The energy absorption of long origami-ending tubes with geometrical imperfections

Abstract

A novel origami-ending tube, which features the origami patterns at the ends, can deform in the diamond mode with an outstanding energy absorption performance. However, many quasi-static axial crushing experimental results showed that the long origami-ending tubes with two modules could deform in the corner symmetric mode and the mixed mode. Thus the SEAs were reduced by up to 38% and 25% compared to the diamond mode. The experimental and numerical results revealed that the local buckling and the initial concave imperfections were the main reasons triggering the corner symmetric mode and the mixed mode, respectively. The imperfection analysis indicated that the opposite local buckling imperfection and opposite concave imperfection had the greatest influence on the collapse mode and the SEA. Therefore, the reinforced metal sheets and slight convex creases were introduced into the tube to reduce the imperfection sensitivity and to improve the stability of deformation. Numerical simulations and quasi-static experiments validated that the performances of the reinforced tubes had been greatly improved in terms of energy absorption and imperfection resistance. Additionally, a simple manufacturing process was proposed, which is hopeful to achieve the mass production of long origami-ending tube.