岩石高压三轴试验机的液压加载系统关键技术研究

RESEARCH ON KEY TECHNOLOGIES OF HIGH PRESSURE HYDRAULIC SYSTEM FOR ROCKS

为模拟岩体地应力与环境水等赋存条件,需开发一套能模拟多种溶液环境的岩石高压三轴试验机。设计了一套同时驱动四压力室的高压液压系统,并对该试验系统的增压方法、连接结构密封、溶液隔离等关键技术进行研究。设计了一级增压结构,为系统提供超高围压;提出T型-斜面密封圈结构设计,增强结构连接处静态密封性能;并设计安装管道隔离膜,将压力室赋存溶液与增压缸相隔离。最后提出采用同等控制结构增强系统同步性能以及使用自适应Fuzzy-PID控制算法增强系统稳定性,并通过MATLAB/Sim-Hydraulic液压仿真模块对所设计的液压加载系统进行仿真模拟,分别分析了自适应Fuzzy-PID算法下同等控制与主从控制液压缸的响应速度,并对比了PID控制和自适应Fuzzy-PID控制下系统的抗干扰性能。研究为类似岩石高压三轴试验机液压加载系统设计提供了参考。

For simulating the stress status and existing environment of the rock mass, a set of high pressure triaxial testing machine that can simulate various solution environments is needed to develop. A high pressure hydraulic system is designed in this paper. It can drive four pressure chambers at the same time. Supercharging of the system, joint structure sealing, the separation of the loading installation and liquids, system control methods are all discussed in details. A supercharging pressure cylinder is added to improve the confining pressure. A slant T-shape sealing method and isolation membrane are designed to strengthen the structure join static sealing performance and isolate the solution from pressure chamber. In the end the designed hydraulic system is simulated using the Sim- Hydraulic in MATLAB.The responsible speed of the co-ordinate control and the master-slave control of hydraulic cylinder is analyzed respectively with the adaptive Fuzzy-PID algorithm. The anti-jamming performance of system is also analyzed with the PID control and the adaptive Fuzzy PID control, respectively. Simulating results show that, the system shows better anti-disturbance ability under the adaptive Fuzzy-PID control comparing to the PID control. The hydraulic cylinder shows faster response speed under the adaptive Fuzzy-PID algorithm. This analysis can provide references to the design of triaxial hydraulic loading installation for rock.