An Extreme Strain Rate Interface Impact Thermomechanical Imaging System Based on Nanomechanical Raman Spectroscopy
Abstract
Recent experiments based on shock compression sector (SCC) and X-Ray phase contrast imaging(X-PCM) have shown that interfaces significantly affect dynamic failure and hot spot initiation inenergetic materials. However, currently there is no quantitative measurement of temperature andstresses in such interfaces at the relevant high strain rates available. Recently, a project was funded by the Air Force Office of Scientific Research (AFOSR, FA9550-15-1-0202) to investigate effect of interface mechanical properties on dynamic failure of energetic materials in Dr. Martin Schmidt’s “Dynamic Materials and Interactions” program. A novel setup of this proposal’s principal investigator (PI), Dr. Vikas Tomar, based on nanomechanical Raman spectroscopy (NMRS) technique (also developed by Dr. Tomar), is being used to measure interface level tensorial mechanical properties of Ammonium Perchlorate (AP)- Hydroxyl-terminated polybutadiene (HTPB) material system and of HMX (Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine)-HTPB based energetic material system under mechanical deformation. The binder-particle system is dynamically loaded at microscale upto a loading rate of 103 s-1. The current setup is able to measure micron scale interface stress tensor as well as interface chemistry changes under quasi-static loading conditions before and after the dynamic loading has taken place using NMRS. Since Raman spectroscopy principles are used, the NMRS measurements also provide information on temperature and chemistry along with stresses. The setup also is able to predict dynamic constitutive behavior of interfaces at strain rates up to 103 s-1. However, Raman and optical imaging of interface behavior during dynamic loading is not yet possible, thereby excluding critical time resolved stress-temperature-chemistry information that could open new insights into dynamic material behavior. Besides, the strain rates are also limited to 103 s-1.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 11, 2018
- Source ID
- FA95501810324
Entities
People
- Vikas Tomar
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Virginia