A Finite Element Method Investigation of Mechanical and Thermal Behavior of Composite Coatings on Steel Bar

Damage to steel structures can be catastrophic in fire incidents due to the ‘softening’ effect of high temperatures on metals. Various coating materials have been developed to protect steel components from dangerously high fire-related temperatures and increase the overall fire ratings of steel-column high-rise buildings. Intumescent coating is one such spray-painted polymer material that expands at high temperatures and creates a thermal barrier to protect the steel components. In this research, we investigate a new type of intumescent coating material consisting of carbon fiber reinforced polymer composites. As carbon fiber is an excellent thermal conductor, it is expected that the surface heat will be conducted away longitudinally while keeping the inner core of steel material protected. In addition, carbon fiber composites have higher strength-to-weight ratios, meaning these coatings are supposed to increase the component strength and stiffness. The thermomechanical analysis is performed on a Finite Element Analysis (FEA) software. Simulations are carried out for various thicknesses of the composite coating layer. The results show increase in stiffness of the hybrid coated plate with a 8/10 mm thickness of the composite layer. Thermal resistance is also increased with the epoxy composite layer. These results suggest that Carbon/Glass fiber-based epoxy composite coatings have the potential to significantly improve the performance and fire ratings of steel structure.