaluate the structure's serviceability when subjected to a variety of stress levels. Two main parameters were investigated: elevated temperature (25 to 40��C) and constant load levels (12%, 24%, and 37%), whereas the pGFRP specimens were monitored for 720�h (30�days). Furthermore, the experimental work has been paired with mathematical models, namely, Findley�s power law model and Burger�s model, to predict the life span of a pGFRP cross-arm according to the data obtained from creep tests. Results showed the specimens failed in a brittle manner as expected under the static 4-point bending tests with an average ultimate strength of 242.6�MPa. Moreover, both models used to simulate the creep behaviour of the GFRP laminates matched very well with the experimental data. However, these models showed a substantial difference in the strain predicted over the 120,000�h period, with Burger�s model predicting the specimens to reach the ultimate strain in 9.4 to 11.4�years, depending on the stress level, while Findley�s model only showed a minimal increase in the total strain. This suggests that Burger�s model might be more conservative and more reasonable for creep at elevated temperatures. � 2023, The Author(s), under exclusive licence to the Korean Fiber Society.