Haim Waisman: Then and Now / 2012 Early Caree

WHAT DID THE 2012 EARLY CAREER AWARD ALLOW YOU TO DO?

My Department of Energy (DOE) Early Career Research Award allowed me to develop innovative computational models in the field of mechanics of materials. Specifically, I focused on fracture phenomena. These models have led to important contributions in the modeling of metal plasticity and ductile fracture. Additionally, we developed high performance enabling technologies that are specifically suited for fracturing solids.

For example, most of the work reported in the literature assumes adiabatic conditions (ie, neglecting the effects of thermal diffusion) when modeling high speed impact into metals. However, our work demonstrates the opposite — that thermal diffusion should not be neglected as it is necessary for capturing important physics. Thermal diffusion also leads to more stable numerical models.

Furthermore, we proposed a single unified model that allowed us to capture more complex behavior of metals under extreme conditions. That is, the same model can reliably predict the response of the material when subjected to either low- or high-speed impact.

The knowledge I gained from the DOE project also allowed me to further expand my research. My team has studied other important applications where fracture plays a critical role. One example is polar ice breaking due to climate warming. Another example is infrastructure aging and deterioration. A better understanding of fracture processes would also help with energy extraction from geological materials and with biological materials such as bones. We also studied how to optimally design structures that will be more resilient.

I am very grateful to DOE for supporting my research. I was able to build a strong research group, push the science envelope in new directions, and gain worldwide recognition. I am also proud for graduating outstanding students and postdocs that are now staff members at national labs, professors in academia, and research engineers in industry.

ABOUT:

Haim Waisman is an associate professor in the Civil Engineering and Engineering Mechanics Department at Columbia University.

SUPPORTING THE DOE SC MISSION:

The Early Career Research Program provides financial support that is foundational to early career investigators, enabling them to define and direct independent research in areas important to DOE missions. The development of outstanding scientists and research leaders is of paramount importance to the Department of Energy Office of Science. By investing in the next generation of researchers, the Office of Science champions lifelong careers in discovery science.

For more information, please go to the Early Career Research Program.

THE 2012 PROJECT ABSTRACT:

Title – Regularized Finite Element Formulations for Shear Band Instabilities in Metals

Abstracts

This project aims for an improved understanding of material instabilities in the development of advanced materials. A striking manifestation of instability in solids is the existence of shear bands, the localization of shear strain into narrow bands during high‐speed deformation of metals such as those that occur in impact or blasts. Shear bands are indicators of irreversible damage that eventually cause fracture.

New multiscale algorithms will be developed for enabling realistic, physics-based predictive models of materials fracture using high-performance computers. By understanding the true mechanisms that drive materials fracture, this research could aid in tackling important issues such as the creation of more durable “green” materials; geologic sequestration of contaminants such as carbon dioxide in the fractured seabed; fracture of ice sheets in polar regions and their effect on global climate change; and the design of infrastructure that is resilient to natural disasters and man‐made hazards.

RESOURCES:

C McAuliffe and H Waisman, “A unified model for metal failure capturing shear banding and fracture.” International Journal of Plasticity, 65131 (2015). [DOI: 10.1016/j.ijplas.2014.08.016]

M Arriaga and H Waisman, “Combined stability analysis of phase-field dynamic fracture and shear band localization.” International Journal of Plasticity, 96, 81 (2017). [DOI: 10.1016/j.ijplas.2017.04.018]

C McAuliffe and H Waisman, “Mesh insensitive formulation for initiation and growth of shear bands using mixed finite elements.” computational mechanics, 51 (5), pp. 807-823, 2013. [DOI: 10.1007/s00466-012-0765-z]

Additional profiles of the Early Career Research Program award recipients can be found at /science/listings/early-career-program.

The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit the Office of Science website.

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