1. PBX Behaviors Accounting for Crystal/Binder Interface Debonding and Binder Viscoelasticity Henry Tan School of Mechanical, Aerospace and Civil Engineering The University of Manchester Collaborators: C. Liu (Los Alamos National Laboratory) P.H. Geubelle (NASA Illinois Space Consortium, UIUC) Y. Huang (Northwestern University) DYMAT Meeting: The High Rate Mechanical Properties of Energetic Materials, their Binders or Simulants

2. PBX 9501 Skidmore et al., 1997. Los Alamos National Lab coarse particle average radius: 125 m fine particle average radius: 4 m Large particle volume fraction Bimodal size distribution of energetic crystals High specific surface of crystal/binder interfaces

3. Cracking under Quasi-Static Loading Rae et al. 2002. Cavendish Laboratory, Cambridge crack HMX crystals Cracks propagate mainly through the debonding of interfaces

4. Objectives 1.To determine the interface cohesive law for plastic bonded energetic materials 2.To establish a constitutive model for plastic bonded composite materials that accounts for nonlinear interface debonding binder viscoelasticity To study the effects of interface debonding and binder viscoelasticity on behaviours of energetic composite materials