Application of 3D Printing Technology in the Mechanical Testing of Complex Structural Rock Masses

Abstract

In the engineering of underground construction, the discontinuous structures in rock mass have important influences on the mechanical behaviors of the subsurface of rock mass. The acquisition of mechanical parameters is the basis of rock mass engineering design, construction, safety, and stability evaluation. However, the mechanical parameters and failure characteristics of the same rock mass under different mechanical conditions cannot be obtained due to the limitations of specimen preparation techniques. In recent years, with the continuous development of 3D printing (3DP) technology, it has been successfully applied to the repetitive preparation of rock mass samples. The combinations of 3DP and other techniques, such as 3D scanning and CT scanning, provided a new approach to study the mechanical behavior of complex structural rock masses. In this study, through a comprehensive review of the technical progress, equipment situation, application fields, and challenges of the use of 3DP technology, the following conclusions were obtained: (1) 3DP technology has advantages over traditional rock mass specimen preparation techniques, and the verification of test results using 3D printed samples shows that the 3DP has broad application prospects in geotechnical engineering. (2) The combination of 3DP and other advanced techniques can be used to achieve the accurate reconstruction of complex structural rock masses and to obtain the mechanical and failure characteristics of the same rock mass structure under different mechanical boundary conditions. (3) The development of 3DP materials with high strength, high brittleness, and low ductility has become the major bottleneck in the application of 3DP in geotechnical engineering. (4) 3D printers need to meet the high precision and large size requirements while also having high strength and long-term printing ability. The development of 3D printers that can print different types of materials is also an important aspect of the application of 3DP in geotechnical engineering.

Evaluating the Accuracy of Bonded Block Models for Prediction of Rockmass Analog Mechanical Behavior

“…Additionally, their study was relatively unique in that the analog specimens prepared were composed of real rock. This is in contrast to most other laboratory-scale rockmass analog studies using non-rock materials like plaster and gypsum [ 8 , 9 , 51 , 52 ], which tend to exhibit less brittle damage mechanisms than real rock [ 51 , 53 ].…”

A mathematical Theory of Elasticity for Photoelastic Experimental Hybrid Method

“…It is now noted that the plane problem of the classical theory of elasticity is reduced to determining a stress function F(x,y) throughout the component or structure such that equation (10) and the boundary conditions of equation ( 4) are satisfied. Equation (10) can now be integrated by writing it symbolically (using the ∆ operator) as in equation (11).…”

“…Modern manufacturing technologies such as rapid prototyping (3-D printing) and digital photoelasticity have made photoelasticity an attractive tool for stress analysis compared to other methods. The application of 3D-printed photoelastic models has made it possible to manufacture complex structures [8][9][10][11]. Although photoelasticity is steadily being incorporated into the engineering design process, the understanding of the mathematical theory of elasticity for photoelasticity is critical because it makes extraction of the stress components from a loaded structure possible.…”

Real-Size Reconstruction of Porous Media Using the Example of Fused Filament Fabrication 3D-Printed Rock Analogues

“…provides an opportunity to reconstruct the complex internal structure of rock void space for its subsequent experimental study. The additive manufacturing of synthetic core specimens often presents with a number of problems related to the clogging of specimen pores with expendable material, inconsistency between petrophysical and mechanical properties of specimens, physical and chemical properties of expendable materials, and rock properties [1][2][3][4][5]. The reasons for a mismatch between the internal structure of synthetic specimens and their originals lie in the accuracy of tomography scanners and the resolution of CT images, errors in the conversion of CT images into digital models, peculiarities of different 3D printing technologies (resolution of 3D printers, etc.…”