Full-Field Strain Measurement and Numerical Analysis of a Microalloyed Steel Subjected to Deformation with Strain Path Change.

Paulina Lisiecka-Graca,Janusz Majta,Krzysztof Muszka

doi:10.3390/ma13235543

Abstract

This study presents an effective technique for taking advantage of the full-field measurement method of Digital Image Correlation (DIC) for the assessment of the strain distribution during the metal forming process when the strain path change was performed. The applied methodology is based on the combination of a numerical simulation for the stress calculation and full-field surface strain measurement in a forward/reverse three-point bending test. In the numerical part, the Chaboche model and dislocation density-based model were selected and verified in terms of the prediction of a softening/hardening effect occurring during strain reversal. The Chaboche model parameters identification procedure, on the basis of a cyclic torsion test, combined with inverse analysis, was also described. The results of the study showed the advantages and disadvantages of both of the analyzed work hardening models. The obtained results were analyzed in the light of the deformation inhomogeneity and reorganization of the dislocation structure during the cyclic deformation test.

Highlights

During metal forming processes, the material undergoes a complex path of deformation that often involves the high level of deformation, and microstructural inhomogeneity, which makes the prediction of material behavior especially difficult [1,2,3]
Two-dimensional Digital Image Correlation (DIC) analysis was applied as a verification tool for the numerical simulation
The solutions based on the dislocation density-based model gave better convergence than the Chaboche model

Summary

Introduction

During metal forming processes, the material undergoes a complex path of deformation that often involves the high level of deformation, and microstructural inhomogeneity, which makes the prediction of material behavior especially difficult [1,2,3]. One of the most important phenomena in such processes is the Bauschinger effect, which is a measure of the resistance of a material to strain reversal [4,5,6,7]. In order to determine the local accumulation of the deformation energy, the measurements of displacements and the resulting strains were used in the analysis of the mechanical properties assessment.

Objectives

Methods

Discussion

Conclusion