1.  Purpose/ Relevance: Conduct fundamental experiments coupled with advanced numerical/analytical modeling to determine the relationship between blast loading and residual life of the reinforcing metallic phase of critical civil structures. This relationship is a required component in blast mitigation design protocols and in efforts aiming at development of a new blast resistant reinforcing phase.  Innovation: A damage and residual life assessment model incorporating three integrated studies: i- Experimental program utilizing a new 3-stage gas gun to deliver TNT equivalent, blast loadings (Fig.1), ii- A mechanistic based deformation criterion associated with high loading rates, and iii- An experimental methodology to determine post blast residual life in terms of ductility reduction and available fracture energy.  This Year outcome: A series of gas gun experiments were carried out to establish a blast deformation criterion for low carbon structural steel based on twin formation. Post-blast residual life has been measured experimentally and correlated with twin volume fraction as a function of impact stress (Fig.2).  Long-range impact: Develop a numerical tool to predict the survivability of structures subjected to blast loading. This tool will be used to identify the force limit for blast mitigation designs suitable for resistance to single and multiple blasts and provide the material dynamic deformation flow characteristics required for the microstructure development of a blast resistant reinforcing metal phase. Damage and Residual Life of Critical Civil Structures under Blast Loadings ; H. Ghonem, O. Gregory, W. Visser, Q. Liu and K. Jeaniouis, U Rhode Island

2. Figure 2 Experimental twin volume fraction in low carbon steel as a function of blast stress and impact speed Figure 1 New design of three stage Gas Gun capable of delivering particle speed up to 1000m/s and force of 20GPa. Pressure Stage Convergence Stage Release Stage Barrel (10ft) Damage and Residual Life of Critical Civil Structures under Blast Loadings ; H. Ghonem, O. Gregory, W. Visser, Q. Liu and K. Jeaniouis, U Rhode Island

3.  Education Students Present & Graduate: -D. Barr, Fall River high school teacher, K. Jeaniouis, undergrad student, William Visser, Masters student, Qian Liu, Ph.D student  Papers/Patents/Presentations: -Microstructural Characterization of Pipe Bomb Fragments, O. Gregory, J. Oxley, J., M. Platek, J. Smith, M. Downey, C. Cummiskey, E. Bernier, H. Ghonem, Materials Characterization, Vol.61, No. 3, p.347- 354, March 2010. -Deformation Criterion for Blast loading in Low Carbon Steel, W. Visser, Y. Sun, O. Gregory and H. Ghonem, Int. J. Material Science and Engineering, submitted December 2010. -Time-Dependent Deformation of Low Carbon Steel at Elevated Temperatures, K. Maciejewski, Y. Sun, O. Gregory and H. Ghonem, Int. J. Steel and iron Research, in press March 2011. -Numerical Applications of Viscoplastic Deformation of Structural Steel, Y. Sun, K. Maciejewski, O. Gregory and H. Ghonem, J. Materials Engng and Performance, submitted January 2011. -Deformation Criterion of Low Carbon Steel Subjected to High Speed Impacts, W. Visser, G. Plume, Y. Sun, C. Rousseau, O. Gregory, H. Ghonem, IMPLAST, Providence, October 14, 2010. -Twin Formation and Influence on Deformation Characteristics of Low Carbon Steel, W. Visser, Y. Sun, O. Gregory, H. Ghonem, 2011 SEM Annual Conference on Experimental and Applies Mechanics, Mohegan Sun, Uncasville, CT, June 13, 2011.  Collaboration with Industry: National Institute of Standards and Technology, FM Global  Next Year: Extend the impact load experiments to a range beyond that of conventional TNT blast energy in order to examine effects of single and multiple blast events on residual life of structural steel and cast iron materials Damage and Residual Life of Critical Civil Structures under Blast Loadings ; H. Ghonem, O. Gregory, W. Visser, Q. Liu and K. Jeaniouis, U Rhode Island