Research On Fatigue Damage Of Argillaceous Dolomite Based On DIC

As a kind of soft rock,argillaceous dolomite is widely distributed in Guizhou.In recent years,with the vigorous promotion of the western construction,the mechanical properties of argillaceous dolomite have attracted more and more attention from scholars.The argillaceous dolomite is undergoing stress.It will inevitably be affected by the repeated actions of machinery and earthquakes.Although many scholars have conducted extensive research on the mechanical properties of muddy dolomite,little research has been done on the fatigue characteristics of argillaceous dolomite.Based on this,the author has studied mud.The research on the fatigue properties of dolomite has mainly done the following work:(1)A uniaxial compression test method for shale dolomite based on Digital Image Correlation(DIC)was established to observe the evolution process of cracks in uniaxial compression of rock,and the apparent strain and RMT test measured by contrast DIC.The overall strain obtained by the machine further validates the accuracy and applicability of the DIC test results.(2)By analyzing the strain cloud diagrams of the uniaxial compression of argillaceous dolomite,it is found that the points with larger values in the strain cloud map are closely related to the development of rock damage.Therefore,the damage is defined by the points in the first 10% of the strain cloud diagrams.Factors,and do damage evolution maps.(3)The uniaxial compressive strength of rock is the reference for fatigue loading.In this paper,the uniaxial compression curve of argillaceous dolomite is statistically analyzed,and a new method for estimating rock strength is proposed.(4)The influence of the upper limit stress,stress amplitude and loading frequency on the muddy dolomite fatigue life is obvious: with the increase of the upper limit stress,the fatigue life of the muddy dolomite tends to decrease;with the increase of the stress amplitude The fatigue life of large and muddy dolomite shows a decreasing trend.With the increase of loading frequency,the fatigue life of muddy dolomite increases.(5)The evolution rule of the muddy dolomite strain cloud diagram in one cycle and different cycle times was analyzed.The results show that due to the high frequency of fatigue loading,the cumulative damage of the rock within a cyclic loading is smalland different.The strain cloud diagram under the cycle number can well reflect the evolution of the crack during fatigue.(6)Based on the strain cloud diagram obtained by the DIC technique,the influence of the upper limit stress,stress amplitude,and loading frequency on the fatigue crack evolution of shale dolomite was analyzed.From the perspective of the evolution of fatigue cracks,the influence of these three factors on the fatigue life of muddy dolomite was explained.