Coal rock three-dimensional strain field visual system and method under complex geological structure

A coal rock three-dimensional strain field visual method under a complex geological structure adopting a coal rock three-dimensional strain field visual system, comprising the following steps:

• 1) heating and melting a transparent base material to uniformly mix with ink microcapsules to prepare a 3D printing wire;
• 2) performing geological structure 3D printing in a model placing cavity of a stress condition simulation system to obtain a strain visual similar model;
• 3) utilizing the stress condition simulation system to simulate a stratum dip angle, a geological structure and a gas-containing situation;
• 4) after the model is cooled, applying a three-dimensional stress to the model, wherein the ink microcapsules are broken under the stress to dye surrounding materials and cracks;
• 5) utilizing a multi-angle high-speed camera to record a cracking and dyeing condition of the ink microcapsules inside the model;
• and
• 6) tracing a displacement of ink dots after the ink microcapsules are cracked, and reconstructing four-dimensional strain fields in the model;
• wherein the coal rock three-dimensional strain field visual system, comprises:
• the stress condition simulation system and a strain monitoring system,
• the stress condition simulation system comprises a similar simulation experiment rack, a loading system and a circular slideway;
• the similar simulation experiment rack comprises a pressure chamber and two visual side plates;
• the pressure chamber is a rectangular frame body as a whole;
• two open ends of the rectangular frame body are sealed by the visual side plates;
• the pressure chamber and the visual side plates are enclosed to define the model placing cavity;
• the loading system comprises a vertical axial pressure loading system and a horizontal stress loading system, the vertical axial pressure loading system loads set vertical loading force to a top and a bottom of the pressure chamber;
• the horizontal stress loading system loads set horizontal loading force to a left side of the pressure chamber;
• the strain monitoring system comprises a plurality of multi-angle high-speed cameras;
• and in work, the vertical axial loading system applies an uneven force on the model to simulate a time-varying law of three-dimensional strain fields inside coal and rock mass under the complex geological structure.