6th World Congress on Integrated Computational Materials Engineering (ICME 2022): Linkage: Structure – Properties - Microstructure
Program Organizers: William Joost; Kester Clarke, Los Alamos National Laboratory; Danielle Cote, Worcester Polytechnic Institute; Javier Llorca, IMDEA Materials Institute & Technical University of Madrid; Heather Murdoch, U.S. Army Research Laboratory; Satyam Sahay, John Deere; Michael Sangid, Purdue University
Monday 1:30 PM
April 25, 2022
Room: Regency Ballroom DE
Location: Hyatt Regency Lake Tahoe
Session Chair: Anton Van der Ven, University of California, Santa Barbara
1:30 PM Invited
ExtremeMat: Towards Microstructure and Composition Sensitive Models for the Creep Deformation of Engineering Steels: Laurent Capolungo1; R. Lebensohn1; A. Kumar1; B. Beets1; A. Chakraborty1; V. Prithivirajan1; M. Gao2; M. Glazoff3; Y. Yamamoto4; M.P. Brady4; 1Los Alamos National Laboratory; 2National Energy Technology Laboratory; 3Idaho National Laboratory; 4Oak Ridge National Laboratory
Structural steels utilized for power generation applications are subjected to particularly complex loading conditions (e.g. stresses, temperatures). Further, with the penetration of renewable into the grid, these are expected to enable flexible operations. A robust knowledge of the evolution of the performance steels, both austenitic and ferritic, with service conditions relies on the degree to which one can establish firm bridges between the microstructure, composition and material performance: such is one of the primary goals of the consortium ExtremeMat. In this presentation, focus will be placed on detailing recent advances made by the consortium in what concerns the development and validation of advance polycrystalline creep models applied to a model engineering austenitic steel: 347H. Among others, leveraging the elastic viscoplastic Fast Fourier Transform polycrystal mechanical solver, a mechanistic constitutive model sensitive to the dislocation content, arrangement, interstitial and substitutional solute content, precipitate content and types will be introduced. In parallel, a detailed analysis of the precipitate formation and evolution processes will be presented and rationalized on the basis of density functional theory simulations. By applying the model against experimental data (i.e. tensile tests, creep tests) gather within the course of this project, the complex role played by solute vs precipitate strengthening processes will be discussed.
2:00 PM
ICME Modeling of Fabrication of U-10%wt Mo Alloys: Ayoub Soulami1; William Frazier1; Kyoo Sil Choi1; Lei Li1; Zhijie Xu1; Yucheng Fu1; Curt Lavender1; Vineet Joshi1; 1Pacific Northwest National Laboratory
Low-enriched uranium alloyed with 10wt% molybdenum (U-10Mo) has been recognized as a promising candidate to replace high-enriched uranium fuel due to its ability to meet the neutron flux demands of U.S. high power research reactors. Manufacturing the U-10Mo alloy involves a complex series of thermomechanical processing steps, including homogenization, hot rolling, annealing, cold rolling, and hot isostatic pressing. As part of these fabrication steps, several models have been developed for the individual processes. The interaction and coupling between individual processes use the concept of ICME which aims to bridge the information passing between interacting models and investigates the impact of manufacturing processes on material microstructure evolution. Additionally, sensitivity and data analysis was performed to analyze the influence of the models’ input parameters on the resultant microstructure. It is shown that the implementation of ICME leads to improved predictions, better understanding of microstructure across multiple processes, and more cost-effective development effort.
2:20 PM
Full-Field Homogenization Including Non-Local Regularization of Ductile Fracture in Heterogeneous Materials by Means of FFT: Mira Toth1; Laurent Adam1; Javier Escudero1; 1e-Xstream engineering
Material engineering relying on homogenization techniques is for several years finding its way toward industrial applications. The rise of computational power, parallelization methods, GPU programming and solvers like FFT/spectral solvers ease the daily usage of full-field homogenization over larger and more representative RVE (i.e. Representative Volume Element). It also enables multi-scale ICME methodologies allowing to bridge process to structural engineering account for material internal structure [1]. In recent years, numerous non-local extensions of ductile fracture have been proposed to suppress the pathological mesh dependence caused by the localization in an element band after the loss of ellipticity. Among them, the implicit gradient regularization introduces some inelastic non-local fields that enter in the constitutive definition of the damage variable. By doing so, the overall formulation results in a coupled problem of mechanics and auxiliary equations of Helmholtz type. In this contribution two models have been used as basis, a model based on Lemaitre´s ductile damage and another one based on Gurson´s model. The models have been extended to a non-local formulation using an implicit approach [2] and implemented using an efficient FFT homogenization framework [3] where the solution of the coupled damage/mechanical problem is calculated exploiting an iterative staggered scheme. The resulting approach is able to simulate the damage evolution in very complex three-dimensional representative volume elements including millions of d.o.f. Several representative numerical examples have been carried out in order study ductile fracture of periodic heterogeneous solids. The effect of voids and rigid inclusions on the microscopic damage evolution in the solid matrix has been analyzed. Moreover, the average stress/stress response is studied for different sizes of the heterogeneities, showing a prominent size-effect in the overall mechanical behavior. The examples to be shown will be generated combining IMDEA internal software as well as Digimat.