ITR-ASE-Sim: Collaborative Research: De Novo Hierarchical Simulations of Stress Corrosion Cracking in Materials

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This award was made on a collaborative proposal submitted to the Division of Materials Research under the Information Technology Research solicitation NSF-04-012. The Division of Materials Research, the Chemistry Division, and the Division of Computing and Communications Foundations fund this award. The other proposals in this multidisciplinary collaborative are 0427188 and 0427540 and involve investigators at Caltech and Purdue. Research activities covered by this award fall under the National Priority Area, "Advances in Science and Engineering," and the Technical Focus Area, "Innovation in Computational Modeling or Simulation in Research." This award supports computational research and algorithm development with the aim of developing new modeling tools for materials failure and with the further aim of applying these tools to advance the understanding of stress corrosion cracking. This award also supports related educational activities some of which involve underrepresented groups.The PIs aim to develop a scalable parallel and distributed computational framework consisting of methods, algorithms, and integrated data handling and visualization tools for: 1) an accurate quantum mechanical-level (QM) description; 2) reactive force fields (ReaxFF) to describe chemical reactions and polarization; 3) molecular dynamics (MD) simulations to extract atomistic mechanisms of SCC; 4) accelerated dynamics for long-time behavior to obtain parameters directly comparable to experiments; and 5) "atomistically informed" continuum models to reach macroscopic length and time scales. Automated model transitioning by novel techniques will be employed to embed higher fidelity simulations inside coarser simulations only when and where they are required, while controlled error propagation will ensure the overall accuracy of the results. The PIs plan to use this hierarchical multiscale computational framework to study stress corrosion cracking (SCC) of aluminum, iron, and nickel-aluminum superalloys in gaseous and aqueous environments. These materials are used widely in industrial applications and their performance and lifetime are often severely limited by stress corrosion in environments containing oxygen and water. Simulations will be used to extract an atomic-level understanding of the basic mechanisms underlying SCC. The PIs plan to investigate SCC inhibition by ceramic coatings (e.g., alumina and silicon carbide), self-assembled monolayers (e.g., oleic imidazolines), and by microorganisms (e.g., Shewanella oneidensis strain MR-1). The PIs will deliver software tools having broad applicability across scientific disciplines and industry. This award supports annual computational science workshops for undergraduate students and faculty mentors from underrepresented groups. Workshops will be organized to foster close interactions between underrepresented minority graduate students at US institutions and postdoctoral level counterparts from Latin American institutions. Undergraduate students will be involved in the research through summer research experiences; at least half are expected to be from underrepresented groups. The PIs will also assist minority institutions in developing computational science curricula, and mentor early-career faculty from minority institutions and EPSCoR states.This award also supports education. Elements of the PIs' education program include: 1) a unique graduate course jointly taught by USC and Caltech faculty emphasizing hands-on experience in hierarchical multiscale material simulations; 2) a dual-degree program at USC offering graduate students the opportunity to obtain a PhD in the physical sciences or engineering and an MS in computer science with specialization in high performance computing and simulations; and 3) summer research experiences for undergraduate students involving a total immersion course in computational science followed by research in simulation, parallel algorithms and visualization. %%%This award was made on a collaborative proposal submitted to the Division of Materials Research under the Information Technology Research solicitation NSF-04-012. The Division of Materials Research, the Chemistry Division, and the Division of Computing and Communications Foundations fund this award. The other proposals in this multidisciplinary collaborative are 0427177 and 0427540 and involve investigators at Caltech and Purdue. Research activities covered by this award fall under the National Priority Area, "Advances in Science and Engineering," and the Technical Focus Area, "Innovation in Computational Modeling or Simulation in Research." This award supports computational research and algorithm development with the aim of developing new modeling tools for materials failure and with the further aim of applying these tools to advance the understanding of stress corrosion cracking. This award also supports related educational activities some of which involve underrepresented groups.Stress corrosion cracking (SCC) is a complex technological and economic problem involving premature and catastrophic failure of materials due to an insidious combination of mechanical stresses and chemically aggressive environments. Safe and reliable operation of structural systems are endangered by uncertainties in SCC, the reduction of which could have enormous economic impact. The PIs plan to develop computational tools that contain essential physics across a wide range of length and time scales to achieve an atomic-level mechanistic understanding of SCC. Because of the large number of atoms and complex physical and chemical processes, these tools will be able to manage distributed computing resources and focus them on SCC simulation.The PIs plan to use these tools to study SCC of aluminum, iron, and nickel-aluminum superalloys in gaseous and aqueous environments. These materials are used widely in industrial applications and their performance and lifetime are often severely limited by stress corrosion in environments containing oxygen and water. Simulations will be used to understand the basic mechanisms underlying SCC. The PIs plan to investigate how various coatings and microorganisms inhibit SSC.This award also supports education. Elements of the PIs' education program include: 1) a graduate course jointly taught by USC and Caltech faculty emphasizing hands-on experience in hierarchical multiscale material simulations; 2) a dual-degree program at USC offering graduate students the opportunity to obtain a PhD in the physical sciences or engineering and an MS in computer science with specialization in high performance computing and simulations; and 3) summer research experiences for undergraduate students.The PIs will deliver software tools having broad applicability across scientific disciplines and industry. This award supports annual computational science workshops for undergraduate students and faculty mentors from underrepresented groups. Workshops will be organized to foster close interactions between underrepresented minority graduate students at US institutions and postdoctoral level counterparts from Latin American institutions. Undergraduate students from underrepresented groups will be involved in the research. In addition, the PIs will assist minority institutions in developing computational science curricula, and mentor early-career faculty from minority institutions and EPSCoR states. ***