An Innovative Inflatable Morphing Body Structure for Crashworthiness of Military and Commercial Vehicles.

Abstract

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 improvements, 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, called the “I-bumper,” is developed in this research for improved crashworthiness and safety of military and commercial vehicles. The developed 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. Another additional innovative means for improving crashworthiness is the use of tubes filled with a granular material to absorb energy during the process of a crash. An analytical design model is also developed in this research for the optimal design of the I-bumper system, with a focus on up-front design. Major design variables include those of the explosive airbag, the morphing lattice structure, and the granular material used in the front posts. The morphing lattice structure is designed to maximize energy absorption during the crash impact. The granular material in the front posts is used for further crash energy management in the passive stage. The new design methodology has been implemented in MATLAB and validation has been conducted at a full vehicle level in order to demonstrate the effectiveness of the I-bumper for improved suitability in a high-speed crash. In future research, this I-bumper can be extended to address other types of crashes (for example, side impacts, rear impacts, roll over, and collision with pedestrian) and to innovative blast-worthiness applications for military vehicles. The main achievement of this work has been an introduction of the I-bumper and the development of an analytical model of the I-bumper for absorbed energy during a crash.Ph.D.Mechanical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/58507/1/sonlee_1.pd