Crack growth and deformation monitoring in additively manufactured pipe ring specimens using contactless measurement

In engineering practice, the integration of additively manufactured parts is becoming common. These parts serve both as temporary functional components within larger assemblies and, increasingly, as permanent replacement parts that effectively replace original parts. Evaluating the fracture resistance of these models is essential because of their frequent interaction with other assembly parts or exposure to external loading, which could compromise their structural integrity. In this work, a new geometry of specimens for fracture examination of pipeline materials is performed on additively manufactured sample. The tests were carried out on pipe ring tensile specimens using a Shimadzu AGS-X universal testing machine (100 kN) and a specially designed tool for cylindrical specimens, in correlation with Aramis 2M Digital Image Correlation System (DIC). The specimens were produced on a EOS Formiga P100 printer from polyamide polymer (PA12) with 100 % infill. A stress concentrator (sharp notch) is fabricated along the longitudinal direction being exposed to forces which act in the hoop direction, mimicking the internal pressure in the pipeline. DIC was used to measure the crack opening displacement (CMOD), crack tip opening displacement (CTOD), crack length (Δa) and, in general, displacement and strain fields. It is concluded that adequate and reproducible results have been obtained by using this technique.