A calculation method for analyzing the tensile load bearing properties of an anchor rod

Abstract

The application discloses a kind of for analyzing the calculation method of anchor rod tensile load bearing characteristics, belong to roadway support numerical calculation field.The application includes seven steps of generating anchor unit, defining large deformation calculation mode, defining attribute parameter, defining fish function "initialise", executing fish function "initialise", defining fish function "modifying", executing fish function "modifying".The application divides anchor unit into elastic stage, yield stage, strain hardening stage, strain softening stage and breakage stage after being pulled.The application proposes yield stage formula, strain hardening stage formula and strain softening stage formula and embeds formula in fish function "modifying".Based on fish function "modifying", the simulation of yield characteristics, strain hardening characteristics and strain softening characteristics of anchor unit can be realized.The application designs breakage stage for anchor unit.When anchor unit is pulled and enters breakage stage, the load bearing capacity of anchor unit drops to zero instantaneously.Compared with original anchor unit calculation, the application can better simulate the tensile load bearing characteristics of anchor rod.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of numerical calculation of roadway support, and particularly relates to a calculation method for analyzing the tensile load-bearing characteristics of an anchor rod. BACKGROUND

[0002] An anchor unit is a structural unit in FLAC3D, a three-dimensional finite difference numerical calculation software. The anchor unit considers the contact relationship between the anchor rod and the surrounding rock, can simulate the mechanical transmission process between the anchor rod and the surrounding rock, and is widely used in the field of numerical calculation of roadway support.

[0003] However, it can be known from the FLAC3D manual that FLAC3D simplifies the anchor unit to an ideal elastic-plastic model and simulates the tensile load-bearing characteristics of the anchor rod in order to simplify the calculation. Based on this assumption, when the anchor rod is simulated by using the anchor unit, the tensile force in the anchor rod linearly increases to the tensile limit as the tensile displacement increases after the anchor rod is subjected to tension; then, the tensile force in the anchor rod remains constant as the tensile displacement continues to increase.

[0004] It can be known from the load-tensile displacement curve obtained by carrying out a tensile experiment on the anchor rod that the load-tensile displacement curve after the anchor rod is subjected to tension can be divided into five stages in detail: an elastic stage, a yield stage, a strengthening stage, a local deformation stage and a breaking stage.

[0005] It can be seen from the comparison between the simulation result of the anchor unit and the experimental result of the anchor rod that the following deficiencies exist when the anchor rod is simulated by using the anchor unit:

[0006] (1) The anchor unit uses an ideal elastic-plastic model to simulate the anchor rod, which excessively simplifies the tensile load-bearing characteristics of the anchor rod. The anchor unit considers the linear elastic deformation characteristics of the anchor rod after the anchor rod is subjected to load. Therefore, the anchor unit can better reflect the linear elastic deformation characteristics of the anchor rod after the anchor rod is subjected to tension. However, the anchor unit uses an ideal plastic model to simulate the yield behavior, strain hardening behavior, strain softening behavior and breaking behavior of the anchor rod after the linear elastic deformation of the anchor rod ends. This is obviously inconsistent with the tensile load-bearing characteristics of the anchor rod in the experiment.

[0007] (2) The anchor unit simplifies the yield load of the anchor rod and the tensile limit of the anchor rod to the same force, and cannot reflect the difference between the yield load of the anchor rod and the tensile limit of the anchor rod. Experimental results show that the tensile limit of the anchor rod is obviously greater than the yield load of the anchor rod. Therefore, the anchor unit cannot reflect the difference between the yield load of the anchor rod and the tensile limit of the anchor rod.

[0008] (3) The anchor unit does not consider the strain hardening characteristics and strain softening characteristics of the anchor rod. The experimental results of the anchor rod show that the anchor rod will exhibit strain hardening characteristics after the yield stage, that is, the tensile force of the anchor rod nonlinearly increases to the tensile limit as the tensile displacement increases. After reaching the tensile limit, the tensile force of the anchor rod nonlinearly decreases as the tensile displacement continues to increase, exhibiting strain softening characteristics. However, the anchor unit does not consider the above two characteristics when simulating the anchor rod.

[0009] (4) Anchor unit does not consider the breaking characteristics of anchor rod. The anchor rod tensile test results show that after the end of the local deformation stage, with the increase of the tensile displacement, the anchor rod will break. At this time, the bearing capacity of the anchor rod rapidly decreases to zero. While the anchor unit uses an ideal plastic model to simulate the anchor rod. Based on the model, the anchor unit simulated anchor rod will not break, but will only show the phenomenon of continuous increase of post-peak tensile displacement and constant tension. This is obviously inconsistent with the actual bearing performance of the anchor rod.

[0010] In view of the above problems, the present application provides a kind of calculation method for analyzing the tensile bearing characteristics of anchor rod based on the modified anchor unit. The calculation method can consider the linear elastic characteristics, yield characteristics, strain hardening characteristics, strain softening characteristics and breaking characteristics in the tensile process of anchor rod, and can be better used in the analysis of anchor rod tensile bearing performance. SUMMARY

[0011] The purpose of the present application is to provide a kind of calculation method for analyzing the tensile bearing characteristics of anchor rod. This method improves the defect that the original anchor unit in FLAC3D cannot effectively simulate the tensile bearing characteristics of anchor rod.

[0012] The present application adopts the following technical scheme, provides a kind of calculation method for analyzing the tensile bearing characteristics of anchor rod, including generating anchor unit, defining large deformation calculation mode, defining attribute parameters, defining fish function "initialise", executing fish function "initialise", defining fish function "modifying", executing fish function "modifying".

[0013] As a further description of the above technical scheme: when generating anchor unit, three parameters of anchor unit starting point, anchor unit end point and anchor unit quantity need to be defined, and the anchor unit quantity is greater than 1.

[0014] As a further description of the above technical scheme: when defining large deformation calculation mode, the large deformation calculation mode is "false".

[0015] As a further description of the above technical solution: the attribute parameters include eleven parameters, including "s2_times", "s3_variable", "s3_power", "s3_interval", "s4_increment", "s4_coefficient", "s5_disp", "recording_flag", "stage_flag", "yield_force", and "tensile_failure_force"; the "s2_times" parameter is the ratio of the tensile displacement at the end of the anchor rod yield stage to the tensile displacement at the beginning of the yield stage; the "s3_variable" parameter, the "s3_power" parameter, and the "s3_interval" parameter are respectively the strain hardening base, the strain hardening shrinkage order of magnitude, and the strain hardening basic increment; the "s4_increment" parameter and the "s4_coefficient" parameter are respectively the strain softening relative initial value and the strain softening shrinkage coefficient; the "s5_disp" parameter is the corresponding tensile displacement when the anchor rod is pulled to break; the "recording_flag" parameter, the "stage_flag" parameter, the "yield_force" parameter, and the "tensile_failure_force" parameter are respectively the recording state parameter, the stage state parameter, the anchor rod yield force, and the anchor rod tensile limit, and the "s4_increment" parameter and the "recording_flag" parameter are both set to 0; the "stage_flag" parameter is set to 1.

[0016] As a further description of the above technical solution: the fish function "initialise" logical structure is as follows: based on the pointer variable pnt, each anchor unit is traversed, and the following operations are performed during the traversal process: the "yield_force" parameter is assigned to the "struct.cable.yield.tension" function; the calculation result of the first formula is assigned to the "struct.cable.area" function; the Young's modulus value of the anchor rod is assigned to the "struct.cable.young" function; and the bond stiffness value of the anchorage interface is assigned to the "struct.cable.grout.stiffness" function.

[0017] As a further description of the above technical solution: the fish function "modifying" logical structure is as follows: the fish function "modifying" is executed at each time step; the unbalanced force of the anchor unit tensile end in the tensile direction is taken out and assigned to the "force" variable, and the tensile displacement of the anchor unit tensile end in the tensile direction is taken out and assigned to the "disp" variable; a first primary judgment flow is executed; and a second primary judgment flow is executed.

[0018] As a further description of the above technical solution: the fish function "modifying" is executed at each time step.

[0019] As a further description of the above technical solution: the first primary judgment process is to judge whether the "force" variable is greater than or equal to the "yield_force" parameter; if the first primary judgment is yes, the first secondary judgment is carried out, that is, to judge whether the "recording_flag" parameter is zero; if the first secondary judgment is yes, the "disp" variable is assigned to the "disp_stage2_start" variable, the calculation result of the second formula is assigned to the "disp_stage2_end" variable, 1 is assigned to the "recording_flag" variable, 2 is assigned to the "stage_flag" variable, and the first secondary judgment is ended; the second secondary judgment is carried out, that is, to judge whether the "disp" variable is greater than the "disp_stage2_end" variable, if the second secondary judgment is yes, the third level judgment is carried out, that is, to judge whether the "force" variable is less than the "tensile_failure_force" parameter, if the third level judgment is yes, the fourth level judgment is carried out, that is, to judge whether the "stage_flag" variable is less than 4, if the fourth level judgment is yes, based on the pointer variable pnt, each anchor unit is traversed, and in the traversal process, the calculation result of the third formula is assigned to the "struct.cable.yield.tension" function; the calculation result of the fourth formula is assigned to the "s3_variable" variable and the fourth level judgment is ended; if the third level judgment is no, 4 is assigned to the "stage_flag" variable and the third level judgment is ended; the second secondary judgment is ended; the first primary judgment is ended.

[0020] As a further description of the above technical solution: the second primary judgment process is to judge whether the "stage_flag" parameter is equal to 4; if the second primary judgment is yes, the third secondary judgment is executed, that is, to judge whether the "disp" variable is less than or equal to the "s5_disp" parameter, if the third secondary judgment is yes, based on the pointer variable pnt, each anchor unit is traversed, and in the traversal process, the calculation result of the fifth formula is assigned to the "struct.cable.yield.tension" function; the calculation result of the sixth formula is assigned to the "s4_increment" variable; if the third secondary judgment is no, based on the pointer variable pnt, each anchor unit is traversed, and in the traversal process, 0 is assigned to the "struct.cable.yield.tension" function, and 1 is assigned to the "struct.cable.young" function; the third secondary judgment is ended; the second primary judgment is ended.

[0021] As a further description of the above technical solution: the first formula is A=0.25πD 2 , wherein A is the cross-sectional area of the anchor rod, and D is the diameter of the anchor rod; the second formula is D se =D ss s t , wherein D se is the tensile displacement of the anchor rod at the end of the yield stage, D ss is the tensile displacement of the anchor rod at the beginning of the yield stage, s t is the "s2_times" parameter value; the third formula is , wherein y is the dynamic tension, y f is the "yield_force" parameter value, s v is the "s3_variable" parameter value, s p is the "s3_power" parameter value; the fourth formula is s v =s v +s i , wherein s i is the "s3_interval" parameter value; the fifth formula is , wherein t f is the "tensile_failure_force" parameter value; s c is the "s4_coefficient" parameter value; s in is the "s4_increment" parameter value; the sixth formula is s in =s in +0.001.

[0022] The application provides a calculation method for analyzing the tensile bearing characteristics of an anchor rod.

[0023] (1) The tensile process of the anchor unit is divided into five stages, namely, the elastic stage, the yield stage, the strengthening stage, the local deformation stage, and the breaking stage. Compared with the original anchor unit calculation method, the application considers the strengthening stage, the local deformation stage, and the breaking stage, and can better reflect the tensile bearing characteristics of the anchor rod.

[0024] (2) The application defines the "yield_force" parameter and the "tensile_failure_force" parameter. The two parameters are the yield force of the anchor rod and the tensile limit of the anchor rod, respectively. Therefore, the application distinguishes the yield force of the anchor rod and the tensile limit of the anchor rod. This point is more consistent with the tensile bearing characteristics of the anchor rod in the experiment.

[0025] (3) For the strengthening stage, the third formula is proposed to describe the strain hardening property of the anchor unit. Based on the third formula, the tensile force of the anchor unit increases nonlinearly with the increase of the tensile displacement to the tensile limit after the anchor unit is in tension and enters the strengthening stage. This is consistent with the strain hardening property of the anchor rod in the experiment.

[0026] (4) For the local deformation stage, the fifth formula is proposed to describe the strain softening property of the anchor unit. Based on the fifth formula, the tensile force of the anchor unit decreases nonlinearly with the increase of the tensile displacement after the anchor unit is in tension and enters the local deformation stage. This is consistent with the strain softening property of the anchor rod in the experiment.

[0027] (5) The present application defines the breaking stage for the anchor unit. The present application designs a judgment criterion for whether the anchor unit enters the breaking stage after being in tension. Based on the judgment criterion, it can be judged whether the anchor unit has entered the breaking stage after being in tension. If the breaking stage is entered, the anchor unit instantly loses the bearing capacity. Compared with the original anchor unit which cannot consider the breaking behavior of the anchor rod, the present application can accurately simulate the breaking behavior of the anchor rod after being in tension. This is consistent with the breaking failure behavior of the anchor rod in the experiment. BRIEF DESCRIPTION OF DRAWINGS

[0028] The accompanying drawings, which form a part of the present application, are used to provide further understanding of the application and are not intended to constitute an improper limitation of the present application. In the drawings:

[0029] Figure 1 is a flow chart of a calculation method for analyzing the tensile bearing property of an anchor rod according to the present application.

[0030] Figure 2 is a logic structure diagram of the fish function "modifying" according to the present application.

[0031] Figure 3 is a first primary judgment logic structure diagram according to the present application.

[0032] Figure 4 is a second primary judgment logic structure diagram according to the present application.

[0033] Figure 5 is a comparison diagram of the calculation result, the original anchor unit calculation result and the experimental result according to the present application. DETAILED DESCRIPTION

[0034] As shown in Figures 1 to 4 , the present application provides a calculation method for analyzing the tensile bearing property of an anchor rod, which comprises generating an anchor unit, defining a large deformation calculation mode, defining attribute parameters, defining a fish function "initialise", executing the fish function "initialise", defining a fish function "modifying", and executing the fish function "modifying".

[0035] In a specific embodiment: when generating the anchor element, the three parameters of the anchor element starting point, the anchor element ending point and the anchor element quantity are defined, and the anchor element quantity is greater than 1.

[0036] In a specific embodiment: when defining the large deformation calculation mode, the large deformation calculation mode is "false".

[0037] In a specific embodiment: the attribute parameters include eleven parameters, including "s2_times", "s3_variable", "s3_power", "s3_interval", "s4_increment", "s4_coefficient", "s5_disp", "recording_flag", "stage_flag", "yield_force", "tensile_failure_force"; the "s2_times" parameter is the ratio of the tensile displacement at the end of the anchor rod yield stage to the tensile displacement at the beginning of the yield stage; the "s3_variable" parameter, the "s3_power" parameter and the "s3_interval" parameter are respectively the strain hardening base, the strain hardening shrinkage order of magnitude and the strain hardening basic increment; the "s4_increment" parameter and the "s4_coefficient" parameter are respectively the strain softening relative initial value and the strain softening shrinkage coefficient; the "s5_disp" parameter is the tensile displacement corresponding to the anchor rod tensile breaking; the "recording_flag" parameter, the "stage_flag" parameter, the "yield_force" parameter and the "tensile_failure_force" parameter are respectively the recording state parameter, the stage state parameter, the anchor rod yield force and the anchor rod tensile limit, and the "s4_increment" parameter and the "recording_flag" parameter are both set to 0; the "stage_flag" parameter is set to 1.

[0038] In a specific embodiment: the "initialise" logic structure of the fish function is as follows: based on the pointer variable pnt, each anchor element is traversed, and the following operations are performed in the traversal process: the "yield_force" parameter is assigned to the "struct.cable.yield.tension" function; the calculation result of the first formula is assigned to the "struct.cable.area" function; the Young's modulus value of the anchor rod is assigned to the "struct.cable.young" function; the bond stiffness value of the anchorage interface is assigned to the "struct.cable.grout.stiffness" function.

[0039] In one embodiment: the fish function "modifying" logic is as follows: the fish function "modifying" is executed at each time step; the unbalanced force in the stretching direction of the stretching end of the anchor element is taken out and assigned to the "force" variable, and the stretching displacement in the stretching direction of the stretching end of the anchor element is taken out and assigned to the "disp" variable; the first primary judgment flow is executed; the second primary judgment flow is executed.

[0040] In one embodiment: the fish function "modifying" is executed at each time step.

[0041] In one embodiment: the first primary judgment flow is to judge whether the "force" variable is greater than or equal to the "yield_force" parameter; if the first primary judgment is yes, the first secondary judgment is carried out, that is, to judge whether the "recording_flag" parameter is zero; if the first secondary judgment is yes, the "disp" variable is assigned to the "disp_stage2_start" variable, the second formula calculation result is assigned to the "disp_stage2_end" variable, 1 is assigned to the "recording_flag" variable, 2 is assigned to the "stage_flag" variable, and the first secondary judgment is ended; the second secondary judgment is carried out, that is, to judge whether the "disp" variable is greater than the "disp_stage2_end" variable, if the second secondary judgment is yes, the third judgment is carried out, that is, to judge whether the "force" variable is less than the "tensile_failure_force" parameter, if the third judgment is yes, the fourth judgment is carried out, that is, to judge whether the "stage_flag" variable is less than 4, if the fourth judgment is yes, based on the pointer variable pnt, each anchor element is traversed, and in the traversal process, the third formula calculation result is assigned to the "struct.cable.yield.tension" function; the fourth formula calculation result is assigned to the "s3_variable" variable and the fourth judgment is ended; if the third judgment is no, 4 is assigned to the "stage_flag" variable and the third judgment is ended; the second secondary judgment is ended; the first primary judgment is ended.

[0042] In one embodiment: the second primary decision process is to determine whether the "stage_flag" parameter is equal to 4; if the second primary decision is yes, a third secondary decision is executed, which is to determine whether the "disp" variable is less than or equal to the "s5 disp" parameter; if the third secondary decision is yes, based on the pointer variable pnt, each anchor element is traversed, and in the process of traversal, the result of the fifth formula is assigned to the "struct.cable.yield.tension" function; the result of the sixth formula is assigned to the "s4_increment" variable; if the third secondary decision is no, based on the pointer variable pnt, each anchor element is traversed, and in the process of traversal, 0 is assigned to the "struct.cable.yield.tension" function, and 1 is assigned to the "struct.cable.young" function; the third secondary decision is ended; the second primary decision is ended.

[0043] In one embodiment: the first formula is A = 0.25πD 2 , where A is the cross-sectional area of the anchor rod, and D is the diameter of the anchor rod; the second formula is D se = D ss s t , where D se is the tensile displacement of the anchor rod at the end of the yield stage, D ss is the tensile displacement of the anchor rod at the beginning of the yield stage, and s t is the value of the "s2_times" parameter; the third formula is where y is the dynamic tension, y f is the value of the "yield_force" parameter, s v is the value of the "s3_variable" parameter, and s p is the value of the "s3_power" parameter; the fourth formula is s v = s v + s i , where s i is the value of the "s3_interval" parameter; the fifth formula is where t f is the value of the "tensile_failure_force" parameter; s c is the value of the "s4_coefficient" parameter; s in is the value of the "s4_increment" parameter; the sixth formula is s in = s in + 0.001.

[0044] In order to verify the effectiveness of the present application, the anchor rod tensile experiment carried out in the paper "Research on the anchoring characteristics of anchor rod under confining pressure and its influencing factors" is taken as an example, and the anchor rod tensile calculation is carried out based on the method proposed in the present application, and the experimental results are compared with the calculation results of the present application.

[0045] The paper carries out the tensile experiment based on the displacement control loading mode on the anchor rod with a diameter of 20mm by using the JAW-1500 type universal testing machine. In the experiment process, the length of the anchor rod body is 400mm, the length of the clamping section on the left and right sides is 75mm, and the length of the middle experimental section is 250mm. The load-tensile displacement curve is recorded in the experiment process.

[0046] The experiment process is simulated based on the method proposed in the present application. Anchor units are generated in FLAC3D, and anchor rods are simulated by using the anchor units. The starting point of the anchor unit is the coordinate origin, and the end point is (0.25, 0, 0), and the number of anchor units is 10. The large deformation calculation mode is defined as "false". The attribute parameters are defined, and there are a total of eleven parameters, including "s2_times" is 1.5; "s3_variable" is 10; "s3_power" is 0.35; "s3_interval" is 0.005; "s4_increment" is 0; "s4_coefficient" is 0.12; "s5_disp" is 0.07; "recording_flag" is 0; "stage_flag" is 1; "yield_force" is 179000; "tensile_failure_force" is 243000.

[0047] The fish function "initialise" is defined. The logical structure of the fish function "initialise" is as follows: based on the pointer variable pnt, each anchor unit is traversed, and the following operations are performed in the traversal process: the "yield_force" parameter is assigned to the "struct.cable.yield.tension" function; the first formula calculation result 3.14x10 -4 is assigned to the "struct.cable.area" function; the Young's modulus of the anchor rod 15x10 9 is assigned to the "struct.cable.young" function; the bond stiffness of the anchoring interface 100x10 6 is assigned to the "struct.cable.grout.stiffness" function. The fish function "initialise" is executed.

[0048] The fish function "modifying" is defined, and the fish function "modifying" is executed.

[0049] The anchor unit is fixed at the node at the origin position, and a tensile load of 1 x 10 -6 m / s and constant. During the stretching process, the load and the stretching displacement of the stretching end of the anchor unit are recorded. 74000 time steps are run. The load-stretching displacement curve calculated based on the present application is compared with the load-stretching displacement curve obtained in the experiment, as shown in Figure 5 The stretching load-stretching displacement curve of the anchor rod in the experiment can be divided into five stages in detail: the elastic stage, the yield stage, the strengthening stage, the local deformation stage and the breaking stage. The stretching process of the anchor unit simulated by the present application also has five stages: the elastic stage, the yield stage, the strengthening stage, the local deformation stage and the breaking stage. This shows that the calculation results of the present application are consistent with the experimental results. In addition, the yield load and the tensile limit obtained by the anchor unit simulated by the present application are 179 kN and 243 kN, respectively, which are close to the yield load and the tensile limit of the anchor rod obtained in the experiment, proving the effectiveness of the present application.

[0050] In addition, Figure 5 The calculation results of the original anchor unit in FLAC3D are shown by pentagram symbols. The calculation results of the original anchor unit for the stretching of the anchor rod only include two stages: the elastic stage and the yield stage. The load-stretching displacement curve obtained by the original anchor unit for simulating the stretching process of the anchor rod is obviously different from the experimental curve. Therefore, the original anchor unit cannot accurately reflect the stretching performance of the anchor rod. Compared with the calculation of the original anchor unit, the calculation method proposed by the present application has obvious advantages.

Claims

1. A computational method for analyzing the tensile load bearing properties of an anchor rod, characterized by: The anchor unit is generated, and three parameters of the anchor unit start point, the anchor unit end point and the anchor unit quantity are defined, and the anchor unit quantity is greater than 1; A large deformation calculation mode is defined, and the large deformation calculation mode is "false"; Attribute parameters are defined, including eleven parameters, including "s2_times", "s3_variable", "s3_power", "s3_interval", "s4_increment", "s4_coefficient", "s5_disp", "recording_flag", "stage_flag", "yield_force" and "tensile_failure_force"; the "s2_times" parameter is the ratio of the tensile displacement at the end of the anchor rod yield stage to the tensile displacement at the beginning of the yield stage; the "s3_variable" parameter, the "s3_power" parameter and the "s3_interval" parameter are respectively a strain hardening base, a strain hardening shrinkage order of magnitude and a strain hardening basic increment; the "s4_increment" parameter and the "s4_coefficient" parameter are respectively a strain softening relative initial value and a strain softening shrinkage coefficient; the "s5_disp" parameter is the tensile displacement corresponding to the anchor rod tensile break; the "recording_flag" parameter, the "stage_flag" parameter, the "yield_force" parameter and the "tensile_failure_force" parameter are respectively a recording state parameter, a stage state parameter, an anchor rod yield force and an anchor rod tensile limit, and the "s4_increment" parameter and the "recording_flag" parameter are both set to 0; the "stage_flag" parameter is set to 1; The fish function "initialise" is defined, and the logic structure is as follows: based on the pointer variable pnt, each anchor unit is traversed, and the following operations are performed in the traversal process: the "yield_force" parameter is assigned to the "struct.cable.yield.tension" function; the calculation result of the first formula is assigned to the "struct.cable.area" function; the Young's modulus value of the anchor rod is assigned to the "struct.cable.young" function; and the bond stiffness value of the anchorage interface is assigned to the "struct.cable.grout.stiffness" function; The fish function "initialise" is executed; The definition of fish function "modifying" is as follows: the fish function "modifying" is executed at each time step; the unbalanced force of the stretching end of the anchor unit in the stretching direction is taken out and assigned to the "force" variable, and the stretching displacement of the stretching end of the anchor unit in the stretching direction is taken out and assigned to the "disp" variable; the first primary judgment process is executed; the second primary judgment process is executed. The fish function "modifying" is executed. The first formula is wherein A is the anchor rod cross-sectional area, D is the anchor rod diameter; the second formula is wherein S2 is the anchor rod tensile displacement at the end of the yield phase, S1 is the anchor rod tensile displacement at the beginning of the yield phase, s2_times is the "s2_times" parameter value; the third formula is wherein F is the dynamic tension, yield_force is the "yield_force" parameter value, s3_variable is the "s3_variable" parameter value, s3_power is the "s3_power" parameter value; the fourth formula is wherein s3_interval is the "s3_interval" parameter value; the fifth formula is wherein tensile_failure_force is the "tensile_failure_force" parameter value; s4_coefficient is the "s4_coefficient" parameter value; s4_increment is the "s4_increment" parameter value; the sixth formula is .

2. A method for analyzing the tensile load bearing properties of an anchor rod according to claim 1, characterized in that: The first primary judgment process is to judge whether the "force" variable is greater than or equal to the "yield_force" parameter; if the first primary judgment is yes, the first secondary judgment is carried out, that is, whether the "recording_flag" parameter is zero; if the first secondary judgment is yes, the "disp" variable is assigned to the "disp_stage2_start" variable, the second formula calculation result is assigned to the "disp_stage2_end" variable, 1 is assigned to the "recording_flag" variable, 2 is assigned to the "stage_flag" variable, and the first secondary judgment is ended; the second secondary judgment is carried out, that is, whether the "disp" variable is greater than the "disp_stage2_end" variable, if the second secondary judgment is yes, the third judgment is carried out, that is, whether the "force" variable is less than the "tensile_failure_force" parameter, if the third judgment is yes, the fourth judgment is carried out, that is, whether the "stage_flag" variable is less than 4, if the fourth judgment is yes, based on the pointer variable pnt, each anchor unit is traversed, and the third formula calculation result is assigned to the "struct.cable.yield.tension" function in the traversal process; the fourth formula calculation result is assigned to the "s3_variable" variable and the fourth judgment is ended; if the third judgment is no, 4 is assigned to the "stage_flag" variable and the third judgment is ended; the second secondary judgment is ended; the first primary judgment is ended.

3. A method for analyzing the tensile load bearing properties of an anchor rod according to claim 1, characterized in that: The second primary judgment process is to judge whether the "stage_flag" parameter is equal to 4; if the second primary judgment is yes, the third secondary judgment is executed, that is, whether the "disp" variable is less than or equal to the "s5_disp" parameter, if the third secondary judgment is yes, based on the pointer variable pnt, each anchor unit is traversed, and the fifth formula calculation result is assigned to the "struct.cable.yield.tension" function in the traversal process; the sixth formula calculation result is assigned to the "s4_increment" variable; if the third secondary judgment is no, based on the pointer variable pnt, each anchor unit is traversed, and 0 is assigned to the "struct.cable.yield.tension" function and 1 is assigned to the "struct.cable.young" function in the traversal process; the third secondary judgment is ended; the second primary judgment is ended.

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