NLFEA Study on the Flexural Behavior of Double Skin Tubular Beams Strengthened with LRS FRP System: Inner Steel Tube Eccentricity Effect

There is an increasing necessity to increase the ductility of essential structural members, such as beams,along with mitigating any possible unfavorable environmental sources consumption, and keeping thestrength-to-weight ratio as high as possible. Therefore, this study adopts the nonlinear finite elementanalysis (NLFEA) method to simulate the flexural behavior of a double skin tubular beam (DSTB)positioned at different concentric and eccentric locations with respect to the geometrical centroid of therectangular beam cross-section. In addition, beams were reinforced with one large rupture strain (LRS) FRPsheet of 1 mm thickness positioned at the bottom of the beam (tensile region) and another one wrappedalong the perimeter of the beam. The position of the inner steel tube was selected to represent the followingeccentricity percentages (-40%, -20%, 0, 20%, and 40%). Results are presented in terms of differentstructural characteristics, including strength, ductility, and recommendations were given for selecting thebest parameters included in the beam design to reach the target structural values.