The mechanical and photoelastic properties of 3D printable stress-visualized materials

Abstract

Three-dimensional (3D) printing technology integrating frozen stress techniques has created a novel way to directly represent and characterize 3D interior discontinuities and the full-field stress induced by mining- or construction-related disturbances of deeply buried rock masses. However, concerns have been raised about the similitude between the mechanical behaviours of the printed model and its prototype rock mass. Ensuring the mechanical properties of the printable materials are as close as possible to those of real rock mass is of critical significance. In this work, a transparent, light, photosensitive polymer material was investigated for applications in frozen stress tests. The chemical composition of the material was determined by integrating the results of infrared spectroscopy (IR spectroscopy), X-ray diffraction (XRD), pyrolysis, gas chromatography and mass spectrometry (PY-GC/MS). Measures to improve the mechanical properties of the printable material, including printing orientation, post-processing, and temperature control, were evaluated by comparing the treated material with its prototype rock. The optical stress sensitivity of the material, including stress-visualized properties and stress-frozen performance, was also tested. This study offers an understanding of how printable materials should be modified to better simulate real rock masses, in terms of not only their geological geometry but also their mechanical performance.

Soil pore system evaluated from gas measurements and CT images: A conceptual study using artificial, natural and 3D‐printed soil cores

“…Nowadays, with 3D printing one can replicate the diversified geometry encountered in a soil at a resolution of few micrometres. However, only a few studies have shown the potential of using 3D prints to better understand physical, mechanical or biological processes in soils (Dal Ferro & Morari, 2015; Otten et al, 2012; Ozelim & Cavalcante, 2019; Wang et al, 2017). X‐ray CT imaging of 3D printed structures using different printing techniques revealed imperfections, such as clogging of parts of the pore space by printing material residues or printing‐aid material, which would introduce artefacts into the physical functioning (Bacher, Schwen, & Koestel, 2015; Dal Ferro & Morari, 2015; Watson et al, 2019).…”

Quantification of Hidden Whole‐Field Stress Inside Porous Geomaterials Via Three‐Dimensional Printing and Photoelastic Testing Methods

“…The strength and elastic modulus are lower than those of the natural Berea sandstone under frozen‐stress temperature, which is a significant challenge for the study of rock mechanics using 3‐D printing techniques. Though some progress has been made to narrow the gap (Wang et al, ), further improvement is still needed. Considering the aim of this study, we intend to discuss this issue in our follow‐up study.…”

Future-Oriented Experimental Characterization of 3D Printed and Conventional Elastomers Based on Their Swelling Behavior

“…The characteristic bands of aliphatic C-H asymmetric and symmetric stretching are in the range from 2956 to 2873 cm −1 . This indicates that the Tango+ material used in this study is a polyurethane acrylate [13,15].…”