Adaptive crash energy absorber based on a granular jamming mechanism

The following discussion concerns the use of innovative smart materials called vacuum-packed particles (VPPs) as active energy absorbers. VPP, also known as a granular jamming system, is a structure composed of granular media contained within an elastomer coating. By changing the vacuum pressure inside the coating, it is possible to control the mechanical properties of the structure. VPPs have many applications, e.g. in medicine, robotics, and vibration damping. No attempts have yet been made to use VPPs to absorb the energy of a collision, although, given their properties, this could very well be an interesting application. In the first part of the paper, the general concept of the absorber is presented. Then a prototype and the empirical tests conducted are precisely described. The middle part of the paper considers the basic properties of VPP and modeling methodology. A proposal for a constitutive equation is presented, and a numerical simulation using LS-Dyna was performed. In the final section, the concept of a smart parking post is presented.