Ultrasonic amplitude-change pole based on Metglas composite pasting layer and simulation method of ultrasonic amplitude-change pole

Abstract

The invention discloses an ultrasonic amplitude-change pole based on a Metglas composite pasting layer and a simulation method of the ultrasonic amplitude-change pole, and belongs to the technical field of mechanical antennae. The ultrasonic amplitude-change pole comprises an amplitude-change pole body and a Metglas amorphous alloy strip layer; the amplitude-change pole body can amplify and transmit ultrasonic mechanical vibration and is a main carrier of vibration energy; the Metglas amorphous alloy strip layer is adhered to the characteristic area of the surface of the amplitude-change pole body, the stress propagation path is changed by utilizing the mechanical property of the Metglas amorphous alloy strip layer, sharp point stress is dispersed into gentle area stress, and loss of vibration energy on the surface of the amplitude-change pole is reduced. According to the amplitude-change pole, the Metglas amorphous alloy strip layer is attached to the stress concentration area, the multi-physical-field coupling simulation and parameterization optimization method is combined, stress concentration is remarkably reduced, the fatigue life is doubled, and the problems that traditional design is low in precision, long in period and single in performance are solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of mechanical antennas, and particularly relates to a structure of an ultrasonic wave amplitude transformer and a design method thereof. More particularly, the present application relates to a composite amplitude transformer by pasting Metglas amorphous alloy strips on the surface of the amplitude transformer to improve its performance, and a multi-physical field coupling simulation method for designing and optimizing the amplitude transformer. BACKGROUND

[0002] The ultrasonic wave amplitude transformer is a core component in an ultrasonic wave system, which mainly functions to amplify the high-frequency mechanical vibration generated by a transducer and efficiently transmit it to a tool head, and is widely used in the fields of ultrasonic wave welding, cutting, cleaning, processing and mechanical antennas. The performance of the amplitude transformer, such as the amplitude amplification ratio, fatigue life and working stability, directly determines the final efficiency and reliability of the entire ultrasonic wave system.

[0003] At present, the design and practice of the amplitude transformer mainly rely on the following two types of technologies, but they all have obvious limitations: 1. Traditional design method based on classical one-dimensional wave theory and empirical formula: This method is simple to calculate, but has inherent defects. First, it cannot accurately calculate the stress concentration effect of the amplitude transformer under complex three-dimensional geometric structures, and stress concentration is the primary cause of fatigue fracture of the amplitude transformer under cyclic loading. Second, this method cannot accurately predict the actual resonant frequency and mode shape of the amplitude transformer after coupling with the piezoelectric transducer, resulting in a significant deviation between the design value and the actual measured value. Therefore, in actual applications, it often needs to go through multiple iterations of "design-trial production-testing-modification", which not only has a long development cycle and high cost, but also the performance of the final product is difficult to achieve the best.

[0004] 2. Finite element analysis method based on computer-aided engineering: With the development of simulation technology, finite element analysis FEA has been introduced into the design of the amplitude transformer to make up for the shortcomings of the traditional method. However, existing finite element analysis is mostly limited to a single solid mechanics module, and does not fully consider key factors such as piezoelectric driving effect and multi-physical field coupling. This simplified simulation model cannot accurately simulate the dynamic response of the amplitude transformer under real working conditions, and the simulation results still have gaps with the actual situation, and its predictive value is limited. More importantly, existing technologies have not systematically applied multi-physical field coupling simulation to guide the application and optimization process of functional composite materials on the amplitude transformer.

[0005] In addition, in order to improve the performance of the amplitude lever, the industry has tried various material and structure optimization schemes, but often only focuses on the improvement of a single performance index, such as optimizing the geometry to pursue high amplification ratio, or only replacing the base material, lacking a systematic solution that can synergistically improve the fatigue life and energy efficiency.

[0006] In summary, the prior art has the following technical problems to be solved: 1. How to accurately predict and effectively suppress the stress concentration of the amplitude lever under complex three-dimensional structure, thereby greatly improving the fatigue life. 2. How to accurately simulate the real resonant characteristics of the amplitude lever under piezoelectric drive: frequency, mode shape, to reduce the number of design iterations, reduce development cost and cycle. 3. How to break through the idea of single performance optimization, realize the synergistic improvement of the amplitude lever in fatigue life, energy transmission efficiency and other functions.

[0007] Therefore, there is an urgent need in the art for a systematic design method and product scheme that integrates multi-physics field coupling simulation and functional material application to break through the bottleneck of traditional design. SUMMARY

[0008] To solve the above problems, the present application provides an ultrasonic amplitude lever based on Metglas composite coating and a simulation method thereof, which synergistically improves the fatigue life and energy efficiency of the amplitude lever by functionally coating Metglas amorphous alloy strips in the stress concentration area of the amplitude lever body; by integrating solid mechanics and piezoelectric effect, a parameterized model is established to realize high-precision prediction and synergistic optimization of the resonant frequency, mode shape and stress distribution of the amplitude lever, and the traditional "design-trial-manufacture-test" research and development process is revolutionized.

[0009] The technical scheme adopted by the present application is: The ultrasonic amplitude lever based on Metglas composite coating comprises an amplitude lever body and a Metglas amorphous alloy strip layer; The input end of the amplitude lever body can be connected with a piezoelectric ceramic transducer, and the output end is connected with a tool head; the amplitude lever body can amplify and transmit ultrasonic mechanical vibration and is the main carrier of vibration energy; The Metglas amorphous alloy strip layer is pasted on the characteristic area of the surface of the amplitude lever body, which is a stress concentration area or a vibration strain significant area determined according to multi-physics field simulation; the Metglas amorphous alloy strip layer utilizes its own mechanical properties to change the stress propagation path, disperses the sharp point stress into a flat area stress, and reduces the loss of surface vibration energy of the amplitude lever; When the amplitude lever vibrates, the Metglas amorphous alloy strip layer deforms, causing changes in the magnetic properties of the coating.

[0010] Further, the amplitude transformer body is in a stepped shape; the Metglas amorphous alloy strip layer is pasted at the stepped transition arc of the stepped amplitude transformer body.

[0011] Further, the amplitude transformer body is in a conical shape; the Metglas amorphous alloy strip layer is pasted at the size end transition zone of the conical amplitude transformer body.

[0012] Further, the amplitude transformer body is in an exponential shape; the Metglas amorphous alloy strip layer is pasted at the amplitude node of the exponential amplitude transformer body.

[0013] Further, an adhesive layer is arranged between the amplitude transformer body and the Metglas amorphous alloy strip layer, the adhesive layer adopts high-strength epoxy resin adhesive, and the adhesive layer ensures that the vibration energy can be efficiently transmitted from the amplitude transformer body to the Metglas amorphous alloy strip layer. The outer surface of the Metglas amorphous alloy strip layer is further covered with an insulating protective layer.

[0014] An ultrasonic amplitude transformer simulation method based on a Metglas composite coating layer, the simulation method is based on the above-mentioned ultrasonic amplitude transformer based on a Metglas composite coating layer, comprising the following steps: S1, parameterized geometric modeling: a parameterized geometric model of a composite structure containing an amplitude transformer body and a Metglas amorphous alloy strip layer is established, and at least one key dimension of the Metglas amorphous alloy strip layer, such as the covering position, thickness, width, and the transition arc radius of the amplitude transformer body, the flange position, and the taper of the shaft body, is set as a variable; S2, build a multi-physical field coupling model: give the geometric model material properties, add solid mechanics module and piezoelectric effect module to establish structure-piezoelectric multi-physical field coupling simulation model, and set the connection between Metglas amorphous alloy strip layer and amplitude transformer body as bonded fixed; S3, simulation analysis and solution: a fixed constraint is applied to the vibration node of the coupling model, a sweep voltage signal is applied to the input end face of the amplitude transformer body, and the resonant frequency, vibration mode, displacement distribution and stress field distribution of the amplitude transformer are solved by performing characteristic frequency analysis and frequency domain analysis; S4, parameterized optimization iteration: taking the maximum amplitude amplification ratio and the minimum maximum equivalent stress as the optimization target, the parameterized scanning or optimization algorithm is adopted to automatically optimize and iterate the key dimension variables; S5, output the final design: according to the optimal parameter combination obtained after optimization iteration, determine the final geometric parameters of the amplitude transformer body, and output the center line coordinates or three-dimensional model data file for numerical control machining.

[0015] Furthermore, in step S1, when defining key variables, initial values ​​and ranges of variation need to be set for them: The initial value of the transition arc radius R is set to 1.0 mm, and the scanning range is 1.0 mm to 5.0 mm; the initial value of the width W of the Metglas amorphous alloy strip layer is set to 5 mm, and the scanning range is 3 mm to 10 mm.

[0016] Furthermore, in step S2, constructing the multiphysics coupling model includes: S2.1, Material Model Definition: Assign a temperature- or frequency-dependent constitutive model to the amplitude transformer body and the Metglas amorphous alloy strip layer; wherein, the Young's modulus of the structural material is defined as a temperature-dependent function: ; For the material at temperature Instantaneous Young's modulus; Reference temperature The initial Young's modulus; The temperature coefficient of Young's modulus of the material; The current operating temperature of the material; The reference temperature is either room temperature or the temperature under stress-free conditions; the piezoelectric coupling matrix is ​​defined for the piezoelectric material. With dielectric matrix ; It is a 3×6 matrix that describes the linear coupling relationship between the electric field and the strain; It is a 3×3 symmetric matrix describing electric displacement. With electric field The relationship between these elements reflects the dielectric properties of the material. S2.2, Establishment of governing equations: The bidirectional coupling between the solid mechanical field and the piezoelectric field is solved using the following governing equations: The momentum conservation equation for a solid mechanical field: ;in, For divergence operators; For Cauchy stress tensor; It is a volume force; The mass density of the material; This is the second-order partial derivative with respect to time; The displacement vector of the material; Constitutive equations of piezoelectric fields and Gauss's law: ;in, It is the electric displacement vector; It is a double dot product; The electric field intensity vector; Stress generated by two physical fields through the piezoelectric effect Bidirectional coupling is performed; where, The stress tensor generated by the inverse piezoelectric effect; piezoelectric coupling matrix Transpose of; S2.3 Adaptive Mesh Generation: The geometric model is subjected to physical field-controlled mesh generation, and local mesh refinement is performed in the stress concentration areas of the Metglas amorphous alloy strip layer and the amplitude transformer body. The size of the local mesh refinement is determined by convergence analysis to ensure that at least five mesh elements are used to accurately capture the complete gradient change of the stress field in areas where the stress gradient changes significantly.

[0017] Furthermore, in step S3, the simulation analysis and solution include: S3.1, Characteristic Frequency Analysis: Solving the Generalized Eigenvalue Problem To obtain the resonant frequency and mode shape of the amplitude transformer; among which, Here is the system stiffness matrix; The system quality matrix; Angular frequency; The eigenvectors are the mode shapes; the eigenvalues ​​are calculated. and the corresponding feature vectors Then, according to the formula: Calculate the first First resonant frequency ; S3.2 Frequency Domain Analysis: Within the defined frequency sweep range, solve the frequency domain dynamic equations: To obtain the displacement frequency response and stress distribution of the amplitude transformer; among which, Here is the system damping matrix; The imaginary unit; This is the frequency domain displacement response vector; The harmonic excitation force vector is obtained by converting the applied sweep frequency voltage through the piezoelectric constitutive relation; the angular frequency is then scanned. The displacement amplitudes at the output and input terminals are obtained, and the amplitude amplification ratio is calculated accordingly.

[0018] Furthermore, in step S4, the parameterized optimization iteration includes: S4.1, Construct the optimization problem: Establish a method to minimize the maximum equivalent stress. and maximizing amplitude amplification ratio To optimize the target, the simulated resonant frequency of the amplitude transformer was used. Falling into the target frequency range This is a multi-objective optimization problem with constraints, where... The target operating frequency; For frequency tolerance; For the defined design variable vector, its optimization space is limited by the preset value boundaries. ; To design a lower bound for the variable vector; To design an upper bound for the variable vector; S4.2, Perform optimization solution: Use parametric scanning method or gradient-based optimization algorithm to solve the optimization problem; among them, the gradient-based optimization algorithm is the method moving asymptote MMA or the sequential quadratic programming SQP algorithm, and sensitivity analysis is performed through the adjoint method or the direct method to drive iterative calculation until the optimal parameter combination that satisfies the optimization objective is obtained; In step S5, the final design output specifically includes: S5.1, Geometric Model Reconstruction: Based on the Optimal Parameter Combination Automatically update the parametric geometric model and generate a solid model with boundary representation through a standard CAD software kernel; S5.2, Output Manufacturing Data: Output centerline coordinates for CNC machining, or export as a 3D model data file in STEP or IGES format.

[0019] The beneficial effects of this invention are: I. The beneficial effects on product performance are as follows: 1. Significantly Improved Fatigue Life and Reliability: By precisely attaching the Metglas amorphous alloy strip layer to the stress concentration area determined by simulation, its excellent mechanical properties effectively alter the stress propagation path, dispersing sharp "point stresses" into gentler "regional stresses." The maximum equivalent stress is drastically reduced from 150MPa in the traditional design to 105MPa, a decrease of approximately 30%. This fundamental improvement in stress state is the key reason for the several-fold increase in the fatigue life of the amplitude transformer, greatly enhancing its operational reliability under long-term, high-intensity cyclic loading.

[0020] 2. Significantly Improved Energy Transfer Efficiency: Metglas material possesses extremely low mechanical loss characteristics; using it as a lamination effectively suppresses the loss of vibration energy on the amplitude transformer surface, thereby significantly reducing temperature rise during operation. This allows more vibration energy to be effectively transferred to the tool head, directly improving the energy utilization efficiency and working efficiency of the entire ultrasonic system.

[0021] II. Beneficial Effects at the Level of R&D Process and Design Methodology 1. Revolutionary Improvement in Design Accuracy and Predictability: This invention employs a multi-physics coupled simulation method, integrating solid mechanics and the piezoelectric effect, enabling high-precision simulation of the vibration characteristics of an amplitude transformer under real piezoelectric drive. It can accurately predict its resonant frequency, mode shape, amplitude amplification effect, and stress distribution, significantly reducing the deviation between simulation results and measured values. This fundamentally overcomes the shortcomings of inaccurate predictions from traditional empirical formulas and single-physics simulations.

[0022] 2. Significantly Reduced Development Cycle and Costs: Through a systematic process of "parametric modeling → automated optimization iteration," performance prediction and parameter optimization can be completed before manufacturing a physical prototype. This significantly reduces the multiple and costly "design-prototype-testing-modification" cycles required in traditional development. The development cycle is thus significantly shortened, and the overall development cost is significantly reduced.

[0023] 3. Optimal matching of functional materials and structure is achieved: The simulation method of this invention is not performed in isolation, but rather by synergistically optimizing the parameters of the Metglas amorphous alloy strip layer and the geometric parameters of the amplitude transformer body. This method can scientifically guide the layout of functional materials, ensuring that they are used effectively and achieving a synergistic effect of "1+1>2". It avoids the blind application based on experience, thus systematically and reliably achieving the ultimate goal of synergistic performance improvement.

[0024] In summary, the beneficial effects of this invention lie in the fact that it is not a simple material replacement or a single simulation application, but rather provides a complete solution from design methodology to product structure. It not only achieves synergistic improvements in fatigue life and energy efficiency for the amplitude transformer itself, but also revolutionizes the traditional R&D paradigm through forward-looking simulation design methods, achieving a comprehensive leap in design accuracy, development efficiency, and product performance. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0026] Figure 1 This is a schematic diagram of the parametric geometric model of the amplitude transformer established in finite element simulation according to the present invention. Figure 2 This is a flowchart of the ultrasonic amplitude transformer simulation method based on Metglas composite layer according to the present invention; Figure 3 This is the mesh generation diagram of the variable amplitude rod model established in finite element simulation according to the present invention; Figure 4 This is a stress distribution cloud map obtained after multiphysics simulation of the amplitude transformer of the present invention; In the figure, 1 is the amplitude transformer body, and 2 is the Metglas amorphous alloy strip layer. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] This embodiment provides an ultrasonic amplitude transformer based on a Metglas composite layer, which aims to improve the fatigue life and energy efficiency of the amplitude transformer through the synergistic effect of the functional composite structure.

[0029] like Figure 1 As shown, the ultrasonic amplitude transformer mainly includes an amplitude transformer body 1, a Metglas amorphous alloy strip layer 2, an adhesive layer, and an optional insulating protective layer.

[0030] I. Amplitude Gimbal Body: The amplitude gear body 1 is the core structural component of the amplitude gear. Its preferred material is TC4 titanium alloy, but other high-strength, low-loss alloys can be selected according to application requirements. The input end of the amplitude gear body 1 is used to connect to the piezoelectric ceramic transducer to receive high-frequency mechanical vibration; its output end is connected to the tool head, such as a welding head or cutting blade. The main function of the amplitude gear body is to amplify the vibration generated by the transducer and efficiently transmit it to the tool head; it is the vibration energy carrier of the entire system. The structural form of the amplitude gear body 1 can be determined according to design requirements, including but not limited to stepped, conical, or exponential types.

[0031] II. Metglas Amorphous Alloy Strip Layer: Metglas amorphous alloy strip layer 2 is a key functional layer for achieving performance improvement. The application position of the Metglas amorphous alloy strip layer is not determined by experience, but is accurately calculated through the multiphysics coupling simulation method described later. It is usually located in the stress concentration area or the area of ​​significant vibration strain during the operation of the amplitude transformer.

[0032] Specifically, for stepped amplitude transformers, the Metglas amorphous alloy strip layer 2 is preferably bonded to the transition arc of the steps; for conical amplitude transformers, the Metglas amorphous alloy strip layer 2 is preferably bonded to the transition area between the large and small ends; and for exponential amplitude transformers, the Metglas amorphous alloy strip layer 2 is preferably bonded to the amplitude node.

[0033] Metglas amorphous alloy strip layer 2 achieves two core functions through its own mechanical properties: Stress homogenization: By changing the propagation path of stress waves, the sharp "point stress" that was originally concentrated in a narrow area is effectively dispersed into a wider "regional stress", thereby significantly reducing the stress concentration factor, inhibiting the initiation and propagation of fatigue cracks, and fundamentally improving the fatigue life of the amplitude transformer.

[0034] Reduced losses: By utilizing the inherently low mechanical loss characteristics of Metglas material, the loss of vibration energy on the surface of the amplitude transformer is reduced, thereby reducing the operating temperature rise and improving the energy transmission efficiency of the entire ultrasonic system.

[0035] III. Adhesive Layer and Insulation Protection Layer: The adhesive layer is located between the amplitude transformer body 1 and the Metglas amorphous alloy strip layer 2, and uses high-strength epoxy resin and other high-performance adhesives. The main function of the adhesive layer is to achieve a high-strength, full-coverage, and firm bond between the two, ensuring that vibration energy can be efficiently transferred between the substrate and the adhesive layer, simulating ideal "bonded" fixed boundary conditions.

[0036] An insulating protective layer covers the outer surface of the Metglas amorphous alloy tape layer 2. Its function is to protect the Metglas tape from oxidation and corrosion in harsh working environments such as moisture and liquid immersion; and to prevent the tape from being scratched or damaged during installation and use.

[0037] The ultrasonic amplitude transformer based on the Metglas composite coating provided in this implementation has the ability to self-sensing its state. The specific working principle is as follows: When the amplitude transformer is in operation, its body 1 vibrates and deforms. This deformation is effectively transmitted to the Metglas amorphous alloy strip layer 2 through the adhesive layer, forcing the Metglas amorphous alloy strip layer 2 to undergo synchronous microscopic mechanical deformation. Due to the inverse magnetostriction effect of the Metglas amorphous alloy strip layer 2 material, its deformation directly causes periodic changes in its magnetic properties, such as permeability. By connecting a detection coil near the amplitude transformer assembly, this change in magnetic properties can be sensed non-contactly and converted into an electrical signal. By analyzing this electrical signal, real-time online monitoring of the amplitude transformer's operating status, such as amplitude, stress, and resonant frequency shift, can be achieved, thus providing a data foundation for predictive maintenance and intelligent control.

[0038] Furthermore, based on the aforementioned ultrasonic amplitude transformer based on a Metaglas composite layer, this embodiment also proposes a simulation method for an ultrasonic amplitude transformer based on a Metaglas composite layer. This method achieves accurate prediction of the composite amplitude transformer's performance and optimized design of its structural parameters through a systematic multiphysics coupling simulation and parametric optimization process. Specifically, it includes the following steps: S1, Parametric geometric modeling: This step is the cornerstone of the simulation design process of this invention. Its core lies in creating a highly flexible and drivable digital amplitude transformer prototype. It completely changes the traditional CAD modeling mode of "fixed dimensions and static geometry" and instead adopts an advanced modeling strategy of "variable-driven and dynamic response," laying a solid foundation for subsequent automated simulation and optimization.

[0039] S1.1, Creation of the parametric model of the composite structure: Model Construction Basis and Initialization: The modeling process does not begin from scratch, but strictly adheres to the design performance indicators of the amplitude transformer, such as the target amplitude amplification ratio, fatigue life requirements, and operating frequency requirements, as initial inputs, such as 20kHz, 40kHz, etc. In finite element software, such as COMSOL Multiphysics and ANSYS, the built-in parametric modeling functions are utilized, or the model is initiated by linking with parametric CAD kernels, such as the parametric functions of SOLIDWORKS and Creo.

[0040] Modeling of the amplitude transformer: First, a three-dimensional solid model of a stepped amplitude transformer is created. This structure is commonly used due to its simple design and large amplitude amplification ratio, but the stress concentration problem at the step is also the most prominent, making it the focus of optimization in this method.

[0041] While creating the geometry, the material properties of the entity are defined as TC4 titanium alloy. This step is not a simple text annotation, but rather assigning initial material parameters of TC4, such as density and initial Young's modulus, to it from the software's material library, preparing it for subsequent physics calculations.

[0042] Integration of Metglas amorphous alloy strip layers: A functional layer is created in the critical step transition region of the amplitude transformer body using one of two high-fidelity methods: "Shell" interface: Create a shell element with a thickness of 0.03 mm on the surface of an existing solid. This method is computationally efficient and is well-suited for thin-layer structures with thicknesses much smaller than other dimensions, accurately simulating their in-plane and normal mechanical behavior.

[0043] Thin-layer solid: By stretching or offsetting a surface, a separate 3D solid with a thickness of 0.03 mm is generated. This method more accurately reflects the true 3D geometry of the layer, especially when considering complex edge effects.

[0044] Material definition: This layer of material is explicitly defined as Metglas 2605SA1, and its corresponding material properties are assigned: density =7180kg / m 3 Young's modulus =125GPa, etc. This ensures that this functional layer participates in calculations with its true physical properties in subsequent simulations.

[0045] S1.2, Parameterized definition and range setting of key design variables: Variable selection logic: The core innovation of this step lies in transforming key geometric features affecting performance from fixed values ​​into optimization variables. All selected variables are based on profound physical insights. The coverage position and width W of the Metglas amorphous alloy strip layer directly determine the coverage range and effect of the functional material in the stress concentration area. An excessively large width may increase costs without improving effectiveness, while an excessively small width is insufficient to disperse stress.

[0046] The transition radius R of the amplitude transformer body is the most sensitive geometric parameter for controlling the stress concentration factor. The smaller the radius, the more severe the stress concentration; increasing the radius can effectively reduce the peak stress, but may affect the overall stiffness and frequency of the amplitude transformer.

[0047] Scientific definition of parameter space: Setting initial values ​​and scan ranges for each variable is key to guiding the optimization algorithm to search efficiently.

[0048] Transition radius R: The initial value is set to 1.0mm, a typical and conservative design value. The scanning range is set to 1.0mm to 5.0mm. The lower limit is usually determined by the minimum tool tip radius and structural strength of the CNC machining tool, while the upper limit is determined by the maximum allowable structural space and frequency drift tolerance.

[0049] Metglas amorphous alloy strip layer width W: Initial value set to 5mm. Scan range 3mm to 10mm. The lower limit ensures that the functional layer can effectively cover high-stress areas, while the upper limit takes into account material cost, weight increase, and whether it will interfere with the installation of other components, such as flanges.

[0050] These ranges together define a multi-dimensional design space within which optimization algorithms will automatically search for the optimal solution.

[0051] This step established a flexible and adjustable geometric model foundation, providing a parametric basis for subsequent optimization iterations and ensuring the model can quickly respond to design changes. Simultaneously, it enabled systematic management of design variables, significantly improving the efficiency of model modification and optimization, and laying the foundation for an automated optimization process.

[0052] S2, Constructing a multiphysics coupling model: This step aims to establish a simulation model that accurately reflects the complex physical behavior of the amplitude transformer under actual working conditions. By comprehensively considering the interactions between multiple physical fields such as structural deformation, piezoelectric actuation, and temperature effects, the simulation results are ensured to have high reliability and predictive accuracy.

[0053] S2.1, Material Model Definition: To accurately simulate the behavior of materials under actual working conditions, this method abandons simple constant material properties and adopts a more accurate constitutive model.

[0054] Thermo-mechanical coupling model of structural materials: The Young's modulus of the amplitude transformer body (TC4 titanium alloy) and the Metglas amorphous alloy strip layer is defined as a function of temperature, and its expression is: ; in, For the material at temperature Instantaneous Young's modulus; Reference temperature The initial Young's modulus; The temperature coefficient of Young's modulus of the material; The current operating temperature of the material; The reference temperature is either room temperature or the temperature under stress-free conditions.

[0055] This model can dynamically reflect the change in stiffness of the amplitude transformer and its impact on the resonant frequency after the temperature rise due to energy dissipation.

[0056] A complete electromechanical coupling model for piezoelectric materials: To accurately describe the transduction mechanism of piezoelectric ceramics, their complete electromechanical properties need to be defined. piezoelectric coupling matrix : is a 3×6 matrix describing the electric field components. With strain components The linear coupling relationship between them. It quantifies the efficiency of the interconversion of electrical energy and mechanical energy.

[0057] Dielectric matrix : is a 3×3 symmetric matrix describing the electric displacement under constant stress. With electric field The relationship between them reflects the dielectric properties of the material.

[0058] The material model precisely characterizes the dynamic changes of material properties with temperature and operating frequency, avoiding simulation errors caused by using fixed parameters. It provides a complete mathematical description for the simulation of the piezoelectric effect, ensuring accurate calculation of the driving process of electrical energy conversion to mechanical energy and the sensing process of mechanical deformation feedback back to the electrical response. This significantly improves the accuracy of the simulation model in predicting resonant frequency, amplitude response, and energy conversion efficiency. Furthermore, it enables the simulation to predict the performance drift of the amplitude transformer under long-term operation and significant temperature rise conditions, which is impossible with traditional simulations.

[0059] S2.2, Physical field setup and governing equation establishment: In finite element software, a complete system model is constructed by adding and coupling multiple physical field interfaces.

[0060] Physics settings: Add a "Solid Mechanics" interface to calculate the deformation, stress, and vibration of the amplitude transformer under load. Add a "Piezoelectric Effect" interface to calculate the electric field and potential distribution within piezoelectric materials. Set the input end face of the amplitude transformer as a piezoelectric driving surface and apply an AC voltage excitation to it to simulate real driving conditions.

[0061] The governing equations form the core of the two-way coupling. Specifically, the system operates by solving the following set of mutually coupled partial differential equations: Solid mechanical field momentum conservation equation: ; This equation describes the relationship between force and motion. Among them, For divergence operators; For Cauchy stress tensor; It is a volume force; The mass density of the material; This is the second-order partial derivative with respect to time; This is the displacement vector of the material. It solves for the deformation and acceleration of the structure under the action of forces.

[0062] Piezoelectric constitutive equation and Gauss's law: ; in, It is the electric displacement vector; It is a double dot product; is the electric field intensity vector.

[0063] This equation is the core equation describing the behavior of piezoelectric materials. It indicates the electric displacement It is contributed by two parts: one is by the Cauchy stress tensor It is generated by the piezoelectric effect, i.e., the positive piezoelectric effect; the other is generated by the electric field intensity vector. It is generated through the dielectric effect.

[0064] Two-way coupling mechanism: Coupling is manifested in two aspects: 1. Inverse piezoelectric effect, i.e., electricity → force: the applied voltage produces an electric field intensity vector. And then through the equation: ; in, The stress tensor generated by the inverse piezoelectric effect; piezoelectric coupling matrix The transpose of the stress tensor generated by the inverse piezoelectric effect in piezoelectric materials. This stress is substituted as a source term into the solid mechanics equations, driving structural vibration.

[0065] 2. Positive piezoelectric effect, i.e., force → electricity: Deformation of the structure changes the stress state within the piezoelectric material, i.e., the Cauchy stress tensor. This, in turn, influences the electric displacement vector through the piezoelectric constitutive equation. The distribution of .

[0066] In the process of setting up the physical field and establishing the control equations, a simulation environment is established that can self-consistently simulate the entire process of "electrical energy input → mechanical vibration → structural response → electrical feedback". This accurately reveals the dynamic interaction between the piezoelectric actuator and the amplitude transformer structure, thereby accurately predicting the system's resonant behavior. The physical field setup and control equation establishment can simulate the actual working state of the amplitude transformer under piezoelectric drive with high fidelity, and the simulation results agree extremely well with measured data. This fundamentally overcomes the shortcomings of traditional single-physics simulations, which simplify the drive to a boundary force or displacement and fail to reflect the overall system impedance and feedback effects.

[0067] S2.3, Contact Setup and Adaptive Mesh Generation: Contact Setup: The connection between the Metglas amorphous alloy strip layer and the titanium alloy substrate is defined as "bonding". This setup simulates an ideal interface formed using a high-strength epoxy resin adhesive, assuming that the interface is mechanically perfect, with displacement and stress completely continuous at the interface, ensuring that vibrational energy can be efficiently transferred between the two layers.

[0068] Adaptive mesh generation: To ensure the accuracy of the calculation results, especially to accurately capture stress concentration phenomena, a region-based mesh generation strategy was adopted. The local mesh of the Metglas amorphous alloy strip layer and its interface region with the substrate is refined.

[0069] The meshing criterion is based on convergence analysis, ensuring that in regions with drastic stress gradient changes, such as stepped transition arcs, at least five mesh elements are used to span the main stress variation range. This follows the fundamental principle of accurately analyzing field variables in finite element analysis.

[0070] Contact settings and adaptive meshing ensure the accurate simulation of the mechanical behavior between different material layers in a composite structure. With limited computational resources, mesh density is prioritized for critical regions that have the greatest impact on the calculation results, guaranteeing solution accuracy in the most economical way. Contact settings and adaptive meshing clearly and accurately reveal the stress concentration regions and maximum stress values ​​of the amplitude transformer under resonant conditions, providing reliable input data for subsequent fatigue life assessment and structural optimization. Simultaneously, it avoids stress calculation distortions caused by improper meshing, such as underestimation or abnormal stress distribution, thus ensuring the scientific rigor and soundness of the simulation results.

[0071] S3, Simulation Analysis and Solution: This step is the core link connecting the theoretical model and performance prediction. Its purpose is to drive the constructed multiphysics coupling model to simulate the dynamic response of the amplitude transformer under real working conditions, thereby accurately extracting its key performance indicators and providing quantitative basis for design verification and optimization.

[0072] S3.1, Application of Boundary Conditions and Excitations: Simulating the Real Working Environment: Boundary conditions—fixed constraints on vibration nodes: Physical basis: In actual ultrasonic systems, the amplitude transformer is mounted on the support structure via a flange. The ideal installation position should be near the displacement node of one of its vibration modes, i.e., the position where the displacement is zero, to minimize the transfer of vibration energy to the support structure and avoid energy loss and system instability.

[0073] Simulation Implementation: Based on the preliminary results of characteristic frequency analysis or calculations according to classical theory, determine the vibration node position of the amplitude transformer at the target resonant frequency. Apply a fixed constraint at this position, restricting displacement in all directions (u=0). This setup accurately simulates the actual installation conditions and is a prerequisite for obtaining accurate resonant frequencies and mode shapes.

[0074] Electrical excitation—sweep frequency voltage signal: Physical basis: The piezoelectric ceramic transducer generates alternating distortion by inputting AC voltage, thereby driving the amplitude transformer.

[0075] Simulation Implementation: A harmonic voltage signal with constant amplitude and a frequency that varies linearly or logarithmically within a preset range is applied to the piezoelectric driving surface of the amplitude transformer input end face. For example, if the target frequency is 20kHz, the sweep frequency range can be set to 18kHz to 22kHz. This excitation method can excite all possible resonant modes within this frequency band.

[0076] The application of boundary conditions and excitations creates a working environment that is as close as possible to physical reality for the simulation model; ensuring that the simulation analysis can systematically detect the global dynamic characteristics of the amplitude transformer within the operating frequency band, rather than just at a single isolated frequency point.

[0077] S3.2, Characteristic Frequency Analysis: Obtaining Natural Vibration Characteristics: Solving the generalized eigenvalue problem: This analysis solves the following governing equations: ; The resonant frequency and mode shape of the amplitude transformer are obtained through this equation. Here is the system stiffness matrix; The system quality matrix; Angular frequency; These are the eigenvectors, i.e., the mode shapes. Mathematically, this equation solves for the natural frequencies and corresponding modes of the simple harmonic motion that the system can maintain when it is not subjected to external forces.

[0078] The solution process involves a finite element solver calculating the eigenvalues ​​of the equation. and the corresponding feature vector .

[0079] Result extraction: 1. Resonant frequency: the first First resonant frequency through The calculation shows that the first-order longitudinal vibration frequency is usually the design operating point for the amplitude transformer.

[0080] 2. Mode shape: Eigenvector It visually demonstrates the frequency. Below, the relative displacement distribution of each point on the amplitude transformer, i.e., the vibration mode, can clearly show the positions of nodes and antinodes.

[0081] Characteristic frequency analysis can identify the inherent resonant frequency of the amplitude transformer, ensuring that the designed operating frequency is consistent with it to achieve efficient energy transfer; the vibration modes can be visualized to verify whether the amplitude transformer works in the expected mode and to eliminate unwanted bending or torsional modes.

[0082] S3.3, Frequency Domain Analysis: Evaluating Steady-State Performance: Solving the frequency domain dynamic equations: Under swept-frequency excitation, the system solves for the steady-state response equation considering damping. ; This equation describes the system under external harmonic excitation. The steady-state response under [condition]. Among them, The system damping matrix is ​​given by the Rayleigh damping model. ; The imaginary unit; This is the frequency domain displacement response vector; The harmonic excitation force vector is obtained by converting the applied sweep frequency voltage through the piezoelectric constitutive relation; the angular frequency is then scanned. The displacement amplitudes at the output and input terminals are obtained, and the amplitude amplification ratio is calculated accordingly.

[0083] The solution and results are as follows: the solver at each frequency sweep point Calculate displacement response .

[0084] 1. Displacement Distribution and Amplitude Amplification Ratio: By extracting the displacement amplitudes at the output and input terminals, displacement frequency response curves can be plotted, and the amplitude amplification ratio can be accurately calculated. The frequency corresponding to the peak value of the curve is the operating frequency, and the peak value is the maximum amplification ratio.

[0085] 2. Stress Field Distribution: In frequency domain analysis, the dynamic stress field of the entire amplitude transformer can be solved simultaneously. The most crucial result is the von Mises equivalent stress distribution cloud map, which comprehensively reflects the complex stress state and is used to assess the yield and fatigue risk of the material.

[0086] Frequency domain analysis can determine the performance of the amplitude transformer under actual working conditions considering damping, including the actual working frequency and amplitude amplification capability; it can also accurately locate the maximum stress area and quantify the stress level, which is a direct basis for evaluating fatigue life and optimizing the structure.

[0087] S4, Parametric optimization iteration: This step is the core and essence of this simulation method. It transforms the traditional experience-based "trial and error" design process into a systematic and automated optimization process based on mathematical optimization theory. Its purpose is to automatically find the combination of design parameters that maximizes the overall performance of the amplitude transformer while satisfying all practical constraints.

[0088] S4.1, Constructing the optimization problem: Defining the mathematical objective and constraints of the design: Establishment of the multi-objective optimization function: The optimization problem is formalized as a mathematical problem involving conflicting objectives: ; in, It is a design variable vector that contains all the parameters to be optimized defined in S1, for example: .

[0089] This is the amplitude amplification ratio, a core indicator of the energy transmission efficiency of the amplitude transformer. We want it to be as high as possible. Since the optimization criterion is usually minimization, we take a negative value. Transform it into a minimization problem. It is the maximum equivalent stress, a key indicator for evaluating fatigue life and reliability; the smaller it is, the better.

[0090] These two objectives are inherently conflicting. For example, simply increasing the radius R of the transition arc can reduce stress, but it may alter the mode shape, leading to a decrease in the amplification ratio. Therefore, optimization does not seek a single "optimal solution," but rather a series of Pareto optimal solutions, i.e., the maximum amplification ratio achievable at a given stress level, or the minimum stress achievable at a given amplification ratio.

[0091] Setting constraints: Subject to: ; The simulated resonant frequency of the amplitude transformer is obtained through characteristic frequency analysis.

[0092] It is the target operating frequency required by the system, such as 20kHz.

[0093] For frequency tolerance, factors such as the performance dispersion of piezoelectric ceramics, manufacturing tolerances, and temperature drift are taken into account.

[0094] The setting of constraints ensures that the optimized design can be effectively matched with the transducer in the actual system, which is the fundamental guarantee of engineering feasibility.

[0095] Defining the design space: Bounds: < < ; Setting upper and lower limits for each design variable creates a multi-dimensional design space, or feasible region. These boundaries are based on: manufacturing constraints, such as the minimum machinable radius of a circle; structural integrity requirements, such as the minimum allowable rod thickness; assembly space constraints, such as the maximum allowable flange position; and physical rationality, such as positive dimensions.

[0096] Define the mathematical objectives and constraints of the design, transforming the vague engineering goal of "better performance" into a precise, computable mathematical problem. Through constraints, ensure that the optimization result not only offers superior performance but is also engineering-feasible and system-compatible. Clearly define the search scope of the optimization algorithm to avoid meaningless searches in physically impossible or unmanufacturable regions.

[0097] S4.2, Execution Optimization Solution: Design Exploration for Driven Automation: Optimization Algorithm Selection and Execution: Based on the complexity of the problem and computational resources, select and execute one of the following two types of algorithms: 1. Parametric Scan: This involves systematically or randomly sampling the design space. For example, in a full factorial design, each variable takes multiple discrete values ​​within its range, and the performance of all possible combinations is calculated. Latin hypercube sampling is an efficient random sampling method that can cover the entire design space well with fewer sample points.

[0098] The process is as follows: automatically run a large number of S3 simulations, calculate the objective function and constraints for each sample point, and finally present the performance spectrum of the entire design space through response surface or database.

[0099] Applicable scenarios include: when there are few design variables, usually ≤4; or when used for preliminary exploration of the design space and construction of proxy models.

[0100] 2. Gradient-based optimization algorithms: These algorithms utilize the sensitivity information (i.e., derivatives) of the objective function and constraints to design variables to predict the search direction, quickly approximating the optimal solution with the fewest iterations. Two advanced algorithms are specifically mentioned: Moving asymptote MMA method: It is particularly suitable for large-scale and complex structural optimization problems and can stably handle a variety of constraints.

[0101] Sequential Quadratic Programming (SQP) is very effective for small to medium-sized nonlinear constrained optimization problems.

[0102] Sensitivity analysis: This is the core of the gradient algorithm. It calculates the rate of change of each performance metric, such as frequency and stress, for each design variable, such as the radius of curvature.

[0103] The adjoint method is an efficient method that can calculate all sensitivities with only one additional equation solution, regardless of the number of design variables. It is extremely suitable for problems with many variables.

[0104] Direct method: Sensitivity is obtained by directly perturbing each variable and recalculating the performance. It is simple and intuitive, but the computational cost increases linearly with the number of variables.

[0105] The process is as follows: This is an iterative loop: Current design → Simulation analysis → Sensitivity calculation → Algorithm update design variables → Convergence judgment → Output optimal solution or enter the next iteration.

[0106] By performing optimization solutions, we can automatically explore a massive number of design schemes and find high-performance design points that are difficult for humans to discover; we can greatly improve design efficiency and free engineers from the tedious cycle of "manual modification-simulation-comparison"; through mathematically rigorous optimization theory, we can ensure that the final solution is the optimal or near-optimal solution under given constraints.

[0107] The improvement brought by this parametric optimization iteration step is: from a "satisfactory solution" to an "optimal solution": traditional design often stops at finding a "usable" solution. This method, through systematic search, can find a Pareto optimal solution that achieves the best balance across multiple performance indicators, significantly improving the upper limit of product performance. It successfully resolves the inherent performance conflict in amplitude transformer design, finding the optimal trade-off point through multi-objective optimization. The entire optimization process is based on comprehensive simulation data; design decisions no longer rely on intuition or limited experience, but on a global insight into the entire design space, making the design process more scientific, transparent, and repeatable. The automated process shortens the design iteration process, which originally required weeks or even months, to hours or days, while reducing the number of physical prototypes produced, achieving a significant reduction in R&D costs and cycle time.

[0108] S5, output the final design: This step is the final output of the entire simulation design method. Its core task is to transform the "optimal parameter combination" that exists in the digital space after multiple rounds of iterative optimization into accurate manufacturing data that can be directly used by the production department; thus completing the key transformation from "optimization results" to "manufacturable drawings".

[0109] S5.1, Geometric Model Reconstruction: From Optimal Parameters to Accurate 3D Model: Automatic model updates driven by parameters: Input: The input for this step is the optimal parameter combination determined after optimization iterations. This vector contains the optimal values ​​for all key dimensions, for example... , Unit: mm.

[0110] The simulation optimization system will The values ​​in the model are automatically assigned to the variables corresponding to the parametric geometric model established in S1. Based on these new values, the parametric CAD system automatically and instantaneously regenerates the three-dimensional geometry of the entire composite amplitude transformer. This process requires no manual modeling or intervention, ensuring the accuracy and efficiency of the results.

[0111] Generate a solid model with precise dimensions and a boundary representation (B-Rep). B-Rep is the standard solid representation method in the CAD field. It accurately describes the geometry and topological relationships of the model, namely: faces, edges, and vertices, providing a solid foundation for any subsequent operations such as rendering, analysis, and manufacturing.

[0112] This process leverages a deep integration of parametric modeling and optimization-driven design. The model is not a static geometry, but a dynamically responsive intelligent system controlled by key parameters. The final parameters determined by the optimization algorithm directly drive the generation of the final design.

[0113] Geometric model reconstruction ensures that the optimized design intent is fully and accurately reflected in the final 3D geometry; it achieves complete automation of the design and modification process, eliminating errors that may be introduced by manual parameter transcription; and it generates a high-quality, defect-free 3D solid model, preparing it for data exchange and CNC programming.

[0114] S5.2, Output Manufacturing Data: Generate authoritative documents to guide production. Manufacturing data format and selection: Based on the equipment and process habits of the manufacturing plant, output manufacturing data in one or more of the following formats: 1. CNC Machining Centerline Coordinates: For turning amplitude transformers, the coordinate set (X, Z) of a series of key points on the contour line of its axial section is typically output. This coordinate set directly defines the tool path during machining. The format can be a plain text file (e.g., .txt, .csv) or a specific NC code file. It is ideally suited for turning rotary amplitude transformers (e.g., stepped, conical types), offering simple, direct, and efficient programming.

[0115] 2. Standard 3D Model Data Exchange Files: Primarily exported as STEP (AP203 / AP214) or IGES formats. These two are internationally recognized and most reliable neutral CAD data exchange standards. The system translates the reconstructed B-Rep solid model into STEP or IGES format files using its internal converter.

[0116] Almost all modern CAD / CAM / CAE software, such as UG / NX, CATIA, and Mastercam, can read the data seamlessly, completely avoiding data compatibility issues. It contains not only geometric information but may also include metadata such as color, layers, and material properties. CAM engineers can import the model for further CNC programming; it can also be used for 3D inspection, comparing the results with those from coordinate measuring machine scans.

[0117] Data authority: The final output manufacturing data, whose geometric dimensions are entirely derived from the optimization results. The decision is a direct reflection of the optimal design scheme that has been verified through multiphysics simulation.

[0118] Outputting manufacturing data bridges the final stage of digital design and physical manufacturing, enabling the accurate and error-free transformation of optimized results into physical products. It provides flexibility to meet the data format requirements of different processing units and processes. It ensures manufacturing precision, guaranteeing from the outset that the final product's geometry perfectly matches the simulation model, thereby ensuring its performance conforms to simulation predictions.

[0119] The final design step of geometric model reconstruction achieves a closed-loop process, eliminating the need for manual interpretation and secondary modeling in the traditional process of converting "drawings" into "manufacturing code." This enables a successful one-time transformation from virtual performance optimization to the physical product. Through automated data transfer, all details of the optimized design are 100% preserved, avoiding dimensional deviations or feature loss that could result from human interpretation and operation. Manufacturing data preparation time is reduced from hours or days to minutes, significantly accelerating product manufacturing. The output standard-format 3D model is the core of product digital lifecycle management and can be directly used to create digital twins and manage quality inspection records.

[0120] Furthermore, to verify the effectiveness, accuracy, and engineering value of the multiphysics coupling simulation method proposed in this invention, this verification example is designed. This verification uses a specific stepped amplitude transformer design case to fully execute the simulation process and compares and analyzes the key results with theoretical expectations and traditional designs.

[0121] 1. Validate model establishment: Using the method of this invention, a stepped amplitude transformer for a 20kHz ultrasonic system is modeled and optimized.

[0122] Amplitude bar body: made of TC4 titanium alloy, with a stepped structure.

[0123] Metglas amorphous alloy strip layer: The material is Metglas 2605SA1. Based on the stress concentration area determined by the preliminary simulation, it is attached to the transition area of ​​the amplitude rod step. The initial model thickness is 0.03 mm.

[0124] Key design variables: In this verification, the radius R of the transition arc of the amplitude transformer and the width W of the Metglas amorphous alloy strip layer are set as optimization variables to verify the method's ability to handle complex geometric parameters.

[0125] 2. Simulation process and mesh independence verification: First, perform model preprocessing according to step S2. Figure 3 The finite element mesh model built for this verification example is shown.

[0126] Meshing strategy: Unstructured tetrahedral elements are used to flexibly fill complex geometries. To control the computational scale while ensuring computational accuracy, a local mesh refinement strategy is implemented.

[0127] Local refinement: Significant mesh refinement was performed in key step transition regions and within and at the interfaces of the Metglas amorphous alloy strip layer. For example... Figure 3 As shown, the grid density in this area is much higher than in other areas.

[0128] Mesh quality: The final mesh size was determined through mesh convergence analysis to ensure that at least five mesh elements accurately capture the complete changes in the stress field in regions with the largest stress gradients. The overall mesh density is appropriate, reflecting the scientific rigor and scientific nature of the method of this invention, and laying the foundation for obtaining reliable simulation results.

[0129] 3. Results Analysis and Method Validation: After applying boundary conditions and a sweep frequency voltage excitation near 20kHz to the model, perform simulation analysis and solution in step S3.

[0130] 3.1. Verification of stress distribution results: Figure 4 The equivalent stress distribution contour map of the amplitude transformer under resonant state is displayed. Stress concentration location: The contour map clearly shows that the maximum stress value occurs at the transition arc of the stepped structure, which is completely consistent with the classic assertion in mechanics of materials and elasticity theory that geometric discontinuities lead to stress concentration, preliminarily verifying the correctness of the simulation model. Stress value quantification: Extracted by software, the maximum equivalent stress value under this condition is 121.5 MPa. This value is far below the fatigue strength limit of TC4 titanium alloy, indicating that the initial design has basic reliability, and providing a clear optimization target area for optimization iteration.

[0131] Metglas Layer Effect Verification: To quantify the effect of the Metglas amorphous alloy strip layer, a comparative example (without a Metglas layer) was established. Simulation comparison shows that, under the same excitation, the maximum equivalent stress at the step in the comparative example is 158.2 MPa, while the maximum stress in the embodiment using the composite structure of this method is 121.5 MPa, a reduction of approximately 23.2% in peak stress. This result strongly verifies that the Metglas layer guided by the simulation method of this invention can effectively homogenize stress and reduce stress concentration.

[0132] 3.2. Frequency Prediction Accuracy Verification: Through characteristic frequency analysis, the first-order longitudinal resonant frequency calculated in this embodiment is 20.15 kHz. This frequency value deviates by 1.75% from the simplified calculation result of 19.8 kHz based on one-dimensional wave theory, proving that the multiphysics model of this method can more accurately predict the dynamic characteristics of the real system. Furthermore, this frequency falls entirely within the target operating frequency range [19.8, 20.2] kHz, satisfying the design constraints.

[0133] 4. Optimize performance verification: Based on the initial simulation results, the parameterized optimization iteration in step S4 is initiated. With the objectives of maximizing the amplitude amplification ratio and minimizing the maximum equivalent stress, the transition arc radius R and the width W of the Metglas amorphous alloy strip layer are jointly optimized.

[0134] After optimization and iteration, the optimal parameter combination was obtained: R=3.2mm, W=8.5mm.

[0135] After adopting the optimal parameters, the simulation results show that the amplitude amplification is improved by 8% compared with the initial design, while the maximum equivalent stress is further reduced to 105.8 MPa. Compared with the comparative model without Metglas, the stress reduction is 33.1%, and the resonant frequency is stabilized at 20.08 kHz.

[0136] 5. Conclusion: This verification example, through a complete simulation process and systematic result analysis, confirms that the ultrasonic amplitude transformer simulation method based on Metglas composite coating has the following outstanding advantages: High-precision prediction capability: It can accurately predict the resonant frequency, mode shape and stress distribution of the amplitude transformer, and can especially accurately capture the three-dimensional stress concentration effect.

[0137] Clear engineering guidance value: It can effectively guide and quantify the performance improvement effect of functional veneer Metglas, and provide a reliable basis for integrated structure-material design.

[0138] Powerful optimization capabilities: Through parametric optimization iteration, it can automatically and efficiently find the design solution with the best overall performance, significantly improving product performance and reliability.

[0139] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An ultrasonic amplitude transformer based on a Metglas composite layer, characterized in that: Including the amplitude transformer body and the Metglas amorphous alloy strip layer; The input end of the amplitude transformer body can be connected to a piezoelectric ceramic transducer, and its output end is connected to a tool head; the amplitude transformer body can amplify and transmit ultrasonic mechanical vibrations and is the main carrier of vibration energy. The Metglas amorphous alloy strip layer is bonded to a specific area on the surface of the amplitude transformer body. This specific area is a stress concentration area or a significant vibration strain area determined by multiphysics simulation. Metglas amorphous alloy strip layer utilizes its own mechanical properties to change the stress propagation path, dispersing sharp point stress into gentle regional stress, and reducing the loss of vibration energy on the surface of the amplitude transformer. When the amplitude transformer vibrates, the Metglas amorphous alloy strip layer deforms, which causes a change in the magnetic properties of the laminate. This change can be used to monitor the working status of the amplitude transformer in real time.

2. The ultrasonic amplitude transformer based on Metglas composite layer according to claim 1, characterized in that: The amplitude transformer body is stepped; the Metglas amorphous alloy strip layer is bonded to the stepped transition arc of the amplitude transformer body.

3. The ultrasonic amplitude transformer based on Metglas composite layer according to claim 1, characterized in that: The amplitude transformer body is conical; the Metglas amorphous alloy strip layer is bonded to the transition area between the large and small ends of the conical amplitude transformer body.

4. The ultrasonic amplitude transformer based on Metglas composite layer according to claim 1, characterized in that: The amplitude transformer body is exponential; the Metglas amorphous alloy strip layer is bonded to the amplitude node of the exponential amplitude transformer body.

5. The ultrasonic amplitude transformer based on Metglas composite layer according to claim 1, characterized in that: An adhesive layer is provided between the amplitude transformer body and the Metglas amorphous alloy strip layer. The adhesive layer uses high-strength epoxy resin. The adhesive layer ensures that vibration energy can be efficiently transferred from the amplitude transformer body to the Metglas amorphous alloy strip layer. The outer surface of the Metglas amorphous alloy strip layer is also covered with an insulating protective layer.

6. A simulation method for an ultrasonic amplitude transformer based on a Metaglas composite layer, wherein the simulation method is based on the ultrasonic amplitude transformer based on a Metaglas composite layer as described in any one of claims 1-5, characterized in that, Includes the following steps: S1, Parametric geometric modeling: Establish a parametric geometric model of the composite structure including the luffing bar body and the Metglas amorphous alloy strip layer, and set at least one of the following key dimensions as variables: the coverage position, thickness, and width of the Metglas amorphous alloy strip layer, as well as the transition arc radius, flange position, and bar taper of the luffing bar body. S2, Construct a multiphysics coupling model: Assign material properties to the geometric model, and add solid mechanics and piezoelectric effect modules to establish a structure-piezoelectric multiphysics coupling simulation model, and set the connection between the Metglas amorphous alloy strip layer and the amplitude rod body to be bonded and fixed. S3, Simulation Analysis and Solution: Apply fixed constraints to the coupled model at the vibration nodes, apply a sweep frequency voltage signal to the input end face of the amplitude transformer body, and solve the resonant frequency, mode shape, displacement distribution and stress field distribution of the amplitude transformer by performing characteristic frequency analysis and frequency domain analysis. S4, Parametric Optimization Iteration: With the optimization objectives of maximizing the amplitude amplification ratio and minimizing the maximum equivalent stress, the key size variables are automatically optimized and iterated using parametric scanning or optimization algorithms; S5, Output Final Design: Based on the optimal parameter combination obtained after optimization iteration, determine the final geometric parameters of the amplitude transformer body, and output the centerline coordinates or three-dimensional model data file for CNC machining.

7. The simulation method for ultrasonic amplitude transformers based on Metglas composite layers according to claim 6, characterized in that: In step S1, when defining key variables, initial values ​​and ranges of variation need to be set for them: The initial value of the transition arc radius R is set to 1.0 mm, and the scanning range is 1.0 mm to 5.0 mm; the initial value of the width W of the Metglas amorphous alloy strip layer is set to 5 mm, and the scanning range is 3 mm to 10 mm.

8. The simulation method for ultrasonic amplitude transformers based on Metglas composite layers according to claim 6, characterized in that: In step S2, constructing the multiphysics coupling model includes: S2.1, Material Model Definition: Assign a temperature- or frequency-dependent constitutive model to the amplitude transformer body and the Metglas amorphous alloy strip layer; wherein, the Young's modulus of the structural material is defined as a temperature-dependent function: ; For the material at temperature Instantaneous Young's modulus; Reference temperature The initial Young's modulus; The temperature coefficient of Young's modulus of the material; The current operating temperature of the material; The reference temperature is either room temperature or the temperature under stress-free conditions; the piezoelectric coupling matrix is ​​defined for the piezoelectric material. With dielectric matrix ; It is a 3×6 matrix that describes the linear coupling relationship between the electric field and strain; It is a 3×3 symmetric matrix describing electric displacement. With electric field The relationship between these elements reflects the dielectric properties of the material. S2.2, Establishment of governing equations: The bidirectional coupling between the solid mechanical field and the piezoelectric field is solved using the following governing equations: The momentum conservation equation for a solid mechanical field: ;in, For divergence operators; For Cauchy stress tensor; It is a volume force; The mass density of the material; This is the second-order partial derivative with respect to time; The displacement vector of the material; Constitutive equations of piezoelectric fields and Gauss's law: ;in, It is the electric displacement vector; It is a double dot product; The electric field intensity vector; Stress generated by two physical fields through the piezoelectric effect Bidirectional coupling is performed; where, The stress tensor generated by the inverse piezoelectric effect; piezoelectric coupling matrix Transpose of; S2.3 Adaptive Mesh Generation: The geometric model is subjected to physical field-controlled mesh generation, and local mesh refinement is performed in the stress concentration areas of the Metglas amorphous alloy strip layer and the amplitude transformer body. The size of the local mesh refinement is determined by convergence analysis to ensure that at least five mesh elements are used to accurately capture the complete gradient change of the stress field in areas where the stress gradient changes significantly.

9. The simulation method for ultrasonic amplitude transformers based on Metglas composite layers according to claim 6, characterized in that: In step S3, the simulation analysis and solution include: S3.1, Characteristic Frequency Analysis: Solving the Generalized Eigenvalue Problem To obtain the resonant frequency and mode shape of the amplitude transformer; among which, Here is the system stiffness matrix; The system quality matrix; Angular frequency; The eigenvectors are the mode shapes; the eigenvalues ​​are calculated. and the corresponding feature vectors Then, according to the formula: Calculate the first First resonant frequency ; S3.2 Frequency Domain Analysis: Within the defined frequency sweep range, solve the frequency domain dynamic equations: To obtain the displacement frequency response and stress distribution of the amplitude transformer; among which, Here is the system damping matrix; The imaginary unit; This is the frequency domain displacement response vector; The harmonic excitation force vector is obtained by converting the applied sweep frequency voltage through the piezoelectric constitutive relation; the angular frequency is then scanned. The displacement amplitudes at the output and input terminals are obtained, and the amplitude amplification ratio is calculated accordingly.

10. The simulation method for an ultrasonic amplitude transformer based on a Metglas composite layer according to claim 6, characterized in that: In step S4, the parameterized optimization iteration includes: S4.1, Construct the optimization problem: Establish a method to minimize the maximum equivalent stress. and maximizing amplitude amplification ratio To optimize the target, the simulated resonant frequency of the amplitude transformer was used. Falling into the target frequency range This is a multi-objective optimization problem with constraints, where... The target operating frequency; For frequency tolerance; For the defined design variable vector, its optimization space is limited by the preset value boundaries. ; To design a lower bound for the variable vector; To design an upper bound for the variable vector; S4.2, Perform optimization solution: Use parametric scanning method or gradient-based optimization algorithm to solve the optimization problem; among them, the gradient-based optimization algorithm is the method moving asymptote MMA or the sequential quadratic programming SQP algorithm, and sensitivity analysis is performed through the adjoint method or the direct method to drive iterative calculation until the optimal parameter combination that satisfies the optimization objective is obtained; In step S5, the final design output specifically includes: S5.1, Geometric Model Reconstruction: Based on the Optimal Parameter Combination Automatically update the parametric geometric model and generate a solid model with boundary representation through a standard CAD software kernel; S5.2, Output Manufacturing Data: Output centerline coordinates for CNC machining, or export as a 3D model data file in STEP or IGES format.

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