Research On Portable Multifunctional Rock Mechanics Testing Machine

In the field of rock mechanics,the existing rock mechanics testing machine is only limited to obtain rock stress,strain and other macro-mechanical properties in the laboratory,but it cannot obtain corresponding mechanical parameters on site during field surveys,and cannot meet the requirements of engineering practice for the portability of field test instruments.The demand for chemistry and intelligence.Based on this,this paper aims to develop a portable multifunctional rock mechanics testing machine,which integrates the functions of rock point load,uniaxial compressive strength,triaxial compressive strength and structural surface friction angle,and cooperates with the mechanical frame and hydraulic system.Controller,can obtain parameters such as stress,displacement and friction angle in the field.The controller is equipped with an LCD screen and an SD card is attached.The experimental data can be displayed on the screen and saved to the machine.At the same time,it supports Bluetooth data sending to the mobile phone client and cloud platform to realize intelligent data collection.The hydraulic loading system is a key part of the rock mechanics test system.It has the characteristics of non-linearity,large load interference,strong cross coupling,and complex modeling.Iterative learning control is suitable for systems with repetitive motion properties and does not require the establishment of precise mathematical models.It can solve the high-order nonlinear problems of the hydraulic system and effectively ensure the tracking error requirements and static and dynamic performance of the hydraulic system.The mathematical model of the electro-hydraulic servo system is established,the transfer function is deduced,the stability,time domain characteristics and frequency domain characteristics of the system are analyzed,and the control effect of iterative learning control in the hydraulic servo system is verified by AMESimSimulink co-simulation.Through co-simulation verification,the electro-hydraulic servo system designed in this paper meets the expected technical requirements.Through point load test,structural surface friction angle and uniaxial compressive strength test on typical rock samples such as cement sample,granite and blue sandstone,15 sets of data were obtained.The correlation between the uncorrected point load index and uniaxial compressive strength that can be obtained through the point load test data by using the size effect is verified;the measured friction angle of the structural surface fluctuates slightly,and the 15 sets of numerical values tend to be one after fitting Smooth straight line;the measured uniaxial compressive strength data is compared with the data measured by the MTS hydraulic servo testing machine on the same graph.The slopes of the two fitting functions are close,the error of the average displacement is0.55%,and the average stress The error is 3.9%,which meets the test requirements.