Micromechanical characterization tools for highly-filled polymers

Groves, S ; DeTeresa, S ; Cunningham, B ; Ciarlo, D ; Allen, D ; Clayton, K ; Yoon, C

Lawrence Livermore National Laboratory

关键词: Plastics;    Dielectric Materials;    Stockpiles;    Binders;    Polymers;   

DOI  :  10.2172/15005378
RP-ID  :  UCRL-ID-137693
RP-ID  :  W-7405-ENG-48
RP-ID  :  15005378

美国|英语

来源: UNT Digital Library

【 摘 要 】

We are attempting to characterize and model the micromechanical response of highly-filled polymers. In this class of materials, the continuous plastic binder used to bond the highly-filled material dominates the observed viscoelastic response. As a result, realistic lifetime analysis of these materials will require a thorough understanding of the contribution of the plastic binder. Laboratory applications of these materials include plastic bonded explosives, propellants, a variety of specialized filled organic materials for stockpile systems, and highly filled epoxy dielectric materials for the National Ignition Facility. We have explored numerous techniques to characterize the local microstructure of plastic bonded explosives. However, insufficient funding was obtained to bring these technologies to maturity, nevertheless our present tool set is significantly better than 2 years ago. We have also made some progress in developing an appropriate micromechanical constitutive modeling framework, based on a finite element method incorporating a cohesive zone model to represent the binder contribution within a Voronoi tesselation mesh structure for the PBX grains. A second modeling approach was used to incorporate analytical micromechanics (generalized self-consistent schemes). However, preliminary theoretical analysis strongly suggested that this approach would be invalid for such extremely high-filled systems like PBX.