Test method for quantitatively studying stress wave propagation law of porous rock

A test method for quantitatively studying a stress wave propagation law of a porous rock, comprising:

• adopting a dynamic true triaxial electromagnetic Hopkinson bar test system for testing, wherein the dynamic true triaxial electromagnetic Hopkinson bar test system comprises a horizontal cross supporting platform, and a central cubic square chest arranged in a middle part of an upper surface of the horizontal cross supporting platform, and further comprises a dynamic true triaxial electromagnetic Hopkinson bar and a test device;
• X+ direction, Y+ direction and Z+ direction square bars of the dynamic true triaxial electromagnetic Hopkinson bar are square incident bars, X− direction, Y− direction and Z− direction square bars are square transmission bars, one sides of the X+ direction, Y+ direction and Z+ direction square bars near an incident stress wave loading end are each provided with one first boss, rear ends of the X− direction, Y− direction and Z− direction square bars away from the X+ direction, Y+ direction and Z+ direction square bars are each provided with one second boss, and rear ends of the second bosses are each provided with one square buffer bar with a cross-section size same as that of X direction, Y direction and Z direction square transmission bars to realize centration with the square bar in the same direction, an X− direction square buffer bar, a Y− direction square buffer bar and a Z− direction square buffer bar are respectively fixed by square buffer bar fixing and supporting frames, a rear side of the square buffer bar is further provided with one energy absorbing and buffering device for absorbing energy transferred by the buffer bar;
• the square incident bars in the X+ direction, the Y+ direction and the Z+ direction and the square transmission bars in the X− direction, the Y− direction and the Z− direction of the dynamic true triaxial electromagnetic Hopkinson bar are respectively fixed on the horizontal cross supporting platform by the square bar fixing and supporting frames, and the square incident bars and the square transmission bars are centered and connected with the central cubic square chest in a square opening;
• and
• the test device comprises an electromagnetic pulse emitting device arranged in an incident direction of the square incident bar, a static pre-stress applying device arranged in an output direction of the square transmission bar, and stress detecting elements respectively arranged on the X+ direction, Y+ direction, Z+ direction, X− direction, Y− direction and Z− direction square bars used for measuring stress wave signal data.
• the test method comprises the following steps:
• step 1:
• quantitatively designing and preparing a cubic porous rock sample required by testing;
• step 2:
• placing the cubic pore rock sample in the central cubic square chest, wherein the central cubic square chest and the horizontal cross supporting platform form an orthogonal coordinate system for accurately positioning and centering the dynamic true triaxial electromagnetic Hopkinson bar and six surfaces of the cubic porous rock sample;
• and
• step 3:
• quantitatively studying a stress wave propagation law of the porous rock on the cubic porous rock sample by adopting the dynamic true triaxial electromagnetic Hopkinson bar test system, wherein:
• in the step 1, a method for quantitatively designing and preparing a cubic porous rock sample required by testing comprises:
• step 101:
• establishing a sample three-dimensional model data plane:
• establishing a cubic three-dimensional model with arbitrary spatial distribution of pores with a set shape based on a MATLAB programming tool, and acquiring a file containing sample three-dimensional model data plane information;
• step 102:
• converting the sample three-dimensional model data plane into a three-dimensional solid:
• converting the sample three-dimensional model data plane of the file into the three-dimensional solid, and processing the three-dimensional solid to obtain a qualified sample three-dimensional solid model containing pores;
• and
• step 103:
• performing slicing and 3D printing processing of the model:
• slicing the processed file of the sample three-dimensional solid model, setting a non-porous medium part in the sample to be cured and a porous medium part to be non-cured, acquiring a code file which is recognized by a 3D printer, and then inputting the code file to the 3D printer for 3D printing, and finally obtaining the cubic porous rock sample for experimental testing.