A welding device and method for stress concentration part of mining machinery

Abstract

The present application relates to the technical field of welding, and discloses a kind of mining machinery stress concentration part welding processing device and method, the method first obtains the initial mechanical boundary condition of mining machinery base material, and the three-dimensional point cloud data of weld toe surface is extracted to obtain initial geometric boundary condition;Subsequently, by constructing integrated multi-physics field coupling calculation model, comprehensive mechanics and geometric boundary conditions, in turn inverse solution overcome local initial tensile stress and the dynamic impact force peak required to cause compression plastic rheological, target ultrasonic amplitude and adaptive travel speed;Finally, according to the calculation parameter control end executes along weld surface plastic strengthening treatment.This application abandons the blindness of traditional process by experience trial and error, introduces subsection equivalent contact curvature model and energy-shape collaborative pre-calibration mechanism, realizes the precise quantitative closed-loop control of ultrasonic impact energy and adaptive travel speed under complex morphology, significantly improves the fatigue life and processing consistency of mining machine stress concentration part.

Description

Technical Field

[0001] This invention belongs to the field of welding technology, and in particular relates to a welding treatment device and method for stress concentration areas in mining machinery. Background Technology

[0002] In the field of mining machinery manufacturing, geometric abrupt changes are common at the weld toe of large welded structural components such as hydraulic supports and scraper conveyors. This area, combined with residual tensile stress from welding, forms a highly concentrated stress field. This stress concentration becomes the core area for fatigue crack initiation, significantly reducing the service reliability of the structural components. While ultrasonic impact treatment technology is currently used for weld toe strengthening in industrial practice, introducing residual compressive stress through plastic deformation and optimizing transition curvature, its process parameter setting process has significant limitations. Specifically, operators mainly rely on subjective experience or repeated trial and error to determine key parameters such as ultrasonic amplitude and travel speed, lacking the ability to quantitatively analyze the actual three-dimensional geometry of the weld toe and the distribution of local residual stress. Due to the complex and variable geometric characteristics and stress states of welded structures in mining machinery, this experience-driven parameter setting method makes it difficult to achieve precise matching of the process, resulting in large fluctuations in treatment effects. Under certain operating conditions, improper parameter selection may lead to the propagation of microcracks on the workpiece surface or insufficient plastic strengthening depth, thereby weakening the overall fatigue resistance of the structural components. Existing technologies have failed to establish a dynamic feedback mechanism based on measured data, and cannot adaptively derive parameters based on the microscopic morphology of the weld toe surface and the initial mechanical state of the material, which restricts the stable application of ultrasonic impact treatment in key parts of mining machinery. Summary of the Invention

[0003] The purpose of this invention is to provide a welding treatment device and method for stress concentration areas in mining machinery, aiming to solve at least one of the above-mentioned problems.

[0004] This invention is implemented as follows: a welding treatment method for stress concentration areas in mining machinery, comprising the following steps: acquiring the mechanical property parameters and initial residual tensile stress data of the base material to which the stress concentration area belongs, and constructing initial mechanical boundary conditions; acquiring three-dimensional point cloud data of the weld toe surface of the stress concentration area; extracting initial geometric features based on the three-dimensional point cloud data, and constructing initial geometric boundary conditions for the weld toe surface; using an integrated multiphysics coupling calculation model, combining the initial mechanical boundary conditions and the initial geometric boundary conditions, sequentially and inversely calculating the peak dynamic impact force, target ultrasonic amplitude, and adaptive travel speed required to overcome local initial tensile stress and induce compressive plastic rheology; and controlling the ultrasonic impact actuator to travel along the weld seam according to the calculated target ultrasonic amplitude and adaptive travel speed, and performing metal surface plastic strengthening treatment on the weld toe.

[0005] A further technical solution involves extracting initial geometric features based on 3D point cloud data, including performing local surface fitting on the 3D point cloud data to extract the initial weld toe transition radius; and constructing a piecewise equivalent contact curvature model, which divides the contact condition between the impact head at the end of the ultrasonic impact actuator and the weld toe surface into a physical interference calibration condition and a conventional Hertz contact condition, and calculates the equivalent contact curvature radius accordingly; the value of the equivalent contact curvature radius is determined by dividing the product of the physical design radius of the impact head and the initial weld toe transition radius by the relative absolute value of the difference between the two; wherein, when the initial weld toe transition radius is less than the physical design radius, the equivalent curvature is output based on the subtrahend and minuend of the inversion difference of the physical geometric interference boundary.

[0006] A further technical solution, based on the multiaxial contact yielding equivalent mechanism, reversely solves the required dynamic impact force peak value according to the equivalent contact curvature radius; the solution model for the dynamic impact force peak value is constrained by overcoming the multiaxial yielding threshold after superimposed initial residual tensile stress; in this solution model, the dynamic impact force peak value is directly proportional to the square of the equivalent contact curvature radius, inversely proportional to the square of the comprehensive equivalent elastic modulus between the impact head and the mining machinery base material, and directly proportional to the cube of the comprehensive yield stress term; the comprehensive yield stress term is composed of the apparent yield strength of the mining machinery base material minus the absolute amplitude of the initial residual tensile stress value of the stress concentration part after correction by the tensor equivalent attenuation coefficient.

[0007] A further technical solution is based on the acoustic-mechanical energy conversion balance model, which establishes an equivalent conservation relationship between the maximum transient mechanical kinetic energy of the adaptive ultrasonic impact actuator and the total elastoplastic deformation work required for the weld toe to undergo target plastic rheology. The target ultrasonic amplitude to be output by the ultrasonic transducer within the ultrasonic impact actuator is synthesized based on the peak value of the dynamic impact force. In the acoustic-mechanical energy conversion balance model, the target ultrasonic amplitude is inversely proportional to the operating frequency of the ultrasonic transducer and directly proportional to the square root of the energy conversion term. The energy conversion term is the ratio of the total elastoplastic deformation work to the equivalent kinematic mass of the adaptive ultrasonic impact actuator. The total elastoplastic deformation work is determined by the combined multiplication of the peak value of the dynamic impact force, the theoretical elastic indentation depth characterizing the Hertzian contact, and the elastoplastic work multiplier. The theoretical elastic indentation depth is a nonlinear power function of the peak value of the dynamic impact force, the equivalent contact curvature radius, and the combined equivalent elastic modulus.

[0008] A further technical solution, based on the volume conservation law of metal plastic rheology, calculates the adaptive travel speed by comprehensively considering the current stress state and target geometry. The adaptive travel speed is obtained by dividing the effective plastic volume transfer rate per unit time by the target deformation area of ​​the weld toe section. The effective plastic volume transfer rate is determined by multiplying the operating frequency of the ultrasonic transducer, the effective volume transfer coefficient of plastic deformation, the physical design radius of the impact head, and the square of the theoretical elastic indentation depth. The target deformation area of ​​the weld toe section is determined by the difference between the square of the final target weld toe transition radius required by the process and the square of the initial weld toe transition radius, combined with the geometric shape coefficient characterizing the weld toe section.

[0009] A further technical solution, before performing the plastic strengthening treatment on the metal surface, includes an energy-shape co-calibration step to obtain the effective volume transfer coefficient and the elastoplastic work multiplier. The pre-calibration step specifically includes: controlling the ultrasonic impact actuator to perform a single-point fixed-point impact test on a calibration test block made of the same material as the mining machinery, and simultaneously recording the total actual mechanical work output by the ultrasonic generator during the impact; obtaining the discrete point cloud elevation data of the actual plastic indentation generated by the single-point impact test; the elastoplastic work multiplier is determined by the ratio of the total actual mechanical work to the theoretical elastic indentation work derived from the peak value of the dynamic impact force and the equivalent radius of curvature during pre-calibration; the effective volume transfer coefficient... The actual plastic indentation volume is calculated by spatial surface integration of discrete point cloud elevation data, and the ratio of this to the theoretical elastic indentation volume derived from the peak dynamic impact force and the equivalent radius of curvature is used to determine the indentation volume.

[0010] A welding treatment device for stress concentration points in mining machinery includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the above-described method.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0012] 1. This invention completely eliminates the limitations of traditional ultrasonic impact processes that heavily rely on trial and error based on manual experience. It innovatively integrates the multiaxial contact yielding equivalent mechanism with an energy-shape collaborative pre-calibration model. By introducing the elastoplastic work multiplier and the effective volume transfer coefficient, it perfectly bridges the ideal elastic work with the actual plastic dissipation, achieving a rigorous mathematical inverse solution for dynamic impact force, ultrasonic amplitude, and travel velocity. This ensures precise energy conversion and significantly improves the consistency of surface plastic strengthening processes.

[0013] 2. To address the challenges of variable transition radii and complex initial stresses in actual mining machinery weld toe applications, this invention cleverly introduces a piecewise equivalent contact curvature model and tensor equivalent attenuation correction for initial residual tensile stress. This scheme not only resolves the geometric interference singularity problem under small curvature radii but also eliminates the nonlinear superposition interference of initial residual stress in the subsurface layer, enabling the method to maintain extremely high algorithm robustness even in narrow or highly irregular stress concentration areas. Attached Figure Description

[0014] Figure 1 A flowchart illustrating the overall steps of a welding treatment method for stress concentration points in mining machinery, provided by this invention;

[0015] Figure 2 The calculation logic diagram of the segmented equivalent contact curvature model provided by this invention;

[0016] Figure 3 This is a flowchart illustrating the reverse solution logic of the multiphysics coupling calculation model provided by the present invention.

[0017] Figure 4 The schematic diagram of the "energy-shape" collaborative precalibration principle provided by the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0019] Stress concentration areas in mining machinery refer to locations where the stress in a localized area is significantly higher than the average stress due to factors such as abrupt changes in structural geometry, uneven load distribution, or welding processes. These areas are weak points where fatigue cracks initiate and propagate, posing a potential threat to the service life of the machinery.

[0020] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0021] like Figure 1 As shown, a welding treatment method for stress concentration points in mining machinery, provided by an embodiment of the present invention, includes the following steps:

[0022] The mechanical property parameters and initial residual tensile stress data of the base material to which the stress concentration point belongs are obtained to construct the initial mechanical boundary conditions. The mechanical property parameters can be obtained by consulting material standard handbooks, conducting laboratory material tests (e.g., tensile tests, hardness tests), or using non-destructive testing techniques (e.g., ultrasonic thickness measurement, eddy current testing). The initial residual tensile stress data acquisition mechanism includes two engineering modes: online real-time acquisition and offline prior database retrieval. In a preferred embodiment, a portable X-ray diffractometer can be used to perform rapid non-destructive measurements on the weld toe surface, and combined with the empirical curves of residual stress depth distribution pre-stored in the material and welding process database, the absolute amplitude of the residual stress in the subsurface layer can be estimated. and its tensor equivalent decay coefficient In another conventional industrial-grade embodiment, for a specific batch of mining machinery components, the present invention supports high-precision micro-destructive testing of welded test blocks from the same batch in advance using the blind hole method or layer-by-layer peel X-ray diffraction method in the laboratory, accurately calibrating the... and The actual distribution model is obtained, and this prior data is input into the calculation system as fixed mechanical boundary conditions for direct use when processing the same batch of workpieces on site. This dual-track mechanism ensures the high feasibility of this method under limited on-site conditions. After collection, this data can be input into the computer system to construct a mathematical model describing the initial mechanical state of the weld toe region, i.e., the initial mechanical boundary conditions. For example, the yield strength and initial residual tensile stress values ​​of the material can be manually input, or data can be acquired in real time and preliminarily processed through a sensor array.

[0023] The mechanical properties of the base material include, but are not limited to, yield strength, tensile strength, elastic modulus, and Poisson's ratio. These parameters characterize the deformation and failure characteristics of the material under stress. Accurately obtaining these parameters is fundamental for mechanical analysis and process parameter calculation. Initial residual tensile stress data refers to the tensile stress that exists within the structure during welding or manufacturing due to factors such as uneven cooling or phase transformation, even without external loads. The superposition of these residual tensile stresses with working stresses significantly reduces the fatigue life of the material. Initial mechanical boundary conditions refer to the mathematical description of the structural stress state and deformation constraints during mechanical analysis. They typically include information such as external loads, support constraints, and the initial stress distribution within the material, providing input for multiphysics coupled computational models.

[0024] Acquiring 3D point cloud data of the weld toe surface at stress concentration points can be achieved in various ways. For example, a handheld laser scanner can be used to scan the weld toe area, or a 3D imaging system based on structured light or photogrammetry can be used. These devices can capture the discrete point coordinates of the weld toe surface, forming a high-density 3D point cloud. Alternatively, a contact probe measurement system can be used, where a robotic arm moves a probe along the weld toe surface, recording the 3D coordinates point by point. 3D point cloud data is a set of discrete points representing the geometry of an object's surface, acquired through 3D scanning equipment. Each point contains 3D coordinate information, enabling accurate reconstruction of the object's surface geometry and providing raw data for subsequent geometric feature extraction.

[0025] Initial geometric features are extracted from 3D point cloud data to construct the initial geometric boundary conditions for the weld toe surface. After acquiring the 3D point cloud data, geometric processing software can be used to process the data, such as denoising, filtering, and surface reconstruction. Subsequently, key geometric features can be extracted from the reconstructed surface model, such as approximating the transition radius of the weld toe by fitting a circular arc or polynomial curve, or characterizing the sharpness of the weld toe by calculating local curvature. These extracted geometric features are then used to construct the initial geometric boundary conditions, for example, parameterizing the geometry of the weld toe and inputting it into the subsequent computational model.

[0026] Initial geometric features refer to key parameters extracted from 3D point cloud data that characterize the geometry of the weld toe region, such as the weld toe transition radius and weld angle. These features directly affect the stress concentration level and are important bases for optimizing the weld toe morphology. Initial geometric boundary conditions refer to the mathematical description of the structure's geometry and dimensions during geometric analysis or numerical simulation. They are usually constructed based on initial geometric features and provide geometric input for multiphysics coupled computational models.

[0027] By integrating the initial mechanical and geometric boundary conditions through a multiphysics coupling calculation model, the dynamic impact peak force, target ultrasonic amplitude, and adaptive travel velocity required to overcome local initial tensile stress and induce compressive plastic rheology are calculated sequentially and inversely. This multiphysics coupling calculation model can be a simulation platform based on finite element analysis (FEA), which integrates mathematical equations of physical fields such as mechanics, acoustics, and plastic deformation. In one implementation, the model can employ an iterative calculation method, gradually approximating the required dynamic impact peak force, target ultrasonic amplitude, and adaptive travel velocity based on the input initial mechanical and geometric boundary conditions through a series of preset empirical formulas or simplified models. For example, an initial impact force can be estimated first based on empirical formulas, then the required amplitude and velocity can be estimated based on this impact force, and finally verified using simple mechanical equilibrium equations.

[0028] Multiphysics coupled computational models are numerical simulation models capable of simultaneously considering the interactions of multiple physical phenomena (such as mechanics, thermodynamics, and acoustics). By integrating equations and boundary conditions from different physical fields, this model can more comprehensively and accurately predict the behavior of complex systems under the influence of multiple factors. The dynamic impact peak force refers to the maximum instantaneous force acting on the weld toe surface during each impact of the ultrasonic impact actuator. This force is a key factor in achieving plastic deformation of the material and introducing residual compressive stress. The target ultrasonic amplitude refers to the maximum vibration displacement that the impact head tip of the ultrasonic impact actuator should achieve during operation. This amplitude directly determines the magnitude of the impact energy and is an important parameter for controlling the plastic strengthening effect. The adaptive travel speed refers to the speed at which the ultrasonic impact actuator travels along the weld seam. This speed can be dynamically adjusted according to the actual geometric and mechanical state of the weld toe. By adaptively adjusting the travel speed, uniform and effective plastic strengthening treatment can be ensured throughout the weld seam area.

[0029] Based on the calculated target ultrasonic amplitude and adaptive travel speed, the ultrasonic impact actuator is controlled to travel along the weld seam, performing surface plastic strengthening treatment on the weld toe. The ultrasonic impact actuator is typically driven by a controller that receives parameters from the computational model. For example, the controller can adjust the output power of the ultrasonic generator based on the calculated target ultrasonic amplitude, thereby changing the vibration amplitude of the impact head. Simultaneously, the controller can also control a robotic arm or guide system to move the impact actuator along the weld seam path based on the calculated adaptive travel speed. In one implementation, the operator can manually input the calculated amplitude and speed parameters and then execute the process by manually adjusting the device knobs or setting parameters on the control interface.

[0030] The ultrasonic impact actuator is the component in an ultrasonic impact device that directly contacts the workpiece and applies impact. It typically includes components such as an ultrasonic transducer, amplitude transformer, and impact head, responsible for converting electrical energy into mechanical vibration energy and transmitting it to the weld toe. Metal surface plastic strengthening treatment refers to using methods such as ultrasonic impact to induce plastic deformation in the surface layer of a metal material, thereby introducing beneficial residual compressive stress, refining grains, and improving surface roughness to enhance the material's fatigue strength and corrosion resistance.

[0031] The following specific example will provide a more in-depth explanation of the above technical solution:

[0032] Suppose that at location A, a stress concentration problem is found at the weld toe of a critical welded structural component of a mining hydraulic support, requiring ultrasonic impact treatment to improve its fatigue life. User A decides to use the method provided in this embodiment for treatment.

[0033] First, User A obtains the mechanical property parameters of the base material to which the hydraulic support weld toe belongs. For example, by consulting the quality certificate of the batch of steel, User A obtains data such as its yield strength, tensile strength, and elastic modulus. Simultaneously, User A uses a portable X-ray diffractometer to scan the weld toe area and obtain the initial residual tensile stress data for that region. These mechanical property parameters and initial residual tensile stress data are input into a computer system to construct the initial mechanical boundary conditions for the weld toe area.

[0034] Next, User A used a high-precision handheld laser 3D scanner to scan the surface of the weld toe and obtain its 3D point cloud data. This point cloud data accurately records the geometry of the weld toe surface, including its irregular transition areas.

[0035] User A then imported the acquired 3D point cloud data into professional point cloud processing software. This software denoised the point cloud data and reconstructed the surface, and further extracted key geometric features such as the initial weld toe transition radius from the reconstructed surface using a geometric fitting algorithm. These extracted geometric features were used to construct the initial geometric boundary conditions of the weld toe surface; for example, parameterizing the actual geometry of the weld toe to facilitate subsequent numerical calculations.

[0036] After obtaining the initial mechanical and geometric boundary conditions, these data are input into an integrated multiphysics coupled computational model. This model is a pre-built simulation platform that integrates mathematical equations describing the mechanical behavior of materials, ultrasonic wave propagation, and plastic deformation. Taking into account the material properties of the weld toe, the initial stress state, and the actual geometry, the model uses a reverse-engineering algorithm to accurately calculate the peak dynamic impact force required to overcome the local initial tensile stress and induce the target compressive plastic rheology, the target ultrasonic amplitude required to achieve this impact force, and the adaptive travel speed required to ensure uniform processing. For example, the model might calculate a peak dynamic impact force of 1000 N, corresponding to a target ultrasonic amplitude of 20 micrometers, and an adaptive travel speed of 5 millimeters per second along the weld.

[0037] Finally, User A adjusts the parameters of the ultrasonic impact device through the control system based on the target ultrasonic amplitude (e.g., 20 micrometers) and adaptive travel speed (e.g., 5 mm / s) calculated by the computational model. The ultrasonic impact actuator is precisely controlled to travel along the weld seam at an amplitude of 20 micrometers and a speed of 5 mm / s, performing plastic strengthening treatment on the weld toe. Throughout the process, the impact actuator can move according to the preset path and speed, ensuring uniform and effective plastic deformation in the weld toe area, thereby introducing beneficial residual compressive stress, improving the geometry of the weld toe, and significantly enhancing the fatigue resistance of the hydraulic support welded structure.

[0038] Based on the above examples, the method provided in this embodiment demonstrates a significant technical contribution to the welding treatment of stress concentration areas in mining machinery.

[0039] In existing technologies, as described in Background Art 1, the setting of ultrasonic impact treatment process parameters generally relies on manual experience or trial and error. This means that when facing the actual situation of the welded toe of the hydraulic support mentioned above, User A may need to conduct multiple experimental impacts, adjusting the amplitude and travel speed by observing the effects or conducting subsequent tests. This is not only time-consuming and labor-intensive, but also makes it difficult to guarantee the stability and consistency of the treatment effect. For example, if the initial parameters are set improperly, it may lead to excessive impact force causing surface damage, or insufficient impact force resulting in an insignificant strengthening effect.

[0040] In contrast, the method in this embodiment provides accurate input for subsequent parameter calculations by acquiring the actual mechanical property parameters of the weld toe, initial residual tensile stress data, and three-dimensional point cloud data. In the example above, user A can obtain the true state information of the weld toe region through techniques such as X-ray diffraction and laser scanning, rather than relying on empirical guesswork.

[0041] More importantly, this embodiment introduces an integrated multiphysics coupling calculation model. This model can comprehensively consider the interaction of various factors such as materials, stress, and geometry, and inversely calculate the dynamic impact peak force, target ultrasonic amplitude, and adaptive travel velocity required to overcome local initial tensile stress and induce compressive plastic rheology. This contrasts sharply with the existing technology that uses empirical or simplified models for parameter setting. In the example above, this model can provide user A with a set of quantitative and customized process parameters, avoiding blind trial and error and ensuring the accuracy of the processing.

[0042] Therefore, based on the calculated target ultrasonic amplitude and adaptive travel speed, the ultrasonic impact actuator is controlled to perform plastic strengthening treatment on the metal surface, achieving adaptive adjustment of process parameters. This means that in the above example, the ultrasonic impact device no longer operates according to fixed, universal parameters, but rather dynamically adjusts according to the actual situation of the specific weld toe. This ensures stable treatment results in complex and variable mining machinery welding structures, effectively avoiding surface damage or insufficient strengthening caused by improper parameters.

[0043] In summary, the method provided in this embodiment overcomes the limitations of existing technologies, such as parameter setting relying on experience and unstable processing results, by introducing precise data acquisition, multi-physics coupling calculation models, and adaptive parameter control. It provides an intelligent, efficient, and reliable solution for welding stress concentration parts of mining machinery, significantly improving the fatigue resistance and service life of key structural components.

[0044] like Figure 2As shown, in a preferred embodiment of the present invention, the extraction of initial geometric features based on three-dimensional point cloud data includes performing local surface fitting on the three-dimensional point cloud data to extract the initial weld toe transition radius; and constructing a piecewise equivalent contact curvature model, which divides the contact condition between the impact head at the end of the ultrasonic impact actuator and the weld toe surface into a physical interference calibration condition and a conventional Hertz contact condition, and calculates the equivalent contact curvature radius accordingly; the value of the equivalent contact curvature radius is determined by dividing the product of the physical design radius of the impact head and the initial weld toe transition radius by the relative absolute value of the difference between the two; wherein, when the initial weld toe transition radius is less than the physical design radius, the equivalent curvature is output based on the subtrahend and minuend of the difference in the physical geometric interference boundary reversal; the calculation formula is:

[0045]

[0046] In the formula, Indicates the equivalent contact curvature radius. Indicates the physical design radius of the impact head. Indicates the initial weld toe transition radius; where, when When the model is used, it characterizes the equivalent curvature based on the physical geometric interference boundary calibration; when... At that time, the model characterizes the equivalent curvature of the concave-convex conformal contact based on the pure theoretical Hertzian contact derivation; before solving the formula, the dimensions of the above parameters are forcibly normalized to the International System of Units (SI) reference units.

[0047] Local surface fitting of 3D point cloud data to extract the initial weld toe transition radius refers to processing discrete 3D point cloud data using mathematical methods to obtain a continuous surface representation and accurately quantify the curvature characteristics of the weld toe region. For example, the least squares method can be used to perform polynomial surface fitting on the local point cloud, or parametric surface techniques such as B-splines and non-uniform rational B-splines (NURBS) can be used to approximate the actual geometry of the weld toe. This approach effectively filters out noise in the point cloud data and accurately calculates the initial transition radius of the weld toe. This radius is a key parameter characterizing the sharpness or smoothness of the weld toe geometry. Constructing a piecewise equivalent contact curvature model refers to establishing an equivalent curvature calculation model that can adaptively adjust based on the actual contact conditions between the impactor and the weld toe surface. This model meticulously divides the contact conditions between the impactor and the weld toe surface into two main types: physical interference calibration conditions and conventional Hertzian contact conditions. This piecewise treatment aims to more accurately reflect the mechanical behavior of impact contact under different geometric conditions. The physical interference calibration conditions specifically refer to the initial weld toe transition radius... Smaller than the physical design radius of the impact head In this case, the impact head and weld toe actually form edge interference contact, and the traditional Hertzian contact theory exhibits geometric singularities. Therefore, this model mathematically constructs a continuous and positive algebraic equivalent curvature by reversing the subtrahend and minuend of the difference. This algebraic equivalent curvature does not precisely describe the actual microscopic contact morphology, but rather provides a monotonically continuous geometric input reference for subsequent calculations. The nonlinear physical response deviation caused by the interference contact will be absorbed and corrected in subsequent steps of this method using pre-calibrated work multiplier and volume transfer coefficient. The conventional Hertzian contact condition specifically refers to the initial weld toe transition radius... Larger than the physical design radius of the impact head Under these conditions, the weld toe surface is relatively smooth, and the contact between the impact head and the weld toe better conforms to the classical Hertzian contact theory. This model uses another set of formulas to characterize the equivalent curvature of the conformal contact derived from pure theoretical Hertzian contact, to be applicable to the contact between the impact head and the relatively smooth weld toe. The equivalent contact curvature radius is calculated. Based on the two different contact conditions mentioned above, an equivalent radius of curvature is determined using the corresponding mathematical expressions. This equivalent contact radius of curvature is... Taking into account the curvature of the impact head itself and the initial transition radius of the weld toe This is a crucial mechanical parameter used for subsequent precise calculations of impact mechanics. Before solving this formula, the dimensions of all the above parameters are forcibly normalized to the International System of Units (SI) to ensure that all physical quantities have a unified unit system during the calculation. This standardization process avoids calculation errors caused by inconsistent units, ensuring the accuracy and reliability of the calculation results.

[0048] This application extracts a continuous and smooth initial weld toe transition radius from discrete measurement data by performing local surface fitting on 3D point cloud data. This step effectively eliminates measurement noise and provides accurate geometric input for subsequent mechanical analysis. Based on this, this application constructs a piecewise equivalent contact curvature model. The core of this model lies in identifying two main working conditions of the contact between the impact head and the weld toe surface: when the weld toe is relatively sharp (i.e., the initial weld toe transition radius...). Smaller than the physical design radius of the impact head When the system enters the physical interference calibration condition, the contact behavior may be more complex, requiring a specific formula to characterize the equivalent curvature; while when the weld toe is relatively flat (i.e., the initial weld toe transition radius...), the system enters the physical interference calibration condition. Larger than the physical design radius of the impact head When the weld toe is in a certain position, the system enters the normal Hertzian contact condition, where the contact behavior is more consistent with classical Hertzian contact theory. Through this segmented processing, the model can adaptively select the most suitable calculation method to determine the equivalent contact curvature radius based on the actual geometry of the weld toe. Equivalent contact radius of curvature The precise calculation of the initial geometric boundary conditions is crucial for solving the dynamic impact peak, target ultrasonic amplitude, and adaptive travel velocity in subsequent multiphysics coupled calculation models. This refined geometric feature extraction and contact model construction ensures the accuracy of the initial geometric boundary conditions, making the calculation results of the entire processing method closer to actual working conditions. Before solving all formulas, the dimensions of each parameter are forcibly normalized to the International System of Units (SI) to further guarantee the rigor of the calculation process and the reliability of the results. This method, through a deep understanding and precise modeling of the weld toe geometry, provides a solid foundation for subsequent impact parameter optimization, enabling the metal surface plastic strengthening treatment to more effectively overcome local initial tensile stress and induce compressive plastic flow.

[0049] The following is a concrete example. After obtaining the 3D point cloud data of the weld toe, a stress concentration area in mining machinery, professional point cloud processing software, such as Geomagic Studio or CloudCompare, can be used to perform local surface fitting on the point cloud data of the weld toe region. Specifically, several subsets of the point cloud data in the weld toe transition region can be selected, and then a non-uniform rational B-spline (NURBS) surface fitting algorithm can be used to generate a smooth surface model. From this NURBS surface model, the initial weld toe transition radius can be accurately extracted. Assuming the physical design radius of the impact head... The initial weld toe transition radius is 5 mm. If the initial weld toe transition radius obtained through the above fitting is... If it is 3 millimeters, then due to The system will identify this as a physical interference calibration condition. At this point, the equivalent contact radius of curvature... According to the formula Perform calculations, that is Millimeters. Conversely, if the fitted initial weld toe transition radius is... If it is 8 millimeters, then due to The system will identify this as a normal Hertzian contact condition. In this case, the equivalent contact radius of curvature... According to the formula Perform calculations, that is Millimeters. Before performing the above calculations, all length parameters involved, such as and All data will be forcibly converted to International System of Units (SI) units, such as from millimeters to meters, to ensure the accuracy of the calculation. In this way, the system can dynamically select an appropriate model to calculate the equivalent contact curvature radius based on the actual geometric characteristics of the weld toe, providing more accurate geometric input for subsequent impact parameter calculations.

[0050] Through the above technical solution, this application overcomes the limitations of traditional methods in handling complex weld toe geometries. By performing local surface fitting on the three-dimensional point cloud data, the initial weld toe transition radius can be extracted more accurately, effectively avoiding errors caused by inaccurate geometric feature extraction. Furthermore, a piecewise equivalent contact curvature model is constructed, and the equivalent contact curvature radius is adaptively calculated based on the actual contact conditions between the impact head and the weld toe surface (physical interference calibration condition or conventional Hertzian contact condition), making the subsequent calculations of dynamic impact peak force, target ultrasonic amplitude, and adaptive travel speed more consistent with actual mechanical behavior. This refined geometric modeling and contact condition identification significantly improves the accuracy of the multiphysics coupling calculation model, thereby ensuring the accuracy and effectiveness of the metal surface plastic strengthening treatment, and ultimately achieving a more thorough elimination of the initial residual tensile stress in the stress concentration area of ​​mining machinery and a more stable plastic strengthening effect.

[0051] like Figure 3 As shown, in a preferred embodiment of the present invention, the required dynamic impact force peak value is obtained by inversely solving based on the equivalent contact curvature radius, according to the multiaxial contact yielding equivalent mechanism (preferably based on the large deformation engineering equivalent of Hertz contact theory).

[0052] The solution model for the dynamic impact force peak value is constrained by overcoming the multiaxial yield threshold after superimposed initial residual tensile stress. In this solution model, the dynamic impact force peak value is directly proportional to the square of the equivalent contact curvature radius, inversely proportional to the square of the comprehensive equivalent elastic modulus between the impact head and the mining machinery base material, and directly proportional to the cube of the comprehensive yield stress term. The comprehensive yield stress term is composed of the apparent yield strength of the mining machinery base material, minus the absolute amplitude of the initial residual tensile stress value of the stress concentration part after correction by the tensor equivalent attenuation coefficient. Its calculation formula is:

[0053]

[0054] In the formula, Indicates the peak value of dynamic impact force. Indicates the equivalent contact curvature radius. This represents the combined equivalent modulus of elasticity between the impact head and the base material of the mining machinery. This indicates the apparent yield strength of the base material used in mining machinery. This represents the absolute magnitude of the initial residual tensile stress at the stress concentration point. This represents the tensor equivalent attenuation coefficient of the initial residual tensile stress at the extreme depth of the subsurface layer.

[0055] The large deformation engineering equivalence based on Hertzian contact theory refers to modifying and extending the classical Hertzian contact theory to describe and analyze the large deformation contact behavior between the impact head and the weld toe surface. Traditional Hertzian contact theory is mainly applicable to small deformation elastic contact, but in the plastic strengthening process of metal surfaces, the contact between the impact head and the weld toe is often accompanied by significant plastic deformation. Therefore, by introducing empirical correction factors, iterative calculation methods, or combining numerical simulation techniques such as finite element analysis, the actual large deformation can be equivalent to a superposition of a series of small deformations, thus approximately describing the contact mechanics behavior under large deformation within the framework of Hertzian contact theory. The reverse calculation of the required dynamic impact force peak value based on the equivalent contact curvature radius refers to deriving the required dynamic impact force peak value to achieve the desired plastic deformation effect or stress state from the reverse direction. Equivalent contact curvature radius... This is a key parameter describing the contact geometry between the impact head and the weld toe surface, comprehensively reflecting the curvature of both. By combining this geometric parameter with the material's mechanical properties (such as yield strength and residual stress), a mechanical model can be constructed, allowing for the inverse calculation of the peak dynamic impact force required to achieve a specific plastic deformation. This reverse solution process can be implemented using numerical iteration methods, such as the Newton-Raphson method, or through a pre-established lookup table or response surface model. (Dynamic impact peak force) This represents the maximum instantaneous force that the impact head can exert on the weld toe surface during ultrasonic impaction, which is a key factor in inducing plastic deformation of the material. The combined equivalent elastic modulus between the impact head and the base material of the mining machinery is also considered. This reflects the combined elastic properties of the impact head material and the base material of the mining machinery in the contact area. The apparent yield strength of the base material of the mining machinery... This refers to the stress value at which the base material begins to undergo macroscopic plastic deformation under impact load. It is the absolute amplitude of the initial residual tensile stress at this stress concentration point. This represents the maximum value of the untreated tensile residual stress existing in the weld toe region after welding. The tensor equivalent attenuation coefficient of the initial residual tensile stress at the subsurface extreme depth. This is a correction factor used to describe the attenuation of initial residual tensile stress from the surface to the interior, and its influence on plastic deformation under complex stress states. The constant in the formula... The constant 3.1 originates from the yield ratio relationship between pure shear and uniaxial tension states in the Von Mises yield criterion; it is derived from the reciprocal of the correlation coefficient of the maximum shear stress amplitude at the subsurface layer of the elastic half-space; and it is also a constant. and Derived from the spatial surface integral coefficients of the semi-ellipsoidal contact stress field in Hertzian contact theory, these constants ensure the physical basis of the calculation. It should be clearly pointed out that the 'peak dynamic impact force required to induce compressive plastic rheology' described in the claims of this invention is, in its actual multiphysics coupled calculation model, derived by first solving for a baseline value of elastoplastic critical contact force, and then using calibration coefficients for equivalent transformation. Specifically, the peak dynamic impact force calculated in this model using the above formula... This is not a precise prediction of the actual peak force corresponding to macroscopic plastic large deformation indentation, but rather an engineering mechanics benchmark quantity for decoupling complex contact stress states. Its core physical significance lies in characterizing: under a given geometry and initial residual stress, the equivalent threshold force required to overcome local stress and trigger the elastoplastic critical contact state. The nonlinear gap between this quasi-static benchmark force and the dynamic energy required to induce macroscopic plastic rheology in the actual target will be addressed by the elastoplastic work multiplier coefficient pre-calibrated in this invention. By absorbing and bridging these connections, a rigorous closed loop is achieved between mathematical logic and engineering applications.

[0056] This application's solution integrates the actual geometry of the weld toe and the mechanical state of the material into the equivalent Hertzian contact theory framework for large deformation engineering, achieving an accurate inverse solution for the peak dynamic impact force. Specifically, after obtaining the mechanical property parameters of the base material to which the stress concentration point belongs (such as apparent yield strength)... ) and initial residual tensile stress data (such as absolute amplitude) and attenuation coefficient Afterwards, this information constitutes the initial mechanical boundary conditions. Simultaneously, by processing the three-dimensional point cloud data of the weld toe surface, the initial weld toe transition radius is extracted. And combined with the physical design radius of the impact head A piecewise equivalent contact curvature model is constructed to calculate the equivalent contact curvature radius. This constitutes the initial geometric boundary conditions. Subsequently, this mechanical and geometric information is integrated into the aforementioned calculation formula, which calculates the peak dynamic impact force. Equivalent contact radius of curvature Comprehensive equivalent elastic modulus apparent yield strength of the base material Initial residual tensile stress and its attenuation coefficient These key parameters are correlated. In this way, the system can deduce the precise peak dynamic impact force based on the actual geometry of the weld toe and the mechanical state of the material. This reverse solution mechanism ensures that the applied impact force can effectively overcome the existing tensile stress and precisely control the degree of plastic deformation, avoiding damage caused by excessive impact. This provides accurate input for subsequent calculations of the target ultrasonic amplitude and adaptive travel speed, making the entire plastic strengthening process more precise and efficient.

[0057] The following is a specific example to illustrate this. Before performing plastic strengthening treatment on the weld toe of a certain mining machinery, it is first necessary to obtain the apparent yield strength of its locally hardened base material through material testing. Assuming the apparent yield strength of this local area is measured... for (Right now Simultaneously, the absolute amplitude of the initial residual tensile stress was obtained by measuring the weld toe region using a portable X-ray diffractometer. for (Right now ), and in conjunction with the prior database, set the equivalent decay coefficient of the second-level tensor. The value is 0.8. Next, high-precision point cloud data is acquired using a 3D scanner. After extracting initial geometric features through surface fitting, the equivalent contact curvature radius is calculated using a piecewise equivalent contact curvature model. (For example, set as) Given the combined equivalent elastic modulus of the impact head and the base material. Approximately After obtaining all the above parameters and forcibly normalizing them to the International System of Units (SI), they are substituted into the formula for calculating the peak dynamic impact force: the system first calculates the comprehensive yield stress term after overcoming residual stress. ,Right now ( Furthermore, by combining the contact curvature and modulus, the quasi-static reference force—the peak dynamic impact force—required to overcome the local initial tensile stress and reach the elastoplastic critical contact state. Approximately (Engineering approximation) This precise mechanical benchmark solution will serve as the core feedforward input parameter for subsequent matching of target ultrasonic amplitude and adaptive travel velocity.

[0058] Through the above technical solution, based on the Hertzian contact theory and large deformation engineering equivalence, and combined with precise calculation formulas, it is possible to determine the actual geometric characteristics of the weld toe (equivalent contact curvature radius) based on the actual geometric characteristics of the weld toe. ) and the mechanical properties of the base material (apparent yield strength) Initial residual tensile stress and attenuation coefficient The required peak dynamic impact force can be precisely solved in reverse. This precise calculation avoids the uncertainties associated with traditional empirical or trial-and-error methods, ensuring that the applied impact force precisely overcomes the initial local tensile stress and effectively induces the required compressive plastic rheology. This provides accurate mechanical parameter inputs for subsequent calculations of the target ultrasonic amplitude and adaptive travel speed. This not only improves processing efficiency and reliability but also effectively prevents material damage due to excessive impact force or poor strengthening effect due to insufficient impact force, significantly enhancing the quality and durability of welding treatment at stress concentration points in mining machinery.

[0059] like Figure 3 As shown, in a preferred embodiment of the present invention, based on the acoustic-mechanical energy conversion balance model, that is, to construct the equivalent conservation relationship between the maximum transient mechanical kinetic energy of the adaptive ultrasonic impact actuator and the total elastoplastic deformation work required for the weld toe to undergo target plastic rheology, the target ultrasonic amplitude to be output by the ultrasonic transducer in the ultrasonic impact actuator is synthesized according to the peak value of the dynamic impact force.

[0060] In the acoustic-mechanical energy conversion balance model, the target ultrasonic amplitude is inversely proportional to the operating frequency of the ultrasonic transducer and directly proportional to the square root of the energy conversion term. The energy conversion term is the ratio of the total elastoplastic deformation work to the equivalent motion mass of the adaptive ultrasonic impact actuator. The total elastoplastic deformation work is determined by multiplying the peak dynamic impact force, the theoretical elastic indentation depth characterizing the Hertzian contact, and the elastoplastic work multiplier. The theoretical elastic indentation depth is a nonlinear power function of the peak dynamic impact force, the equivalent contact curvature radius, and the combined equivalent elastic modulus. Its calculation formula is as follows:

[0061]

[0062] In the formula, Indicates the target ultrasonic amplitude. This indicates the operating frequency of the ultrasonic transducer. Indicates the peak value of dynamic impact force. This represents the equivalent kinematic mass of the adaptive ultrasonic impact actuator. This parameter does not refer to the physical weight of the actuator. Because the ultrasonic impact system operates in a high-frequency resonant state, its impact mechanics includes the propagation of elastic longitudinal waves within components such as the amplitude transformer; therefore, this equivalent kinematic mass... This refers to a rigid body modal mass, which is equivalent to the distributed mass participating in impact motion at a specific ultrasonic resonant frequency in terms of mechanical kinetic energy conversion. For a given hardware system, this parameter is a constant and can be obtained experimentally through prior dynamic modal analysis or by measuring the impact force and acceleration response characteristics in a free state. Indicates the equivalent contact curvature radius. Represents the comprehensive equivalent elastic modulus. The coefficient for the work done by elastic-plastic forces is used to characterize the ratio of total deformation work, including plastic dissipation work, to pure elastic strain energy. The denominator constant 5 is derived from the combined proportionality constant after balancing the physical equation coefficient (1 / 2) characterizing the maximum transient mechanical kinetic energy and the nonlinear integral coefficient (2 / 5) characterizing the Hertzian contact indentation deformation work. The constants 9 and 16 are derived from the square of the geometric integral constant term of the elastic indentation depth. Before solving this formula, the dimensions of all the above parameters are forcibly normalized to the International System of Units (SI) standard units.

[0063] The acoustic-mechanical energy conversion balance model aims to describe how the mechanical vibration energy generated by the ultrasonic transducer is effectively converted into deformation energy in the contact area between the impact head and the workpiece during ultrasonic impact. It focuses on the conversion efficiency and conservation relationship between different forms of energy, serving as a crucial bridge connecting the input parameters of the ultrasonic equipment with the material response. This model can be constructed based on theoretical mechanics, materials mechanics, and acoustic principles. For example, it can be established by analyzing the energy dissipation and transfer mechanisms during the collision between the impact head and the workpiece, or through experimental calibration to establish empirical relationships for energy conversion. The core of the acoustic-mechanical energy conversion balance model is the equivalent conservation relationship between the maximum transient mechanical kinetic energy of the adaptive ultrasonic impact actuator and the total elastoplastic deformation work required for the weld toe to achieve the target plastic rheological transformation. It explicitly states that at the instant of ultrasonic impact, the maximum mechanical kinetic energy that the impact actuator can provide must be equal to the total deformation work (including elastic deformation work and plastic dissipation work) required for the weld toe region to achieve the preset degree of plastic rheological transformation. This equivalent conservation relationship ensures precise energy matching, avoiding the problems of excessive energy leading to over-processing or insufficient energy leading to inadequate plastic rheological transformation. This relationship can be established by creating a kinematic model of the impact head and a constitutive model of the material, linking the instantaneous velocity and mass of the impact head with the stress-strain response of the material, or by simulating and verifying it using numerical methods such as finite element simulation. The target ultrasonic amplitude is the peak vibration displacement that the ultrasonic transducer needs to output during operation. It is a key parameter that directly controls the impact energy at the end of the ultrasonic impact actuator. By adjusting the amplitude, the instantaneous velocity and kinetic energy of the impact head when it strikes the workpiece can be precisely controlled, thereby affecting the degree of plastic deformation of the material. Determining the target ultrasonic amplitude is a prerequisite for achieving precise plastic strengthening treatment. It can be directly set and output by the ultrasonic generator, or dynamically adjusted based on real-time feedback through a closed-loop control system.

[0064] In order to obtain the calculated peak dynamic impact force To convert these into controllable device parameters, this application proposes a method based on a acoustic-mechanical energy conversion balance model. The core of this method lies in constructing an equivalent conservation relationship between the maximum transient mechanical kinetic energy of the adaptive ultrasonic impact actuator and the total elastoplastic deformation work required for the weld toe to undergo target plastic rheology. Specifically, the ultrasonic impact actuator, driven by an ultrasonic transducer, impacts the weld toe at a certain frequency... and amplitude During high-frequency reciprocating motion, when the impact head contacts the weld toe surface, its transient mechanical kinetic energy is converted into impact energy on the weld toe. To ensure that the weld toe undergoes the expected plastic rheology, this transient mechanical kinetic energy must be precisely equal to the total elastoplastic deformation work required for the weld toe to achieve the target plastic rheology. This equivalent conservation relationship is expressed through a specific calculation formula for the target ultrasonic amplitude. Peak dynamic impact force Operating frequency of ultrasonic transducers Equivalent motion mass of adaptive ultrasonic shock actuator Equivalent contact curvature radius Comprehensive equivalent elastic modulus and the elastic-plastic work ratio factor These parameters are correlated. Among them, the peak dynamic impact force... Equivalent contact curvature radius and comprehensive equivalent elastic modulus All of these are based on the precise analysis and calculation of the base material's mechanical properties, initial residual tensile stress, and weld toe geometry obtained in the aforementioned steps. Elastic-plastic work ratio coefficient. This represents the ratio of plastic dissipation work to pure elastic strain energy in the total deformation work, reflecting the actual energy dissipation of a material under impact. Using this formula, the known peak dynamic impact force can be determined. Using other relevant parameters, the target ultrasonic amplitude that the ultrasonic transducer needs to output is calculated in reverse. This energy-conservation-based calculation method ensures that the ultrasonic impact actuator can output just enough energy to induce plastic rheology in the target, thereby achieving precise control over the plastic strengthening treatment of the weld toe surface.

[0065] As a specific implementation method, the peak dynamic impact force at the stress concentration point of mining machinery is obtained. (For example, calculated by the pre-module as) Afterwards, it can be input into a preset control module. This control module integrates the aforementioned acoustic energy conversion balance model and pre-stores or calibrates relevant hardware and material parameters, such as the operating frequency of the ultrasonic transducer. Set as Equivalent motion mass of adaptive ultrasonic shock actuator Calibrated as The combined equivalent elastic modulus between the steel base material and the impact head Approximately Simultaneously, the equivalent contact curvature radius is received. (like ) and the pre-calibrated elastic-plastic work ratio coefficient (Set as 2.0). The control module uses these specific parameters and the provided calculation formula to perform real-time energy conservation calculations: the internal algorithm first calculates the theoretical elastic indentation depth term characterizing the Hertzian contact as approximately... Then, by combining the energy conversion term composed of elastoplastic deformation work and equivalent mass, and taking the square root, the target ultrasonic amplitude required for the ultrasonic transducer to be output can be accurately synthesized. Approximately (Right now ), then, The target ultrasonic amplitude command is directly sent to the ultrasonic generator, which drives the transducer to generate ultrasonic vibrations of corresponding amplitude, thereby precisely controlling the output of the execution end to match the transient mechanical kinetic energy.

[0066] Through the above technical solution, this application is able to obtain the peak dynamic impact force calculated theoretically. Effectively converts into target ultrasonic amplitude that can be directly controlled by ultrasonic impact equipment. This precise calculation based on the acoustic-mechanical energy conversion balance model ensures that the ultrasonic impact actuator can output transient mechanical kinetic energy that matches the total elasto-plastic deformation work required for the target plastic rheology of the weld toe. This avoids the under- or over-processing problems caused by improper energy matching in traditional methods, thus significantly improving the accuracy and efficiency of welding treatment in stress concentration areas of mining machinery. By precisely controlling the ultrasonic amplitude, the initial residual tensile stress can be overcome more effectively, inducing uniform and controllable compressive plastic rheology in the material, thereby improving the fatigue life and stress corrosion resistance of the weld toe area, providing a more reliable guarantee for the safe operation of mining machinery.

[0067] like Figure 3As shown, in a preferred embodiment of the present invention, based on the volume conservation law of metal plastic rheology, and considering the current stress state and target geometry, the adaptive travel speed is calculated; the adaptive travel speed is obtained by dividing the effective plastic volume transfer rate per unit time by the target deformation area of ​​the weld toe section; wherein, the effective plastic volume transfer rate is determined by multiplying the operating frequency of the ultrasonic transducer, the effective volume transfer coefficient of plastic deformation, the physical design radius of the impact head, and the square of the theoretical elastic indentation depth; the target deformation area of ​​the weld toe section is determined by the difference between the square of the final target weld toe transition radius required by the process and the square of the initial weld toe transition radius, combined with the geometric shape coefficient characterizing the weld toe section; its calculation formula is:

[0068]

[0069] In the formula, Indicates adaptive travel speed. The effective volume transfer coefficient representing plastic deformation. This indicates the operating frequency of the ultrasonic transducer. Indicates the physical design radius of the impact head. Indicates the peak value of dynamic impact force. Indicates the equivalent contact curvature radius. Represents the comprehensive equivalent elastic modulus. This indicates the final target weld toe transition radius required by the process. Indicates the initial weld toe transition radius. The geometric shape coefficient of the weld toe section is represented; among them, constant 9 and constant 16 are derived from the square of the geometric integral constant term of elastic indentation depth in Hertz contact theory; before solving this formula, the dimensions of the above parameters are forcibly normalized to the International System of Units (SI) standard units.

[0070] The law of volume conservation in the plastic rheology of metals is a fundamental principle in materials mechanics, stating that the volume of a material remains constant during plastic deformation. This means that under ultrasonic impact, when a material undergoes plastic indentation, the indented volume will shift to the surrounding area, but the total volume will not change. This principle provides the basis for quantifying plastic deformation. The current stress state refers to the peak value of the instantaneous dynamic impact force applied by the ultrasonic impact actuator to the weld toe surface. The resulting stress field distribution reflects the material's immediate response to impact. The target geometry refers to the desired final geometry of the weld toe surface after ultrasonic impact treatment, specifically the final target weld toe transition radius required by the process. This is the ideal state set by the process designer based on the structural fatigue life requirements. Adaptive travel speed. This refers to the speed at which the ultrasonic impact actuator travels along the weld seam. This speed can be dynamically adjusted according to the current material state, stress conditions, and desired final geometry. The aim is to ensure uniform plastic strengthening throughout the process and to accurately achieve the preset geometric target. The formula uses the physical design radius of the impact head. Combining theoretical elastic indentation depth The transfer volume of a single impact is calculated using the power function term (i.e., the term within parentheses), aiming to establish a theoretical elastic envelope volume benchmark with a clear geometric definition. On this benchmark, the effective volume transfer coefficient of plastic deformation... It is defined as a comprehensive equivalent correction coefficient. Its physical meaning lies in: reconciling the ideal spherical contact assumption with the real complex weld toe surface (subject to equivalent curvature). The geometrical differences in the influence of these differences, as well as the differences in work hardening mechanisms during the transition from purely elastic strain to large deformation plastic flow, are uniformly absorbed and equivalently represented. This modeling approach of 'ideal geometric theoretical benchmark + comprehensive correction coefficient' effectively solves the problem of obtaining accurate analytical solutions for complex surface plastic rheology theories. The operating frequency of the ultrasonic transducer... This refers to the frequency of ultrasonic vibrations generated by the ultrasonic transducer, which determines the frequency at which the impact head impacts the weld toe surface. The physical design radius of the impact head... This refers to the geometric radius of the impact head used in the ultrasonic impact actuator, and is an important parameter affecting the impact contact area and stress distribution. Dynamic impact peak force. This refers to the maximum instantaneous force exerted by the ultrasonic impact actuator on the weld toe surface during each impact. Equivalent contact radius of curvature. This parameter comprehensively considers the geometry of the impact head and weld toe surfaces, simplifying contact calculations in Hertzian contact theory and reflecting the equivalent curvature of the contact region. (Comprehensive equivalent elastic modulus) This parameter combines the elastic modulus and Poisson's ratio of the impact head material and the base material of the mining machinery, and is used to characterize the equivalent elastic stiffness of the two during contact deformation. The final target weld toe transition radius required by the process. This is the ideal transition radius that the weld toe should achieve after treatment, set according to design requirements or fatigue life optimization targets. Initial weld toe transition radius. The original transition radius of the weld toe surface before ultrasonic impact treatment was obtained by extracting 3D point cloud data. The geometric shape coefficient of the weld toe cross-section... This coefficient is used to characterize the influence of the specific geometry of the weld toe section on the calculation of plastic deformation volume. To avoid blind trial and error, those skilled in the art can obtain this coefficient through the following explicit engineering geometric mapping relationship: For standard planar butt welds, since their local deformation section is approximately an ideal sector, The value can be directly set to 1.0; for T-type fillet welds or areas with complex asymmetric geometric transitions, the coefficient... The coefficient can be precisely determined in advance by performing a 3D CAD model of a typical joint morphology and calculating the dimensionless ratio of its actual geometric interference cross-sectional area to the ideal theoretical sector area using Boolean operations. This determined coefficient will then be directly input into the control system as a fixed process parameter.

[0071] This application treats the plastic strengthening treatment of the weld toe surface by the ultrasonic shock actuation end as a series of discrete impact events. Each impact induces a certain amount of plastic deformation on the weld toe surface, accompanied by a redistribution of material volume. Based on the volume conservation law of metal plastic rheology, the dynamic impact force peak value generated by each impact is comprehensively considered. Physical design radius of the impact head Equivalent contact curvature radius and comprehensive equivalent elastic modulus This allows for the estimation of the plastic indentation depth and corresponding plastic deformation volume resulting from a single impact. Based on this, combined with the operating frequency of the ultrasonic transducer... This allows us to obtain the total volume of plastic deformation per unit time. Simultaneously, in order to transition the weld toe from the initial weld toe radius... Change to the final target weld toe transition radius required by the process. This requires achieving a specific volume of material plastic transfer along the weld direction. Therefore, by balancing the volume of plastic deformation generated per unit time with the volume of geometrical change required to travel along the weld per unit time, an effective volume transfer coefficient for plastic deformation is introduced. and the geometric shape factor of the weld toe section This corrects for actual volume transfer efficiency and geometric effects, thereby accurately calculating the adaptive travel speed. This calculation method enables the ultrasonic impact actuator to dynamically adjust according to the initial geometry of the weld toe, the target geometry requirements, and the impact parameters, ensuring that the plastic strengthening effect is uniform and consistent throughout the entire process, and accurately achieving the preset geometric target.

[0072] In one specific implementation, the calculation of the adaptive travel speed can be performed by a controller integrated into the ultrasonic impact treatment system. Before the treatment begins, the system will pre-acquire or the operator will input fixed parameters of the equipment and process, such as the physical design radius of the impact head. (set as) ), operating frequency ( The desired final target weld toe transition radius (like and the geometric shape coefficient of planar butt welds (Take 1.0). Meanwhile, the dynamic variable parameters obtained from the aforementioned calculations, such as the peak dynamic impact force... ( Equivalent contact radius of curvature ( Initial weld toe transition radius ( ) and the pre-obtained effective volume transfer coefficient (Set to 0.8). This will also be input to the controller in real time. After receiving all necessary parameters, the controller uses the above volume conservation formula to calculate: The system first calculates the effective plastic volume transfer rate per unit time based on the frequency, correction coefficient, and the square of the theoretical elastic indentation depth. ; then, divide it by The target deformation area is determined together with the square difference of the transition radius. Thus, the current adaptive travel speed can be accurately derived. for (Right now ), then the controller will Precise speed commands are sent to the motion control system (such as a multi-axis robot) that drives the ultrasonic impact to move the end effector, ensuring that the cumulative speed of plastic deformation is perfectly matched with the preset geometric evolution target.

[0073] Through the above technical solution, this application overcomes the problem of uneven plastic strengthening effect or inability to accurately achieve the target geometry due to improper travel speed in the welding treatment of stress concentration areas in mining machinery. By utilizing the volume conservation law of metal plastic rheology, and considering the current stress state and target geometry, an adaptive travel speed is accurately calculated, allowing the ultrasonic impact actuator to dynamically adjust according to the actual situation and process requirements of the weld toe. This ensures that the cumulative effect of plastic deformation highly matches the desired geometric change throughout the weld treatment process, thereby achieving precise control of the weld toe transition radius and uniformity of the plastic strengthening effect. Compared with methods relying solely on fixed or empirical speeds, this solution significantly improves the accuracy and consistency of the treatment, effectively avoiding local over- or under-treatment, and thus enhancing the fatigue resistance and service life of stress concentration areas in mining machinery.

[0074] like Figure 4 As shown, in a preferred embodiment of the present invention, before performing the metal surface plastic strengthening treatment, an energy-shape synergistic pre-calibration step is further included to obtain the effective volume transfer coefficient. and the elastic-plastic work ratio factor The pre-calibration step specifically includes: controlling the ultrasonic impact actuator to perform a single-point fixed-point impact test on a calibration test block made of the same material as the mining machinery, and simultaneously recording the total actual mechanical work output by the ultrasonic generator during the impact; acquiring the discrete point cloud elevation data of the actual plastic indentation generated by the single-point impact test; the elastic-plastic work multiplier is determined by the ratio of the total actual mechanical work to the theoretical elastic indentation work derived from the peak value of the dynamic impact force and the equivalent radius of curvature during pre-calibration; its calculation formula is:

[0075]

[0076] The effective volume transfer coefficient The actual plastic indentation volume is calculated by spatial surface integration of discrete point cloud elevation data, and determined by the ratio of this volume to the theoretical elastic indentation volume derived from the peak dynamic impact force and the equivalent radius of curvature. The calculation formula is as follows:

[0077]

[0078] In the formula, Indicates the work-to-efficiency ratio of elastic-plastic processes; This represents the total amount of actual mechanical work fed back from the ultrasonic generator's power monitoring module and calculated using equivalent conversion. Indicates the effective volume transfer coefficient; The integral projection area represents the actual plastic indentation formed on the surface of the calibration block by a single-point impact; This represents the elevation value of a coordinate point in discrete point cloud elevation data; This indicates the reference elevation value of the initial surface of the calibration block; Indicates the physical design radius of the impact head; Indicates the peak value of the dynamic impact force during pre-calibration; This indicates the test equivalent radius of curvature between the impact head and the plane of the calibration block during pre-calibration; It represents the comprehensive equivalent elastic modulus; before the formula is solved, the dimensions of each parameter are forcibly normalized to the International System of Units (SI) standard units.

[0079] The energy-shape co-calibration step aims to obtain key parameters of material energy dissipation and volumetric deformation during ultrasonic impact plastic strengthening treatment through experimental measurement and data analysis. Its role is to calibrate the theoretical model, making it closer to the actual physical process, thereby improving the accuracy and reliability of subsequent calculations. This step can be implemented using offline calibration or online real-time calibration. Effective volume transfer coefficient. This coefficient characterizes the ratio between the actual volume transferred and the theoretical elastic indentation volume during plastic deformation of a material under ultrasonic impact. It reflects the efficiency and characteristics of plastic flow under impact and is a key parameter for precisely controlling plastic deformation. This coefficient can be obtained through experimental measurement, numerical simulation, or a combination of both. Elastic-plastic work ratio coefficient. This represents the ratio of total deformation work, including plastic dissipation work, to pure elastic strain energy during ultrasonic impact. It quantifies the degree of energy dissipation under impact and is crucial for accurately calculating the required ultrasonic energy input. This coefficient can be calculated using the principle of energy conservation combined with experimental data, or predicted using numerical methods such as finite element analysis. The ultrasonic impact actuator is controlled to perform a single-point, fixed-point impact test on a calibration block made of the same material as the mining machinery, while simultaneously recording the total actual mechanical work output by the ultrasonic generator during the impact. This step simulates the actual processing process by impacting the standard block under controlled conditions. By recording the actual total mechanical work, real data at the energy input end can be obtained, providing a basis for subsequent energy conversion efficiency calculations. This test can be monitored in real time using high-precision force and displacement sensors, or data can be acquired through the power monitoring module built into the ultrasonic generator. Discrete point cloud elevation data of the actual plastic indentation generated by the single-point impact test is obtained. This step aims to acquire detailed data on the surface morphology of the test block after impact using high-precision measuring equipment. These data form the basis for calculating the actual plastic indentation volume, which is then used to determine the plastic deformation characteristics of the material. This data can be measured non-contactly using equipment such as laser scanners, white light interferometers, or confocal microscopes. The elastic-plastic work ratio factor is mentioned. The effective volume transfer coefficient is calculated based on the ratio of actual mechanical work done to theoretical elastic compressive work. This calculation method quantifies the energy dissipation during plastic deformation by comparing the actual input mechanical energy with the energy required for theoretically pure elastic deformation. This calculation method based on experimental data can effectively correct the deviation between the theoretical model and the actual situation. The actual plastic indentation volume is calculated by spatial surface integration of discrete point cloud elevation data and then compared with the theoretical elastic indentation volume. This calculation method uses actually measured indentation morphology data to accurately calculate the actual plastic volume transfer of the material. By comparing it with the theoretical elastic indentation volume, a more realistic volume transfer coefficient can be obtained, thereby improving the accuracy of plastic deformation control. It is important to emphasize that, due to the inevitable strong work hardening effect accompanying the plastic strengthening process of mining metal base materials, the elastic-plastic work ratio factor... With effective volume transfer coefficient At the microscopic level, this manifests as a high-order nonlinear function relating to local contact curvature and the initial hardening state. However, within a specific workpiece material and target transition radius process window, this invention, through physical co-calibration under approximate initial stress and geometric conditions, has converged the aforementioned nonlinear drift error within a controllable range. Therefore, this method can legally and accurately... and Approximating the input system as a local calibration constant enables complex multiphysics coupled systems, which originally suffered from the "curse of dimensionality," to possess extremely high engineering closed-loop solution speed and control robustness.

[0080] This application's solution introduces an energy-shape co-calibration step to precisely calibrate the working characteristics of the ultrasonic impact actuator and the material's response behavior before formally welding the stress concentration areas of the mining machinery. Specifically, this pre-calibration step first controls the ultrasonic impact actuator to perform a single-point fixed-point impact test on a calibration test block made of the same material as the mining machinery. During this process, the ultrasonic generator simultaneously records the total actual mechanical work output during the impact, providing accurate input data for subsequent energy conversion analysis. Simultaneously, discrete point cloud elevation data of the actual plastic indentation generated by the single-point impact test are acquired using high-precision measuring equipment. This data details the actual deformation of the material under impact. Based on these measured data, the elastic-plastic work ratio factor is determined. The effective volume transfer coefficient is calculated by the ratio of the actual total mechanical work done to the theoretical elastic compressive work, thus accurately reflecting the energy dissipation during the impact process. Similarly, the effective volume transfer coefficient... The actual plastic indentation volume is calculated by spatial surface integration of discrete point cloud elevation data, and then the ratio is calculated to the theoretical elastic indentation volume, thus accurately quantifying the plastic flow efficiency of the material. The precise acquisition of these two coefficients allows for more accurate calculation of the dynamic impact peak force, target ultrasonic amplitude, and adaptive travel velocity required to overcome local initial tensile stress and induce compressive plastic rheology in subsequent multiphysics coupled calculation models. In this way, the proposed method overcomes the calculation errors caused by uncertainties in material parameters and energy conversion efficiency in traditional methods, ensuring the accuracy and reliability of ultrasonic impact plastic strengthening treatment.

[0081] As a specific implementation method, before welding the stress concentration areas of mining machinery, energy-form co-calibration can be performed first. For example, a steel plate in the same state as the base material of the mining machinery to be treated is selected as a calibration test block and placed vertically on a test platform. A peak value of dynamic impact force is set through the control system. (For example ), in testing equivalent radius of curvature for And the material's overall equivalent elastic modulus Given the known conditions, a single-point impact test is performed. During the impact, the built-in electrical power monitoring module calculates the actual total mechanical work done in this single impact process in real time. for After the impact, a high-precision 3D laser scanner was used to acquire discrete point cloud elevation data of the crater. The actual volume of the plastic crater was then precisely quantified using spatial surface integration. Meanwhile, the computational model automatically calculates based on the input parameters measured in the actual experiment, deriving the baseline elastic indentation work under purely theoretical Hertzian contact (approximately...). ) and theoretical elastic indentation volume reference (approximately At this point, the system will measure the actual data. Total merit and By comparing the theoretical work, the elastic-plastic work multiplier under the current hardening response can be obtained. Approximately 2.12; similarly, the actual rheological volume... Divide by the theoretically calculated volume The effective volume transfer coefficient can then be obtained. The value is 0.80. These two parameters closely approximate real physical dissipation. and It will be written as a characteristic constant into the multiphysics coupling calculation model, providing a crucial truth benchmark for subsequent inverse closed-loop solutions.

[0082] By employing the above technical solution, an energy-shape synergistic pre-calibration step is introduced before performing metal surface plastic strengthening treatment, which can accurately obtain the effective volume transfer coefficient. and the work ratio factor of elastic-plasticity The accuracy of these coefficients is crucial for subsequent calculations of the target ultrasonic amplitude and adaptive travel speed based on a multiphysics coupling computational model. Through measurement and analysis of the actual total mechanical work and the actual plastic indentation morphology, the proposed scheme effectively calibrates the deviation between the theoretical model and the actual physical process, significantly improving the accuracy of the calculation parameters. This enables the ultrasonic impact actuator to perform surface plastic strengthening treatment on the weld toe with more precise target ultrasonic amplitude and adaptive travel speed, thereby more effectively overcoming local initial tensile stress, inducing the required compressive plastic rheology, and ultimately achieving refined control over the welding treatment of stress concentration areas in mining machinery, improving the stability and reliability of the treatment effect.

[0083] In some embodiments described above in this application, the welding treatment method for stress concentration points in mining machinery involves complex calculations of mechanical parameters, extraction of geometric features, and precise calculation and control of dynamic impact force, ultrasonic amplitude, and travel speed. Relying solely on manual operation or general-purpose computing equipment makes it difficult to guarantee the real-time performance, accuracy, and automation level of the process, potentially leading to low processing efficiency and difficulty in accurately achieving the expected plastic strengthening effect.

[0084] In this regard, this application further proposes a welding treatment device for stress concentration parts of mining machinery, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method when executing the program.

[0085] Memory is a hardware component used to store data and instructions. It can be volatile memory, such as random access memory (RAM), used for temporary storage of data and instructions during program execution; or non-volatile memory, such as read-only memory (ROM), flash memory, or solid-state drive (SSD), used for long-term storage of the operating system, applications, and various configuration parameters and historical data. Memory provides the processor with the necessary information to ensure that programs can be loaded and executed smoothly. The processor is the core computing unit of the device, responsible for executing instructions in the computer program and performing data processing and calculations. It can be a central processing unit (CPU), such as a general-purpose microprocessor, possessing powerful general-purpose computing capabilities; or a digital signal processor (DSP), adept at high-speed digital signal processing and floating-point operations; or a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC), used to implement specific, high-performance parallel computing tasks. The processor executes programs to solve complex algorithms and precisely control actuators. A computer program is a collection of instructions designed to guide the processor to complete a specific task. This program can be pre-programmed into the device's non-volatile memory as firmware or loaded into the operating system as an application program. It contains all the logic required to implement the aforementioned welding treatment method for stress concentration points in mining machinery, including modules for data acquisition, parameter calculation, model building, and control command generation. When the processor executes the program, it implements the method described above, meaning that the processor can automatically complete all steps of the welding treatment method for stress concentration points in mining machinery by running a pre-written computer program. This includes acquiring mechanical property parameters, initial residual tensile stress data, and three-dimensional point cloud data; extracting geometric features; constructing boundary conditions; calculating the dynamic impact peak force, target ultrasonic amplitude, and adaptive travel speed; and finally controlling the ultrasonic impact actuator to perform plastic strengthening treatment.

[0086] The device described in this application organically combines a memory, a processor, and a computer program to form an intelligent control system, enabling automated and precise execution of a welding method for stress concentration areas in mining machinery. Specifically, the memory stores the computer program required to implement the method, various input data (such as base material mechanical property parameters, initial residual tensile stress data, and 3D point cloud data), intermediate results generated during calculation, and final control parameters (such as dynamic impact force peak value, target ultrasonic amplitude, and adaptive travel speed). The processor, as the core computing unit, reads and executes the computer program from the memory. This program contains all the logic for implementing the method steps, including a data processing module, a mathematical model solving module, and a control instruction generation module. The processor first processes the mechanical property parameters, initial residual tensile stress data, and 3D point cloud data obtained from sensors according to the program instructions, and constructs initial mechanical boundary conditions and initial geometric boundary conditions based on these data. Subsequently, the processor calls the multiphysics coupling calculation model in the program, integrates these boundary conditions, and accurately calculates the dynamic impact force peak value, target ultrasonic amplitude, and adaptive travel speed required to overcome local initial tensile stress and induce compressive plastic rheology. Finally, based on the calculated target ultrasonic amplitude and adaptive travel speed, the processor generates corresponding control commands and sends them to the ultrasonic impact actuator via an interface. This precisely controls the actuator's movement along the weld seam and performs surface plastic strengthening treatment on the weld toe. This integrated device design enables a high degree of automation and intelligence in the entire process, ensuring the accuracy of complex calculations and the real-time nature of control.

[0087] As a specific implementation, the welding treatment device for stress concentration areas in mining machinery can be configured with an industrial-grade embedded processor, such as a multi-core processor based on the ARM architecture, to provide sufficient computing power to handle complex multiphysics coupling calculations. The memory can include high-speed DDR4 synchronous dynamic random access memory (SDRAM) as running memory for program execution and data caching; it is also equipped with NAND flash memory as non-volatile memory for storing the operating system, applications, and preset material databases and historical processing records. The computer program can adopt a modular design, including a data acquisition module, a geometric feature extraction module, a mechanical boundary condition construction module, a multiphysics coupling solution module, a motion control module, and a user interface module. For example, the data acquisition module is responsible for receiving input data from a 3D scanner and mechanical testing equipment; the geometric feature extraction module implements local surface fitting of 3D point cloud data and the construction of an equivalent contact curvature model; the multiphysics coupling solution module encapsulates the calculation formulas and logic for dynamic impact peak force, target ultrasonic amplitude, and adaptive travel speed; and the motion control module is responsible for converting the calculation results into specific motion commands and impact parameters for the ultrasonic impact actuator. When the device is started, the processor loads the operating system and application from the flash memory into the SDRAM, and then executes the above method steps in sequence according to the program instructions to realize the automated and precise processing of the weld toe of the stress concentration part of the mining machinery.

[0088] The aforementioned device integrates the complex calculations and precise control processes involved in welding stress concentration areas of mining machinery into an automated system. This device efficiently and accurately acquires and processes various input data, performing real-time multiphysics coupling calculations based on this data to precisely calculate the dynamic impact peak force, target ultrasonic amplitude, and adaptive travel speed. The processor, by executing a computer program, directly converts these calculation results into precise control commands for the ultrasonic impact actuator, ensuring the automation and high precision of the metal surface plastic strengthening process. This significantly improves processing efficiency and repeatability, reduces errors that may be introduced by manual operation, and ensures precise matching of processing parameters, effectively overcoming the shortcomings of traditional methods in terms of real-time performance, accuracy, and automation, ultimately achieving a more stable and reliable weld toe plastic strengthening effect.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for welding stress concentration points in mining machinery, characterized in that, Includes the following steps: Obtain the mechanical property parameters and initial residual tensile stress data of the parent material to which the stress concentration point belongs, and construct the initial mechanical boundary conditions; Obtain three-dimensional point cloud data of the weld toe surface at the stress concentration point; Initial geometric features are extracted from 3D point cloud data to construct initial geometric boundary conditions for the weld toe surface; By integrating the multiphysics coupling calculation model, the initial mechanical boundary conditions and the initial geometric boundary conditions are combined, and the dynamic impact force peak, target ultrasonic amplitude and adaptive travel speed required to overcome the local initial tensile stress and induce compressive plastic rheology are calculated in reverse order. Based on the calculated target ultrasonic amplitude and adaptive travel speed, the ultrasonic impact actuator is controlled to travel along the weld seam to perform metal surface plastic strengthening treatment on the weld toe.

2. The welding treatment method for stress concentration points in mining machinery according to claim 1, characterized in that, The initial geometric features extracted based on three-dimensional point cloud data include local surface fitting of the three-dimensional point cloud data to extract the initial weld toe transition radius; and constructing a piecewise equivalent contact curvature model, which divides the working condition of the ultrasonic impact actuator head contacting the weld toe surface into physical interference calibration working condition and conventional Hertz contact working condition, and calculates the equivalent contact curvature radius accordingly. The value of the equivalent contact curvature radius is determined by dividing the product of the physical design radius of the impact head and the initial weld toe transition radius by the relative absolute value of the difference between the two; wherein, when the initial weld toe transition radius is less than the physical design radius, the equivalent curvature is output based on the minuend and subtrahend of the inversion difference of the physical geometric interference boundary.

3. The method for welding stress concentration points in mining machinery according to claim 2, characterized in that, Based on the multiaxial contact yielding equivalent mechanism, the required peak dynamic impact force is solved in reverse according to the equivalent contact curvature radius. The solution model for the peak dynamic impact force is constrained by overcoming the multiaxial yield threshold after superimposed initial residual tensile stress. In this solution model, the peak dynamic impact force is proportional to the square of the equivalent contact curvature radius, inversely proportional to the square of the comprehensive equivalent elastic modulus between the impact head and the mining machinery base material, and proportional to the cube of the comprehensive yield stress term. The comprehensive yield stress term is composed of the apparent yield strength of the mining machinery base material minus the absolute amplitude of the initial residual tensile stress value of the stress concentration part after correction by the tensor equivalent attenuation coefficient.

4. The welding treatment method for stress concentration points in mining machinery according to claim 3, characterized in that, Based on the acoustic-mechanical energy conversion balance model, that is, to construct the equivalent conservation relationship between the maximum transient mechanical kinetic energy of the adaptive ultrasonic impact actuator end and the total elastoplastic deformation work required for the weld toe to undergo target plastic rheology, the target ultrasonic amplitude to be output by the ultrasonic transducer in the ultrasonic impact actuator end is synthesized according to the peak value of the dynamic impact force. In the acoustic-mechanical energy conversion balance model, the target ultrasonic amplitude is inversely proportional to the operating frequency of the ultrasonic transducer and directly proportional to the square root of the energy conversion term. The energy conversion term is the ratio of the total elastoplastic deformation work to the equivalent motion mass of the adaptive ultrasonic impact actuator. The total elastoplastic deformation work is determined by the combined multiplication of the peak dynamic impact force, the theoretical elastic indentation depth characterizing the Hertzian contact, and the elastoplastic work multiplier. The theoretical elastic indentation depth is a nonlinear power function of the peak dynamic impact force, the equivalent contact curvature radius, and the combined equivalent elastic modulus.

5. The method for welding stress concentration points in mining machinery according to claim 4, characterized in that, Based on the volume conservation law of metal plastic rheology, and taking into account the current stress state and target geometry, the adaptive travel speed is calculated. The adaptive travel speed is obtained by dividing the effective plastic volume transfer rate per unit time by the target deformation area of ​​the weld toe section. The effective plastic volume transfer rate is determined by the product of the operating frequency of the ultrasonic transducer, the effective volume transfer coefficient of plastic deformation, the physical design radius of the impact head, and the square of the theoretical elastic indentation depth; the target deformation area of ​​the weld toe section is determined by the difference between the square of the final target weld toe transition radius required by the process and the square of the initial weld toe transition radius, combined with the geometric shape coefficient characterizing the weld toe section.

6. The method for welding stress concentration points in mining machinery according to claim 5, characterized in that, Before performing the plastic strengthening treatment on the metal surface, an energy-shape co-calibration step is also included to obtain the effective volume transfer coefficient and the elastoplastic work ratio coefficient. The precalibration step specifically includes: The ultrasonic impact actuator is controlled to perform a single-point fixed-point impact test on a calibration test block made of the same material as the mining machinery, and the total amount of actual mechanical work output by the ultrasonic generator during the impact is recorded simultaneously. Obtain discrete point cloud elevation data of the actual plastic indentation generated by single-point impact testing; The elastic-plastic work multiplier is determined by the ratio of the actual total mechanical work done to the theoretical elastic indentation work derived from the peak value of the test dynamic impact force and the test equivalent radius of curvature based on the pre-calibration time. The effective volume transfer coefficient The actual plastic indentation volume is calculated by spatial surface integration of discrete point cloud elevation data, and the ratio of this to the theoretical elastic indentation volume derived from the peak dynamic impact force and the equivalent radius of curvature is used to determine the indentation volume.

7. A welding treatment device for stress concentration points in mining machinery, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the method as described in any one of claims 1 to 6.

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