Energy absorption anchor rod free section-decoupling section calculation and energy absorption regulation method and system

Abstract

The present application belongs to the technical field of mining engineering and geotechnical engineering, and discloses a method and system for calculating and regulating the free section-decoupling section of an energy-absorbing anchor rod. The present application constructs a rod displacement field time series function based on an elastoplastic mechanics model; uses a dynamic boundary identification algorithm to automatically quantify the length of the free section and the length of the decoupling section; fuses measured strain data and theoretical model fitting to generate a load-displacement curve; calculates the energy absorption value by numerical integration method to optimize the material parameters of the decoupling section, and realizes the maximization of the energy absorption value; feeds back the optimized material parameters of the decoupling section to the engineering design or construction link to form an intelligent regulation closed loop of perception, analysis, optimization and execution. The present application effectively solves the problem that the energy-absorbing anchor rod cannot fully exert its energy-absorbing potential during actual service, and maximizes the performance of the energy-absorbing anchor rod under complex geological conditions.

Description

Technical Field

[0001] This invention belongs to the fields of mining engineering and geotechnical engineering, and particularly relates to a method and system for calculating and controlling the energy absorption of the free section-decoupling section of an energy-absorbing anchor. Background Technology

[0002] In the process of deep resource development, as the mining depth continues to increase, the geomechanical environment faced by the surrounding rock of the tunnel becomes increasingly complex, with frequent geological disasters such as rock bursts and large deformations, placing higher demands on the safety and adaptability of the support structure. Material-type energy-absorbing anchors, as a new type of support component that achieves energy absorption through the material's own plastic deformation and controllable fracture mechanism, have been widely used in the control of deep, high-stress surrounding rock. Their core advantage lies in their ability to continuously absorb energy during large deformations of the surrounding rock, delaying structural failure and significantly improving the overall toughness and stability of the support system. In existing technologies, the division and length determination of the free and decoupled sections of energy-absorbing anchors largely rely on experience-based settings or simplified theoretical assumptions during the design phase, lacking dynamic identification and quantification methods for the segment lengths during actual anchor stress. The free section, as the main area for load transmission, and the decoupled section, as the key part for energy absorption, directly affect the deformation behavior and overall energy absorption efficiency of the anchor. Existing methods struggle to dynamically adjust the segment lengths based on real-time load conditions, resulting in the anchors failing to fully realize their energy absorption potential during actual service.

[0003] Furthermore, most existing energy absorption performance evaluation methods are based on idealized load-displacement relationships or simplified mechanical models, failing to fully consider the nonlinear deformation behavior, material hardening characteristics, and interaction between the anchor bolt and the surrounding rock during actual stress processes. This leads to discrepancies between calculated energy values ​​and actual absorption capacity, hindering the scientific optimization of material parameters and structural forms in the decoupling section. Currently, there is a lack of a systematic method that integrates real-time monitoring data, dynamic segment identification, and energy absorption feedback optimization to maximize the performance of energy-absorbing anchor bolts under complex geological conditions.

[0004] Based on the above analysis, the problems and shortcomings of the existing technology are as follows: The determination of segment length relies on experience and lacks dynamic identification: In traditional anchor bolt design, the division between free segment and decoupled segment mostly relies on experience setting or simplified theoretical assumptions, and cannot be dynamically identified and quantified according to the actual stress state of the anchor bolt, resulting in the energy absorption potential not being fully utilized.

[0005] Inaccurate energy assessment: Existing energy absorption performance assessment methods fail to fully consider the nonlinear deformation behavior of anchor bolts during actual stress processes, material hardening characteristics, and the interaction between the surrounding rock and the anchor bolt interface, resulting in discrepancies between the calculated energy values ​​and the actual absorption capacity.

[0006] Lack of systematic feedback optimization mechanism: A closed-loop control system integrating real-time monitoring, dynamic segmentation identification and parameter optimization feedback has not yet been formed, making it difficult to achieve continuous improvement in energy absorption efficiency during the design and on-site stages. Summary of the Invention

[0007] To overcome the problems existing in related technologies, this invention discloses a method and system for calculating and controlling the energy absorption of the free section and decoupling section of an energy-absorbing anchor bolt. Specifically, it relates to a method for calculating the free section and decoupling section of an energy-absorbing anchor bolt and a method for controlling its energy absorption performance. This invention will significantly improve the adaptability and reliability of energy-absorbing anchor bolts in deep, high-stress environments, providing a scientific basis and technical support for rock mass support design in projects such as deep coal mine roadways, metal mine mining areas, and deep-buried tunnels. Through the organic combination of real-time monitoring, dynamic segmentation, and parameter optimization, it can not only extend the service life of the anchor bolt but also provide important technical guarantees for the safe and efficient mining of deep resources, possessing broad engineering application prospects and promotional value.

[0008] The technical solution is as follows: a method for calculating and controlling the energy absorption of the free section and decoupling section of an energy-absorbing anchor bolt, including the following steps: S1. Construct the time series function of the rod displacement field based on the elastoplastic mechanical model and the power law hardening model, and consider the frictional slip effect of the surrounding rock-anchor interface to introduce the interface shear constitutive relation to construct the time series function of the rod displacement field; S2. Based on the constructed time-series function of the rod displacement field, the length of the free segment is automatically quantified using a dynamic boundary recognition algorithm. With decoupling segment length ; S3. Convert the measured strain data into local stress and integrate to obtain the total axial force. Combine the rod end displacement to construct the measured load-displacement curve. Using the interface shear parameters and the material power-law hardening parameters as variables to be corrected, construct the objective function that minimizes the sum of squared errors between the measured load and the theoretical model predicted load. Solve the function to obtain the optimal parameter combination to correct the theoretical model and generate the load-displacement curve. S4. Based on the generated load-displacement curve, calculate the energy absorption value using a numerical integration method. ; S5, based on energy absorption value To provide feedback indicators, while meeting structural strength constraints, the material parameters of the decoupling section are optimized to maximize energy absorption. S6. Feed back the optimized decoupled section material parameters to the engineering design or construction phase to form an intelligent control closed loop of perception, analysis, optimization, and execution.

[0009] In step S2, the dynamic boundary recognition algorithm includes: (1) For the displacement field function Find the spatial derivative; (2) Define the free segment as a region of uniform displacement. The decoupling section is the region of displacement gradient change, making Mutual or non-linear growth; (3) Using a sliding window and inflection point detection algorithm, the length of the free segment is automatically identified. With decoupling segment length .

[0010] In step S3, the load-displacement curve is fitted using the least squares method to fit the measured curve with the theoretical model in order to correct the model parameters; specifically, this includes: S3.1, Measured strain data Converted into local stress Integrating, we obtain the total axial force, expressed as: ; In the formula, This refers to the cross-sectional area of ​​the anchor rod. This represents the total axial force acting on the anchor bolt. S3.2, Combined rod end displacement Construct measured load-displacement curves ; S3.3, Using the least squares method to convert the measured load-displacement curve Fit the model to the theoretical model and correct the model parameters; First, the measured strain data are converted into local stress and integrated to obtain the total axial force. Combined with the rod end displacement, the measured load-displacement curve is constructed. Then, using the interface shear parameters and the material power-law hardening parameters as variables to be corrected, an objective function is constructed to minimize the sum of squared errors between the measured load and the load predicted by the theoretical model. By solving for the minimum value of this objective function, the optimal parameter combination is obtained and updated into the model.

[0011] In step S4, the numerical integration method uses the trapezoidal rule or Simpson's rule to calculate the area under the load-displacement curve, i.e., the energy absorption value. The expression is: ; In the formula, For strength, For displacement.

[0012] In step S5, optimizing the material parameters of the decoupling section includes adjusting the yield strength of the material in the decoupling section. Elastic modulus Cross-sectional area Or decoupling segment length At least one parameter in the parameters; the optimized material parameters for the decoupling section specifically include: S5.1, based on energy absorption value To optimize the objective function; S5.2. Using gradient descent, genetic algorithm, or Bayesian optimization algorithm, maximize the energy absorption value while satisfying structural strength constraints. .

[0013] In step S6, the intelligent control closed loop includes: Design phase control: Optimize the material parameters of the decoupling section for the design and manufacturing of energy-absorbing anchor bolt products; select polymer material A and polymer material B as decoupling materials to conduct anchor bolt decoupling effect tests; select different decoupling lengths according to the selected decoupling materials; and select the anchor bolt end fastening length. By constructing constitutive relations and calculating load-displacement relationships, the energy absorption effect of the new energy-absorbing anchor bolt is determined. On-site phase control: Dynamically adjust the decoupling section length of in-service anchor bolts according to optimization instructions.

[0014] Constructing constitutive relations and calculating load-displacement relationships includes: Calculation of load-displacement relationship for threaded steel anchor bolts + decoupling layer + end anchorage in full-length anchorage; and, Calculation of load-displacement relationship in end anchoring: threaded steel anchor rod + decoupling layer + end anchoring.

[0015] Furthermore, in full-length anchorage, the load-displacement relationship calculation for the threaded steel anchor bolt + decoupling layer + end anchorage includes: (1.1) Elastic phase, ,in, This is the elastic limit displacement. The load-displacement relationship in the elastic stage is as follows: (This is because the load-displacement relationship in the elastic stage is as follows:) ; In the formula, Let be the cross-sectional area of ​​the rod. This refers to the residual frictional shear stress at the interface. Perimeter; (1.2) Yield point and yield stage, ,in, This represents the displacement at the end of the yielding stage; the load-displacement relationship during the yielding stage is corrected as follows: ; In the formula, For the lower yield load, The lower yield strength; (1.3) Strengthening phase, ;in, This represents the displacement corresponding to the peak load; the load-displacement relationship is: ; In the formula, For actual stress, The material strength coefficient, The strain hardening index; Peak point: The load reaches its maximum value. The corresponding displacement is ; (1.4) Neck constriction stage, The linear softening model is as follows: ; In the formula, The frictional resistance provided for the decoupling section The anchoring force provided to the anchorage section This represents the displacement at the point where the anchor bolt eventually breaks. (1.5) The load-displacement relationship of the threaded steel anchor rod + decoupling layer + end anchor is as follows: ; In the formula, Load on the anchor bolt (1.6) Elongation: ; In the formula, For the initial length, To achieve the maximum displacement / length after fracture.

[0016] Furthermore, in the end anchoring process, the load-displacement relationship calculation for the threaded steel anchor bolt + decoupling layer + end anchoring includes: (2.1) Elastic phase, The load-displacement relationship in the elastic stage is as follows: ; (2.2) Yield point and yield stage, The load-displacement relationship during the yielding stage is corrected as follows: ; (2.3) Strengthening phase, The load-displacement relationship is as follows: ; (2.4) The neck constriction stage, The linear softening model is as follows: ; (2.5) The load-displacement relationship of the threaded steel anchor rod + decoupling layer + end anchor is as follows: ; Another objective of this invention is to provide a calculation and energy absorption control system for the free section-decoupling section of an energy-absorbing anchor bolt. This system implements the aforementioned calculation and energy absorption control method for the free section-decoupling section of an energy-absorbing anchor bolt. The system includes: The module for constructing the time series function of the rod displacement field is used to construct the time series function of the rod displacement field based on the elastoplastic mechanical model. The free segment length and decoupled segment length quantization module is used to automatically quantize the free segment length using a dynamic boundary recognition algorithm. With decoupling segment length ; The load-displacement curve generation module is used to fuse measured strain data with theoretical models to generate high-precision load-displacement curves. The energy absorption value calculation module is used to calculate the energy absorption value using numerical integration methods. ; The decoupling section material parameter optimization module is used to optimize energy absorption values. To optimize the decoupling section material parameters and maximize the energy absorption value, feedback indicators are used. The intelligent control closed-loop module is used to feed back the optimized decoupling section material parameters to the engineering design or construction stage, forming an intelligent control closed loop of perception, analysis, optimization, and execution. The intelligent control closed loop includes design stage control and on-site stage control. Design stage control includes using the optimized parameters for the design and manufacturing of energy-absorbing anchor bolt products. On-site stage control includes dynamically adjusting the decoupling section length of the in-service anchor bolts according to the optimization instructions.

[0017] Combining all the above technical solutions, the beneficial effects of this invention are as follows: First, this invention constructs a time-series function of the rod displacement field based on an elastoplastic mechanical model, and automatically quantifies the lengths of the free segment and the decoupled segment using a dynamic boundary recognition algorithm; then, it integrates measured strain data to fit a high-precision load-displacement curve, and calculates the energy absorption value through numerical integration. Ultimately To provide feedback metrics, an intelligent optimization algorithm is used to reverse-regulate the material and geometric parameters of the decoupled section, forming an intelligent closed loop of perception-analysis-optimization-execution. This maximizes energy absorption efficiency during the design and on-site stages, effectively solving the problems of traditional anchor bolt design relying on experience and inaccurate energy assessment, and significantly improving its reliability and adaptability in high-stress rock mass support. This invention effectively solves the problem that energy-absorbing anchor bolts cannot fully realize their energy absorption potential during actual service, maximizing the performance of energy-absorbing anchor bolts under complex geological conditions.

[0018] Secondly, this invention differs from traditional anchor bolts and energy-absorbing anchor bolts. The anchor bolt body of this invention consists of a decoupled section and a free section, and a calculation method for the decoupled section is proposed. This invention can significantly improve the support safety in high-stress rock mass engineering such as deep mines and deep-buried tunnels. By maximizing the energy absorption efficiency of the energy-absorbing anchor bolt, it delays structural failure caused by large deformation of the surrounding rock and rockbursts, reduces roadway repair rates, downtime losses, and safety accident risks, and extends the life cycle of the support system. It solves the problem that anchor bolts, due to their fixed segment lengths, cannot adapt to complex deformation of the surrounding rock, leading to the decoupled section's ineffective participation in pressure relief and the anchor bolt's susceptibility to early brittle fracture or pull-out failure. It also solves the problem of serious discrepancies between existing theoretical calculations and the actual energy absorption capacity of anchor bolts, introducing measured data correction and true constitutive relationships to achieve accurate prediction of energy absorption effects. This invention overcomes the shortcomings of existing models that do not consider nonlinear deformation, material hardening, and interface slip, and solves the technical problem of integrating measured strain data, power-law hardening model and interface shear constitutive relationship of decoupled energy-absorbing anchor bolts, fitting load-displacement curves and performing full-process energy integration calculation. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the disclosure of this invention and, together with the description, serve to explain the principles of this disclosure; Figure 1 This is a flowchart of the calculation and energy absorption control method for the free section-decoupling section of the energy-absorbing anchor provided in an embodiment of the present invention; Figure 2 These are displacement-load curves of three decoupling types of anchor bolts provided in the embodiments of the present invention; Figure 3 This is a comparison chart of load-displacement curves for a 300mm decoupling section length provided in an embodiment of the present invention; Figure 4 This is a comparison chart of load-displacement curves for a 600mm decoupling section length provided in an embodiment of the present invention; Figure 5 This is a comparison chart of load-displacement curves for a 900mm decoupling section length provided in an embodiment of the present invention; Figure 6 This is a comparison chart of load-displacement curves for a 1200mm decoupling section length provided in an embodiment of the present invention; Figure 7 This is the energy integration diagram of the 300mm decoupling segment of the anchor bolt test process curve provided in this embodiment of the invention; Figure 8 This is the energy integration diagram of the 900mm decoupling segment of the anchor bolt test process curve provided in this embodiment of the invention; Figure 9 This is the energy integration diagram of the 1200mm decoupling segment of the anchor bolt test process curve provided in this embodiment of the invention; Figure 10 This is a displacement-load curve diagram comparing high-energy support with soft support and hard support provided in the embodiments of the present invention. Detailed Implementation

[0020] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0021] The innovation of this invention lies in the following: Based on elastoplastic mechanics and a power-law hardening model, this invention constructs a displacement field time-series function, and a dynamic boundary identification algorithm automatically and accurately quantifies the lengths of the free segment and the decoupled segment. Furthermore, it integrates measured strain data to correct the theoretical model, generates a load-displacement curve, and calculates the energy absorption value throughout the process. Finally, using the energy absorption value as a feedback indicator, it employs an intelligent algorithm to inversely optimize the decoupled segment parameters, constructing a perception-analysis-optimization-execution intelligent closed loop. This overcomes the bottleneck of traditional anchor bolt design relying on experience and inaccurate energy assessment, achieving global maximization of the energy absorption efficiency of energy-absorbing anchor bolts under complex geological conditions.

[0022] Example 1.

[0023] The algorithm involved in this invention constructs a time-series evolution function of the rod displacement field based on elastoplastic mechanics and a power-law hardening model; and employs a dynamic boundary identification algorithm to automatically identify and quantify the length of the free segment. With decoupling segment length By integrating measured strain data with theoretical models, load-displacement curves are fitted with high precision; the energy absorption value of the anchor bolt during the entire deformation process is calculated using numerical integration methods. Ultimately As a feedback indicator, the material or geometric parameters of the decoupling section are optimized in reverse to maximize the energy absorption efficiency.

[0024] Specifically, such as Figure 1 As shown, the calculation and energy absorption control method for the free section-decoupling section of the energy-absorbing anchor bolt includes the following steps: S1. Construct the time series function of the rod displacement field based on the elastoplastic mechanical model and the power law hardening model, and consider the frictional slip effect of the surrounding rock-anchor interface to introduce the interface shear constitutive relation to construct the time series function of the rod displacement field; S2. Based on the constructed time-series function of the rod displacement field, the length of the free segment is automatically quantified using a dynamic boundary recognition algorithm. With decoupling segment length ; S3. Convert the measured strain data into local stress and integrate to obtain the total axial force. Combine the rod end displacement to construct the measured load-displacement curve. Using the interface shear parameters and the material power-law hardening parameters as variables to be corrected, construct the objective function that minimizes the sum of squared errors between the measured load and the theoretical model predicted load. Solve the function to obtain the optimal parameter combination to correct the theoretical model and generate the load-displacement curve. S4. Based on the generated load-displacement curve, calculate the energy absorption value using a numerical integration method. ; S5, based on energy absorption value To provide feedback indicators, while meeting structural strength constraints, the material parameters of the decoupling section are optimized to maximize energy absorption. S6. Feed back the optimized decoupled section material parameters to the engineering design or construction phase to form an intelligent control closed loop of perception, analysis, optimization, and execution.

[0025] For example, in step S1, the elastoplastic mechanical model is based on elastoplastic mechanics and a power-law hardening model, and considers the frictional slip effect at the rock-anchor interface, introducing an interface shear constitutive relation; the interface shear constitutive relation adopts an ideal elastoplastic model, and the interface shear stress remains at the residual frictional shear stress after slippage. This relationship is directly applied to the calculation of macroscopic loads, mainly manifested in the calculation of interfacial frictional resistance.

[0026] Elastoplastic mechanics is calculated using a constitutive model for steel tubes, while the power-law hardening model is... ,in, For actual stress, The material strength coefficient, To respond realistically, Assuming the strain hardening exponent, the displacement field evolution equation of the rod under axial load is established. ; For example, in step S2, the dynamic boundary recognition algorithm includes performing spatial derivative analysis on the displacement field time series function to obtain the local deformation rate, and automatically identifying the boundary positions of the free segment and the decoupled segment through a sliding window and inflection point detection algorithm.

[0027] Specifically, it includes: (1) For the displacement field function Finding the spatial derivative; that is, the change of the displacement at the end of the anchor bolt with time, finding the spatial derivative is to find the spatial derivative of the spatial variable. Find the partial derivatives; (2) Define the free segment as a region of uniform displacement. The decoupling section is the region where the displacement gradient changes significantly. (mutation or non-linear growth); (3) Using a sliding window and inflection point detection algorithm, the length of the free segment is automatically identified. With decoupling segment length .

[0028] As can be seen, in the implementation examples, the optimal length is not a fixed, universally applicable value due to the complexity of the situation. Sliding window and inflection point detection algorithms are commonly used fault monitoring methods. The difference between this invention and existing technologies lies in the different application scenarios. For example, in step S3, the load-displacement curve is fitted using the least squares method to fit the measured curve with the theoretical model in order to correct the model parameters.

[0029] S3.1, Measured strain data Converted into local stress Integrating, we obtain the total axial force, expressed as: ; In the formula, This refers to the cross-sectional area of ​​the anchor rod. This represents the total axial force acting on the anchor bolt. S3.2, Combined rod end displacement Construct measured load-displacement curves ; S3.3, Using the least squares method to convert the measured load-displacement curve Fit the model to the theoretical model and correct the model parameters; First, the measured strain data are converted into local stress and integrated to obtain the total axial force. Combined with the rod end displacement, the measured load-displacement curve is constructed. Then, using interface shear parameters (such as bond stiffness, peak and residual shear stress) and material power-law hardening parameters as variables to be corrected, an objective function is constructed to minimize the sum of squared errors between the measured load and the load predicted by the theoretical model. By solving for the minimum value of this objective function, the optimal parameter combination is obtained and updated into the model.

[0030] In step S4, the numerical integration method uses the trapezoidal rule or Simpson's rule to calculate the area under the load-displacement curve, i.e., the energy absorption value. .

[0031] Among them, the area under the load-displacement curve represents the absorbed energy value, and the trapezoidal rule and Simpson's rule are both used for high-precision approximate calculation of definite integrals.

[0032] For example, based on the load-displacement curve, the energy absorption value of the entire process is calculated using a numerical integration method (preferably Simpson's rule, while balancing accuracy and efficiency): ; In the formula, For strength, For displacement.

[0033] In step S5, the optimized decoupling section material parameters include adjusting at least one of the following parameters: material yield strength, elastic modulus, cross-sectional area, or length of the decoupling section.

[0034] The optimized decoupling section material parameters use intelligent optimization algorithms, including gradient descent, genetic algorithm, or Bayesian optimization.

[0035] Another example is the optimization of material parameters for the decoupling section, which specifically includes: S5.1, based on energy absorption value To optimize the objective function; S5.2. Using gradient descent, genetic algorithm, or Bayesian optimization algorithm, maximize the energy absorption value while satisfying structural strength constraints. .

[0036] It is known that the load-displacement relationship of energy-absorbing anchors involves multiple nonlinear stages such as elasticity, yielding, strengthening, and necking. The energy absorption value is a complex nonlinear function of multiple variables such as length, strength, and modulus. Existing trial-and-error methods are insufficient to solve this problem. Therefore, intelligent algorithms are used to quickly lock the optimal combination of multiple parameters in the global space.

[0037] By combining real-time on-site monitoring data, the algorithm can quickly recalculate and output control commands, enabling the support system to adapt to changes in deep rock mass stress; this invention provides quantitative research and development guidance.

[0038] For example, in step S6, the intelligent control closed loop includes: Design phase control: Optimize the material parameters of the decoupling section for the design and manufacturing of energy-absorbing anchor bolt products; On-site phase control: Dynamically adjust the decoupling section length of in-service anchor bolts according to optimization instructions.

[0039] Another example is that the optimal parameter combination of the decoupled section output by the parameter optimization subroutine is fed back to the engineering design and construction stages, forming a complete intelligent control closed loop of perception-analysis-optimization-execution. Specific execution methods include: Design phase adjustments: Optimization results (such as suggested material yield strength) will be incorporated. Elastic modulus Cross-sectional area Or decoupling segment length As an input parameter for the design and manufacturing of the new generation of energy-absorbing anchor bolts, it improves the energy absorption performance of anchor bolt products from the source.

[0040] For example, the design phase control includes: selecting polymer material A and polymer material B as decoupling materials to conduct anchor bolt decoupling effect tests; Based on the selected decoupling material, different decoupling lengths and anchor bolt end fastening lengths are chosen. By constructing constitutive relations and calculating load-displacement relationships, the energy absorption effect of the new energy-absorbing anchor bolt is determined.

[0041] On-site stage control: For installed anchor bolts with adjustable mechanisms, the length of the decoupling section can be dynamically adjusted on-site according to optimization instructions, so as to realize real-time calibration and improvement of the energy absorption performance of the in-service anchor bolts.

[0042] Effect Verification and Iteration: After adjusting the parameters, the system continues to collect real-time data and repeats steps S1 to S5 to verify the energy absorption value. Did it achieve the expected goals? If not, restart the optimization process until the anchor bolt performance meets the project requirements.

[0043] As another example, the method is applicable to the design and optimization of material-type energy-absorbing anchors in deep high-stress rock mass support engineering.

[0044] Example 2.

[0045] The energy absorption anchor free section-decoupling section calculation and energy absorption control system includes: The module for constructing the time series function of the rod displacement field is used to construct the time series function of the rod displacement field based on the elastoplastic mechanical model. The free segment length and decoupled segment length quantization module is used to automatically quantize the free segment length using a dynamic boundary recognition algorithm. With decoupling segment length ; The load-displacement curve generation module is used to fuse measured strain data with theoretical models to generate high-precision load-displacement curves. The energy absorption value calculation module is used to calculate the energy absorption value using numerical integration methods. ; The decoupling section material parameter optimization module is used to optimize energy absorption values. To provide feedback metrics, optimize the material parameters of the decoupling section (such as material strength, elastic modulus, or geometric dimensions) to maximize energy absorption.

[0046] The intelligent control closed-loop module is used to feed back the optimized decoupling section material parameters to the engineering design or construction stage, forming an intelligent control closed loop of perception, analysis, optimization, and execution. The intelligent control closed loop includes design stage control and on-site stage control. Design stage control includes using the optimized parameters for the design and manufacturing of energy-absorbing anchor bolt products. On-site stage control includes dynamically adjusting the decoupling section length of the in-service anchor bolts according to the optimization instructions.

[0047] Example 3.

[0048] This embodiment 3 is an example of the calculation method of the free section-decoupled section of an energy-absorbing anchor bolt under different decoupling materials and the control of energy absorption performance in the design stage; including: using polymer material A and polymer material B as decoupling materials to conduct anchor bolt decoupling effect tests; This experiment analyzes the coupling effect of different decoupling materials on the anchor bolt and anchoring agent. Threaded steel anchor bolts were used in the experiment, and various decoupling materials were selected to test their decoupling effects. The decoupling materials included polymer A and polymer B, etc., and their parameters are shown in Table 1. The thread height of the anchor bolt was 0.6 mm, and the bolt radius was 0.95 mm. The thickness of the progressively thinned decoupling material on the bolt surface affected the degree of coupling between the anchor bolt and the decoupling material; the total thickness of the progressively thinned decoupling material should not exceed 0.6 mm.

[0049] Table 1. Material selection and parameter settings for stepwise decoupling

[0050] (a) Constructing constitutive relations and calculating load-displacement relationships; The detailed calculation process will be explained in Example 4; the calculation process for this scheme is omitted here. The displacement-load curves for the three decoupling types of anchors are shown below. Figure 2 .

[0051] (ii) Obtain parameter optimization and control schemes; This embodiment aims to visually demonstrate the impact of different decoupling materials, primarily through a comparison of peak loads. The energy absorption calculation and parameter optimization process described in this method is also applicable to such cases and can accurately quantify differences in energy absorption. Under the same anchoring conditions, after an anchoring length of 300mm, the displacement-load relationships of the three different types of anchors are as follows: Figure 2 As shown, the anchor bolt without decoupling material (sample 3-3-1) exhibited the best anchoring performance, pulling out at a peak load of 207 kN. The anchor bolt with decoupling using polymer material A (sample 1-2-1) saw its peak load decrease to 122 kN, a reduction of 41.1%. The anchor bolt with decoupling using thermoplastic tubing (sample 4-1-1) saw its peak load further decrease to 28 kN, a reduction of 86.5%. Under material decoupling, the anchoring force under tension significantly decreased, making decoupling between the bolt and the anchoring agent more likely to occur.

[0052] Example 4.

[0053] Example 4 uses the calculation method of free section-decoupling section of energy-absorbing anchor at different progressive decoupling lengths and the control of energy absorption performance in the design stage as an example.

[0054] By setting different decoupling lengths, the influence on the energy absorption effect of the new type of anchor was determined. The test anchor was set to 2000mm in length, and the decoupling section lengths were 300mm, 600mm, 900mm, and 1200mm, respectively. The anchor end fastening length was 100mm under different schemes. Based on the step-by-step decoupling effect test under different materials, polymer material was selected as the decoupling material. The specific parameters are shown in Table 2.

[0055] Table 2 Parameter settings for energy-absorbing anchor bolts

[0056] For example, based on the selected decoupling material, different decoupling lengths and anchor bolt end fastening lengths are chosen. By constructing constitutive relations and calculating load-displacement relationships, the energy absorption effect of the new energy-absorbing anchor bolt is determined.

[0057] For example, constructing constitutive relations and calculating load-displacement relationships includes: In full-length anchorage, the load-displacement relationship calculation for threaded steel anchor bolts + decoupling layer + end anchorage includes: (1.1) Elastic phase, ,in, This is the elastic limit displacement. This results in axial displacement after being subjected to tension; At this stage, the stress is less than the yield strength, and the material obeys Hooke's Law: stress-strain relationship: Load: Strain-displacement relationship: ;in, For stress, In response to the situation; The load-displacement relationship in the elastic stage is as follows: ; In the formula, Let be the cross-sectional area of ​​the rod. This refers to the residual frictional shear stress at the interface. Perimeter; (1.2) Yield point and yield stage, ,in, This represents the displacement at the end of the yielding stage; when the stress reaches the yield strength, the corresponding load and displacement are the yield load and yield displacement, respectively. When the load exceeds the elastic limit, the material begins to undergo macroscopic plastic deformation. For rebar, the yielding phenomenon is divided into two stages: upper yield and lower yield. When the stress reaches the upper yield strength (… When the load reaches its peak value... Subsequently, the load suddenly dropped to the lower yield strength ( Ignoring initial transient effects, the stress remains essentially constant at this stress level, forming a yield plateau. At this point, displacement increases significantly while the load does not. In engineering macroscopic mechanical models, to simplify derivation and reflect the system's stable bearing capacity, the instantaneous extreme value of the upper yield point is usually ignored, and the lower yield strength is taken. As a constant stress during the yielding stage.

[0058] The load-displacement relationship during the yielding stage is corrected as follows: ; In the formula, For the lower yield load, The lower yield strength; (1.3) Strengthening phase, ;in, This represents the displacement corresponding to the peak load. After yielding, metallic materials exhibit a significant hardening effect, and their load-bearing capacity slowly increases again with increasing plastic deformation. Therefore, a power-law hardening model is used for calculation. The load-displacement relationship is: ; In the formula, For actual stress, The material strength coefficient, The strain hardening index; Peak point: The load reaches its maximum value. The corresponding displacement is ; (1.3) Strengthening Phase ( ); Metallic materials exhibit a significant hardening effect after yielding, and their load-bearing capacity slowly increases again with increasing plastic deformation. Therefore, a power-law hardening model is used for calculations. The strength coefficient, The strain hardening index is denoted as .

[0059] (1.4) Neck constriction stage, When the load exceeds When a material enters a state of plastic instability, deformation will no longer be uniform but will be highly concentrated in a certain local area. The cross-sectional area of ​​this region... The load decreases sharply. Due to the complex triaxial stress state and geometric nonlinearity at the necking point, accurate analytical derivation of this stage is extremely difficult. In engineering, the load descent phase is usually described based on experimental data.

[0060] The linear softening model is as follows: ; In the formula, The frictional resistance provided for the decoupling section The anchoring force provided to the anchorage section This represents the displacement at the point where the anchor bolt eventually breaks. (1.5) The load-displacement relationship of the threaded steel anchor rod + decoupling layer + end anchor is as follows: ; In the formula, The load on the anchor bolt; (1.6) Elongation: As can be seen from the above embodiments, the difference from the conventional method is that, under full-length anchoring, the decoupling layer acts as a weak medium or sliding layer, which allows relative slippage between the rod and the anchoring agent, or crush deformation, by actively weakening the original full-length bonding stiffness. That is, the initial anchoring stiffness and part of the anchoring force of the system are abandoned in exchange for the pressure relief space.

[0061] ; In the formula, For the initial length, To achieve the maximum displacement / length after fracture.

[0062] In end anchoring, the load-displacement relationship calculation for threaded steel anchor bolt + decoupling layer + end anchoring includes: (2.1) Elastic phase, When the stress is less than the yield strength, the material obeys Hooke's Law: stress-strain relationship: Load: Strain-displacement relationship: The load-displacement relationship in the elastic stage is as follows: ; The decoupling layer provides interfacial friction resistance: ; The load-displacement relationship in the elastic stage is as follows: ; (2.2) Yield point and yield stage, When the stress reaches the yield strength, the corresponding load and displacement are the yield load and yield displacement, respectively. When the load exceeds the elastic limit, the material begins to undergo macroscopic plastic deformation. For rebar, the yielding phenomenon is divided into two stages: upper yield and lower yield. When the stress reaches the upper yield strength (… When the load reaches its peak value... Subsequently, the load suddenly dropped to the lower yield strength ( Ignoring initial transient effects, the stress remains essentially constant at this stress level, forming a yield plateau. At this point, displacement increases significantly while the load does not. In engineering macroscopic mechanical models, to simplify derivation and reflect the system's stable bearing capacity, the instantaneous extreme value of the upper yield point is usually ignored, and the lower yield strength is taken. As the constant stress during the yielding stage, the load-displacement relationship during the yielding stage is corrected to: ; (2.3) Strengthening phase, Metallic materials exhibit a significant hardening effect after yielding, and their load-bearing capacity slowly increases again with increasing plastic deformation. Therefore, a power-law hardening model is used for calculations.

[0063] True stress-true strain relationship: According to Hollomon's equation, true stress With real response The relationship is: ; Engineering strain: ; True strain-displacement relationship: ; Considering changes in cross-sectional area: based on the assumption of constant volume ( The current cross-sectional area is: ; Load-displacement relationship: ; Peak point: The load reaches its maximum value. (Tensile strength load), the corresponding displacement is .

[0064] (2.4) The neck constriction stage, When the load exceeds When a material enters a state of plastic instability, deformation will no longer be uniform but will be highly concentrated in a certain local area. The cross-sectional area of ​​this region... The load decreases sharply. Due to the complex triaxial stress state and geometric nonlinearity at the necking point, accurate analytical derivation of this stage is extremely difficult. In engineering, the load decrease phase is usually described based on experimental data. The linear softening model is as follows: ; (2.5) The load-displacement relationship of the threaded steel anchor rod + decoupling layer + end anchor is as follows: ; As can be seen, under end anchoring, since there is no full-length bonding force, the decoupling layer, acting as a deformation regulator, can prevent the free section of the rod from being subjected to local compression, bending, or stress concentration by the surrounding rock, ensuring that the rod can deform uniformly under tension. Simultaneously, the decoupling material can provide additional physical relief stroke. Existing technologies only derive the calculation formula for ordinary anchor rods; this invention innovatively proposes this energy-absorbing anchor rod.

[0065] For example, test results: length of anchor bolt after test The elongation of the anchor rod after the test can be calculated according to the formula, and the correctness of the load-displacement relationship curve can be verified. The mechanical parameters of the anchor rod under different decoupling lengths are shown in Table 3.

[0066] Table 3 Results of pull-out tests on anchor bolts with different decoupling lengths

[0067] The test was stopped after the anchor bolt failed. The tensile process of the anchor bolt goes through the elastic stage, yielding stage, strengthening stage, and necking stage. The anchor bolt temperature rises when it reaches the yield stress, and necking begins to occur after reaching the maximum load. Figure 2 As shown, the anchor rod quickly enters the elastic stage after the tensile test begins. When the tensile load reaches 150kN, the anchor rod enters the yield stage. At this time, the average yield load of the anchor rod with a decoupling section of 300mm is 151kN, the peak load reaches 235kN, and the maximum tensile displacement of the anchor rod reaches 210mm. The average yield loads of the decoupling sections of 900mm and 1200mm are 153kN and 152kN, respectively, the peak loads are 238kN and 241kN, respectively, and the maximum displacements are 318mm and 442mm, respectively. Compared with the anchor rod with a decoupling section of 300mm, the tensile amount increases by 5.4% and 11.6%, respectively. In Table 3, 1, 3, and 4 meet the anchor rod performance requirements. As the length of the decoupling section gradually increases, the maximum displacement of the anchor rod increases accordingly, and the energy that can be absorbed also increases accordingly.

[0068] like Figures 3-6 The load-displacement curves of anchor bolts (Ø22mm×2000mm) with different progressively decoupling section lengths are compared. The energy absorption of the new anchor bolts with different decoupling section lengths shows a linear correlation. When the displacement reaches 210mm, the absorbed energy is 45kJ; when the displacement reaches 318mm, the maximum absorbed energy reaches 68kJ; and when the tensile displacement reaches 442mm, the absorbed energy reaches 95.89kJ. The calculated energy absorption efficiency is 0.204-0.217kJ / mm. Meanwhile, samples 3 and 4, with only a threaded anchorage section of less than 1m, still maintain the deformation characteristics of the anchor bolts, indicating that the anchor head is safe and reliable.

[0069] For example, Figures 7-9 This is the energy integral graph of the anchor bolt test process. Figure 7 The energy integration diagram for the 300mm decoupling section is shown. Figure 8 The energy integration diagram for the 900mm decoupling section is shown. Figure 9 This is the energy integration diagram for the 1200mm decoupling section.

[0070] (III) Parameter optimization and control schemes were derived. Based on pull-out tests and energy analysis, an optimization target of energy absorption value E was proposed. Intelligent algorithms were used to dynamically adjust the decoupling section length (recommended 900–1200 mm), material strength, and geometric parameters, forming a closed-loop control mechanism of "monitoring-analysis-optimization-execution." This maximized energy absorption efficiency (up to 95.89 kJ, efficiency 0.204–0.217 kJ / mm) during the design and field stages, significantly improving the adaptability and reliability of anchor bolts in high-stress rock masses. Through case studies, it was recommended to gradually replace the optimized anchor bolt material with ultra-high strength, ultra-high plasticity, and ultra-high energy absorption 3U material (see support characteristics in...). Figure 10 The displacement-load curves of high-energy support are compared with those of soft and hard support to meet the needs of harsh geological environments such as large deformation and rock bursts in deep engineering and mining.

[0071] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention and within the spirit and principles of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for calculating and controlling energy absorption in the free section-decoupling section of an energy-absorbing anchor bolt, characterized in that, The method includes the following steps: S1. Construct the time series function of the rod displacement field based on the elastoplastic mechanical model and the power law hardening model, and consider the frictional slip effect of the surrounding rock-anchor interface to introduce the interface shear constitutive relation to construct the time series function of the rod displacement field; S2. Based on the constructed time-series function of the rod displacement field, the length of the free segment is automatically quantified using a dynamic boundary recognition algorithm. With decoupling segment length ; S3. Convert the measured strain data into local stress and integrate to obtain the total axial force. Combine the rod end displacement to construct the measured load-displacement curve. Using the interface shear parameters and the material power-law hardening parameters as variables to be corrected, construct the objective function that minimizes the sum of squared errors between the measured load and the theoretical model predicted load. Solve the function to obtain the optimal parameter combination to correct the theoretical model and generate the load-displacement curve. S4. Based on the generated load-displacement curve, calculate the energy absorption value using a numerical integration method. ; S5, based on energy absorption value To provide feedback indicators, while meeting structural strength constraints, the material parameters of the decoupling section are optimized to maximize energy absorption. S6. Feed back the optimized decoupled section material parameters to the engineering design or construction phase to form an intelligent control closed loop of perception, analysis, optimization, and execution.

2. The method for calculating and controlling the energy absorption of the free section-decoupling section of an energy-absorbing anchor bolt according to claim 1, characterized in that, In step S2, the dynamic boundary recognition algorithm includes: (1) For the displacement field function Find the spatial derivative; (2) Define the free segment as a region of uniform displacement. The decoupling section is the region of displacement gradient change, making Mutual or non-linear growth; (3) Using a sliding window and inflection point detection algorithm, the length of the free segment is automatically identified. With decoupling segment length .

3. The method for calculating and controlling the energy absorption of the free section-decoupling section of an energy-absorbing anchor bolt according to claim 2, characterized in that, In step S3, the load-displacement curve is fitted using the least squares method to fit the measured curve with the theoretical model in order to correct the model parameters; specifically, this includes: S3.1, Measured strain data Converted into local stress Integrating, we obtain the total axial force, which is expressed as: ； In the formula, This refers to the cross-sectional area of ​​the anchor rod. This represents the total axial force acting on the anchor bolt. S3.2, Combined rod end displacement Construct measured load-displacement curves ; S3.3, Using the least squares method to convert the measured load-displacement curve Fit the model to the theoretical model and correct the model parameters; First, the measured strain data are converted into local stress and integrated to obtain the total axial force. The measured load-displacement curve is then constructed by combining the rod end displacement. Subsequently, using the interface shear parameters and the material power-law hardening parameters as variables to be corrected, an objective function is constructed to minimize the sum of squared errors between the measured load and the load predicted by the theoretical model. By solving for the minimum value of this objective function, the optimal parameter combination is obtained and updated into the model.

4. The method for calculating and controlling the energy absorption of the free section-decoupling section of an energy-absorbing anchor bolt according to claim 3, characterized in that, In step S4, the numerical integration method uses the trapezoidal rule or Simpson's rule to calculate the area under the load-displacement curve, i.e., the energy absorption value. The expression is: ； In the formula, For strength, For displacement.

5. The method for calculating and controlling the energy absorption of the free section-decoupling section of an energy-absorbing anchor bolt according to claim 4, characterized in that, In step S5, optimizing the material parameters of the decoupling section includes adjusting the yield strength of the material in the decoupling section. Elastic modulus Cross-sectional area Or decoupling segment length At least one parameter in the parameters; the optimized material parameters for the decoupling section specifically include: S5.1, based on energy absorption value To optimize the objective function; S5.

2. Using gradient descent, genetic algorithm, or Bayesian optimization algorithm, maximize the energy absorption value while satisfying structural strength constraints. .

6. The method for calculating and controlling the energy absorption of the free section-decoupling section of an energy-absorbing anchor bolt according to claim 5, characterized in that, In step S6, the intelligent control closed loop includes: Design phase control: Optimize the material parameters of the decoupling section for the design and manufacturing of energy-absorbing anchor bolt products; select polymer material A and polymer material B as decoupling materials to conduct anchor bolt decoupling effect tests; select different decoupling lengths according to the selected decoupling materials; and select the anchor bolt end fastening length. By constructing constitutive relations and calculating load-displacement relationships, the energy absorption effect of the new energy-absorbing anchor bolt is determined. On-site phase control: Dynamically adjust the decoupling section length of in-service anchor bolts according to optimization instructions.

7. The method for calculating and controlling the energy absorption of the free section-decoupling section of an energy-absorbing anchor bolt according to claim 6, characterized in that, Constructing constitutive relations and calculating load-displacement relationships includes: Calculation of load-displacement relationship for threaded steel anchor bolts + decoupling layer + end anchorage in full-length anchorage; and, Calculation of load-displacement relationship in end anchoring: threaded steel anchor rod + decoupling layer + end anchoring.

8. The method for calculating and controlling the energy absorption of the free section-decoupling section of an energy-absorbing anchor bolt according to claim 7, characterized in that, In full-length anchorage, the load-displacement relationship calculation for threaded steel anchor bolt + decoupling layer + full-length anchorage includes: (1.1) Elastic phase, ,in, This is the elastic limit displacement. The load-displacement relationship in the elastic stage is as follows: (This is because the load-displacement relationship in the elastic stage is as follows:) ； In the formula, Let be the cross-sectional area of ​​the rod. This refers to the residual frictional shear stress at the interface. Perimeter; (1.2) Yield point and yield stage, ,in, This represents the displacement at the end of the yielding stage; the load-displacement relationship during the yielding stage is corrected as follows: ； In the formula, For the lower yield load, The lower yield strength; (1.3) Strengthening phase, ;in, This represents the displacement corresponding to the peak load; the load-displacement relationship is: ； In the formula, For actual stress, The material strength coefficient, The strain hardening index; Peak point: The load reaches its maximum value. The corresponding displacement is ; (1.4) Neck constriction stage, The linear softening model is as follows: ； In the formula, The frictional resistance provided for the decoupling section The anchoring force provided to the anchorage section This represents the displacement at the point where the anchor bolt eventually breaks. (1.5) The load-displacement relationship of the threaded steel anchor bolt + decoupling layer + full-length anchorage is as follows: ； In the formula, The load on the anchor bolt; (1.6) Elongation: ； In the formula, For the initial length, To achieve the maximum displacement / length after fracture.

9. The method for calculating and controlling the energy absorption of the free section-decoupling section of an energy-absorbing anchor bolt according to claim 7, characterized in that, In end anchoring, the load-displacement relationship calculation for threaded steel anchor bolt + decoupling layer + end anchoring includes: (2.1) Elastic phase, The load-displacement relationship in the elastic stage is as follows: ； (2.2) Yield point and yield stage, The load-displacement relationship during the yielding stage is corrected as follows: ； (2.3) Strengthening phase, The load-displacement relationship is as follows: ； (2.4) The neck constriction stage, The linear softening model is as follows: ； (2.5) The load-displacement relationship of the threaded steel anchor rod + decoupling layer + end anchor is as follows: 。 10. A calculation and energy absorption control system for the free section-decoupling section of an energy-absorbing anchor bolt, characterized in that, The system implements the calculation and energy absorption control method for the free section-decoupling section of the energy-absorbing anchor bolt as described in any one of claims 1-9, and the system includes: The module for constructing the time series function of the rod displacement field is used to construct the time series function of the rod displacement field based on the elastoplastic mechanical model. The free segment length and decoupled segment length quantization module is used to automatically quantize the free segment length using a dynamic boundary recognition algorithm. With decoupling segment length ; The load-displacement curve generation module is used to fuse measured strain data with theoretical models to generate high-precision load-displacement curves. The energy absorption value calculation module is used to calculate the energy absorption value using numerical integration methods. ; The decoupling section material parameter optimization module is used to optimize energy absorption values. To optimize the decoupling section material parameters and maximize the energy absorption value, feedback indicators are used. The intelligent control closed-loop module is used to feed back the optimized decoupling section material parameters to the engineering design or construction stage, forming an intelligent control closed loop of perception, analysis, optimization, and execution. The intelligent control closed loop includes design stage control and on-site stage control. Design stage control includes using the optimized parameters for the design and manufacturing of energy-absorbing anchor bolt products. On-site stage control includes dynamically adjusting the decoupling section length of the in-service anchor bolts according to the optimization instructions.

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