Energy damping system (EDS) is required to absorb/damp mechanical energy when they are under the external mechanical load, which are widely used for protecting against the damage caused by impact or blast load, e.g. protection layer of electronics, car bumper and helmet. Due to a long response time, a localized deformation under high loading rate and unable to reuse, the conventional EDS is not effective to resist the high-speed loads (e.g. blast or high-speed impact), and, thus, developing a new EDS is very necessary.

A new tunable reusable energy damping system was developed, which is based on the nanoporous particles with nonwetting liquid sealed inside a container. The working mechanism of the new EDS is as follows: Under the normal condition, the nonwetting liquid is outside of the nanopores; and when the system is under the external load, the nonwetting liquid will be pressed into the nanopores. The work done by the external load can be converted into the solid-liquid interfacial energy and internal friction energy (dissipated as heat), and, thus, the mechanical energy is damped. Due to the high specific surface area/mass ratio, this system have the potential of becoming ultrahigh performance EDS.

Both the numerical and experimental studies are employed to understand the mechanism of energy damping and the effects of the system parameters on the energy damping performance, e.g. the nanopore size, liquid flow rate inside nanopore, liquid viscosity and solid-liquid surface interaction energy. The results show that the new EDS can be a potential candidate to effectively damp the mechanical energy for both static and dynamic loads. In addition, by adjusting the system parameters, the system can be not only tunable to resist the different pressure levels to make it more effective for all purpose protections but can also be reused to protect against the repeatable loads.

 

 

Dr. Guoxin Cao is currently a research assistant professor in the Department of Engineering Mechanics in the University of Nebraska-Lincoln. Before joining the University of Nebraska-Lincoln, he was working as a Postdoctoral Research Scientist in the Department of Civil Engineering and Engineering Mechanics in Columbia University. He received his Bachelor’s degree from Dalian University of Technology in 1993, Master’s degree from Inner Mongolia Polytechnic University in 1996, and his PhD in Material Science and Engineering from Clemson University in 2004.  His research areas are mainly about multiscale simulations of the processes, properties, performances of materials and structures, nanomechanics, biomechanics, nanofluidics and renewable energy applications based on the advanced nanomaterials. He has authored and co-authored over 50 journal papers.