Nonperfect Aluminum Beams Subjected to Concentrated Loading

The response of aluminum beams subjected to concentrated loading is investigated experimentally through a series of 52 tests. Three different aluminum alloy AA6082-T6 extrusions are included in the test program: one double T section and two square hollow sections with different wall thicknesses (SHS-3 and SHS-5). These profiles were tested as simply supported beams loaded either at the midspan or at the end supports. The results show that web thickness, flange stiffness, beam span and overhang are important factors that influence the capacity. In addition, the influence of applying the concentrated load through a circular or a rectangular bar was investigated for the SHS-5 extrusion, and for all cases where bending was limited, the circular bar loading significantly increased the capacity. The beams were rotated systematically about the longitudinal axis in order to investigate the influence of loading the specimens on their different sides, and the effect was measured in the range of 3.2 - 11.4 % of the mean values for each cross section and loading case. Furthermore, comprehensive measurements of the material properties and the initial geometry, including geometrical imperfections, were important for investigation of the influence of material and geometry variations on the member response.