Fibre fibre reinforced polymer (FRP) sections have been increasingly used in civil engineering applications. FRP profiles have important advantages in construction, such as high strength, light weight, corrosion resistance, convenient installation, and electromagnetic transparency. However, due to the specificities of the manufacturing process, FRP is a highly anisotropic material with superior mechanical properties along the fibre directions. However, the stress induced by loading of engineering structures is complex which may introduce premature failure of FRP composite materials. For example, web crippling may occur due to transverse loading to pultruded FRP sections. And it is difficult to avoid transverse stresses to profile members in engineering applications, e.g. reaction forces at beam ends, coupling forces at beam-to-column connections. I am one of the first researchers in the world investigating web crippling and I have developed theoretical models to describe this special mechanical failure of pultruded FRP composites. These models can be used in design specifications promoting new FRP constructions.
Above figure shows the pultrusion process for manufacturing fibre polymer composite sections. These sections have the same shape as ordinary cold formed steel sections, and can be used in constructions. However, due to the pultrusion process, the fibres are mainly aligned in the longitudinal direction, that makes the material highly orthotropic. When loaded in the transverse direction, the section exhibits prematrue failure at web-flange junctions. This special failure is called web crippling and the group is one of the pioneers in this area.
