1、 Overview of microcomputer controlled triaxial rheological testing machine for rocks
The control system of the RLW-600/1000/2000 microcomputer controlled rock triaxial rheological testing machine adopts the EDC fully digital servo measurement and control device imported from DOLI company in Germany. This type of measurement and control device has multiple measurement channels, which can perform closed-loop control on any one of the channels, and can also perform impact free conversion on the control channel during testing. The measurement and control device is easy to operate, has strong fault tolerance, accurate measurement, comprehensive protection functions, and high control accuracy. This controller can work independently or be controlled by a computer for operation.
The host loading frame of this machine adopts an integrated door frame structure cast as a whole, which has a very high stiffness (>10 GN/m).
This machine can complete various forms of long-term tests, and can perform test force control (rheological test) and deformation control (relaxation test) during the test. The loading system of this machine adopts servo motor and ball screw loading system, which can work continuously for more than one year. The advantages of this system are high control accuracy (long-term control fluctuation ≤ 0.1%), low noise (≤ 40Db), no need for cooling (the system does not generate heat), low power consumption (≤ 1kW), low cost, and stable operation.

2、 Structure and working principle of microcomputer controlled rock triaxial rheological testing machine instrument
1. Axial and confining pressure loading system:
The loading method of the axial and confining pressure systems of the RLW-2000 microcomputer controlled rock triaxial rheological testing machine adopts a servo motor to push the ball screw type for operation. This working method has no noise, no temperature rise, and low power consumption (the power consumed during rheological testing is about 10% of the total power). Moreover, it can maintain the loading value of the system for a short period of time (about 5 hours) when the power is off, and the change in system loading value is very small (≤ 2%).
2. Enclosed triaxial pressure chamber:
The three-axis pressure chamber is a device used to apply confining pressure to the specimen. This pressure chamber adopts our company's patented technology to manufacture a self balancing pressure chamber. It has no effect on the axial pressure when applying confining pressure and no effect on the confining pressure when applying axial pressure. The pressure chamber is equipped with a socket for deformation sensors. Our company's strain gauge deformation sensor can be directly installed on the specimen to measure its deformation directly. In addition, an air permeation device (pressure sensor and permeation switch, etc.) is installed on the pressure chamber base. Gas permeation test can be conducted simultaneously during rheological testing.
3. Control and measurement system:
The control system of this machine (DOLI servo controller from Germany) includes not only axial pressure, confining pressure, deformation measurement and control, but also temperature, osmotic pressure, and exudation pressure measurement. These parameters can be displayed, processed, stored, and various test curves can be drawn in real time.
4. Computer System:
A computer system includes the hardware, software, and printer of a computer.

3、 Main technical parameters of microcomputer controlled triaxial rheological testing machine for rocks
1. The host is a door frame structure with a stiffness greater than 10 GN/m.
2. The maximum axial test force is 2000kN, and the effective measurement range is 20kN-2000kN,
Force measurement resolution 10N, force measurement accuracy ≤± 1%
Test force loading speed range 0.01---20kN/s
3. Maximum confining pressure 70Mpa, confining pressure measurement accuracy ± 1% FS
The confining pressure resolution is 0.0005MPa.
Range of confining pressure loading speed 0.001-0.1MPa/s
4. Deformation measurement and control range: axial 0-8mm, radial 0-5mm
Measurement resolution 0.0001mm, measurement accuracy ± 0.5%
Deformation speed control range 0.001mm ---1mm/min
5. Control accuracy (fluctuation, greater than 2000 hours):
Axial pressure ≤± 0.1%; Deformation ≤± 0.2%
Confining pressure ≤± 0.1%; ≤±0.03% FS）
6. Extreme control: It can automatically protect when parameters such as axial deformation, radial deformation, time reach their limit values or pre-set values, when the sample breaks, when the oil circuit is blocked, and when the oil temperature is too high.
7. Rock sample size ø 50 × (100~125), ø 100 × (200~250)
8. Host dimensions (width X height X depth): 900X2300X800mm
9. Host dimensions: 950 × 700 (including 1500 guide rails) × 2200mm
10. Power consumption of the whole machine: three-phase five wire 380V 2kW