Influences of different internal stiffeners on energy absorption behavior of square sections during the flattening process

The present article introduces some novel patterns of internal blades as the stiffener into thin-walled square aluminum sections to enhance energy absorption behavior of reinforced structures under the lateral loading by the experimental methods. To prepare the specimens, a thin-walled square columns made of aluminum with external cross-sectional dimensions of 34.4 mm×34.4 mm were prepared and cut to the constant nominal length of 40 mm. Then, some internal blades with thickness of 1.25 mm were prepared and after the shaping process, the formed blades were positioned into the square specimens by the point-welding. The manufactured specimens were positioned between two rigid platens and the quasi-static lateral load was performed on the specimens and the samples were laterally compressed in the flattening process. Furthermore, a simple square specimen without any stiffener was used in the lateral compressed test and its energy absorption capacity and specific absorbed energy were measured as the benchmark. The experiments show that by reinforcing the thin-walled square section with the internal blades, a new structure is achieved that can absorb the kinetic energy up to 2.99 times of the simple square section of the benchmark. In addition, according to the results, it is found that absorbed energy/mass ratio of the best reinforced specimen is 1.92 times of the benchmark.