the mechanical and photoelastic properties of 3d printable stress-visualized materials

Three-dimensional (3D)
The printing technology that integrates freeze stress technology creates a new way to directly represent and characterize the 3D in-house continuity and integrity
Site stress caused by mining
Or building-
Related disturbance of buried deep rock bodies.
However, concerns were raised about the similarity between the mechanical properties of the printing model and its prototype rock blocks.
It is critical to ensure that the mechanical properties of printable materials are as close to the real rock quality as possible.
In this work, a transparent, light, photosensitive polymer material for freezing stress testing was studied.
Determine the chemical composition of the material by integrating the results of the infrared spectrum (Infrared spectrum, X-
Ray diffraction (XRD)
, Pyrolysis, gas chromatography and mass spectrometry (PY-GC/MS).
Measures to improve the mechanical properties of printable materials, including printing direction, rear
Processing and temperature control were evaluated by comparing the treated material with its prototype rock.
Optical stress sensitivity of the material, including stress-
Visual properties and stress-
Freezing performance was also tested.
This study provides an understanding of how to modify printable materials in order to better simulate real rock not only from geological geometry, but also from mechanical properties.
Mining and construction activities on deeply buried rocks may result in large deformation and geological disturbance of surrounding rocks
Causing serious geological disasters.
Accurate Description of complex strata structures and stress fields is essential for optimizing the energy and other resources stored in the deep underground of mining, as well as effective early warning, to prevent and control the rock disasters caused by such mining.
However, the intangible and intangible properties and complex structures of the rock matrix and various geological bodies make it extremely difficult to directly display complex formation structures and physical extraction stress fields.
These problems have become the bottleneck of traditional detection methods and theoretical analysis, which are used to characterize the 3D discontinuous and full-stress fields of rock mass.
The 3D printing technology combined with freezing stress technology provides a new and promising method for the physical display of complex underground structures and the detection of formation stress fields.
3D printing is widely used in making complex 3D solid objects of various shapes.
In solving some rock mechanics problems, it has proved its great potential.
However, the work of these reports cannot physically directly demonstrate the stress field and its evolution within the medium, which is a key factor in solving the related rock mechanics problems.
The advanced commercial 3D printer Objet connecx series, using PolyJet 3D printing technology, has the unique printing capability of the highest number of different materials reported so far.
VeroClear is one of the printable materials available for Objet 3D printers.
It is transparent and has favorable pressure.
Optical sensitivity.
This material has been successfully used to make physical models representing natural rocks.
The ultimate goal of our study is to provide the applicability of 3D printing and photoelasticity techniques to quantitatively visualize and characterize the stress fields of actual rocks with non-uniform structures.
A preliminary study was conducted and attention was drawn.
However, there is a certain mismatch between the printed model and its prototype rock.
Due to the inherent nature of these materials, this mismatch is related to mechanical and deformation properties.
In order to ensure that the deep rock of the physical and mechanical response can accurately reflect the 3D-
Printing geological models, improving the similarity between the printing model and the physical and mechanical properties of the real underground rock is of vital significance.
However, due to the different deposition and molding processes of natural reservoir rocks, their internal structure and physical and mechanical properties vary greatly, which brings great difficulties to the development of transparent 3D printing materials, optical stress sensitive with the same or similar mechanical properties as natural rocks.
Printing the same model as real rock samples in terms of mechanical properties remains a major challenge.
Raw materials and manufacturing processes may have a great impact on the mechanical response of objects constructed by 3D printing, and due to the stacking of printing models, the mechanical properties of the printing model will introduce a certain degree of heterogeneitylayer nature.
Most published results indicate that the mechanical properties of the parts manufactured by the bunches depend on UV (UV)
Exposure time and building orientation.
On the other hand, after
Treatment using heat is widely used to change the physical and chemical properties of the material and can sometimes be used to achieve specific desired results, such as hardening or softening of the material.
There is a consensus in the literature that, in general, heat treatment can improve the mechanical properties of cured composites.
Heat treatment helps to reduce the processing stress generated during resin polymerization and finishing. Moreover, post-
Curing heating of resin materials can reduce the content of unreactive monomer after initial illumination
Curing stage, helps to improve stability and reduce UV exposure time
The relevant properties of the materials used.
Some studies have looked at the mechanical properties of printed materials used in PolyJet 3D printers, including fill patterns, building directions, layer thickness, heat treatment, etc. .
However, most of the printed materials investigated are opaque and non-transparentstress-visible (i. e.
Do not let the pressure visible).
Due to different printing materials resulting in different physical and mechanical properties, previous test results cannot be used directly to characterize the performance of VeroClear.
There are very few published results after the investigation.
Effect of heat treatment on mechanical properties of UV curing 3D printing materials.
In addition, so far, few studies have been made to analyze the chemical composition of this printed material and characterize its properties.
The main purpose of this study is to introduce a transparent photoelastic printable material, to study and modify its physical and mechanical properties, and to improve its strength and stiffness similarity to natural rocks.
First, determine its main chemical composition.
Subsequently, the impact of building orientation and heat
Effect of treatment temperature on 3D-Mechanical properties
The printed samples were evaluated, including single-axis compression strength, direct tensile strength, and three-axis compression strength.
Finally, its unique pressure
The visualization performance is studied.
This study is expected to provide a reference for further modification of printed materials that can accurately simulate natural rocks in terms of geometry and mechanical properties.
In addition, this study also aims to provide a way to reveal the engineering-
Related geological disasters.