Automatic testing system and method for shear strength of mine filling body

Abstract

The invention relates to the technical field of mechanical testing of materials, in particular to an automatic testing system and method for shear strength of a mine filling body, and the system comprises a critical state recognition module which collects real-time data of shear force and shear displacement of the mine filling body in the process of testing the shear strength of the mine filling body and converts the real-time data into a curve for representation; and calculating a gradient mutation point of the curve, and marking a key state change position in the shearing process by referring to the gradient mutation point to obtain parameter characteristics at the shear failure moment. According to the method, dynamic data of shearing force and shearing displacement are collected in real time and converted into a shearing curve, gradient mutation points in the curve are accurately calculated, key state changes of the shearing process are marked, the critical state of converting the shearing bearing capacity of the material into structural instability is recognized, and a key basis is provided for analysis of the shearing strength.

Description

Technical Field

[0001] The invention relates to the technical field of material mechanics testing, and in particular to an automated testing system and method for shear strength of mine filling bodies. Background Art

[0002] The field of material mechanics testing technology includes technologies for measuring and analyzing the mechanical properties of materials under external forces. The core content of this technical field is to study the performance parameters of materials such as strength, deformation and stability. By testing and analyzing the mechanical properties of materials under different loading conditions, it provides important data support for engineering design, structural safety assessment and material modification.

[0003] Among them, the mine backfill shear strength automatic test system is a special equipment used to measure the shear strength of mine backfill materials under shear force. The system is aimed at the shear performance test of mine backfill materials. By placing the backfill sample in the shear test equipment and applying a certain shear force and normal pressure, the mechanical parameters under the failure state are recorded to complete the shear strength measurement. Specifically, an automated loading device is used to accurately apply and control the shear force and normal pressure, and sensors are equipped to collect mechanical data in real time. The entire test process is completed through automatic calculation and recording.

[0004] It is difficult for existing technologies to accurately capture the key turning point from load-bearing to instability of materials during shear strength testing. Usually, they can only be analyzed through maximum shear force and displacement values, and fail to effectively mark the critical state of the material. For example, in the process of shear damage of the filling body, the existing method cannot dynamically analyze the changing trend of the curve according to real-time data, resulting in a lag in the identification of key states. In addition, it is difficult for existing technologies to analyze the dynamic laws of the shear damage stage section by section during the test process. For example, it is impossible to accurately extract the characteristics of shear force attenuation and shear displacement growth, and it is difficult to reveal the synergistic relationship between the two. For the phenomenon of local stress concentration during the test process, the existing technology lacks flexible adjustment of the loading ratio and path, which may lead to uneven loading, thereby affecting the stability and accuracy of the data. Taking stress concentration as an example, when the local shear force surges, the existing method cannot intervene in the change of mechanical parameters in a timely manner, which may cause deviations in the test results. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose an automatic testing system and method for the shear strength of mine filling bodies.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: The automatic testing system for shear strength of mine filling body comprises: The critical state identification module collects the real-time data of shear force and shear displacement of the mine filling body during the shear strength test of the mine filling body and converts it into a curve representation, calculates the gradient mutation point of the curve, and marks the key state change position in the shear process with reference to the gradient mutation point to obtain the parameter characteristics of the shear failure moment; A loading response prediction module is used to predict the future dynamic development of the shear force and shear displacement after the critical point from the dynamic change trend of the shear force and shear displacement in the parameter characteristics at the moment of shear failure, and to generate a dynamic development sequence of the shear failure stage; The loading path optimization module performs segmented analysis on the attenuation law of the shear force and the growth rate of the shear displacement in the dynamic development sequence of the shear failure stage, analyzes the synergistic relationship between the shear force and the shear displacement in each stage, and generates segmented shear loading relationship analysis results; The loading coordination control module monitors the change ratio of shear force and shear displacement of each segment in the shear loading segment relationship analysis result in real time, identifies the local stress concentration phenomenon based on the coordinated relationship between shear force and shear displacement, adjusts the loading distribution of shear force and shear displacement according to the identification result, and generates the shear strength test result of the mine filling body.

[0007] As a further solution of the present invention, the step of calculating the gradient mutation point of the curve is specifically: Collect the real-time data of shear force and shear displacement of the mine filling body during the shear strength test of the mine filling body, convert the shear force and shear displacement changes in the real-time data into a curve representation, wherein the horizontal axis of the curve represents the shear displacement and the vertical axis represents the shear force, and obtain the shear curve diagram of the mine filling body; Based on the data in the shear curve of the mine filling body, the shear force is , the shear displacement is , using the formula: ; Calculate the gradient change value of the curve ,when When reaching the extreme value, the corresponding point is determined to be the gradient mutation point of the curve; in, Indicates the shear force on the mine filling during the test. is the gradient change value, It indicates the displacement of the mine filling body along the shear direction during the shear test. is the interval displacement difference of the slope change amplitude.

[0008] As a further solution of the present invention, the step of obtaining the parameter characteristics at the shear failure moment is specifically as follows: According to the gradient mutation point of the curve in the shear curve diagram of the mine filling body, the position of the gradient mutation point is marked, and by analyzing the change trend of the shear force before and after the marked point, the transition of the mine filling body from shear bearing capacity to structural instability is identified, and the critical state transition position is obtained; Based on the critical state transition position, the shear force and shear displacement correlation data at the shear failure moment are extracted, and combined with the change trend near the failure point, the parameters are integrated to generate the parameter characteristics of the shear failure moment.

[0009] As a further solution of the present invention, the steps for obtaining the dynamic development sequence of the shear failure stage are specifically as follows: The dynamic change trend of shear force and shear displacement is extracted from the parameter characteristics at the shear failure moment, using the formula: ; Calculate the next moment Shear force , in Newtons ( ), and obtain the dynamic change prediction result; in, Indicates the shear force measured in the shear test at the current moment, is the adjustment factor, is the sliding window length, is the sliding mean of the shear force, Indicates the shear force value at the moment; Based on the dynamic change prediction results, the attenuation law of shear force and the growth rate of shear displacement in the shear failure stage are analyzed, the change characteristics of shear force and shear displacement are extracted point by point, and the dynamic development sequence of the shear failure stage is generated.

[0010] As a further solution of the present invention, the step of obtaining the shear loading segment relationship analysis result is specifically as follows: Based on the dynamic development sequence of the shear failure stage, the shear force attenuation law and the shear displacement growth rate are analyzed segment by segment, and the shear force change amplitude and shear displacement change amount are extracted segment by segment to generate the shear force and shear displacement change characteristics within the segment. Based on the variation characteristics of shear force and shear displacement within the segment, the formula is adopted: ; Calculation represents the total score of shear force and shear displacement after the corresponding segmented collaborative optimization , and obtain the analysis results of the shear loading segment relationship; in, Indicates the number of the segment in the dynamic development sequence of the shear failure stage, represents the total number of segments in the dynamic development sequence of the shear failure stage, Indicates The weight of the segment in the overall collaborative optimization objective, Indicates Score for the synergy between shear force and shear displacement within a segment.

[0011] As a further solution of the present invention, the step of identifying the local stress concentration phenomenon is specifically: The changes of shear force and shear displacement of each segment in the shear loading segment relationship analysis results are monitored in real time, using the formula: ; Calculate the The ratio of shear force to shear displacement ; in, It is The segment shear force change amplitude indicates the total change of shear force in the current segment. It is Segment shear displacement variation; Based on the change ratio and in combination with the synergistic relationship between shear force and shear displacement, the local stress concentration phenomenon of each segment is identified to obtain the stress concentration analysis result.

[0012] As a further solution of the present invention, the steps for obtaining the shear strength test results of the mine filling body are specifically as follows: Based on the stress concentration analysis results, the shear force change and shear displacement change data in each segment are extracted, and the shear force loading rate and shear displacement change trend of the abnormal segment are adjusted by analyzing the deviation range of the segment loading ratio, and dynamic monitoring and adjustment are performed to generate the overall mechanical response analysis results; Based on the overall mechanical response analysis results, key parameter data of maximum shear force, maximum shear displacement and failure time are extracted, compared with benchmark data, and the loading adjustment records and change ratios are integrated to generate the shear strength test results of the mine filling body.

[0013] The automatic test method for the shear strength of mine filling body is based on the automatic test system for the shear strength of mine filling body, and comprises the following steps: S1: Based on the real-time data of shear force and shear displacement during the shear strength test of mine filling, the data are converted into curve representation, the gradient mutation points of the curve are calculated, the key state change positions in the shear process are marked with reference to the gradient mutation points, and the parameter characteristics of the shear failure moment are generated; S2: Based on the parameter characteristics at the moment of shear failure, the dynamic change trend of shear force and shear displacement is analyzed, the future dynamic development of shear force and shear displacement after the critical point is predicted, and a dynamic development sequence of the shear failure stage is generated; S3: Based on the dynamic development sequence of the shear failure stage, the attenuation law of the shear force and the growth rate of the shear displacement are analyzed, the synergistic relationship between the shear force and the shear displacement in each stage is analyzed, and the segmented relationship analysis results of the shear loading are generated; S4: Based on the analysis results of the shear loading segment relationship, the change ratio of shear force and shear displacement of each segment is monitored in real time. Combined with the synergistic relationship between shear force and shear displacement, the local stress concentration phenomenon is identified, and the loading distribution of shear force and shear displacement is adjusted to generate the shear strength test results of the mine filling body.

[0014] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, by real-time acquisition of dynamic data of shear force and shear displacement, and converting them into shear curves, the gradient mutation points in the curves are accurately calculated, the key state changes of the shear process are marked, and the critical state of the material from shear bearing capacity to structural instability is identified, which provides a key basis for the analysis of shear strength. Combined with the prediction of the dynamic change trend of shear force and shear displacement, the scheme predicts the short-term trend of shear force changes by the sliding average method, further analyzes the mechanical laws of the shear failure stage, extracts key mechanical features and generates a dynamic development sequence. In the segmented optimization, the scheme extracts the characteristics of shear force attenuation and shear displacement growth section by section, deeply analyzes the synergistic relationship between the two, identifies the stress concentration phenomenon in each test section, avoids local imbalance problems, and flexibly adjusts the proportion distribution during the test process. Finally, by extracting key parameters such as maximum shear force, maximum shear displacement and failure time, and comparing them with benchmark data, the mechanical response is fully quantified, the accuracy and efficiency of the test are improved, and data support is provided for the shear strength test of the material. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a system flow chart of the present invention; Figure 2 A flow chart of calculating the gradient mutation point of a curve of the present invention; Figure 3 A flow chart of obtaining parameter characteristics of shear failure moment for the present invention; Figure 4 A flow chart for obtaining a dynamic development sequence of the shear failure stage in the present invention; Figure 5 A flow chart for obtaining the shear-loading segment relationship analysis result of the present invention; Figure 6 A flow chart for identifying local stress concentration phenomena according to the present invention; Figure 7 The present invention is a flow chart for obtaining the shear strength test results of mine filling bodies. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0017] See also Figure 1 The present invention provides a technical solution: an automatic testing system for shear strength of mine filling bodies comprises: The critical state identification module collects the real-time data of shear force and shear displacement of the mine filling body during the shear strength test of the mine filling body and converts it into a curve representation, calculates the gradient mutation point of the curve, and marks the key state change position in the shear process with reference to the gradient mutation point to obtain the parameter characteristics of the shear failure moment; The loading response prediction module predicts the future dynamic development of shear force and shear displacement after the critical point from the dynamic change trend of shear force and shear displacement in the parameter characteristics at the moment of shear failure, and generates the dynamic development sequence of the shear failure stage; The loading path optimization module analyzes the attenuation law of shear force and the growth rate of shear displacement in the dynamic development sequence of the shear failure stage in sections, analyzes the synergistic relationship between shear force and shear displacement in each stage, and generates the analysis results of the shear loading section relationship; The loading coordination control module monitors the change ratio of shear force and shear displacement in each segment in the shear loading segment relationship analysis results in real time, identifies the local stress concentration phenomenon based on the coordinated relationship between shear force and shear displacement, adjusts the loading distribution of shear force and shear displacement according to the identification results, and generates the shear strength test results of the mine filling body; The parameter characteristics at the moment of shear failure specifically include the position where the shear bearing capacity decreases, the starting position of structural instability, and the key change points of shear force and shear displacement; the dynamic development sequence of the shear failure stage includes the shear force attenuation trend sequence, the shear displacement growth trend sequence, and the predicted value of the shear parameter change after the critical point; the results of the shear loading segmented relationship analysis specifically include the shear force segmented change characteristics, the shear displacement segmented growth law, and the segmented coordinated relationship between shear force and shear displacement; the shear strength test results of mine filling bodies include shear strength test data, shear stage response characteristics, and overall mechanical parameters of the shear failure stage.

[0018] See also Figure 2 , the steps for calculating the gradient mutation point of the curve are as follows: Collect the real-time data of shear force and shear displacement of the mine filling body during the shear strength test of the mine filling body, convert the shear force and shear displacement changes in the real-time data into a curve representation, wherein the horizontal axis of the curve represents the shear displacement and the vertical axis represents the shear force, and obtain the shear curve diagram of the mine filling body; The real-time data of shear force and shear displacement of mine filling bodies are collected during the shear strength test of mine filling bodies. The signals collected by shear force sensor and displacement sensor are input into the computer using data acquisition software such as LabVIEW. The collected real-time data are processed and visualized through the software, and the numerical signals of shear force and shear displacement are sorted into corresponding time series data. The corresponding relationship between shear force and shear displacement is constructed using time series data, and a smooth curve is generated through data interpolation method. The horizontal axis of the generated curve is set to shear displacement, and the vertical axis is set to shear force, completing the curve conversion of shear force and shear displacement changes.

[0019] Based on the data in the shear curve of the mine filling body, the shear force is , the shear displacement is , using the formula: ; Calculate the gradient change value of the curve ,when When reaching the extreme value, the corresponding point is determined to be the gradient mutation point of the curve; in, It indicates the shear force on the mine filling during the test, in Newton ( ), collected in real time by a shear tester, which uses a force sensor to monitor the shear force corresponding to each unit displacement during the test and records it as discrete point data to form a data set of the relationship between shear force and shear displacement. Indicates the displacement in the shear direction during the test, in millimeters ( ), collected in real time by displacement sensors. In the experiment, the shear displacement is directly recorded by the sensor and recorded at the displacement point of each loading step. It is the gradient change value, and also represents the absolute value of the second-order derivative of shear force with displacement. It is used to measure the severity of shear force change, and its unit is Newton per square millimeter ( ), through the shear force The acquisition point sequence is numerically calculated and the calculation formula is: , is the interval displacement difference of the slope change amplitude, the formula is: , is the shear force discrete data points, representing the The shear force corresponding to each sampling displacement point is in Newton ( ), collected directly by a shear tester, for example, if The displacement points are , and its corresponding shear force value is , is the shear force discrete data points, representing the The shear force corresponding to each sampling displacement point is in Newton ( ), collected directly by a shear tester, for example, if The displacement points are , and its corresponding shear force value is , is the shear force discrete data points, representing the The shear force corresponding to each sampling displacement point is in Newton ( ), collected directly by a shear tester, for example, if The displacement points are , and its corresponding shear force value is , is the th discrete data point of shear displacement, indicating the sampling displacement points, in millimeters ( ), collected directly by a shear tester, e.g. The displacement point may be , is the shear displacement discrete data points during the shear test. sampling displacement points, in millimeters ( ), collected directly by a shear tester, e.g. The displacement point may be , is the shear displacement discrete data points during the shear test. sampling displacement points, in millimeters ( ), collected directly by a shear tester, e.g. The displacement point may be .

[0020] If the following shear force and shear displacement data points are collected through experiments (unit: ): ; Calculate the gradient change value: According to the formula: ; ; In the calculated gradient change value sequence, is the maximum value, so is the gradient mutation point.

[0021] See also Figure 3 , the specific steps for obtaining the parameter characteristics of the shear failure moment are: According to the gradient mutation point of the curve in the shear curve diagram of the mine filling body, the position of the gradient mutation point is marked, and by analyzing the change trend of the shear force before and after the marked point, the transition of the mine filling body from shear bearing capacity to structural instability is identified, and the critical state transition position is obtained; First, the discrete points of shear force and shear displacement are extracted from the shear test data, and the gradient change value of shear force as shear displacement changes is calculated. , determine the location of the gradient mutation point, and change the gradient mutation point Mark the key state change position; take the gradient mutation point as the reference point and record the shear force value corresponding to the mutation point and shear displacement values , and then analyze the changing trends of shear force and shear displacement before and after the marking point. By observing the stable increase of shear force before the marking point and the rapid decrease trend after the marking point, the transition of mine filling from shear bearing capacity to structural instability is identified; for example, in a certain experiment, when the shear displacement increases from 0mm to 10mm, the collected shear force change trend shows a staged increase from 0N to 500N, but when the shear displacement reaches the gradient mutation point corresponding to 10mm, the shear force drops rapidly to 300N, and the shear displacement continues to increase. Therefore, it is judged that the rapid decrease of shear force is a manifestation of structural instability of mine filling, and the gradient mutation point is the location of the critical state transition.

[0022] Based on the critical state transition position, the shear force and shear displacement correlation data at the shear failure moment are extracted, and the parameter characteristics at the shear failure moment are generated by integrating the parameters in combination with the change trend near the failure point. Combined with the gradient mutation points identified above And its corresponding shear force value , analyze the characteristics of the shear failure moment, extract the shear force and shear displacement change trends near the failure moment from the collected shear test data, and record the change amplitude of the shear force before and after the gradient mutation point. For example, the shear force drops from 500N to 300N, corresponding to the shear displacement increase from 10mm to 12mm; by statistically analyzing the gradient change values ​​at the key state change positions and shear force value , these data are integrated into a parameter feature set at the moment of shear failure, and the critical parameters of mine filling bodies in the shear failure stage are further calibrated to quantify the shear strength characteristics.

[0023] See also Figure 4 , the specific steps for obtaining the dynamic development sequence of the shear failure stage are: The dynamic change trend of shear force and shear displacement is extracted from the parameter characteristics at the moment of shear failure using the formula: ; Calculate the next moment Shear force , in Newtons ( ), and obtain the dynamic change prediction result; in, Indicates the shear force measured in the shear test at the current moment, in Newtons ( ), directly collected by the force sensor in the shear tester, is the adjustment coefficient, which indicates the weight ratio of the current shear force and the historical average shear force to the future predicted value, and its value range is [0,1]. The specific value of is set according to the volatility of the shear force data. By analyzing the fluctuation range of historical shear force data, it is determined that a smaller value (such as 0.4) is used when it is relatively stable, and a larger value (such as 0.7) is used when the volatility is strong. is the sliding window length, which indicates the number of historical data points used for sliding average calculation. It has no unit and its specific value is set by the shear force sampling frequency and the number of experimental historical data points. For example, if the sampling is performed once per second and the data of the last 5 seconds is analyzed, then , is the sliding average of the shear force, which means from the moment arrive of The sum of shear force data, unitless, calculated from the historical data of the sliding window, Represents the time index within the sliding window, and its value range is arrive , obtained by traversing historical data points, Indicates the shear force value at the moment, in Newton ( ), collected directly by the shear tester, is the weight of the historical shear force average value, indicating the influence ratio of the sliding average value in the prediction formula, with a value range of [0,1]. The values ​​of are determined complementary to each other.

[0024] If the shear force data collected by the shear tester during the shear test is: , the sliding window length is , the adjustment factor is , the sliding average calculation formula is: , calculate the sliding average: The sliding window length is , current moment , then take and Substitute the shear force data into the formula: ; Prediction Moment Shear force value: According to the prediction formula: ; Substitute known parameters: Current moment Shear force ; Sliding average ; Adjustment coefficient .but ; The results show that the calculated time The predicted shear stress is .

[0025] Based on the dynamic change prediction results, the attenuation law of shear force and the growth rate of shear displacement in the shear failure stage are analyzed, the change characteristics of shear force and shear displacement are extracted point by point, and the dynamic development sequence of the shear failure stage is generated; The shear force and shear displacement values ​​corresponding to each moment are extracted from the predicted shear force data and shear displacement data, and the changing trend of the shear force is analyzed point by point. The shear force change amplitude between adjacent moments is calculated, the shear force attenuation value is recorded, and the shear displacement growth value at the corresponding moment is calculated in combination with the shear displacement data, and the changing relationship between the shear force and the shear displacement is recorded; in the analysis process, the decreasing amplitude of the shear force and the increasing speed of the shear displacement over time are compared according to the order of the data points, the shear force attenuation rate and the shear displacement growth rate are extracted, and the attenuation rate and the growth rate are combined to form the dynamic change characteristics of the shear failure stage; for example, in a certain test, the predicted shear force decreases from 174N to 150N, and the shear displacement increases from 10mm to 12mm. By recording the shear force attenuation amplitude of 24N and the shear displacement growth of 2mm point by point, the characteristics of the shear failure stage are further analyzed in combination with the time span of the changes of the two, and finally the attenuation law of the shear force and the growth rate of the shear displacement are integrated to generate a dynamic development sequence of the shear failure stage.

[0026] See also Figure 5 , the specific steps for obtaining the shear loading segment relationship analysis results are: Based on the dynamic development sequence of the shear failure stage, the shear force attenuation law and the shear displacement growth rate are analyzed segment by segment, and the shear force change amplitude and shear displacement change amount are extracted segment by segment to generate the shear force and shear displacement change characteristics within the segment. The attenuation law of shear force and the growth rate of shear displacement in the dynamic development sequence of the shear failure stage are analyzed segment by segment. The dynamic development sequence of the shear failure stage is divided into multiple segments in chronological order to extract the change characteristics of shear force and shear displacement in each segment. First, according to the collected shear force and shear displacement data, the entire sequence is divided into several segments with equal time intervals, and the shear force value and shear displacement value at the starting point and the end point of each segment are recorded. Then, the attenuation amplitude of shear force and the growth amplitude of shear displacement in each segment are calculated to extract their numerical characteristics. In the specific operation, the shear force change and shear displacement change in each segment are used as characteristic descriptions to analyze the distribution of these characteristics in the time dimension segment by segment. For example, in a test sequence, the data of shear force decreasing from 180N to 150N and shear displacement increasing from 10mm to 12mm are divided into a segment, and the change amplitude of shear force in the segment is recorded as -30N, and the change of shear displacement is +2mm. By extracting these segment characteristics in sequence, a segment change characteristic set of shear force and shear displacement in the entire failure stage is formed, which lays the foundation for the subsequent analysis of the correlation between each segment.

[0027] Based on the variation characteristics of shear force and shear displacement within the segment, the formula is adopted: ; The calculation represents the total score of shear force and shear displacement after coordinated optimization of each segment , and obtain the analysis results of the shear loading segment relationship; in, Indicates the segment number in the dynamic development sequence of the shear failure stage, and its value range is , determined by the result of segment analysis, the unique number of each segment obtained by segment division, The total number of segments representing the dynamic development sequence of the shear failure stage, unitless, determined by the segmentation analysis method, such as the number of segments obtained by time interval division or change characteristic division, Indicates The weight of the segment in the overall collaborative optimization objective is determined by factors such as the importance of the segment and the length of the segment. For example, by evaluating the segment with a larger change in shear force, a higher weight is given. Indicates The score of the synergy between shear force and shear displacement within a segment is unitless and is calculated by the degree of matching between the magnitude of shear force change and the magnitude of shear displacement increase within the segment, for example by quantifying the correlation between the changes of the two through normalization methods.

[0028] If the number of segments of the dynamic development sequence of the shear failure stage is , the weight coefficient and synergy score of each segment are as follows: Segment 1: , ; Segment 2: , .

[0029] Calculate the overall synergy score : ; Substitute known parameters: ; Calculation results It represents the overall synergy score after optimization, indicating that the shear force and shear displacement have a certain degree of matching relationship between the segments; by comparing the weights and scores of different segments, the characteristics of each segment can be further optimized to improve the overall synergy effect.

[0030] See also Figure 6 , the specific steps for identifying local stress concentration phenomena are: Real-time monitoring of the changes in shear force and shear displacement of each segment in the shear loading segment relationship analysis results, using the formula: ; Calculate the The ratio of shear force to shear displacement ; in, It is The segment shear force change amplitude indicates the total change of shear force in the current segment, in Newtons ( ), obtained by the difference of shear force data between the starting point and the ending point of the segment: , and They represent the shear force values ​​at the starting point and the ending point of the segment respectively. The shear force data is collected by the force sensor of the shear tester, such as the real-time shear force value recorded in the experiment. It is Segment shear displacement change, indicating the total change in shear displacement within the current segment, in millimeters ( ), obtained by the difference of shear displacement data between the starting point and the ending point of the segment: , and They respectively represent the shear displacement values ​​of the starting point and the ending point of the segment. The shear displacement data is collected by the displacement sensor of the shear tester, such as the real-time displacement data recorded in the experiment.

[0031] If in the shear test, the segment Initial shear force , end shear force ; Initial shear displacement , end shear displacement .

[0032] Shear force changes: ; Shear displacement change: ; Calculate the change ratio: ; Calculation results Indicates segmentation The negative growth ratio of internal shear force to shear displacement.

[0033] Based on the change ratio and the synergistic relationship between shear force and shear displacement, the local stress concentration phenomenon of each segment is identified and the stress concentration analysis results are obtained; By analysing the synergy scores of each segment and change ratio The comprehensive analysis of each segment is used to screen out the possible local stress concentration segments. The distribution statistics of the values ​​are compared with the benchmark change ratio range. For example, in the experiment, the benchmark ratio range is set to , if the change ratio of a segment Beyond this range, e.g. , then it is determined that there is a significant abnormal change in the segment; then combined with the synergy score , further evaluate the overall coordination of abnormal segments, such as a segment And lower than other segment scores , it is further confirmed that the shear force and shear displacement of the segment have poor synergy; finally, by analyzing the characteristics of the abnormal segment, such as combining the shear force change amplitude and shear displacement variation For example, the shear force variation is And the shear displacement variation is , based on this comprehensive judgment, this segment may be a local stress concentration area.

[0034] See also Figure 7 , the specific steps for obtaining the shear strength test results of mine filling bodies are as follows: Based on the stress concentration analysis results, the shear force change and shear displacement change data in each segment are extracted. By analyzing the deviation range of the segment loading ratio, the shear force loading rate and shear displacement change trend of the abnormal segment are adjusted, and dynamic monitoring and adjustment are performed to generate the overall mechanical response analysis results. First, extract the shear force change and shear displacement change in each segment, and calculate the loading ratio deviation of each segment. For example, set the loading balance range to , when the change ratio of a segment exceeds this range, the segment is marked as abnormal loading; by performing distribution analysis on the shear force and shear displacement data of the abnormal loading segment, for example, recording the shear force change of a segment as , the shear displacement changes to , change ratio , the degree of load imbalance of the segment is determined according to the deviation amplitude; then, combined with the real-time loading record of the segment, the shear force loading rate of the abnormal segment is reduced through the dynamic loading adjustment method, for example, the shear force loading rate is reduced from Adjust to , and monitor the change trend of shear displacement at the same time to ensure the load balance range after adjustment; finally, by comparing the change ratio of shear force and shear displacement before and after adjustment of each segment, for example, comparing the load ratio restored to , confirming that the loading balance is improved after adjustment, forming the overall mechanical response analysis results, including the dynamic change trend of shear force and shear displacement, the loading imbalance segmented adjustment record, and the change ratio before and after adjustment.

[0035] Based on the overall mechanical response analysis results, the key parameter data of maximum shear force, maximum shear displacement and failure time are extracted, compared with the benchmark data, and the loading adjustment records and change ratios are integrated to generate the shear strength test results of the mine filling body; Extract key parameter data, including maximum shear force value, maximum shear displacement value, loading adjustment coefficient and failure time, etc. For example, the maximum shear force in the experiment is recorded as The maximum shear displacement is , the loading adjustment factor is The final destruction time is ; Compare and analyze the extracted key parameters with the historical benchmark data. For example, the maximum shear force of the historical benchmark data is , the maximum shear force of the current experiment is higher than the benchmark value , thereby judging that the current mine filling body has a higher shear resistance; then the adjustment records of the shear force and shear displacement of each segment in the experimental record are integrated into the test report, for example, the change ratio of each segment after adjustment is restored to to The range of load balance is significantly improved; finally, the above key parameters, adjustment records and benchmark data comparison results are compiled into a shear strength test report of the mine filling body, which serves as the basis for subsequent evaluation and engineering application, forming a complete test result including various shear characteristic parameters.

[0036] The automatic test method for the shear strength of mine filling body is based on the automatic test system for the shear strength of mine filling body, and comprises the following steps: S1: Based on the real-time data of shear force and shear displacement during the shear strength test of mine filling, the data are converted into curve representation, the gradient mutation points of the curve are calculated, the key state change positions in the shear process are marked with reference to the gradient mutation points, and the parameter characteristics of the shear failure moment are generated; S2: Based on the parameter characteristics at the moment of shear failure, the dynamic change trend of shear force and shear displacement is analyzed, the future dynamic development of shear force and shear displacement after the critical point is predicted, and the dynamic development sequence of the shear failure stage is generated; S3: Based on the dynamic development sequence of shear failure stages, the attenuation law of shear force and the growth rate of shear displacement are analyzed, the synergistic relationship between shear force and shear displacement in each stage is analyzed, and the segmented relationship analysis results of shear loading are generated; S4: Based on the results of the shear loading segment relationship analysis, the change ratio of shear force and shear displacement of each segment is monitored in real time. Combined with the synergistic relationship between shear force and shear displacement, the local stress concentration phenomenon is identified, and the loading distribution of shear force and shear displacement is adjusted to generate the shear strength test results of the mine filling body.

[0037] The above are only preferred embodiments of the present invention and are not intended to limit the present invention in other forms. Any technician familiar with the profession may use the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes and apply them to other fields. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. The automatic testing system for shear strength of mine filling body is characterized by: include: The critical state identification module collects the real-time data of shear force and shear displacement of the mine filling body during the shear strength test of the mine filling body and converts it into a curve representation, calculates the gradient mutation point of the curve, and marks the key state change position in the shear process with reference to the gradient mutation point to obtain the parameter characteristics of the shear failure moment; A loading response prediction module is used to predict the future dynamic development of the shear force and shear displacement after the critical point from the dynamic change trend of the shear force and shear displacement in the parameter characteristics at the moment of shear failure, and to generate a dynamic development sequence of the shear failure stage; The loading path optimization module performs segmented analysis on the attenuation law of the shear force and the growth rate of the shear displacement in the dynamic development sequence of the shear failure stage, analyzes the synergistic relationship between the shear force and the shear displacement in each stage, and generates segmented shear loading relationship analysis results; The loading coordination control module monitors the change ratio of shear force and shear displacement of each segment in the shear loading segment relationship analysis result in real time, identifies the local stress concentration phenomenon based on the coordinated relationship between shear force and shear displacement, adjusts the loading distribution of shear force and shear displacement according to the identification result, and generates the shear strength test result of the mine filling body.

2. The automatic testing system for shear strength of mine filling according to claim 1 is characterized in that: The step of calculating the gradient mutation point of the curve is specifically as follows: Collect the real-time data of shear force and shear displacement of the mine filling body during the shear strength test of the mine filling body, convert the shear force and shear displacement changes in the real-time data into a curve representation, wherein the horizontal axis of the curve represents the shear displacement and the vertical axis represents the shear force, and obtain the shear curve diagram of the mine filling body; Based on the data in the shear curve of the mine filling body, the shear force is , the shear displacement is , using the formula: ； Calculate the gradient change value of the curve ,when When reaching the extreme value, the corresponding point is determined to be the gradient mutation point of the curve; in, Indicates the shear force on the mine filling during the test. is the gradient change value, It indicates the displacement of the mine filling body along the shear direction during the shear test. is the interval displacement difference of the slope change amplitude.

3. The automatic testing system for shear strength of mine filling according to claim 2 is characterized in that: The steps for obtaining the parameter characteristics of the shear failure moment are specifically as follows: According to the gradient mutation point of the curve in the shear curve diagram of the mine filling body, the position of the gradient mutation point is marked, and by analyzing the change trend of the shear force before and after the marked point, the transition of the mine filling body from shear bearing capacity to structural instability is identified, and the critical state transition position is obtained; Based on the critical state transition position, the shear force and shear displacement correlation data at the shear failure moment are extracted, and combined with the change trend near the failure point, the parameters are integrated to generate the parameter characteristics of the shear failure moment.

4. The automatic testing system for shear strength of mine filling according to claim 3 is characterized in that: The steps for obtaining the dynamic development sequence of the shear failure stage are specifically as follows: The dynamic change trend of shear force and shear displacement is extracted from the parameter characteristics at the shear failure moment, using the formula: ； Calculate the next moment Shear force , in Newtons ( ), and obtain the dynamic change prediction result; in, Indicates the current time The shear force measured in the shear test, is the adjustment factor, is the sliding window length, is the sliding mean of the shear force, Indicates time Shear force value; Based on the dynamic change prediction results, the attenuation law of shear force and the growth rate of shear displacement in the shear failure stage are analyzed, the change characteristics of shear force and shear displacement are extracted point by point, and the dynamic development sequence of the shear failure stage is generated.

5. The automatic testing system for shear strength of mine filling according to claim 4 is characterized in that: The steps for obtaining the shear loading segment relationship analysis results are specifically as follows: Based on the dynamic development sequence of the shear failure stage, the shear force attenuation law and the shear displacement growth rate are analyzed segment by segment, and the shear force change amplitude and shear displacement change amount are extracted segment by segment to generate the shear force and shear displacement change characteristics within the segment. Based on the variation characteristics of shear force and shear displacement within the segment, the formula is adopted: ； Calculation represents the total score of shear force and shear displacement after the corresponding segmented collaborative optimization , and obtain the analysis results of the shear loading segment relationship; in, Indicates the number of the segment in the dynamic development sequence of the shear failure stage, represents the total number of segments in the dynamic development sequence of the shear failure stage, Indicates The weight of the segment in the overall collaborative optimization objective, Indicates Score for the synergy between shear force and shear displacement within a segment.

6. The automatic testing system for shear strength of mine filling according to claim 5 is characterized in that: The steps of identifying the local stress concentration phenomenon are specifically as follows: The changes of shear force and shear displacement of each segment in the shear loading segment relationship analysis results are monitored in real time, using the formula: ； Calculate the The ratio of shear force to shear displacement ; in, It is The segment shear force change amplitude indicates the total change of shear force in the current segment. It is Segment shear displacement variation; Based on the change ratio and in combination with the synergistic relationship between shear force and shear displacement, the local stress concentration phenomenon of each segment is identified to obtain the stress concentration analysis result.

7. The automatic testing system for shear strength of mine filling according to claim 6 is characterized in that: The steps for obtaining the shear strength test results of the mine filling body are specifically as follows: Based on the stress concentration analysis results, the shear force change and shear displacement change data in each segment are extracted, and the shear force loading rate and shear displacement change trend of the abnormal segment are adjusted by analyzing the deviation range of the segment loading ratio, and dynamic monitoring and adjustment are performed to generate the overall mechanical response analysis results; Based on the overall mechanical response analysis results, key parameter data of maximum shear force, maximum shear displacement and failure time are extracted, compared with benchmark data, and the loading adjustment records and change ratios are integrated to generate the shear strength test results of the mine filling body.

8. An automated test method for shear strength of mine fillings, characterized in that: The automatic testing system for shear strength of mine filling body according to any one of claims 1 to 7 comprises the following steps: S1: Based on the real-time data of shear force and shear displacement during the shear strength test of mine filling, the data are converted into curve representation, the gradient mutation points of the curve are calculated, the key state change positions in the shear process are marked with reference to the gradient mutation points, and the parameter characteristics of the shear failure moment are generated; S2: Based on the parameter characteristics at the moment of shear failure, the dynamic change trend of shear force and shear displacement is analyzed, the future dynamic development of shear force and shear displacement after the critical point is predicted, and a dynamic development sequence of the shear failure stage is generated; S3: Based on the dynamic development sequence of the shear failure stage, the attenuation law of the shear force and the growth rate of the shear displacement are analyzed, the synergistic relationship between the shear force and the shear displacement in each stage is analyzed, and the segmented relationship analysis results of the shear loading are generated; S4: Based on the analysis results of the shear loading segment relationship, the change ratio of shear force and shear displacement of each segment is monitored in real time. Combined with the synergistic relationship between shear force and shear displacement, the local stress concentration phenomenon is identified, and the loading distribution of shear force and shear displacement is adjusted to generate the shear strength test results of the mine filling body.

Images