Superspeed centrifuge rotor rupture rotating speed prediction method based on Hosford yield criterion

Abstract

The invention discloses a Hosford yield criterion-based ultra-high-speed centrifuge rotor rupture rotating speed prediction method, which comprises the following steps of: sampling a rotor material and carrying out a room-temperature tensile test to obtain an engineering stress-strain curve; fitting an elastic-plastic constitutive model based on the curve in combination with a correlation flow rule and a nonlinear isotropic hardening rule to obtain a true stress-true strain curve; constructing a three-dimensional geometric model, performing grid division, and obtaining a finite element model based on material attribute parameters obtained by fitting an elastic-plastic constitutive model and a true stress-true strain curve; temperature field distribution is calculated and unidirectionally coupled to stress field analysis, the rotating speed is gradually increased, a quasi-static nonlinear control equation is solved by using a large deformation arc length method, and stress field distribution at different rotating speeds is obtained; and the yield condition is judged based on the Hosford yield criterion, the rotating speed and radial displacement data in the time history are extracted, and the rupture rotating speed and mode are determined. The method can effectively predict the rotor rupture rotating speed, and guarantees efficient and stable operation of the centrifugal machine.

Description

Technical Field

[0001] The present invention relates to the technical field of centrifuge rotor structure failure prediction, and in particular to a method for predicting the fracture speed of an ultra-high-speed centrifuge rotor based on the Hosford yield criterion. Background Art

[0002] Ultracentrifuges are essential instruments for routine experiments in biology, chemistry, medicine, and pharmacology. They are widely used for separating and purifying substances such as proteins, nucleic acids, viruses, organelles, and nanoparticles. Ultracentrifuges rely on high-speed rotor rotation to separate substances, and their safety and reliability are directly linked to production continuity, product quality, and the safety of personnel and equipment. Under ultracentrifugal conditions, the rotor is subjected to tremendous centrifugal forces. If a rotor breaks during use, it can not only damage expensive equipment and interrupt production, but can also cause serious safety incidents such as the leakage of hazardous materials and the splashing of debris, posing a threat to personnel safety.

[0003] Existing research methods are mostly used in the design research of aircraft engine disks. The structural design of centrifuge rotors is more complex and the stress conditions are less clear. In addition, the existing Hallinan method and local stress-strain method are not accurate enough to meet the engineering needs of rotor fracture speed prediction.

[0004] Therefore, how to provide a method for effectively predicting the breakage speed of an ultracentrifuge rotor is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] In response to the above research status, the present invention provides a method for predicting the rotor rupture speed of an ultra-high-speed centrifuge based on the Hosford yield criterion. The method can effectively predict the rotor rupture speed, set reasonable safe operating parameters for the equipment, and prevent the dangers caused by overspeed. At the same time, it provides a basis for optimizing the rotor design, improves material utilization and structural strength, and ensures the efficient and stable operation of the centrifuge, which is of extremely important practical significance.

[0006] The present invention provides a method for predicting the fracture speed of an ultracentrifuge rotor based on the Hosford yield criterion, comprising the following steps: S1: sampling the ultracentrifuge rotor in a set direction to obtain a material sample, performing a room temperature tensile test on the material sample to obtain an engineering stress-strain curve of the ultracentrifuge rotor material;

[0007] S2: Based on the engineering stress-strain curve, the elastic-plastic constitutive model of the centrifugal rotor material is fitted by combining the associated flow law and the nonlinear isotropic hardening law to obtain the true stress-true strain curve;

[0008] S3: constructing a three-dimensional geometric model of the centrifugal rotor and performing meshing, obtaining material property parameters based on the elastic-plastic constitutive model and the true stress-true strain curve fitting and using them as input for finite element analysis to obtain a finite element model of the centrifugal rotor;

[0009] S4: Calculate the temperature field distribution of the ultra-high-speed centrifugal rotor, introduce the temperature field distribution into the stress field analysis process of the centrifugal rotor finite element model in a unidirectional coupling manner, define periodic symmetry constraints, gradually increase the speed, and use the large deformation arc length method to solve the quasi-static nonlinear control equation to obtain the stress field distribution results under different speed time histories;

[0010] S5: Determine the yield condition based on the Hosford yield criterion in the principal stress space of the centrifugal rotor finite element model, extract the speed during the time history and the radial displacement data of the nodes in the centrifugal rotor finite element model, and confirm the fracture speed and fracture mode.

[0011] Preferably, the S1 includes:

[0012] Sampling is performed along the radial and chord directions of the ultra-high-speed centrifugal rotor to obtain material samples, which are then heated, cooled, and then subjected to aging treatment. A room temperature uniaxial tensile test is performed on the material samples, and the deformation and stress values ​​at each stage are recorded to obtain the basic performance values ​​and engineering stress-strain curve of the ultra-high-speed centrifugal rotor material.

[0013] Preferably, the associated flow law expression in S2 is:

[0014]

[0015] Where, is the plastic strain increment tensor; i and j represent the spatial direction index of the tensor respectively; dλ is the plastic multiplier, which is a positive scalar indicating the size of the plastic strain increment; is the partial derivative of the yield function with respect to the stress tensor, and its direction is perpendicular to the yield surface.

[0016] Preferably, an isotropic hardening model is constructed in S2; the yield surface of the isotropic hardening model expands uniformly during the stress-strain process, and the hardening law is a nonlinear function, which is specifically expressed as:

[0017]

[0018] Where σ y is the current yield strength; σ y0 is the initial yield strength; is the equivalent plastic strain of the material; r0, r1, r2, r3 are hardening parameters that control the contribution of different hardening terms to the yield strength; b1, b2, b3 are hardening rate parameters that control the rate of each hardening term.

[0019] Preferably, the expression for calculating the true stress-strain curve according to the engineering stress-strain curve in S2 is:

[0020] ε t =ln(ε e +1);

[0021] σ t =σ e (ε e +1);

[0022] Where σ e ,ε e are engineering stress and engineering strain, respectively.

[0023] Preferably, the S3 includes:

[0024] S31: Construct the three-dimensional geometric model of the centrifugal rotor as an axisymmetric three-dimensional solid model with cyclic symmetry constraints;

[0025] S32: performing a preliminary static analysis on the model, calculating the stress distribution when the rotation speed is lower than the set value, splitting the three-dimensional solid model into multiple sub-solid models according to the stress cycle distribution law, and meshing the sub-solid models;

[0026] S33: Customizing a material constitutive model according to the elastic-plastic constitutive model and the true stress-true strain curve, and constructing a sub-entity finite element model based on the material constitutive model.

[0027] Preferably, the step of calculating the temperature field distribution of the ultracentrifuge rotor in S4 includes:

[0028] The heat conduction equation of the centrifuge rotor is:

[0029]

[0030] Where α is the thermal diffusivity; Q is the heat source term; T is the temperature, and t is the time; is the Laplace operator, which represents the diffusion rate of heat flow; in the cylindrical coordinate system, the Laplace operator is:

[0031]

[0032] Where (r, θ, z) are the parameters of the cylindrical coordinate system;

[0033] Based on the given boundary conditions and initial conditions of the heat conduction equation, the time and space variables of the three-dimensional geometric model are discretized by the finite element analysis method, a finite element solution model is established, and the thermal field distribution of the centrifugal rotor is calculated by iterative solution.

[0034] The centrifugal rotor thermal field distribution is unidirectionally coupled into the stress field analysis process of the centrifugal rotor finite element model, and the thermal strain is used as the initial strain to calculate the stress field distribution results under different speed time histories.

[0035] Preferably, the step of using the large deformation arc length method to solve the quasi-static nonlinear control equation in S4 includes:

[0036] The large deformation arc length method is used to solve the quasi-static nonlinear control equation. The quasi-static nonlinear control equation of the sub-entity model is:

[0037] F(u,λ)=0;

[0038] Where u is the node displacement vector, λ is the loading parameter;

[0039] Introducing the arc length parameter s, so that u = u(s), λ = λ(s), the enhanced equation system constructed by combining the original equation and the arc length constraint equation is:

[0040]

[0041] Where G(u,λ,s) is the arc length constraint equation.

[0042] The enhanced equations are iteratively solved by a finite element iterative solver until convergence.

[0043] Preferably, in S5:

[0044] The Hosford yield criterion in the principal stress space is expressed as:

[0045] (σ1-σ2) n +(σ2-σ3) n +(σ3-σ1) n =2σ0 n ;

[0046] Where σ1, σ2, σ3 are the principal stresses, σ0 represents the yield strength of the material; n is the Hosford index, which ranges from 1 to ∞;

[0047] When the Hosford index n approaches ∞, the Hosford criterion degenerates into the Tresca yield criterion:

[0048] Max(|σ1-σ2|,|σ2-σ3|,|σ3-σ1|)=σ0;

[0049] When the Hosford index n = 2, the Hosford criterion degenerates into the von Mises yield criterion:

[0050] (σ1-σ2) 2 +(σ2-σ3) 2 +(σ3-σ1) 2 =2σ0 2 ;

[0051] The value of n is determined according to the centrifuge rotor material.

[0052] Preferably, in S5, after the finite element calculation of the centrifugal rotor reaches convergence, the displacement data curve data is extracted, and the rotation speed corresponding to the maximum value of the displacement data is determined as the maximum rupture rotation speed of the centrifugal rotor.

[0053] Compared with the prior art, the present invention has the following beneficial effects:

[0054] The present invention realizes the prediction of centrifuge rotor rupture speed by integrating multi-physical field coupling, and realizes accurate prediction of the mechanical properties and stability failure behavior of the rotor under multiple working conditions such as complex stress, strain and high temperature. It improves the quantitative evaluation of the safety and reliability of ultra-high-speed centrifuge rotors under extreme working conditions, and provides a basis for the failure prevention of rotating parts and the formulation of safe operation assurance strategies in high-risk environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only embodiments of the present invention. Those skilled in the art can also derive other drawings based on the provided drawings without inventive effort.

[0056] Figure 1 This is a flow chart of a method for predicting the fracture speed of an ultra-high-speed centrifuge rotor based on the Hosford yield criterion provided in an embodiment of the present invention;

[0057] Figure 2 Schematic diagram of stress-strain curve of room temperature axial tensile test of a sample provided by an embodiment of the present invention;

[0058] Figure 3 A schematic diagram of a finite element model of a horizontal rotor provided in an embodiment of the present invention;

[0059] Figure 4 A schematic diagram of stress results from a finite element simulation of a horizontal rotor provided by an embodiment of the present invention;

[0060] Figure 5 Schematic diagram of the execution steps of the method for predicting the rupture speed of an ultra-high-speed centrifuge rotor based on the Hosford yield criterion provided by the present invention. DETAILED DESCRIPTION

[0061] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0062] The ultracentrifuge rotor described in this invention utilizes high-strength, lightweight materials for its primary structure. Precision forging and surface treatment processes ensure high rigidity and fatigue resistance. The rotor's internal cavity features a multi-stage involute structure, optimizing the sample flow path during centrifugation and reducing airflow resistance and eddy currents. The rotor surface is polished for improved wear resistance and airtightness. The rotor and drive shaft utilize a quick-disconnect design, with tapered surfaces mating to achieve efficient docking transmission.

[0063] An embodiment of the present invention discloses a method for predicting the fracture speed of an ultracentrifuge rotor based on the Hosford yield criterion, comprising the following steps:

[0064] S1: Sampling the ultracentrifugal rotor in a set direction to obtain a material sample, performing a room temperature tensile test on the material sample to obtain an engineering stress-strain curve of the ultracentrifugal rotor material;

[0065] S2: Based on the engineering stress-strain curve, the elastic-plastic constitutive model of the centrifugal rotor material is fitted by combining the associated flow law and the nonlinear isotropic hardening law to obtain the true stress-true strain curve;

[0066] S3: constructing a three-dimensional geometric model of the centrifugal rotor and performing meshing, obtaining material property parameters based on the elastic-plastic constitutive model and the true stress-true strain curve fitting and using them as input for finite element analysis to obtain a finite element model of the centrifugal rotor;

[0067] S4: Calculate the temperature field distribution of the ultra-high-speed centrifugal rotor, introduce the temperature field distribution into the stress field analysis process of the centrifugal rotor finite element model in a unidirectional coupling manner, define periodic symmetry constraints, gradually increase the speed, and use the large deformation arc length method to solve the quasi-static nonlinear control equation to obtain the stress field distribution results under different speed time histories;

[0068] S5: Determine the yield condition based on the Hosford yield criterion in the principal stress space of the centrifugal rotor finite element model, extract the speed data during the time history and the radial displacement data of the nodes in the centrifugal rotor finite element model, and confirm the fracture speed and fracture mode.

[0069] In one embodiment, S1 includes: taking samples along the radial and chord directions of the ultra-high-speed centrifugal rotor to obtain material samples, heating and cooling the material samples, and then performing aging treatment; performing a tensile test on the material samples using a room temperature unidirectional tensile test, recording the deformation and stress values ​​at each stage, and obtaining the basic performance values ​​and engineering stress-strain curve of the ultra-high-speed centrifugal rotor material.

[0070] In this embodiment, the centrifugal rotor is manufactured by free forging round discs, and samples are taken in radial and chord directions. Three samples are taken in the radial and chord directions away from the edge and center of the disc. The sample rods are heated to 830°C and then loaded into the furnace. They are kept warm for 2 hours and then cooled to 720°C. After that, they are sent to the electric heating chamber to 750°C and kept warm for 2 hours before being taken out of the furnace. After air cooling for 4 hours, they are subjected to aging treatment. The temperature is then set to 618°C, and the furnace is loaded at this temperature. They are kept warm for 6 hours and then cooled to 459°C before being taken out of the furnace and air cooled. The sample rods are subjected to tensile tests using a room temperature unidirectional tensile test, and the deformation and stress values ​​at each stage are recorded, as well as the basic performance values ​​of the material such as yield strength, tensile strength, and elongation after fracture. Figure 2 The figure shows the stress-strain curve of the sample under axial tensile test at room temperature.

[0071] In one embodiment, the associated flow law in S2 describes the relationship between the direction of the plastic strain increment and the stress state when the material enters the plastic deformation stage. The core of the associated flow law is that the direction of plastic flow is consistent with the normal direction of the yield surface. The expression is:

[0072]

[0073] Where, is the plastic strain increment tensor; i and j represent the spatial direction index of the tensor in the Cartesian coordinate system, respectively, and are represented by three orthogonal directions, namely the x, y, and z directions. i and j can be substituted into xyz, respectively, to obtain three normal stresses, xx, yy, and zz, or three shear stresses, xy, xz, and yz; dλ is the plastic multiplier, which is a positive scalar and represents the size of the plastic strain increment; is the partial derivative of the yield function with respect to the stress tensor, and its direction is perpendicular to the yield surface.

[0074] The direction of the plastic strain increment under a given stress state is determined by the associative flow law and used as the input of the stress updating process in the finite element calculation to construct the finite element model of the centrifugal rotor.

[0075] In one embodiment, an isotropic hardening model is constructed in S2. In the isotropic hardening model, the yield surface expands uniformly during the stress-strain process, that is, the shape and center remain unchanged, only the radius increases, and the hardening law is a nonlinear function, specifically expressed as:

[0076]

[0077] Where σ y is the current yield strength, unit: MPa; σ y0 is the initial yield strength, in MPa, i.e. the yield strength when the plastic strain is zero; is the equivalent plastic strain of the material, which describes the amount of plastic deformation experienced by the material; r0, r1, r2, and r3 are hardening parameters that control the contribution of different hardening terms to the yield strength; b1, b2, and b3 are hardening rate parameters that control the rate of each hardening term.

[0078] The isotropic hardening model obtains the yield strength under a given stress state, which is used as the criterion for judging whether the material begins to yield in the finite element calculation to construct a centrifugal rotor finite element model. The stage state exceeding the yield strength value is considered to have begun the plastic deformation stage.

[0079] In one embodiment, the true stress and true strain are the ratio of the applied external force to the real-time cross-sectional area and the continuous logarithmic change of the material length. The specific expressions are:

[0080]

[0081] Where σ t is the true stress at the current moment, in MPa; P t is the load applied to the round bar specimen at the current moment; A t is the actual area in the current stretching process;

[0082]

[0083] Where, ε t is the true strain, which is the elongation dl of the gauge section of the specimen at a certain moment and the gauge section length l at the corresponding moment t The ratio of l0 is the initial gauge length, unit is mm.

[0084] The expression for calculating the true stress-strain curve in S2 based on the engineering stress-strain curve is:

[0085] ε t =ln(ε e +1);

[0086] σ t =σ e (ε e +1);

[0087] Where σ e ,ε e They are engineering stress, unit MPa, and engineering strain respectively.

[0088] In one embodiment, S3 includes:

[0089] S31: Construct the three-dimensional geometric model of the centrifugal rotor as an axisymmetric three-dimensional solid model with cyclic symmetry constraints;

[0090] S32: Perform a preliminary static analysis on the model and calculate the stress distribution when the speed is lower than the set value, such as Figure 3 As shown in FIG, the three-dimensional solid model is split into multiple sub-solid models according to the stress cycle change distribution law, and the sub-solid models are meshed;

[0091] S33: Input the elastic-plastic constitutive model and true stress-true strain curve data into the finite element software to customize the material constitutive model, and construct the sub-entity finite element model based on the material constitutive model.

[0092] In this example, a three-dimensional solid model is split into 1 / n solid models based on the distribution of cyclic stress variations, where n is the number of test tubes designed to be loaded on the centrifuge rotor. Based on the initial stress calculation results, areas with sufficient stress safety margins in the 1 / n solid model are simplified, while areas with stress concentration or low safety factors are refined. Meshing is then performed and controlled by region, resulting in a high-precision, high-fidelity 1 / n finite element model.

[0093] It should be noted that the number of samples (such as test tubes) that a centrifuge rotor can accommodate, depending on its internal structural design and experimental requirements, determines how to simplify the model during finite element analysis for more efficient calculations.

[0094] In one embodiment, the step of calculating the temperature field distribution of the ultracentrifuge rotor in S4 includes:

[0095] The heat conduction equation of the centrifuge rotor is:

[0096]

[0097] Where α is the thermal diffusivity; Q is the heat source term; T is the temperature, and t is the time; is the Laplace operator, which represents the diffusion rate of heat flow; in the cylindrical coordinate system, the Laplace operator is:

[0098]

[0099] Where (r, θ, z) are the parameters of the cylindrical coordinate system;

[0100] Based on the given boundary conditions and initial conditions of the heat conduction equation, the time and space variables of the three-dimensional geometric model are discretized by the finite element analysis method, a finite element solution model is established, and the thermal field distribution of the centrifugal rotor is calculated by iterative solution.

[0101] The one-way coupling of the centrifugal rotor thermal field distribution is introduced into the stress field analysis process of the centrifugal rotor finite element model, and the thermal strain is used as the initial strain to calculate the stress field distribution results under different speed time histories.

[0102] It's important to note that boundary conditions define the heat exchange between the system and the environment, such as fixed temperature, heat flux, or convection. Initial conditions specify the temperature distribution at the initial moment. One-way coupling means that the thermal field affects the stress field, but changes in the stress field do not feed back into the thermal field. The resulting temperature field is used as input for stress analysis, and thermal strains are calculated. These thermal strains are then added to the total strains to yield the stress distribution and displacement field.

[0103] In one embodiment, the large deformation arc length method, as a numerical method for dealing with nonlinear problems, introduces an arc length parameterization method to parameterize points on the solution path into arc lengths. The steps of using the large deformation arc length method to solve the quasi-static nonlinear control equation in S4 include:

[0104] The large deformation arc length method is used to solve the quasi-static nonlinear control equation. The quasi-static nonlinear control equation of the sub-entity model is:

[0105] F(u,λ)=0;

[0106] Where u is the node state variable (such as displacement vector), λ is the loading parameter (such as load scaling factor);

[0107] Introducing the arc length parameter s, so that u = u(s), λ = λ(s), the enhanced equation system constructed by combining the original equation and the arc length constraint equation is:

[0108]

[0109] Where G(u,λ,s) is the arc length constraint equation.

[0110] The enhanced equations are iteratively solved by the finite element iterative solver until convergence, and the stability and solution accuracy are enhanced by adjusting Δs, such as Figure 4 The figure shows the stress results of the finite element simulation of the centrifugal rotor horizontal rotor.

[0111] In this embodiment, the displacement of any node of the 1 / n ultracentrifugal rotor finite element model reaching a certain value is set as the stopping condition for the iterative calculation. At the same time, the value should be greater than the estimated value of the maximum radial displacement of the rotor before the rotor breaks.

[0112] In one embodiment, in S5:

[0113] The Hosford yield criterion in the principal stress space is expressed as:

[0114] (σ1-σ2) n +(σ2-σ3) n +(σ3-σ1) n =2σ0 n ;

[0115] Where σ1, σ2, σ3 are the principal stresses, σ0 represents the yield strength of the material; n is the Hosford index, which ranges from 1 to ∞;

[0116] When the Hosford index n approaches ∞, the Hosford criterion degenerates into the Tresca yield criterion:

[0117] Max(|σ1-σ2|,|σ2-σ3|,|σ3-σ1|)=σ0;

[0118] This indicates that when n is large, the yield of the material is controlled by the maximum principal stress difference. When the yield of the material in the centrifugal rotor is mainly dominated by the maximum shear stress, such as metals or non-metallic materials with poor toughness, the Hosford criterion is degenerated into the Tresca yield criterion for calculation.

[0119] When the Hosford index n = 2, the Hosford criterion degenerates into the von Mises yield criterion:

[0120] (σ1-σ2) 2 +(σ2-σ3) 2 +(σ3-σ1) 2 =2σ0 2 ;

[0121] This indicates that the material's yield is governed by the octahedral shear stress. For isotropic metals, n can be set to 2, degenerating into the von Mises yield criterion. For anisotropic materials, the value of n can be fitted experimentally. This expression is then input into the finite element software in APDL format to construct the material's yield criterion.

[0122] In one embodiment, in S5, after the finite element calculation of the centrifugal rotor reaches convergence, the displacement data curve data is extracted, and the speed corresponding to the maximum displacement data is determined as the maximum fracture speed of the centrifugal rotor. A cloud map is calculated based on the stress field distribution results, and the portion with a relatively high value in the cloud map is predicted to obtain the fracture mode. The fracture mode can be divided into axial cracking, radial cracking, fracture at a certain weak point, etc. Figure 5 FIG. 1 is a schematic diagram of the execution steps of the method for predicting the breakage speed of the ultracentrifuge rotor. FIG.

[0123] The above is a detailed introduction to the method for predicting the breakage speed of an ultra-high-speed centrifuge rotor based on the Hosford yield criterion provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the ideas of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

[0124] In this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

Claims

1. A method for predicting the rotor fracture speed of an ultra-high-speed centrifuge based on the Hosford yield criterion, characterized in that: The steps include: S1: Sampling the ultracentrifugal rotor in a set direction to obtain a material sample, performing a room temperature tensile test on the material sample to obtain an engineering stress-strain curve of the ultracentrifugal rotor material; S2: Based on the engineering stress-strain curve, the elastic-plastic constitutive model of the centrifugal rotor material is fitted by combining the associated flow law and the nonlinear isotropic hardening law to obtain the true stress-true strain curve; S3: constructing a three-dimensional geometric model of the centrifugal rotor and performing meshing, obtaining material property parameters based on the elastic-plastic constitutive model and the true stress-true strain curve fitting and using them as input for finite element analysis to obtain a finite element model of the centrifugal rotor; S4: Calculate the temperature field distribution of the ultra-high-speed centrifugal rotor, introduce the temperature field distribution into the stress field analysis process of the centrifugal rotor finite element model in a unidirectional coupling manner, define periodic symmetry constraints, gradually increase the speed, and use the large deformation arc length method to solve the quasi-static nonlinear control equation to obtain the stress field distribution results under different speed time histories; S5: Determine the yield condition based on the Hosford yield criterion in the principal stress space of the centrifugal rotor finite element model, extract the speed during the time history and the radial displacement data of the nodes in the centrifugal rotor finite element model, and confirm the fracture speed and fracture mode.

2. The method for predicting the fracture speed of an ultra-high-speed centrifuge rotor based on the Hosford yield criterion according to claim 1, characterized in that: Said S1 comprises: Sampling is performed along the radial and chord directions of the ultra-high-speed centrifugal rotor to obtain material samples, which are then heated, cooled, and then subjected to aging treatment. A room temperature uniaxial tensile test is performed on the material samples, and the deformation and stress values ​​at each stage are recorded to obtain the basic performance values ​​and engineering stress-strain curve of the ultra-high-speed centrifugal rotor material.

3. The method for predicting the fracture speed of an ultra-high-speed centrifuge rotor based on the Hosford yield criterion according to claim 1, characterized in that: The expression of the associated flow law in S2 is: Where, is the plastic strain increment tensor; i and j represent the spatial direction index of the tensor respectively; dλ is the plastic multiplier, which is a positive scalar that represents the size of the plastic strain increment; is the partial derivative of the yield function with respect to the stress tensor, and its direction is perpendicular to the yield surface.

4. The method for predicting the fracture speed of an ultra-high-speed centrifuge rotor based on the Hosford yield criterion according to claim 1, characterized in that: In S2, an isotropic hardening model is constructed; in the isotropic hardening model, the yield surface expands uniformly during the stress-strain process, and the hardening law is a nonlinear function, which is specifically expressed as: Where σ y is the current yield strength; σ y0 is the initial yield strength; is the equivalent plastic strain of the material; r0, r1, r2, r3 are hardening parameters that control the contribution of different hardening terms to the yield strength; b1, b2, b3 are hardening rate parameters that control the rate of each hardening term.

5. The method for predicting the fracture speed of an ultra-high-speed centrifuge rotor based on the Hosford yield criterion according to claim 1, characterized in that: The expression for calculating the true stress-strain curve according to the engineering stress-strain curve in S2 is: e t =ln(ε e +1); s t =s e (e e +1); Where σ e ,ε e are engineering stress and engineering strain, respectively.

6. The method for predicting the fracture speed of an ultra-high-speed centrifuge rotor based on the Hosford yield criterion according to claim 1, characterized in that: The S3 includes: S31: Construct the three-dimensional geometric model of the centrifugal rotor as an axisymmetric three-dimensional solid model with cyclic symmetry constraints; S32: performing a preliminary static analysis on the model, calculating the stress distribution when the rotation speed is lower than the set value, splitting the three-dimensional solid model into multiple sub-solid models according to the stress cycle distribution law, and meshing the sub-solid models; S33: Customizing a material constitutive model according to the elastic-plastic constitutive model and the true stress-true strain curve, and constructing a sub-entity finite element model based on the material constitutive model.

7. The method for predicting the fracture speed of an ultracentrifuge rotor based on the Hosford yield criterion according to claim 1, characterized in that: The step of calculating the temperature field distribution of the ultracentrifuge rotor in S4 includes: The heat conduction equation of the centrifuge rotor is: Where α is the thermal diffusivity; Q is the heat source term; T is the temperature, and t is the time; is the Laplace operator, which represents the diffusion rate of heat flow; in the cylindrical coordinate system, the Laplace operator is: Where (r, θ, z) are the parameters of the cylindrical coordinate system; Based on the given boundary conditions and initial conditions of the heat conduction equation, the time and space variables of the three-dimensional geometric model are discretized by the finite element analysis method, a finite element solution model is established, and the thermal field distribution of the centrifugal rotor is calculated by iterative solution. The centrifugal rotor thermal field distribution is unidirectionally coupled into the stress field analysis process of the centrifugal rotor finite element model, and the thermal strain is used as the initial strain to calculate the stress field distribution results under different speed time histories.

8. The method for predicting the fracture speed of an ultra-high-speed centrifuge rotor based on the Hosford yield criterion according to claim 6, characterized in that: The step of using the large deformation arc length method to solve the quasi-static nonlinear control equation in S4 includes: The large deformation arc length method is used to solve the quasi-static nonlinear control equation. The quasi-static nonlinear control equation of the sub-entity model is: F(u,λ)=0; Where u is the node displacement vector, λ is the loading parameter; Introducing the arc length parameter s, so that u = u(s), λ = λ(s), the enhanced equation system constructed by combining the original equation and the arc length constraint equation is: Where G(u,λ,s) is the arc length constraint equation. The enhanced equations are iteratively solved by a finite element iterative solver until convergence.

9. The method for predicting the fracture speed of an ultracentrifuge rotor based on the Hosford yield criterion according to claim 1, characterized in that: In said S5: The Hosford yield criterion in the principal stress space is expressed as: (σ1-σ2) n +(σ2-σ3) n +(σ3-σ1) n =2σ0 n ; Where σ1, σ2, σ3 are the principal stresses, σ0 represents the yield strength of the material; n is the Hosford index, which ranges from 1 to ∞; When the Hosford index n approaches ∞, the Hosford criterion degenerates into the Tresca yield criterion: Max(|σ1-σ2|,|σ2-σ3|,|σ3-σ1|)=σ0; When the Hosford index n = 2, the Hosford criterion degenerates into the von Mises yield criterion: (σ1-σ2) 2 +(σ2-σ3) 2 +(σ3-σ1) 2 =2σ0 2 ; The value of n is determined according to the centrifuge rotor material.

10. The method for predicting the fracture speed of an ultra-high-speed centrifuge rotor based on the Hosford yield criterion according to claim 1, characterized in that: In S5, when the finite element calculation of the centrifugal rotor reaches convergence, the displacement data curve data is extracted, and the rotation speed corresponding to the maximum value of the displacement data is determined as the maximum rupture rotation speed of the centrifugal rotor.

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