Woodruff School of Mechanical Engineering

COE/Structural Mechanics Seminar


Framework for Multi-Phase Material Modeling using Stabilized Interface and Crystal Plasticity Finite Element Methods


Dr. Timothy Truster


University of Tennessee, Knoxville


Thursday, September 9, 2021 at 2:00:00 PM   Add to Calendar


Virtual Building, Room https://bluejeans.com/427293159/3702


Dr. David McDowell


Dr. Truster is an associate professor in the Department of Civil and Environmental Engineering at the University of Tennessee. He earned his PhD in Civil Engineering with a concentration in structures from the University of Illinois at Urbana-Champaign in 2013. His teaching interests include finite element modeling, nonlinear finite element methods, and structural analysis. Truster's current research interests include computational interface mechanics, process modeling of titanium alloys, creep modeling in natural and engineered materials, stabilized finite element methods, and high-performance computing. He was the recipient of a National Science Foundation CAREER grant in 2018 on the topic Predictive Fatigue Behavior of Structural Materials Through Computationally-Informed Textural and Microstructural Influences.


As computational resources have continued to expand, the drive for developing computational methods with higher fidelity for complex material modeling problems has continued to increase. A persistent challenge in computational multi-phase modeling is the robust treatment of non-smooth features or interfaces, such as grain boundaries in metals, interphases between constituents in composite materials, lubricated and bolted joints in structural systems, etc. Across these diverse applications, the major bottleneck revolves around imposing kinematic conditions upon discontinuous discrete functions in a mathematically consistent fashion. These interface challenges are often enhanced due to the nonlinearity in the bulk materials, such as high temperature crystal plasticity. This talk explores our efforts on deriving and advancing a stable computational framework for modeling solid mechanics problems with a range of interface kinematics. The framework serves as a robust platform for predictive modeling of mechanical and material systems containing interfaces due to the underlying philosophy of the variational multiscale method; two applications are the frictional dissipation in bolted mechanical joints and the debonding of fibrous composites. Also, our computational efforts have borne fruit through collaborations with materials characterization groups to elucidate material mechanisms through physics-based crystal plasticity modeling. One area of interest is the creep behavior of Grade 91 ferritic/martensitic steel, particularly to extrapolate behavior from short-life/high-stress experiments to operating regimes. Our second area of interest is the modeling of microstructure and texture evolution during alpha-beta processing of titanium alloy Ti6242S to improve dwell fatigue resistance. Time-permitting, contributions related to uncertainty quantification, plasticity in natural and artificial halite, and open-source software will be highlighted.