06/10/2024
By Danielle Fretwell

The Francis College of Engineering, Department of Mechanical Engineering, invites you to attend a Doctoral Dissertation defense by Patrick Drane on: "An Experimental and Computational Investigation of Energy Absorption in Helmet Liner Systems under Low-Velocity Impact."

Candidate Name: Patrick Drane
Degree: Doctoral
Defense Date: Friday, June 21, 2024
Time: 8:30 to 10:30 a.m.
Location: Falmouth Hall 209

Committee:

  • Advisor: Murat Inalpolat, Associate Professor, Mechanical and Industrial Engineering, University of Massachusetts Lowell
  • James Sherwood, Dean, Francis College of Engineering, University of Massachusetts Lowell
  • Nese Orbey, Associate Proressor, Chemical Engineering, University of Massachusetts Lowell
  • Scott Stapleton, Associate Professor, Mechanical and Industrial Engineering, University of Massachusetts Lowell
  • Jennifer Gorczyca, Associate Dean, Engineering, Southern New Hampshire University

Brief Abstract:
The modern combat helmet consists of a shell and liner system which must protect against increasing threats from ballistic, blast and blunt impacts. This dissertation focuses on a multi-level experimental and computational investigation of energy absorption in helmet systems for repeated low-velocity impact to provide design guidance for a new liner for combat helmets which can protect against these increased threats from blunt impact. Specifically, this dissertation research has examined the effects of adding an impact force dispersion layer (facing) on the surface of the energy absorbing foam material to reduce localized foam compression and delay the onset of a rapid rise in acceleration. This dissertation builds upon collaborative projects with the U.S. Army DEVCOM Soldier Center by examining: (1) the energy absorption of foams for repeated deformation under high strains, (2) the energy absorption mechanism of a multi-layer foam-facing system, and (3) repeated impacts of a multi-layer liner component in a combat helmet system. The dissertation has contributed to the existing literature with three journal papers. The first paper presented the development of a novel characterization process for cross-linked high-density polyethylene (HDPE) foam, which exhibits a high energy absorption efficiency in the range of strain energy density necessary for combat helmets. The second paper expanded the literature by investigating a foam-facing layered component as a load dispersion mechanism to allow for greater consistency for repeated impacts. The third paper then presented the analysis of an experimental system-level combat helmet utilizing this novel multi-layer liner. The fundamental understanding and validation of this multi-material non-linear system is critical to unlocking its potential in improving helmets and any packaging protection applications.