Three dimensional image correlation from X-Ray computed tomography of solid foam

TL;DR

This paper introduces a global method to estimate 3D displacement fields from X-Ray CT images of solid foam, using finite element shape functions, demonstrated on a compression test of polypropylene foam.

Contribution

It presents a novel global approach for 3D displacement estimation from XCMT images, focusing on continuous displacement fields with finite element basis functions.

Findings

Stable displacement field measurements across various voxel sizes

Effective application to polypropylene foam compression test

Advances in 3D image correlation techniques

Abstract

A new methodology is proposed to estimate 3D displacement fields from pairs of images obtained from X-Ray Computed Micro Tomography (XCMT). Contrary to local approaches, a global approach is followed herein that evaluates {\em continuous} displacement fields. Although any displacement basis could be considered, the procedure is specialized to finite element shape functions. The method is illustrated with the analysis of a compression test on a polypropylene solid foam (independently studied in a companion paper). A good stability of the measured displacement field is obtained for cubic element sizes ranging from 16 voxels to 6 voxels.