Method and system for analyzing mechanical property and energy evolution of red sandstone under impact load

Abstract

The invention relates to the technical field of rock blasting, in particular to a method and a system for analyzing mechanical properties and energy evolution of red sandstone under impact load. The analysis method provided by the invention comprises the following steps: acquiring test data and a morphological image of jointed red sandstone; utilizing the test data to obtain a mechanical curve and an energy curve of the jointed red sandstone; analyzing the mechanical properties of the jointed red sandstone under the impact load according to the mechanical curve and the morphological image; and analyzing the energy evolution of the jointed red sandstone under the impact load through the energy curve. The dynamic uniaxial compression test is carried out on the jointed red sandstone through the Hopkinson pressure bar test device, the dynamic mechanical properties and energy dissipation characteristics of the cement jointed red sandstone with different joint inclination angles are explored, and guidance and reference are provided for blasting construction of jointed rock mass.

Description

Technical Field

[0001] The invention relates to the technical field of rock blasting, and in particular to a method and system for analyzing the mechanical properties and energy evolution of red sandstone under impact load. Background Art

[0002] A large number of natural joints are formed in the rock mass during the evolution of geological structures. Usually, the joints are not completely closed, and the gaps often contain soft fillings, which significantly reduce the strength of the joints. In order to improve the strength of the surrounding rock, rock grouting is often used in engineering to improve the surrounding rock structure. Therefore, when using grouting reinforcement for engineering construction, the impact of the physical and mechanical properties of cement jointed rock mass on engineering safety must be considered. The stability and safety evaluation of rock structures is of great significance during underground engineering construction.

[0003] Under actual construction conditions, jointed rock mass is often affected by dynamic disturbances. Therefore, analyzing jointed rock mass under dynamic conditions is of great engineering significance. Indoor dynamic tests are an effective means to study the mechanical properties of jointed rock mass under dynamic conditions. In recent years, many scholars at home and abroad have enriched the research content by using the Hopkinson bar test combined with high-speed cameras and numerical simulation models.

[0004] Since the destruction of rocks is dominated by energy, some scholars have revealed the entire destruction process of the specimen from the perspective of energy by combining mechanical properties with energy dissipation laws and structural degradation. The composition and morphology of natural joints are complex and diverse, and the type and morphology of joint fillings have a great influence on the strength of jointed rock masses. Some scholars have conducted Hopkinson tests on rock masses with different types of joints and morphologies to explore the influence of joint fillings and joint morphology on the strength and energy dissipation laws of jointed rock masses.

[0005] The research contents involved in the above research results are mostly idealized indoor tests, and do not consider the stability and safety of cement jointed rock mass formed after grouting reinforcement under impact load in actual engineering. Therefore, it is necessary to study the dynamic mechanical properties and energy dissipation laws of cement jointed rock mass to provide reference for actual engineering.

[0006] At present, there is not much research on the mechanical properties and energy evolution and dissipation laws of jointed red sandstone, and there is no specific analysis method for the mechanical properties and energy evolution of jointed red sandstone under impact load. Summary of the invention

[0007] In view of the defects in the prior art, the present invention provides a method and system for analyzing the mechanical properties and energy evolution of red sandstone under impact load.

[0008] On the one hand, the analysis method includes the following steps: obtaining test data and morphological images of jointed red sandstone; using the test data, obtaining mechanical curves and energy curves of jointed red sandstone; analyzing the mechanical properties of jointed red sandstone under impact load according to the mechanical curves and the morphological images; and analyzing the energy evolution of jointed red sandstone under impact load through the energy curve. The present invention obtains test data and morphological images of jointed red sandstone through dynamic uniaxial impact tests, providing comprehensive insights into the mechanical properties and energy evolution of jointed red sandstone under impact load. The specific effects are as follows: First, the precisely captured test data is converted into intuitive mechanical and energy curves, which not only reveals the strength and deformation characteristics of jointed red sandstone under dynamic loading, but also depicts the dynamic process of energy absorption and dissipation; second, combined with morphological image analysis, the intuitiveness and accuracy of the mechanical behavior interpretation are enhanced, making the influence of the joint structure on the mechanical properties clear at a glance; third, a detailed analysis of the mechanical response and energy evolution mechanism of jointed red sandstone under complex impact environment is achieved, providing guidance and reference for the blasting construction of jointed rock masses.

[0009] Optionally, the method of obtaining the test data and morphological images of the jointed red sandstone includes: obtaining the thickness, volume, joint inclination, dynamic compressive strength, elastic modulus, strain, stress, incident energy, reflected energy, transmitted energy, absorbed energy data and final destruction morphological images of the jointed red sandstone. When deeply analyzing the mechanical properties and energy evolution of the jointed red sandstone, the present invention comprehensively obtains its multi-dimensional test data and morphological images; the test data covers the basic parameters, mechanical parameters and energy parameter data of the jointed red sandstone; the morphological images are the destruction morphological images of the rock after the impact test. The specific effects are as follows: First, it intuitively displays the characteristics of the destruction mode of the jointed red sandstone; second, it provides a solid foundation for an in-depth understanding of the behavior mechanism of the jointed red sandstone under complex stress states, ensuring the scientificity and accuracy of subsequent analysis.

[0010] Optionally, the use of the test data to obtain the mechanical curve and energy curve of the jointed red sandstone includes: using the test data to obtain the dynamic mechanical characteristic analysis curve of the jointed red sandstone; using the test data to obtain the energy dissipation characteristic analysis curve of the jointed red sandstone. The present invention describes a dual characteristic analysis process of jointed red sandstone based on test data. The specific effects are as follows: First, the stress-strain relationship and mechanical response mechanism of the jointed red sandstone under dynamic loading conditions are revealed, providing an important basis for evaluating its strength, toughness and stability; second, the energy dissipation characteristic analysis curve is drawn, which intuitively shows the absorption, storage and dissipation laws of energy in the jointed red sandstone during the destruction process, providing a new perspective for understanding the destruction mechanism and energy conversion mechanism of rocks.

[0011] Optionally, the method of using the test data to obtain the dynamic mechanical characteristic analysis curve of the jointed red sandstone includes: using the test data to obtain the dynamic mechanical characteristic analysis curve of stress and strain of the jointed red sandstone; using the test data to obtain the dynamic mechanical characteristic analysis curve of dynamic compressive strength and joint inclination of the jointed red sandstone; using the test data to obtain the dynamic mechanical characteristic analysis curve of peak strain and joint inclination of the jointed red sandstone; using the test data to obtain the dynamic mechanical characteristic analysis curve of dynamic elastic modulus and joint inclination of the jointed red sandstone. The present invention depicts multiple dimensions of comprehensively analyzing the dynamic mechanical characteristics of jointed red sandstone using test data. The specific effects are as follows: First, it covers the dynamic change curves of stress and strain, and deeply analyzes the basic mechanical behavior of rocks under dynamic loading; second, it refines the relationship between dynamic compressive strength and joint inclination, and reveals the influence of joint structure on rock strength; third, it intuitively displays the mechanical response of the critical state of rock failure; fourth, it explores the relationship between dynamic elastic modulus and joint inclination, which provides a basis for evaluating the stiffness characteristics of rocks under dynamic conditions.

[0012] Optionally, the use of the test data to obtain an energy dissipation characteristic analysis curve of jointed red sandstone includes: using the test data to obtain an energy dissipation characteristic analysis curve of jointed red sandstone energy and joint inclination; using the test data to obtain an energy dissipation characteristic analysis curve of jointed red sandstone unit volume dissipated energy and joint inclination; using the test data to obtain an energy dissipation characteristic analysis curve of jointed red sandstone energy reflection coefficient and joint inclination. The present invention describes a multi-dimensional analysis of the energy dissipation characteristics of jointed red sandstone using test data. The specific effects are as follows: First, it intuitively shows the differences and laws of rock energy dissipation under different joint structures; second, it quantifies the energy loss in the rock destruction process; third, it reveals the significant influence of joints on energy dissipation efficiency; fourth, it explores the reflection characteristics of jointed red sandstone during energy input, providing a new perspective for understanding the complex mechanism of energy conversion and dissipation of jointed red sandstone.

[0013] Optionally, the analysis of the mechanical properties of jointed red sandstone under impact load according to the mechanical curve and the morphological image includes: obtaining the dynamic mechanical properties analysis result of the jointed red sandstone according to the dynamic mechanical properties analysis curve; and analyzing the mechanical properties of the jointed red sandstone under impact load according to the dynamic mechanical properties analysis result and the morphological image. The present invention outlines the process of comprehensively analyzing the mechanical properties of jointed red sandstone under impact load by combining the mechanical curve and morphological image of red sandstone. The specific effects are as follows: First, the key mechanical parameters and their changing trends of jointed red sandstone under dynamic loading are extracted, laying a solid foundation for mechanical properties analysis; second, the accuracy of the mechanical data is verified, revealing the intrinsic connection between the microscopic mechanism and the macroscopic manifestation in the rock failure process.

[0014] Optionally, the analysis of the energy evolution of jointed red sandstone under impact load through the energy curve includes: obtaining the energy dissipation characteristic analysis result of the jointed red sandstone through the energy dissipation characteristic analysis curve; and analyzing the energy evolution of the jointed red sandstone under impact load through the energy dissipation characteristic analysis result. The present invention describes the steps of using energy curves to conduct in-depth analysis of the energy evolution of jointed red sandstone under impact load. The specific effects are as follows: First, the key characteristics of energy dissipation of jointed red sandstone during the impact process are extracted, providing a solid data foundation for the analysis of energy evolution; second, based on the energy dissipation characteristic analysis results, the dynamic process of energy evolution of jointed red sandstone under impact load is analyzed, revealing the energy conversion and dissipation mechanism; third, the understanding of the energy evolution law of jointed red sandstone is deepened, and a scientific basis is provided for effectively controlling energy release and preventing disasters in engineering practice.

[0015] Optionally, the dynamic mechanical characteristic analysis results of the jointed red sandstone obtained according to the dynamic mechanical characteristic analysis curve include: obtaining the dynamic mechanical characteristic analysis results of the stress-strain relationship of the jointed red sandstone according to the dynamic mechanical characteristic analysis curve; obtaining the dynamic mechanical characteristic analysis results of the relationship between the dynamic compressive strength and the joint inclination of the jointed red sandstone according to the dynamic mechanical characteristic analysis curve; obtaining the dynamic mechanical characteristic analysis results of the relationship between the peak strain of the jointed red sandstone and the joint inclination according to the dynamic mechanical characteristic analysis curve; obtaining the dynamic mechanical characteristic analysis results of the relationship between the dynamic elastic modulus and the joint inclination of the jointed red sandstone according to the dynamic mechanical characteristic analysis curve. The present invention demonstrates how to comprehensively reveal the mechanical behavior characteristics of the jointed red sandstone under dynamic loading through the dynamic mechanical characteristic analysis curve. The specific effects are as follows: First, it covers the dynamic analysis of the relationship between stress and strain, and deeply explores the stress response and deformation characteristics of jointed red sandstone under dynamic conditions; second, it analyzes the relationship between dynamic compressive strength and joint inclination, and reveals the influence of joint structure on the compressive performance of rock; third, it explores the relationship between strain peak and joint inclination, clarifies the ultimate strain state before rock failure and its intrinsic connection with joint parameters; fourth, it analyzes the relationship between dynamic elastic modulus and joint inclination, quantifies the stiffness change of jointed red sandstone under dynamic loading, and provides an important basis for evaluating the overall mechanical properties of jointed red sandstone.

[0016] Optionally, the energy dissipation characteristic analysis results of the jointed red sandstone obtained through the energy dissipation characteristic analysis curve include: obtaining the energy dissipation characteristic analysis results of the relationship between the energy and the joint inclination of the jointed red sandstone through the energy dissipation characteristic analysis curve; obtaining the energy dissipation characteristic analysis results of the relationship between the dissipated energy per unit volume of the jointed red sandstone and the joint inclination through the energy dissipation characteristic analysis curve; obtaining the energy dissipation characteristic analysis results of the relationship between the energy reflection coefficient of the jointed red sandstone and the joint inclination through the energy dissipation characteristic analysis curve. The present invention describes a comprehensive analysis of the energy dissipation characteristics of the jointed red sandstone using the energy dissipation characteristic analysis curve. The specific effects are as follows: First, the differences and laws of energy dissipation modes under different joint inclinations are demonstrated; second, the energy consumed per unit volume of the rock during the destruction process is quantified, providing a direct basis for evaluating the energy absorption capacity of the rock; third, the dimension of the energy dissipation characteristic analysis is expanded, revealing the reflection characteristics of the rock during the energy input process and its influence on the energy dissipation efficiency.

[0017] In the second aspect, the present invention provides a red sandstone mechanical properties and energy evolution analysis system under impact load, the system includes an input device, a processor, an output device and a memory, the input device, the processor, the output device and the memory are interconnected, wherein the memory is used to store a computer program, the computer program includes program instructions, the processor is configured to call the program instructions, and the system uses the red sandstone mechanical properties and energy evolution analysis method under impact load. The system provided by the present invention has high integration and smooth information transmission between components. It can comprehensively evaluate the mechanical behavior of jointed red sandstone under impact load, deeply analyze the energy evolution characteristics, and ensure the comprehensiveness and accuracy of the analysis results; through the automated data analysis process, it significantly improves research efficiency, reduces human errors, and provides rapid support for rock blasting engineering applications; it supports dynamic visualization of energy dissipation and mechanical properties, intuitively presents the energy and mechanical state changes of jointed red sandstone during the impact process, and facilitates in-depth understanding and analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a flow chart of a method for analyzing mechanical properties and energy evolution of red sandstone under impact load according to an embodiment of the present invention; Figure 2 The actual picture of red sandstone with different joints according to the embodiment of the present invention; Figure 3 A schematic diagram of a Hopkinson pressure bar system according to an embodiment of the present invention; Figure 4 This is a stress-strain curve diagram of a sample with a joint inclination angle of 30° according to an embodiment of the present invention; Figure 5 The stress-strain curves at various joint inclination angles under different impact gas pressures of an embodiment of the present invention; Figure 6 A curve diagram showing the relationship between the dynamic compressive strength and the joint inclination angle of an embodiment of the present invention; Figure 7 A curve diagram showing the relationship between the peak strain and the joint inclination angle of an embodiment of the present invention; Figure 8 is a curve diagram showing the relationship between the dynamic elastic modulus and the joint inclination angle according to an embodiment of the present invention; Fig. 9 This is a diagram of the final failure morphology of a joint specimen according to an embodiment of the present invention; Fig.10 A curve diagram showing the relationship between energy and joint inclination according to an embodiment of the present invention; Fig.11 A curve diagram showing the relationship between unit volume dissipated energy and joint inclination angle according to an embodiment of the present invention; Fig.12 The energy reflection coefficient of the embodiment of the present invention varies with the joint inclination angle; Fig.13 Schematic diagram of the structure of the red sandstone mechanical properties and energy evolution analysis system under impact load according to an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are only for illustration and are not intended to limit the present invention. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details do not need to be adopted to implement the present invention. In other examples, in order to avoid confusing the present invention, known circuits, software or methods are not specifically described.

[0020] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or subcombination. In addition, it should be understood by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale.

[0021] See also Figure 1 The embodiment of the present invention provides a method for analyzing the mechanical properties and energy evolution of jointed red sandstone under impact load, the method comprising the following steps: S1. Obtain test data and morphological images of jointed red sandstone.

[0022] Wherein, step S1 comprises the following steps: S11. Obtain the joint dip, thickness and volume data of the jointed red sandstone specimen.

[0023] Specifically, the steps include: S111. Obtain joint dip data of jointed red sandstone specimen.

[0024] In one embodiment, red sandstone from Chuxiong, Yunnan was selected. All rock samples were cut from the same large rock mass along a fixed direction to ensure the uniformity of particles inside the rock sample.

[0025] Furthermore, the complete rock sample is precisely cut into two parts according to a pre-designed angle.

[0026] Furthermore, the cut rock samples were subjected to prefabricated joint filling treatment, and cement mortar (R42.5 ordinary Portland cement, water, and fine sand in a mass ratio of 1:0.59:2.1) was used as the filling material.

[0027] Furthermore, the samples were cured in a SHBY-40B standard constant temperature and humidity curing box at a humidity of more than 95% and a temperature of 20±1°C for 28 days.

[0028] Furthermore, jointed red sandstone samples were obtained, such as Figure 2 The angle between the crack on the surface of the jointed red sandstone sample and the horizontal direction is the joint inclination angle.

[0029] S112. Obtain thickness data of jointed red sandstone sample.

[0030] In the process of obtaining the thickness of the jointed red sandstone sample, the obtaining methods include but are not limited to using a vernier caliper measurement method.

[0031] In one embodiment, a vernier caliper with an accuracy of 0.01 mm is selected, and the jaws of the vernier caliper are ensured to be clean and free of wear to ensure the accuracy of the measurement. The specific measurement steps are as follows: First, place the jointed red sandstone specimen steadily on a horizontal table surface, ensuring that its bottom surface is in good contact with the table surface without shaking or tilting.

[0032] Furthermore, the jaws of the vernier caliper are gently opened so that they can be easily inserted into both sides of the sample. Note that the opening degree of the jaws should be slightly larger than the expected thickness of the sample to avoid damaging the sample or affecting the measurement accuracy due to the friction between the jaws and the sample during the measurement process.

[0033] Further, gently push the jaws of the vernier caliper into both sides of the sample until they are in close contact with the surface of the sample. During the pushing process, keep a steady hand movement to avoid tilting or shaking the vernier caliper. At this point, the reading of the vernier caliper is the thickness of the sample.

[0034] S113. Obtain volume data of jointed red sandstone sample.

[0035] The method for obtaining the volume of the jointed red sandstone sample includes but is not limited to a drainage method, a gas expansion method, a vernier caliper method and a laser scanning method.

[0036] In one embodiment, a laser scanning method is used to obtain the volume of a jointed red sandstone sample.

[0037] Specifically, according to the size, shape and surface characteristics of the jointed red sandstone sample, a suitable 3D laser scanner is selected to ensure that the accuracy, scanning speed and scanning range of the laser scanner can meet the measurement requirements.

[0038] Furthermore, the jointed red sandstone specimens were placed in a stable, unobstructed scanning area to ensure sufficient and uniform light during the scanning process and to avoid the influence of shadows and reflections on the scanning results.

[0039] Furthermore, calibration was performed according to the laser scanner's instructions to ensure the accuracy and reliability of the scanned data.

[0040] Further, the laser scanner is started, and appropriate parameters such as scanning interval, scanning speed and scanning angle are set and scanning is started.

[0041] Furthermore, the three-dimensional point cloud data obtained by scanning are preprocessed, three-dimensionally modeled, and volume calculated to obtain the volume of the jointed red sandstone sample.

[0042] In another embodiment, a vernier caliper method is used to obtain the volume of the jointed red sandstone sample by measuring the length, width and thickness of the jointed red sandstone sample. The measuring method is as described in step S112. It should be noted that the measuring method of length and width is the same as that of thickness, but the measuring angle is different.

[0043] S12. Obtain dynamic compressive strength, elastic modulus, incident energy, reflected energy, transmitted energy, absorbed energy, strain and stress data of jointed red sandstone specimens.

[0044] In one embodiment, a dynamic uniaxial impact test is performed using a Hopkinson pressure bar system. Figure 3 shown.

[0045] Specifically, the jointed red sandstone was processed into cylindrical specimens that met the test requirements of the Hopkinson pressure bar system, and surface treatment was performed to ensure good contact between the specimen and the pressure bar.

[0046] Furthermore, the Hopkinson pressure bar system is installed, including the incident bar, the sample, the transmission bar, and the matching sensors and data acquisition system.

[0047] Furthermore, the system was started, and the ejection velocity of the impact bullet was changed by controlling the size of the impact gas pressure to obtain impact loads of different sizes; the strain data was recorded by the strain gauge and the ultra-dynamic strain gauge on the elastic steel rod, and then the test data was obtained by computer processing. Before the test, the rock sample was tested to determine the impact gas pressure range of 0.2MPa-0.24MPa. The gradient was 0.2MPa, with a total of 3 impact gas pressures.

[0048] The dynamic compressive strength, elastic modulus, energy, strain and stress of the jointed red sandstone specimen were obtained through this test. The specific steps are as follows: S121. Obtain strain data of jointed red sandstone specimens.

[0049] In this embodiment, high-sensitivity strain gauges are installed on the incident rod and the transmission rod to measure the deformation of the rod during loading.

[0050] Furthermore, during the test, the strain gauge converts the deformation of the rod into an electrical signal, which is recorded by the data acquisition system.

[0051] Furthermore, according to the output signal of the strain gauge and the geometric dimensions of the rod, the strain of the sample during the loading process is calculated to obtain the strain data.

[0052] S122. Obtain stress data of jointed red sandstone specimens.

[0053] In this embodiment, the collected impact air pressure is subjected to waveform analysis to extract the waveform parameters of the sample during the loading process.

[0054] Furthermore, the stress value of the sample during the loading process is calculated according to the waveform parameters and the sample size.

[0055] S123. Obtain dynamic compressive strength data of jointed red sandstone specimens.

[0056] In this embodiment, the collected data is processed to extract the waveform parameters of the incident wave, the reflected wave and the transmitted wave.

[0057] Furthermore, the maximum stress value of the sample at the moment of failure is calculated according to the waveform parameters and the sample size, which is the dynamic compressive strength of the red sandstone.

[0058] S124. Obtain elastic modulus data of jointed red sandstone specimens.

[0059] In this embodiment, stress and strain data of the sample during the loading process are extracted from the collected impact air pressure signal.

[0060] Furthermore, the stress and strain data are plotted into a curve, and a characteristic line segment is found, which includes a line connecting the peak strength point and the 50% peak strength point and a line connecting the 50% peak strength point and the origin.

[0061] Furthermore, the average value of the slopes of the above two characteristic line segments is calculated and used as the elastic modulus of the jointed red sandstone sample. The calculation formula is as follows: in, is the peak stress, is 50% peak stress, for The corresponding strain value is for The corresponding strain value is is the elastic modulus of the jointed red sandstone specimen.

[0062] It should be noted that the elastic modulus of a rock sample is the stress value corresponding to unit strain when the rock sample is deformed under the action of external forces. It is an important physical quantity that reflects the rock sample's resistance to elastic deformation.

[0063] S125. Obtain incident energy, reflected energy, transmitted energy and absorbed energy data of jointed red sandstone specimens.

[0064] In this embodiment, according to the one-dimensional stress wave theory and the law of conservation of energy, the incident energy is constructed. , reflection energy , transmission energy and absorption energy The calculation expression is as follows: in, is the elastic modulus of the compression rod, is the cross-sectional area of ​​the steel rod, is the longitudinal wave velocity, is the stress wave transmission time.

[0065] It should be noted that the absorbed energy is the energy acting on the sample, and the present invention defines the absorbed energy involved in the destruction of the sample as the crushing dissipated energy.

[0066] S13. Obtain the final failure morphology image of the jointed red sandstone.

[0067] In this embodiment, the fragments after the test are collected and classified according to the joint inclination angles of the corresponding samples to obtain the final failure forms of jointed red sandstone with joint inclination angles of 0°, 15°, 30°, 45°, 60°, 75° and 90°.

[0068] Furthermore, the above final damage forms are photographed by using a camera to obtain the final damage form images, such as Figure 8 shown.

[0069] S2. Using the test data, obtain the mechanical curve and energy curve of jointed red sandstone.

[0070] Wherein, step S2 further comprises the following steps: S21. Using the test data, obtain a dynamic mechanical properties analysis curve of jointed red sandstone.

[0071] Specifically, step S21 includes the following steps: S211. Using the test data, obtain the dynamic mechanical characteristics analysis curve of stress and strain of jointed red sandstone.

[0072] In one embodiment, a Hopkinson pressure bar system is used to adjust the impact gas pressure to 0.22 MPa to obtain stress and strain data of a 30° joint specimen at different thicknesses.

[0073] Furthermore, the stress and strain data were plotted using data analysis software Origin. The curve includes four stages, namely, compaction stage (OA stage), linear elastic stage (AB stage), crack initiation stage (BC stage) and unloading stage (CD stage), as shown in FIG. Figure 4 shown.

[0074] In another embodiment, the Hopkinson pressure bar system is used to adjust the impact gas pressure to 0.2 MPa, 0.22 MPa and 0.24 MPa, respectively, to obtain stress and strain data of joint specimens with joint inclination angles of 0°, 15°, 30°, 45°, 60°, 75° and 90°.

[0075] Furthermore, the stress and strain data were plotted using the data analysis software Origin, and the plot also added a type I curve, such as Figure 5 This type I curve has been documented in the prior art and describes the stress and strain curve of a complete red sandstone sample under low impact gas pressure.

[0076] It should be noted that the differences in stress and strain curves of different joint inclination angles are mainly reflected in the following four aspects: compaction stage, plastic stage, stress double peaks and post-peak morphology.

[0077] S212. Using the test data, obtain the dynamic mechanical characteristic analysis curve of the dynamic compressive strength and joint inclination of jointed red sandstone.

[0078] In one embodiment, the Hopkinson pressure bar system is used to adjust the impact gas pressure to 0.2 MPa, 0.22 MPa and 0.24 MPa, respectively, to obtain the dynamic compressive strength of the joint inclination angles of 0°, 15°, 30°, 45°, 60°, 75°, 90° and the complete joint specimens.

[0079] Furthermore, the data analysis software Origin was used to draw a curve showing the dynamic compressive strength of jointed red sandstone under different impact pressures and the change of different joint inclination angles. Figure 6 shown.

[0080] S213. Using the test data, obtain the dynamic mechanical property analysis curve of the jointed red sandstone peak strain and joint inclination.

[0081] In one embodiment, peak strain data under different impact gas pressures and different joint inclination angles are obtained based on the stress and strain curves of jointed red sandstone.

[0082] Furthermore, the data analysis software Origin was used to plot the impact pressure, joint inclination and peak strain data. Figure 7 shown.

[0083] S214. Using the test data, obtain the dynamic mechanical characteristic analysis curve of the dynamic elastic modulus and joint inclination of the jointed red sandstone.

[0084] In one embodiment, the Hopkinson pressure bar system is used to adjust the impact gas pressure to 0.2 MPa, 0.22 MPa and 0.24 MPa, respectively, to obtain the dynamic elastic modulus of the joint inclination angles of 0°, 15°, 30°, 45°, 60°, 75°, 90° and the complete joint specimen.

[0085] Furthermore, the data analysis software Origin was used to draw a curve showing the dynamic elastic modulus of the jointed red sandstone under different impact pressures and the changes in the joint inclination angles. Figure 8 shown.

[0086] S22. Using the test data, obtain an energy dissipation characteristic analysis curve of jointed red sandstone.

[0087] Wherein, step S22 further includes the following steps: S221. Using the test data, obtain energy dissipation characteristic analysis curves of jointed red sandstone energy and joint inclination.

[0088] In one embodiment, the method of step S125 is used to obtain incident energy, reflected energy, transmitted energy and dissipated energy data of the jointed red sandstone sample at different joint inclination angles.

[0089] Furthermore, the data analysis software Origin was used to plot the joint inclination angle and the corresponding incident energy, reflected energy, transmitted energy and dissipated energy data. The curve is shown in Fig.10 shown.

[0090] S222. Using the test data, obtain energy dissipation characteristic analysis curves of unit volume dissipation energy and joint inclination of jointed red sandstone.

[0091] In one embodiment, based on the volume and dissipated energy of the jointed red sandstone, the dissipated energy per unit volume of the jointed red sandstone is obtained, and the calculation method is as follows: in, is the energy dissipated per unit volume, is the absorbed or dissipated energy, Indicates the sample volume.

[0092] Furthermore, the relationship curve between the unit volume dissipation energy of jointed red sandstone and the joint inclination angle under different impact pressures is plotted, such as Fig.11 shown.

[0093] S223. Using the test data, obtain the energy dissipation characteristic analysis curve of the jointed red sandstone energy reflection coefficient and the joint dip angle.

[0094] In one embodiment, based on the reflection energy and incident energy of the jointed red sandstone, the energy reflection coefficient of the jointed red sandstone is obtained, and the calculation method is as follows: in, is the energy reflection coefficient, is the reflected energy, is the incident energy.

[0095] Furthermore, the relationship curve between the energy reflection coefficient of jointed red sandstone and the inclination angle of joints under different impact pressures is plotted, such as Fig.12 shown.

[0096] S3. According to the mechanical curve and the morphological image, the mechanical properties of the jointed red sandstone under impact load are analyzed.

[0097] Wherein, step S3 further comprises the following steps: S31. According to the dynamic mechanical property analysis curve, the dynamic mechanical property analysis results of the stress and strain relationship of the jointed red sandstone are obtained.

[0098] In this embodiment, Figure 4 The stress and strain curves of 30° joint specimens with different thicknesses under the impact gas pressure of 0.22MPa are divided into four stages: OA, AB, BC, and CD, and the characteristics of each stage are analyzed: (1) The compaction stage (OA section) is divided into the compaction of cement joints and the compaction of the red sandstone matrix. Due to the large porosity of cement, it is compacted first when subjected to dynamic load. There are also a large number of tiny defects and cracks in the red sandstone matrix that are compressed and closed. As the sample is gradually compacted, its stress-strain curve bends upward.

[0099] (2) In the linear elastic stage (segment AB), the cracks of the specimen itself have closed, and the specimen is in an elastic deformation state that conforms to Hooke's law. The stress-strain relationship is linear, and the change in the joint inclination angle affects the slope of the linear elastic stage. At this time, the elastic modulus of the joint specimen can be calculated based on the image data.

[0100] (3) The crack initiation stage (BC segment) is followed by the linear elastic stage, and the specimen transitions from the linear elastic state to the plastic deformation state.

[0101] (4) Unloading stage (CD segment): Due to the development and interconnection of new and old cracks, the elastic energy stored in the sample is released, the bearing capacity of the joint sample gradually decreases until it is lost, and the sample undergoes macroscopic damage, which is represented by a stress decrease after the peak value on the stress and strain graph.

[0102] In this embodiment, Figure 5 The differences in stress and strain curves of different joint inclinations shown are mainly reflected in the following four aspects: (1) Compacting stage. At small angles of 0°, 15°, and 30°, the compacting stage of the jointed specimen is mainly controlled by the compaction of the joints because the joints are subjected to nearly vertical axial impact loads. Therefore, the compacting stage has a large span. As the joint inclination increases, the compacting stage gradually decreases. At 90°, the compacting stage is almost the same as that of the complete specimen.

[0103] (2) Plastic stage. Joints weaken the dynamic characteristics of the rock mass, weaken the brittle failure characteristics of the rock mass, and reflect plastic deformation. The plastic stage range of the specimens at 0°, 15°, and 30° inclinations is larger than that of other specimens, indicating that their plastic deformation capacity is stronger than that of specimens at other angles. The plastic stage at 75° and 90° inclinations is smaller, and the stress and strain curves of the 90° specimen are very similar to those of the intact specimen, both reflecting the characteristics of brittle failure.

[0104] (3) Double stress peaks. The stress and strain curves of the specimen at an inclination angle of 45° show a "double stress peak" phenomenon, and the peak stress of the first peak is significantly higher than the second peak stress, resulting in a "stress drop phenomenon".

[0105] (4) Post-peak morphology. There is also a significant difference in the post-peak stage of the stress and strain curves. Under low impact pressure, the stress and strain curves of the jointed red sandstone specimens are typical type I curves. After the peak, the stress slowly decreases with the increase of strain. As the impact pressure increases, the post-peak curves of the specimens at 0°, 15°, 75° and 90° inclinations slowly approach the type II curve mode, that is, the rockburst curve. Among them, the curve at the 90° inclination is the most representative. After the peak, the stress decreases faster with the increase of strain. This shows that the jointed red sandstone still retains a certain bearing capacity in the post-peak stage and does not lose strength instantly. The specimens at 30°, 45° and 60° inclinations show changes in the type I curve regardless of how the impact pressure changes.

[0106] S32. According to the dynamic mechanical property analysis curve, the dynamic mechanical property analysis results of the relationship between the dynamic compressive strength and joint inclination of the jointed red sandstone are obtained.

[0107] In this embodiment, as shown in Figure 6, it can be found that the dynamic peak stress of the red sandstone containing cement joints is lower than that of the complete specimen. The joints in the specimens greatly reduce the dynamic compressive strength of the jointed red sandstone, and with the increase of the joint inclination angle, the dynamic compressive strength first decreases and then increases, and the dynamic compressive strength curve shows a V-shaped change.

[0108] When the inclination angle is from 0° to 45°, the dynamic compressive strength decreases gradually with the increase of the joint inclination angle. When the joint inclination angle is 45°, the curve shows a trough, and then increases slightly at 60°, and then the dynamic compressive strength increases sharply at 75° and 90°.

[0109] With the increase of impact pressure, the dynamic compressive strength increases, showing the strain rate effect. When the impact pressure is 0.24MPa, the dynamic peak stress decreases slowly when the joint inclination angle is 0° to 45°, and the peak stress rises sharply when the joint inclination angle is 60° to 90°. The difference between the peak stresses at two adjacent angles is large, and at 90°, it is very close to the complete sample, and the U-shaped change trend is more obvious.

[0110] The dynamic compressive strength of jointed red sandstone is from large to small, respectively, joint inclination 90°> joint inclination 0°> joint inclination 75°> joint inclination 15°> joint inclination 30°> joint inclination 60°> joint inclination 45°. When the impact pressure is 0.24MPa, the strength of 0°, 15°, 30°, 45°, 60°, 75°, and 90° jointed red sandstone is 56.8%, 49.9%, 38.9%, 14.9%, 17.5%, 53.6%, and 91.3% of the dynamic peak strength of the intact red sandstone. When the impact pressure is 0.2MPa and 0.22MPa, similar conclusions can be drawn. The joint inclination has a significant effect on the magnitude of the dynamic peak stress.

[0111] S33. According to the dynamic mechanical property analysis curve, the dynamic mechanical property analysis results of the relationship between the joint red sandstone strain peak value and the joint inclination angle are obtained.

[0112] In this embodiment, from Figure 7 It can be seen that the dynamic peak strain of the sample with a joint inclination of 0° is greater than that of the complete red sandstone sample, and the dynamic peak strain of the sample with a joint inclination of 15° is almost the same as that of the complete red sandstone sample. This is because cement joints are a porous material with a higher plastic deformation capacity than sandstone. When the joint inclination is 0°, it is mainly subjected to axial impact loads. At this time, the strain is the superposition of the compression deformation of the cement joints and the deformation of the red sandstone matrix. Therefore, the peak strain will be higher than that of the complete red sandstone sample. When the joint inclination is 15° and 30°, the compression deformation of the cement joints is reduced compared to 0°, and the deformation of the red sandstone matrix is ​​also reduced. The corresponding peak strain is also smaller than that at 0° joint inclination. The complete sample shows an inverted V-shaped change trend to a joint inclination of 30°.

[0113] When the joint inclination is 45°, a double stress peak appears, and the peak stress and peak strain of the first peak are very small. At this time, the deformation of the cement joint is small, and the corresponding compression deformation of the red sandstone matrix is ​​not large. Therefore, the peak strain drops sharply in the stage of joint inclination of 30° to 45°.

[0114] When the joint inclination is 60°, the cement joint is located at the edge of the sample. At this time, the strain of the sample is basically determined by the deformation of the cement joint, and the matrix hardly produces strain. Therefore, the deformation reaches the minimum value.

[0115] Subsequently, when the joint inclination angle is 75°, the cement joint runs through both ends of the sample, and the red sandstone matrix is ​​hit head-on. At this time, the deformation is restored to the state of 15° and 30°, which is determined by the superposition of the compression deformation of the cement joint and the deformation of the red sandstone matrix, among which the deformation of the matrix is ​​dominant. Therefore, the peak strain is greatly increased compared with the 60° joint sample.

[0116] When the joint inclination is 90°, the sample is equivalent to two pieces of red sandstone cemented in the middle and a cement joint, forming a matrix-joint-matrix (hamburger type) sample for impact. At this time, the strain is the superposition of the compression deformation of the cement joint and the deformation of the red sandstone matrix, and the peak strain is the maximum value among all sample types.

[0117] S34. According to the dynamic mechanical property analysis curve, the dynamic mechanical property analysis results of the relationship between the dynamic elastic modulus and the joint inclination of the jointed red sandstone are obtained.

[0118] Depend on Figure 8 It can be seen that the elastic modulus of the jointed red sandstone is significantly smaller than that of the intact red sandstone. At 0° and 15° angles, at low strain rates (i.e., when the impact pressure is 0.2MPa and 0.22MPa), the elastic modulus increases with the increase of the angle, and the range of change is not large, and there is no obvious change pattern. This is because at low strain rates, the slope of the linear stage is small and due to the cohesion and internal friction angle between the joint surface and the matrix, the cohesion and friction of the cementing surface have not reached the limit value, and the sample has strong resistance to deformation. At this time, the change of the elastic modulus is not large, while at high strain rates (i.e., when the impact pressure is 0.24MPa), the cohesion and friction of the cementing surface reach the limit value. At this time, the degree of slip of the sample along the joint surface is aggravated, and the sample's ability to resist deformation is weakened. Therefore, the dynamic elastic modulus decreases with the increase of the joint angle.

[0119] At a joint angle of 45°, Figure 5 It can be seen that there are double stress peaks. In this paper, the first peak is selected as the peak stress. At this time, the elastic modulus at the four angles of 30°, 45°, 60°, and 75° is not much different, and there is basically no change. This is because the damage at these four joint inclinations is mainly controlled by the damage of the joints. The peak stress and its corresponding peak strain are not large, and are much smaller than those of the complete specimen. Therefore, the deformation resistance at these four angles is much weaker than that of the complete specimen.

[0120] The elastic modulus at the 90° joint inclination angle is much higher than that at other angles under the same air pressure, and is very close to the elastic modulus of the complete sample. This is because the joint surface of the 90° joint is parallel to the direction of the impact load. At this time, the sample is equivalent to two pieces of red sandstone cemented in the middle and a cement joint to form a matrix-joint matrix (hamburger type) structure for impact. The deformation resistance at this time is also superior to that of samples at other inclination angles. S35. According to the morphological image, the dynamic mechanical characteristics analysis results of the jointed red sandstone failure mode are obtained.

[0121] In this example, the final failure mode of the specimen is as follows: Fig. 9As shown in the figure, when the joint inclination angles are 0°, 15°, 75°, and 90°, the final failure modes are similar, with a small number of large fragments and a large number of flaky fragments. Among them, the 90° sample is closest to the failure mode of the complete sample, but the overall strength of the sample is weakened by the presence of joints, so the degree of fragmentation is greater. Compared with other angles, the sample integrity of 30°, 45°, and 60° samples is significantly higher. When the joint inclination angles are 45° and 60°, the integrity of the sample is better because it is mainly affected by interface shear failure, and a large volume of red sandstone matrix is ​​retained. In particular, the sample with a joint inclination angle of 60° is broken into two halves along the joint, and the locations where the failure occurs are almost all near the joints.

[0122] S4. Through the energy curve, the energy evolution of jointed red sandstone under impact load is analyzed.

[0123] Wherein, step S4 further comprises the following steps: S41. According to the energy dissipation characteristic analysis curve, an energy dissipation analysis result of the relationship between the energy of the jointed red sandstone and the joint inclination angle is obtained.

[0124] In this embodiment, as shown in FIG10 , under the same impact pressure, compared with the intact sample, the value of the reflected energy of the joint sample is obviously closer to the incident energy, and the transmitted energy and the absorbed energy are very close. And the value of the transmitted energy is always smaller than the absorbed energy and the reflected energy, indicating that only a small amount of energy is transmitted through the sample. With the increase of the joint inclination angle, the transmitted energy and the absorbed energy first increase and then decrease. The absorbed energy is the smallest at 45° and 60°, and the absorbed energy is the largest at 0° and 90°, showing a U-shaped change trend.

[0125] Due to the large difference in wave impedance between the elastic steel rod, the red sandstone matrix and the cement joint, when the incident energy acts on the contact surface between the incident rod and the red sandstone matrix, due to the mismatch in wave impedance between the two, part of the energy is reflected back to the incident rod to form reflected energy, and the remaining incident energy acts on the red sandstone matrix. When it reaches the contact surface between the red sandstone matrix and the cement joint, due to the large difference in wave impedance between the two, part of the energy is reflected back. Most of the energy passing through the cement joint specimen is absorbed by the rough cement joint surface and the red sandstone matrix and then lost, and only a small part passes through the specimen to reach the transmission rod to form a transmission wave. Therefore, compared with the complete specimen, the transmission energy of the joint specimen to the transmission rod is smaller.

[0126] When the joint inclination is 45° and 60°, the volume of the joint that needs to be penetrated is the largest, and the relative slip at the joint surface is the most serious. The reflected energy is the largest at this time, and more energy is reflected back, and the corresponding absorption energy and transmission energy are the smallest. The incident energy and the reflected energy are very close, the energy absorbed by the sample is the smallest, and the energy utilization rate acting on the sample destruction is the smallest. When the joint inclination is 75° and 90°, the cement joint runs through both ends of the sample, and the red sandstone matrix is ​​hit head-on. At this time, the volume of the joint that needs to be penetrated is small, so the absorption energy is large and is almost the same as that at a 0° inclination.

[0127] As the strain rate increases, each energy is increasing. At different strain rates, incident energy>reflected energy>dissipated energy>transmitted energy. From the comparison of the three figures, although the incident energy fluctuates due to the different bullet exit velocities in each test, in general, as the impact velocity increases, the transmission energy increases relatively, and the corresponding reflected energy, transmitted energy, and absorbed energy all increase, showing an obvious strain rate effect.

[0128] S42. According to the energy dissipation characteristic analysis curve, the energy dissipation analysis results of the relationship between the unit volume dissipation energy of the jointed red sandstone and the joint inclination angle are obtained.

[0129] In this embodiment, under different impact pressures, the energy density per unit volume is as follows: Fig.11 As shown in the figure, it can be seen that with the change of joint inclination, the energy density per unit volume first decreases and then increases with the increase of inclination, showing a U-shaped change trend. It shows an obvious strain rate effect and increases with the increase of impact gas pressure. Combined with the analysis of the morphology of the crack initiation stage of the specimen, when the joint inclination is 0°, the energy absorption rate is the largest, most of the energy is used to destroy the red sandstone matrix, the energy utilization rate is the highest, and the energy density per unit volume is the largest.

[0130] When the joint inclination angles are 15°, 30°, and 45°, the dissipated energy per unit volume gradually decreases as the joint inclination angle increases. The dissipated energy per unit volume at 45° is the smallest. A large amount of energy is not absorbed by the sample and does not participate in the destruction of the sample, but is directly transmitted through the sample to the transmission rod and converted into transmission energy.

[0131] At the 60° joint, the energy dissipated per unit volume is the minimum when the low impact pressure is 0.2MPa. It is slightly greater than 45° at 0.22MPa, and is much different from 45° at 0.24MPa. This is because the greater the impact pressure, the greater the impact velocity, and the shorter the time the energy acts on the sample.

[0132] When the joint is 75°, the energy dissipation density per unit volume is between 0° and 15°. When the joint inclination is 90°, the sample is equivalent to two pieces of red sandstone cemented in the middle and a cement joint to form a matrix-joint-matrix (hamburger type) structure under dynamic impact. The energy dissipation density per unit volume is lower than 75° at 0.22MPa and 0.24MPa, but higher than 75° at 0.2MPa due to the lower impact velocity.

[0133] S43. According to the energy dissipation characteristic analysis curve, an energy dissipation analysis result of the relationship between the energy reflection coefficient of the jointed red sandstone and the joint dip angle is obtained.

[0134] In this embodiment, under different impact pressures, the energy reflection coefficient is as follows: Fig.12 As shown in the figure, with the increase of joint inclination, the energy reflection coefficient first increases and then decreases, reaching minimum values ​​at 0° and 90° and maximum values ​​at 45° and 60°, and the dissipated energy density per unit volume shows an inverted U-shaped change trend.

[0135] From 0° to 45°, the energy reflection coefficient increases gradually. Figure 6 It can be seen that its dynamic compressive strength also gradually decreases. At this time, the angle at which the joint volume that needs to be penetrated is the largest, and more energy is reflected back without causing damage to the sample. Therefore, the energy reflection coefficient gradually increases and reaches a peak at 45°.

[0136] At 60° to 90°, the energy reflection coefficients are similar because the failure modes at 45° and 60° are similar. As the inclination angle increases, the energy reflection coefficient decreases gradually, and the failure mode changes from sliding along the joint surface at 60° to tensile failure around the joint. Figure 6 It can be seen that its dynamic compressive strength gradually increases, the volume of joints that need to be penetrated gradually decreases, the energy reflected back gradually decreases, and more energy acts on the destruction of the sample.

[0137] The curve shows an obvious strain rate effect, and it decreases with the increase of the impact pressure. This is because the greater the impact pressure, the greater the impact velocity, the greater the incident energy, the less obvious the effect caused by the wave impedance difference between the elastic rigid rod, the red sandstone matrix and the cement joint, and the smaller the corresponding reflection energy. Therefore, the greater the absorption energy acting on the sample damage and the transmission energy passing through the sample, the smaller the ratio of the reflection energy to the incident energy, that is, the energy reflection coefficient.

[0138] See also Fig.13 , Fig.13The schematic diagram of the structure of a red sandstone mechanical properties and energy evolution analysis system under impact load in an embodiment of the present invention. The system includes an input device, a processor, an output device and a memory, wherein the input device, the processor, the output device and the memory are interconnected, wherein the memory is used to store a computer program, the computer program includes program instructions, the processor is configured to call the program instructions, and the system uses the red sandstone mechanical properties and energy evolution analysis method under impact load.

[0139] In this embodiment, the input device includes a scanner and a touch screen. The scanner is used to scan the final failure form of the joint sample under different joint inclination angles, and the touch screen is used to input the thickness, volume, joint inclination angle, dynamic compressive strength, elastic modulus, strain, energy and stress parameters of the jointed red sandstone.

[0140] The processor includes a data processing module and a data analysis module. The data processing module is used to process data on parameters related to mechanical properties and energy evolution of red sandstone under impact load and form a data set; the data analysis module is connected to the data processing module to analyze the relationship between the data sets.

[0141] The output device includes an intelligent display screen, which is used to display the data set obtained by the processor in the form of a curve and display the analysis results of the curve data.

[0142] In summary, the relevant curve of the present invention shows an obvious strain rate effect, and it decreases with the increase of the impact pressure. This is because the greater the impact pressure, the greater the impact speed, the greater the incident energy, the less obvious the effect caused by the wave impedance difference between the elastic rigid rod, the red sandstone matrix and the cement joint, and the smaller the corresponding reflection energy. Therefore, the greater the absorption energy acting on the sample damage and the transmission energy transmitted through the sample, the smaller the ratio of the reflection energy to the incident energy, that is, the energy reflection coefficient.

[0143] The present invention uses a Hopkinson test system to conduct uniaxial impact compression tests on red sandstone samples with different joint arrangements. Based on the test results, the intact samples and joint samples are compared to study the influence of joint morphology on the stress-strain curve, elastic modulus, dynamic compressive strength, and peak strain of the joint samples. At the same time, the energy evolution characteristics of joints with different inclination angles are studied in combination with the failure morphology and energy dissipation theory. The main conclusions can be summarized as follows: (1) In the Hopkinson bar test, the stress-strain curve can be divided into four stages: compaction stage, linear elastic stage, crack initiation stage, and unloading stage. The curve of the 45° inclination specimen shows an obvious stress double peak phenomenon. At small angles of 0°, 15°, and 30°, the compaction stage has a large span, the brittle deformation capacity is weakened, and good plastic deformation capacity is reflected. At 75° and 90°, the compaction stage and the plastic deformation stage have a small span, reflecting brittle failure characteristics similar to those of the intact specimen.

[0144] (2) With the increase of the joint inclination angle, the dynamic compressive strength and its corresponding peak strain first decrease and then increase, and reach the minimum value at 45°. At this time, the strength of the joint specimen is the lowest, and the bearing capacity is lost when the strain is small. The elastic modulus does not change much at small angles of 0°, 15° and 30°. The dynamic elastic modulus at an inclination of 90° is the highest, which is closest to the complete specimen, indicating that it has a strong ability to resist deformation. Its dynamic mechanical properties are closest to the complete specimen.

[0145] (3) Through calculation, it is found that the incident energy, reflected energy, and transmitted energy in the uniaxial impact test all increase steadily with the increase of the impact pressure. The minimum value is at 60°, at which time the energy acting on the sample is the smallest. Under uniaxial compression conditions, the unit volume dissipated energy is closely related to the dynamic compressive strength. The change trends of the two are also similar, both showing a U-shaped change, and increase with the increase of the impact pressure, showing a strain rate effect. However, the energy reflection coefficient is opposite to its change trend and shows an inverted U-shape, which decreases with the increase of the impact pressure.

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for analyzing the mechanical properties and energy evolution of red sandstone under impact load, characterized in that: The method comprises the following steps: Obtain test data and morphological images of jointed red sandstone; Using the test data, a mechanical curve and an energy curve of jointed red sandstone are obtained; According to the mechanical curve and the morphological image, the mechanical properties of the jointed red sandstone under impact load are analyzed; The energy curve is used to analyze the energy evolution of jointed red sandstone under impact load.

2. The method for analyzing mechanical properties and energy evolution of red sandstone under impact load according to claim 1 is characterized in that: The method of obtaining the test data and morphological images of the jointed red sandstone includes: The thickness, volume, joint inclination, dynamic compressive strength, elastic modulus, strain, stress, incident energy, reflected energy, transmitted energy, absorbed energy data and final failure morphology images of jointed red sandstone are obtained.

3. The method for analyzing mechanical properties and energy evolution of red sandstone under impact load according to claim 1 is characterized in that: The method of obtaining the mechanical curve and energy curve of the jointed red sandstone by using the test data includes: Using the test data, a dynamic mechanical property analysis curve of jointed red sandstone is obtained; By using the test data, an energy dissipation characteristic analysis curve of jointed red sandstone is obtained.

4. The method for analyzing mechanical properties and energy evolution of red sandstone under impact load according to claim 3 is characterized in that: The method of obtaining the dynamic mechanical property analysis curve of jointed red sandstone by using the test data includes: Using the test data, a dynamic mechanical characteristic analysis curve of stress and strain of jointed red sandstone is obtained; Using the test data, a dynamic mechanical characteristic analysis curve of the dynamic compressive strength and joint inclination of jointed red sandstone is obtained; Using the test data, a dynamic mechanical characteristic analysis curve of the peak strain and joint inclination of jointed red sandstone is obtained; By using the test data, dynamic mechanical characteristic analysis curves of the dynamic elastic modulus and joint inclination of jointed red sandstone are obtained.

5. The method for analyzing mechanical properties and energy evolution of red sandstone under impact load according to claim 3 is characterized in that: The method of obtaining the energy dissipation characteristic analysis curve of jointed red sandstone by using the test data includes: Using the test data, an energy dissipation characteristic analysis curve of jointed red sandstone energy and joint dip angle is obtained; Using the test data, an energy dissipation characteristic analysis curve of the jointed red sandstone unit volume dissipation energy and the joint inclination angle is obtained; By using the test data, energy dissipation characteristic analysis curves of jointed red sandstone energy reflection coefficient and joint dip angle are obtained.

6. The method for analyzing mechanical properties and energy evolution of red sandstone under impact load according to claim 1 is characterized in that: The analysis of the mechanical properties of jointed red sandstone under impact load according to the mechanical curve and the morphological image includes: According to the dynamic mechanical property analysis curve, the dynamic mechanical property analysis results of jointed red sandstone are obtained; According to the dynamic mechanical characteristics analysis results and the morphological images, the mechanical properties of jointed red sandstone under impact load are analyzed.

7. The method for analyzing mechanical properties and energy evolution of red sandstone under impact load according to claim 1 is characterized in that: The analysis of the energy evolution of jointed red sandstone under impact load by using the energy curve includes: The energy dissipation characteristic analysis results of jointed red sandstone are obtained through the energy dissipation characteristic analysis curve; The energy dissipation characteristic analysis results are used to analyze the energy evolution of jointed red sandstone under impact load.

8. The method for analyzing mechanical properties and energy evolution of red sandstone under impact load according to claim 6 is characterized in that: The dynamic mechanical property analysis results of the jointed red sandstone are obtained according to the dynamic mechanical property analysis curve, including: According to the dynamic mechanical characteristic analysis curve, the dynamic mechanical characteristic analysis results of the stress and strain relationship of jointed red sandstone are obtained; According to the dynamic mechanical property analysis curve, the dynamic mechanical property analysis results of the relationship between the dynamic compressive strength and joint inclination of jointed red sandstone are obtained; According to the dynamic mechanical characteristic analysis curve, the dynamic mechanical characteristic analysis results of the relationship between the joint red sandstone strain peak value and the joint inclination angle are obtained; According to the dynamic mechanical property analysis curve, the dynamic mechanical property analysis results of the relationship between the dynamic elastic modulus and the joint inclination of the jointed red sandstone are obtained.

9. The method for analyzing mechanical properties and energy evolution of red sandstone under impact load according to claim 7 is characterized in that: The energy dissipation characteristic analysis results of the jointed red sandstone obtained by the energy dissipation characteristic analysis curve include: Through the energy dissipation characteristic analysis curve, the energy dissipation characteristic analysis results of the relationship between the energy of jointed red sandstone and the joint inclination angle are obtained; Through the energy dissipation characteristic analysis curve, the energy dissipation characteristic analysis results of the relationship between the unit volume dissipation energy and the joint inclination of the jointed red sandstone are obtained; Through the energy dissipation characteristic analysis curve, the energy dissipation characteristic analysis results of the relationship between the energy reflection coefficient of jointed red sandstone and the joint dip angle are obtained.

10. A red sandstone mechanical properties and energy evolution analysis system under impact load, the system using a red sandstone mechanical properties and energy evolution analysis method under impact load according to any one of claims 1 to 9, characterized in that: The system includes an input device, a processor, an output device and a memory, wherein the input device, the processor, the output device and the memory are connected to each other, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions.

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