Digital Image Correlation and its Application for Accelerated Testing of Specimens Manufactured by 3D Printing

Abstract

My thesis is focused on the experimental study of the specimens manufactured by 3D printing using Digital Image Correlation and its application for accelerating testing. The Finite Element Method is applied to validate the proposed approach in particular cases. This study contains two separate parts, accelerated testing for stress-strain behaviour investigation of 3D printed Stainless Steel 316L and for creep analysis of ONYX material of Markforged company. All tests on both parts were performed under room temperature on the LabControl 100kN/1000Nm hydraulic testing machine in the VSB-Technical University of Ostrava. This contribution provides a new approach for determining more data from fatigue tests and creep tests based on the application of Digital Image Correlation. The full-field strain analysis brings with it the possibility of measuring the 3D strain and strain accumulation on a curved part of the specimen that is currently used under axial-torsional load. The resulting strain response curves and cyclic creep curves can then be used to verify and precise model predictions for the future research in cyclic plasticity domain. A new specimen geometry has also been developed for accelerated creep testing. The new approach saves amounts of material and results in a shorter experimental time.