Simulation Analysis And Experimental Study Of Temperature Effect On Rock Failure

Due to the high vacuum in the moon surface and the complex temperature environment,a large amount of heat will be generated between the drill and the rock in the drilling sampling process,and the heat cannot be diffused in time.On the one hand,the heat generation will affect the damage of the rock and the life of the drill and the drilling efficiency,on the other hand will also affect the impact of the bit on the rock crushing and coring.In order to ensure the smooth progress of the lunar drilling sampling task,this paper mainly studies the effect of temperature effect on the damage and destruction of rocks,which is also of great significance for the optimization of drilling tool load.This paper mainly uses the methods of theoretical analysis,experimental research and simulation to study the damage evolution of rock under the effect of temperature and temperature-force coupling.The main research work is as follows:Firstly,based on the related theories of rock mechanics,the micro-crack propagation conditions related to the elastic modulus are given,and the evolution of micro-cracks is analyzed.Under the temperature load,the physical and mechanical parameters of the rock change.In this paper,the rock thermal damage model based on the elastic modulus is mainly established to reflect the damage of the rock.Secondly,the micro-damage test of rock after high temperature action was carried out,and the change law of the microstructure characteristics of rock with temperature was clarified.With the increase of temperature,according to the occurrence of cracks and the deterioration of minerals,the rock damage is divided into three stages: a slight damage stage,a deepening stage and a severe damage stage.Combined with the rock uniaxial compression deformation test,the damage of thermal damaged rock samples under force loading and the relationship between microdamage and macroscopic damage of rock are clarified.Thirdly,using RFPA(rock failure process analysis)software to simulate the damage process of rock under temperature loading,the change law of stress field and the evolution law of micro-cracks during temperature rise were obtained.The relationship between the rock surface damage test and the simulation results is established under the condition of uniform temperature rise.The results show that the evolution law of microcrack in the test phase and the simulation phase is consistent.