The greatest demand facing the automotive industry has been to provide safer vehicles with high fuel efficiency at minimum cost. Current automotive vehicle structures have one fundamental handicap: a short crumple zone for crash energy absorption. This leaves limited room for further safety improvement, especially for high-speed crashes. Breakthrough technologies are needed. One potential breakthrough is to use active devices instead of conventional passive devices.
An innovative inflatable bumper concept [1], called the “I-bumper,” is being developed by the authors for crashworthiness and safety of military and commercial vehicles. The proposed I-bumper has several active structural components, including a morphing mechanism, a movable bumper, two explosive airbags, and a morphing lattice structure with a locking mechanism that provides desired rigidity and energy absorption capability during a vehicular crash. It has additional innovative means for crashworthiness, which is to use tubes filled with a granular material to absorb crash energy.
An analytical design model is developed in this paper for the optimal design of the I-bumper system, with a focus on up-front design. Major design variables include those for the explosive airbag, a morphing lattice structure, and granular material used in the front-rails (tubes) for further energy absorption. A new design model will be developed for the optimal design of the morphing lattice structure and external airbag, and for maximizing energy absorption in the active state. The use of granular material in the front-rails (tubes) will also be examined for crash energy management in the passive stage. The new design methodology will be implemented in Matlab. Validation will be conducted at a full vehicle level in order to demonstrate the effectiveness of the I-bumper for improved suitability in a high-speed crash.