Session: MF-06-01 Materials and Technologies for Nuclear Power Plants-1

Paper Number: 123063

123063 - Strain-Rate-Dependent Parameters of Lithium as a Plasma Facing Material for Magnetized Target Fusion Application 

Lithium can be used as a plasma facing material due to its low atomic mass. Compressed liners made of lithium are used as a flux conserver for Magnetized Target Fusion (MTF) application. Lithium has been extensively examined in the literature aiming at its mechanical properties for its various applications, and yet the knowledge about its mechanical properties is insufficient for the MTF application in two aspects. First, most of the available studies focus on the quasi-static loading cases. Second, the tests in those studies were commonly performed via uniaxial tensile test where the stress state was not representative for the compression loading scenario.

 

In this paper, we present an approach to estimate parameters that govern lithium’s behavior at high strain rates up to 500 s-1. In our approach, a series of drop-hammer experiments were combined with ANSYS LS-DYNA simulation to determine the material parameters. The bi-linear strain hardening model and Johnson-Cook material model were considered in our studies where the former one accounts for the plastic stress-strain relationship and the latter one describes the plastic stress-strain relationship with the strain-rate effects. In our drop-hammer experiments, we use high-speed camera imaging and a feature tracking algorithm to record the velocity and extract the hammer impact time. A bi-linear strain hardening model was initially used to estimate plastic behavior of lithium. The strain-rate dependent material parameters were then determined using a reverse engineering approach with the help of numerical simulations that reproduce the tests. A series of numerical simulations with different combinations of material parameters were computed to establish the combination of material parameters that best fit the test results.

 

The proposed material model will be used in the lithium compression experiments for MTF applications, which accounts for the hardening behavior at different strain rates

Presenting Author: Yu Miao General Fusion

Presenting Author Biography: Dr. Yu Miao, a dedicated Stress Engineer with a Ph.D. and P.Eng credentials, has amassed over a decade of expertise in structural analysis and finite element modeling, consistently delivering innovative solutions to complex engineering challenges. Currently, Yu Miao is a Stress Engineer at General Fusion in Vancouver, British Columbia, where they play a pivotal role in ensuring the structural integrity of a major nuclear fusion reactor. Their responsibilities encompass comprehensive FE dynamic analysis, material characterization, and fluid-structural interaction simulations. They also excel in automating tasks through Python scripting, liaising with mechanical engineers and CFD experts, and coordinating material requisitions.
Before their role at General Fusion, Yu Miao worked as a Stress Engineer at Wood, where they excelled in large bore buried pipeline stress analysis, leveraging their expertise in ABAQUS and Python. Their contributions were integral to major pipeline projects like Coastal Gaslink, Keystone, and Pioneer Pipeline. Additionally, they have a wealth of experience from their tenure at Lanmark Engineering, where they focused on piping and vessel stress analysis, non-linear stress assessments, and interdisciplinary collaboration.
Their academic journey includes a Ph.D. and EIT experience at the University of Saskatchewan, where they made significant contributions to nano-scale strain sensors and published research in prestigious journals. With a proven track record of successfully completing numerous projects and a deep skill set in stress analysis, finite element modeling, and programming, Yu Miao is a respected professional in the engineering field, consistently pushing the boundaries of structural analysis and contributing to the advancement of technology and safety in the industry.

Authors:

Yu Miao General Fusion
Michael Sexsmith General Fusion
Soegiarto Hartono General Fusion
Claire Preston General Fusion
Benjamin Tsai General Fusion
Jean-Sebastien Dick General Fusion Inc.
Nick Sirmas General Fusion