ABSTRACT
This chapter deals with the response of FRP composite components under axial compression forces. If axial forces are induced in the axial direction of a component (e.g., truss member) with a relatively low level of end restraints, and small magnitude of bending, then it can be designed as a concentrically loaded column. It should be noted that very short columns under axial loads fail in crushing, especially at the corners of a cross section. Otherwise, axially loaded columns fail due to local or global buckling, with local buckling being the most likely cause. Likely, FRP columns may even fail catastrophically. Such failure is attributed to instability due to bending induced from out-of-plane deformations multiplied by the axial compression forces. In addition, the bending effects may come from column crookedness or unsymmetrical fabric layup during manufacturing. Even residual stress build-up, especially at the corners of FRP components during the post-curing (after manufacturing) process, can result in uneven stress distribution leading to premature failure. The above premature failures are possible before developing the full crushing strength of the FRP laminates. Therefore, a thorough understanding of the FRP column failure modes and stability is essential before designing for axial load responses. Such issues are dealt with in the following sections.
