Mechanical Assessment of Fiber Reinforced Composite Hollow Circular Beams

This thesis presents a study on fiber reinforced hollow beams. The theoretical background is based on published works and some extensions to the present researches. For some, simple, cases exact solutions are made available, however hollow composite beams have to be studied using 3D modeling in order to capture their actual anisotropic behavior. At first, we start to investigate if we have enough information to successfully design a structure using FRP materials. Then after studying some published works in this field, we understood that there is a lack of some important details. We tried to fill this void by first understanding the behavior of FRP beams and prepare a fast and easy way for engineers to use these composite beams and design structures. To do that, we used existing analytical methods. Although analytical, these methods are limited for studying fiber reinforced beams. Thus, a new approach is here presented based on an equivalent 3D shell model which is used to defined a 3D finite element beam element for frame structural analysis. This approach is simple and clearly considers the anisotropy inherited in such profiles. Applications of this procedure are given which show the quality of the present results and the advantages of using composite beams with respect to classical steel beams in civil applications.