Application of sub-miniaturized bending tests to extract tensile properties from neutron-irradiated metallic alloys

In this work, we demonstrate the applicability of sub-miniaturized three-point bending (3PB) testing for the extraction of tensile plastic properties of metallic materials, such as yield stress and work hardening rate. The approach is developed and validated on the example of tungsten. For this, dedicated finite ele-ment method (FEM) simulations are performed to reveal the correlation between the flexural stress-strain response in 3PB tests and yield stress in tensile tests. Furthermore, a dedicated inverse FEM procedure utilizing rate-sensitive isotropic physical model is developed to extract both yield stress and work hard-ening rate from the available set of bending tests. Both FEM-based approaches are first benchmarked on unirradiated materials and then validated using neutron-irradiated tungsten grades. The accuracy of the tensile properties extracted using both methods is discussed along with the estimation of a number of 3PB tests required to reach a target precision. The applicability of 3PB geometry for the extraction of ten-sile properties from unirradiated bending tests below ductile-to-brittle transition temperature (DBTT) is also addressed. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

This study demonstrates the applicability of sub-miniaturized three-point bending testing for extracting tensile plastic properties of metallic materials, such as yield stress and work hardening rate. Finite element method simulations were used to validate the correlation between flexural stress-strain response in 3PB tests and yield stress in tensile tests, as well as to develop an inverse FEM procedure to extract yield stress and work hardening rate. The accuracy of the extracted tensile properties using both methods was discussed, along with the estimation of the number of 3PB tests required to reach a target precision.