Dynamic Behavior of Materials IX: On-Demand Poster Session
Sponsored by: TMS Structural Materials Division, TMS: Mechanical Behavior of Materials Committee
Program Organizers: Eric Brown, Los Alamos National Laboratory; Saryu Fensin, Los Alamos National Laboratory; George Gray, Los Alamos National Laboratory; Marc Meyers, University of California, San Diego; Neil Bourne, University of Manchester; Avinash Dongare, University of Connecticut; Benjamin Morrow, Los Alamos National Laboratory; Cyril Williams, US Army Research Laboratory
Monday 8:00 AM
March 14, 2022
Room: Mechanics & Structural Reliability
Location: On-Demand Poster Hall
Machine Learning Based Approach to Modeling and Predicting Material Behavior and Failure Criteria in Composites: Tyler Dillard1; Nolan Lewis1; Abhijeet Dhiman1; Vikas Tomar1; 1Purdue University
The complex inhomogeneous nature of composites raises particularly difficult challenges when trying to understand, model, and predict the material behavior of composites under load. This work aims to prove the viability and potential benefits of machine learning and other data science-based approaches when predicting material behavior and failure criteria in composites. Composite samples with different microstructures were simulated to indentify different failure scenarios under tensile loading. These failure scenarios serve as a high-fidelity data to train machine learning model. After multiple regression techniques were utilized to trim the data, the data was then fed to a multi-fidelity neural network with machine learning in order to produce crack propagation and failure scenario predictions. These predictions are then compared to the corresponding low fidelity, high fidelity, and mixed fidelity FEM simulation data.
Mesoscale Modeling of Deformation Behavior of Fe-based Microstructure under Shock Loading Conditions: Ke Ma1; Avanish Mishra1; Avinash Dongare1; 1University of Connecticut
A novel mesoscale modeling method, Quasi-Coarse-Grained Dynamics (QCGD) is utilized to model the shock deformation behavior of single-crystal and poly-crystal iron microstructures. The QCGD method expands the capability of molecular dynamics (MD) simulations to mesoscale by reducing the number of simulated atoms with scaled interatomic potential. MD and QCGD simulations are carried out to investigate the phase transformation (pressure-induced bcc-to-hcp transition), and reverse transition led deformation twinning behavior in Fe microstructures at various shock loading conditions. The rotation matrix and angle/axis pair are utilized to characterize the deformation twinning and grain recrystallization behavior during various stages of shock loading. MD and QCGD simulations reveal that Fe oriented along [110] direction is prone to twin with the arrival of the release wave compared to other loading orientations. The role of loading conditions and microstructural configuration on the phase transformation and twinning/de-twinning behavior in Fe under shock loading conditions will be discussed.
Modeling of Laser Interactions with Metals Using a Hybrid Atomistic-continuum Approach: Ching Chen1; Sergey Galitskiy1; Avanish Mishra1; Avinash Dongare1; 1University Of Connecticut
The modeling of interaction of metallic materials with lasers requires an accurate description of laser energy absorption, heat generation/transfer, and energy dissipation that can result in ablation, spallation, melting and shock compression. Such a capability is available through a hybrid atomistic-continuum method that combines classical molecular dynamics (MD) with the two-temperature model (TTM) to model the ultra-fast heating, melting, and shock generation in metals. The MD-TTM framework is extended to FCC Al and BCC Ta systems, wherein the electronic-temperature-dependent electron heat capacity, electron thermal conductivity, and electron-phonon coupling factor are parameterized via first principles simulations. The capability is demonstrated by investigating the spall failure behaviors of Al and Ta single-crystal systems under femtosecond laser shock loading. The talk will discuss the details of MD-TTM simulations, including the implementation of the framework, the parameterization of the TTM, and the interaction of lasers with microstructure of Al and Ta systems.
Bulk Crystallographic Texture and Dynamic Elastic Modulus Variation in Laser Additively Manufactured Ti6Al4V: Mangesh Pantawane1; Teng Yang1; Yuqi Jin1; Sameehan Joshi1; Sriswaroop Dasari1; Abhishek Sharma1; Arkadii Krokhin1; Srivilliputhur Srinivasan1; Rajarshi Banerjee1; Arup Neogi1; Narendra Dahotre1; 1University of North Texas
Recently developed effective bulk modulus elastography (EBME) technique was employed on laser powder bed fusion fabricated and wrought Ti6Al4V samples. The corresponding dynamic elastic constants were compared and evaluated with respect to the static elastic constants measured using the nanoindentation technique. The EBME technique produced maps of elastic constants from the scanned region, with an improved spatial resolution with increased ultrasound frequency. The dynamic elastic constants were (5-8 %) lower than the static elastic constants for both additively manufactured and wrought Ti6Al4V. In addition, the EBME technique coupled with shear wave velocity measurement inside the material identified the bulk crystallographic texture response, wherein significant attenuation of shear wave velocity occurred at 45o and 90o orientations of shear wave plane with respect to the build plane of the printed Ti6Al4V. In contrast, wrought Ti6Al4V reflected an isotropic response.
Design of Metals and Alloys with High Spall Strengths: Keara Frawley1; Harikrishna Sahu1; Naresh Thadhani1; Rampi Ramprasad1; 1Georgia Institute of Technology
Dynamic tensile failure, or spall failure, is an important property for understanding a materials’ response to high-strain-rate deformation and shock-wave compression. Spall strength measurements have been performed on many metals and alloys, however, the physical properties that influence the spall strengths of this broad category of materials are not well understood. The measured spall strengths for metals and alloys have been obtained from literature and tabulated for examination through data analytic techniques. The spall strength values have been correlated to other, more easily accessible properties that are expected to control spall behavior, such as yield and tensile strengths, elastic moduli, and other physical material properties – referred to in this work as “proxy properties.” These proxy properties have been used to establish design guidelines that can predictively classify a metal’s spall strength as high or low.
DynamicTensile Testing of Cu/Ta Multilayered Metal Composites: Liya Semenchenko1; Lauren Poole2; Francis Zok2; Michael Demkowicz1; 1Texas A&M University; 2University of California Santa Barbara
We conduct dynamic uniaxial tensile testing of multilayered Cu/Ta composites via split Hopkinson pressure bar (SHPB). Samples of varying stacking sequence and layer thickness are investigated, presenting an opportunity to explore the synchronous effect of interfaces and phase distribution on high strain rate mechanical response. Moreover, we examine the influence of layer discontinuities on plastic flow and ultimate failure mechanisms in these materials. Our work offers new insights into the effect of multiphase microstructure on the high strain rate behavior of metal composites.
Microscale Spall Strength Measurement for CoCrFeMnNi High Entropy Alloy: Abhijeet Dhiman1; Leonardo Facchini1; Andrew Kustas2; Remi Dingreville2; Vikas Tomar1; 1Purdue University; 2Sandia National Laboratories
In this talk, we will discuss spall-strength measurements and spall-failure mechanisms in equiatomic CoCrFeMnNi high entropy alloy (HEA). We will first describe the method of fabrication based on additive manufacturing using selective laser sintering. We will then discuss our spall-strength measurement procedure which consists of laser-based flyer-plate impact experiments to induce shock pressures up to 5 GPa using asymmetric impact. We estimated the maximum tensile stress during spalling through measurements of velocity pullback using photon Doppler velocimetry. Based on our experimental measurements and fractography analysis of spall planes, we will discuss what can be learnt on the spall-failure mechanisms in these alloys and their implications of using such a class of alloys to operate in extreme environments. SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525
Amorphization Mechanism under Shock Loading in the Medium Entropy Alloy CoCrNi: Wu-Rong Jian1; Shuozhi Xu1; Irene Beyerlein1; 1University of California, Santa Barbara
The medium entropy alloy CoCrNi has been shown to exhibit an exceptional performance under quasi-static loading, e.g., a combination of high strength and good ductility. By using molecular dynamics simulations, we further investigate its dynamic properties under high-speed shock loading in a configuration with completely random atomic distribution. For comparison, we repeat shock loading along two crystallographic orientations, i.e., <111> and <110>. Compared to the <110> direction, the <111> direction behaves more shock-resistant and generates smaller amounts of dislocations and twinning at the same shock velocity. For both loading directions, we find that the deformation mode changes from dislocation slip and twinning to amorphization with the increase in the shock velocity. When amorphization occurs, the effect of shock loading direction on shock-induced structural evolution disappears, since the sample behind the shock wave front enters the hydrostatic compressive state quickly