Load identification method and system for typical rudder structure in thermal field environment

Abstract

The invention discloses a load identification method and system for a typical rudder structure in a thermal field environment, and the method comprises the steps: building a structural finite element mesh model in the thermal environment based on the physical characteristics of the structure and the thermal field environment, verifying the accuracy of the built finite element model through a thermal vibration test platform, and improving the reliability of the model. Then, a finite element transfer function and a Tikhonov regularization load recognition method are combined, and a rudder structure vibration table load spectrum in the high-temperature environment is effectively recognized; according to the method, the input load of the typical rudder structure in the high-temperature environment can be effectively identified.

Description

Technical Field

[0001] The invention belongs to the technical field of inverse problems of thermal field structural dynamics, and in particular relates to a load identification method and system for a typical rudder structure in a thermal field environment. Background Art

[0002] During flight, aircraft structures are subject to comprehensive environmental stresses such as aerodynamics, aerodynamic heating, overload, vibration, etc. Ground tests use thermal-vibration combined tests to test the dynamic characteristics of structural parts and provide effective test data for model design or performance test data for structural products.

[0003] Currently, in ground thermal vibration tests, it is often impossible to directly monitor the vibration response of the point of concern because the structural response of the point of concern is often in the high temperature area. Now, the transmission relationship between the vibration table and the point of concern of the test structure is measured under normal temperature environment, and the control spectrum of the vibration table control is formulated according to the required response of the point of concern of the structure. In the combined thermal and vibration environment, the vibration table is directly used to indirectly control the vibration. When the structure is in a thermal environment, the stiffness and damping characteristics of the structure will change. This change often shows nonlinear characteristics, causing the structure to be over-tested or under-tested in the thermal-vibration combined test. How to improve or prevent over-testing or under-testing in the thermal-vibration combined test, there is an urgent need for new measurement and control methods or means to improve the similarity between the ground environment simulation and the real environment. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a load identification method and system for a typical rudder structure in a thermal field environment in view of the deficiencies in the above-mentioned prior art, so as to solve the technical problems of over-testing or under-testing in the current thermal vibration test.

[0005] The present invention adopts the following technical solutions: A load identification method for a typical rudder structure in a thermal field environment comprises the following steps: Based on the rudder structure geometry model and material properties, a structural finite element mesh model is established, and the structural finite element mesh model is modified based on the test mode; Based on the modified structural finite element mesh model, a normal temperature vibration table modal test was built and carried out to obtain the structural test modal information; Considering the quartz lamp heat flow model and combining the obtained structural test modal information, the finite element method is used to perform heat transfer simulation calculation to obtain the temperature distribution of the rudder structure. Based on the obtained temperature distribution of the rudder structure, a structural thermal vibration modal test was carried out. The quartz lamp radiated heating on both sides of the structure to obtain the modal frequencies of the rudder structure at different temperatures. The finite element model combined with the Tikhonov regularized load identification method is used to calculate the input load of the rudder structure at different temperatures based on the modal frequencies of the rudder structure at different temperatures.

[0006] Preferably, the structural finite element mesh model is modified based on the test mode as follows: For a typical rudder structure, the adapter and the mounting base plate are connected by bolts. The connection method has a great influence on the stiffness. By optimizing the connection and contact between the parts, the result of the finite element modal correction can meet the requirements.

[0007] Preferably, the structural finite element mesh model is specifically: For the typical rudder solid structure, its geometric model is simplified and the structural finite element mesh model is established.

[0008] Preferably, the structural test modal information specifically includes: The modal test measurement points are evenly arranged on the rudder surface of a typical rudder structure. The test uses the moving hammer method to obtain the modal frequency and modal vibration shape information of the structure.

[0009] Preferably, the temperature distribution of the rudder structure is as follows: Finite element method is used to perform heat transfer calculation, and the quartz lamp temperature loading device is considered. A heat insulation board is installed between the heating device and the vibration table slide. The quartz lamp heating device uses 25 to 30 quartz lamps.

[0010] Preferably, during the simulation, the emissivity of the quartz lamp is 1 and the ambient temperature is 18-22°C.

[0011] Preferably, the structural thermal vibration modal test is carried out as follows: The radiation heating method using a quartz lamp as the heating device simulates the aerodynamic heating state of the outer surface of the structure of the control surface during flight. The excitation methods such as rapid scanning and broadband random vibration are used to measure the vibration response of the structure, and the thermal modal parameters are obtained using the working modal analysis or transmissibility analysis method. The vibration table provides random excitation signals to simulate the working state and obtain the response signal data. The modal frequency and modal vibration shape are identified by correlation analysis and spectrum analysis.

[0012] Preferably, the finite element model is combined with the Tikhonov regularized load identification method as follows: Assume that the load position is known, the number of loads is m, the number of response points is n (n ≥ m), and the relationship between the response x and the load f in the frequency domain is , is the displacement frequency response function, velocity frequency response function, and acceleration frequency response function; when n=m, the frequency response function matrix is a square matrix, and the identification load is ; Establish the objective function Used to solve optimization problems; the Tikhonov regularization method contains the following constraints: The second norm of the residual vector Constraint, the second norm of the solution vector constraint; The transfer function and response results at different temperatures are calculated using the finite element model, and the input load of the rudder structure at different temperatures is obtained.

[0013] Preferably, the objective function is as follows:

[0014] Among them, α is the regularization parameter.

[0015] In a second aspect, an embodiment of the present invention provides a load identification system for a typical rudder structure in a thermal field environment, comprising: A correction module is used to establish a structural finite element mesh model based on the rudder structure geometry model and material properties, and to correct the structural finite element mesh model based on the test mode; The data module builds and conducts normal temperature vibration table modal tests based on the modified structural finite element mesh model to obtain structural test modal information; The calculation module considers the quartz lamp heat flow model, combines the obtained structural test modal information, and uses finite element method to perform heat transfer simulation calculation to obtain the temperature distribution of the rudder structure; Experimental module: Based on the obtained temperature distribution of the rudder structure, the thermal vibration modal test of the structure is carried out. The quartz lamp radiates heating on both sides of the structure to obtain the modal frequency of the rudder structure at different temperatures. The identification module uses the finite element model combined with the Tikhonov regularized load identification method to calculate the input load of the rudder structure at different temperatures based on the modal frequencies of the rudder structure at different temperatures.

[0016] In a third aspect, a computer device comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the load identification method for a typical rudder structure under the thermal field environment when executing the computer program.

[0017] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, comprising a computer program, which, when executed by a processor, implements the steps of the load identification method for a typical rudder structure in a thermal field environment.

[0018] In a fifth aspect, a chip comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the load identification method for a typical rudder structure under the thermal field environment when executing the computer program.

[0019] In a sixth aspect, an embodiment of the present invention provides an electronic device, comprising a computer program, which, when executed by the electronic device, implements the steps of the load identification method for a typical rudder structure in a thermal field environment.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects: A load identification method for a typical rudder structure in a thermal environment. In a thermal environment, the structural characteristics of the structure will change, causing the structure to be over-tested or under-tested in the thermal-vibration combined test, and it is impossible to effectively evaluate the environmental adaptability of the aircraft structure in a thermal-vibration combined environment. Therefore, considering the actual rudder structure geometry model and material properties, a structural finite element mesh model is established, and the structural test modal information is obtained by using a normal temperature vibration table modal test, and the structural finite element mesh model is modified. Considering the quartz lamp heat flow model, the finite element is used to perform heat transfer simulation calculations, and the temperature distribution of the rudder structure is obtained and the thermal modal information is calculated. The finite element model in the thermal environment is verified by comparing the same thermal test modal. Then, the finite element transfer function and Tikhonov regularized load identification method are combined to effectively identify the vibration table load spectrum of the rudder structure in a high temperature environment. The whole set of methods provides certain technical support for evaluating the environmental adaptability of aircraft structures in a thermal-vibration combined environment.

[0021] Furthermore, in the process of establishing the finite element model, the geometric model is usually simplified to a certain extent, the nonlinear characteristics of the material are ignored, and certain assumptions are made on the connection conditions between the components, which makes the finite element model have a certain deviation from the inherent characteristics of the actual structure. It is necessary to correct the finite element model of the typical structure of the rudder through the experimental modal analysis method to obtain a more realistic structural model.

[0022] Furthermore, mode is an important parameter to characterize the dynamic characteristics of the structure. Its accuracy can reflect the accuracy of the structural dynamic model. The finite element model of the structure can be effectively corrected by using the experimental modal frequency and vibration shape.

[0023] Furthermore, quartz lamp array radiation heating has been widely used in structural thermal analysis due to its small thermal inertia, easy control, convenient structural adjustment, and strong adaptability to complex structures. Considering the quartz lamp temperature loading device, the finite element method is used to perform heat transfer calculations to obtain the structural temperature distribution under different thermal environments, providing a basis for subsequent thermal mode and response calculations.

[0024] Furthermore, a radiation heating method using a quartz lamp as a heating device is used to simulate the aerodynamic heating state of the structural outer surface of the rudder during flight. The vibration table excitation application method is considered, and excitation methods such as rapid scanning and broadband random vibration are adopted. By measuring the vibration response of the structure, the thermal modal parameters are obtained using methods such as operating modal analysis or transmissibility analysis to verify the accuracy of the finite element model under thermal environment.

[0025] Furthermore, considering that in the actual test process, the signal acquisition cannot completely avoid the influence of various noise problems in the environment, there are errors in the measured response x and the frequency response function matrix H. Therefore, the Tikhonov regularization method is introduced to effectively identify the structural load.

[0026] It can be understood that the beneficial effects of the second aspect mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0027] In summary, this method is based on the actual aircraft rudder structure, takes into account the high temperature load environment, and applies a parallel strategy of numerical simulation and experimental methods to effectively identify the input load of the structure in a thermal-vibration composite environment, thereby further revealing a more realistic and complex service environment of the structure.

[0028] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a flow chart of the present invention; Figure 2 Assemble the model for typical rudder surface geometry; Figure 3 It is a schematic diagram of finite element model correction; Figure 4 This is a typical rudder surface normal temperature modal test; Figure 5 is a comparison of vibration modes of typical rudder surface structures at normal temperature; Figure 6 Finite element heating simulation for a typical rudder surface; Figure 7 shows the calculation results of the typical rudder surface temperature; Figure 8 This is a typical rudder surface thermal vibration test arrangement; Figure 9 shows the load identification comparison of typical rudder surfaces at different temperatures; Fig.10 A schematic diagram of a computer device provided by an embodiment of the present invention; Fig.11 A block diagram of a chip provided according to an embodiment of the present invention; Figure 12 is a comparison of the high temperature vibration responses of typical rudder surfaces. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0031] In the description of the present invention, it should be understood that the terms “include” and “comprises” indicate the presence of described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0032] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0033] It should be further understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in the present invention generally indicates that the associated objects are in an "or" relationship.

[0034] It should be understood that, although the terms first, second, third, etc. may be used to describe preset ranges, etc. in the embodiments of the present invention, these preset ranges should not be limited to these terms. These terms are only used to distinguish preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0035] The word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)", depending on the context.

[0036] Various structural schematic diagrams of the embodiments disclosed in the present invention are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0037] The present invention provides a load identification method for a typical rudder structure under a thermal field environment. Firstly, based on the physical characteristics of the structure and the thermal field environment, a finite element mesh model of the structure under the thermal environment is established, and the accuracy of the established finite element model is verified by a thermal vibration test platform. Then, the finite element transfer function and the Tikhonov regularized load identification method are combined to effectively identify the load spectrum of the vibration table of the rudder structure under the high temperature environment. The high temperature vibration response of the rudder structure is calculated by the identified load, and by comparing with the thermal vibration test response, it is proved that the method of the present invention can effectively identify the input load of the typical rudder structure under the high temperature environment.

[0038] See also Figure 1 The present invention provides a load identification method for a typical rudder structure under a thermal field environment, comprising the following steps: S1. Based on the rudder structure geometry model and material properties, a structural finite element mesh model is established, and the model is modified based on the experimental mode; See also Figure 2 , is the structural geometry diagram, the material used is titanium alloy TA15.

[0039] In the process of establishing the finite element model, the geometric model is usually simplified to a certain extent, the nonlinear characteristics of the material are ignored, and certain assumptions are made on the connection conditions between the components, which causes a certain deviation between the finite element model and the inherent characteristics of the actual structure. It is necessary to correct the finite element model of the typical rudder structure through the experimental modal analysis method. The specific correction process is as follows: Figure 3 For a typical rudder structure, the adapter and the mounting base plate are connected by bolts. The connection method has a great influence on the stiffness. By optimizing the connection and contact between the parts, the result of the finite element modal correction meets the requirements.

[0040] S2. Build and carry out normal temperature vibration table modal test to obtain structural test modal information; The modal test measurement points are arranged on the rudder surface of the typical rudder structure. Considering the test factors such as installation and heating, it is necessary to add a transition component between the rudder and the fixed base plate. For modal test, please refer to Figure 4 The frequency comparison between the structural test modal information and the finite element calculation results is shown in Table 1. Table 1

[0041] The vibration mode comparison is shown in Figure 5; Figure 5 (a) is the first-order vibration mode comparison, Figure 5 (b) is the third-order vibration mode comparison, and Figure 5 (c) is the fifth-order vibration mode comparison. The MAC values ​​of the first five modes are all greater than 0.8, and the fourth-order MAC value is the smallest, with a value of 0.854. The second-order mode frequency deviation is 53.1%, and the first-order mode frequency deviation is 12%.

[0042] S3. Considering the quartz lamp heat flow model, the finite element method is used to perform heat transfer simulation calculation to obtain the temperature distribution of the rudder structure; Quartz lamp array radiation heating has been widely used in structural thermal tests due to its small thermal inertia, easy control, convenient structure adjustment and strong adaptability to complex structures. High-temperature loading simulation requires the establishment of models such as the geometric contour of the rudder test piece, the test boundary and the quartz lamp heating system.

[0043] Using finite element method to calculate heat transfer, the geometric model of temperature loading device is established as follows: Figure 6 As shown in the figure, the quartz lamp, the rudder and the quartz lamp reflector structure are shown. A heat insulation board is installed between the heating device and the vibration table slide. The other parts in the figure. The quartz lamp heating device uses 28 quartz lamp tubes. The relevant parameters of the quartz lamp tubes are as follows: The quartz lamp is used as a heat source in the simulation, so the emissivity of the quartz lamp is considered to be 1. The ambient temperature is 20°C.

[0044] Please refer to Figure 7 for the specific temperature distribution of the rudder structure. Figure 7 (a) is the temperature distribution at a heating temperature of 200°C, Figure 7 (b) is the temperature distribution at a heating temperature of 300°C, and Figure 7 (c) is the temperature distribution at a heating temperature of 500°C. The characteristic parameters of titanium alloy at different temperatures are shown in Table 2.

[0045] S4. Conduct structural thermal vibration modal test, where quartz lamps radiate heating on both sides of the structure to obtain the modal frequencies of the rudder structure at different temperatures; This step uses a quartz lamp as a heating device to simulate the aerodynamic heating state of the outer surface of the control surface during flight. Considering the vibration table excitation application method, rapid scanning and broadband random vibration are used to obtain thermal modal parameters by measuring the vibration response of the structure and using methods such as working modal analysis or transmissibility analysis. The vibration table provides a random excitation signal to simulate the working state to obtain the response signal data, and uses correlation analysis (autocorrelation and cross-correlation) and spectrum analysis (auto-power spectrum and cross-power spectrum) to identify the modal frequency and modal vibration shape. For details, please refer to Figure 8 , is the structural thermal vibration modal test, the comparison between the modal frequency of the rudder structure at different temperatures and the simulation calculation results is shown in Table 3 Table 3

[0046] The maximum deviation of the first five natural frequencies is 9.5%, which shows that the modal frequencies in thermal environment obtained by this method have high credibility with the corrected transfer characteristics.

[0047] S5. Using the finite element model combined with the Tikhonov regularized load identification method, the input load of the rudder structure at different temperatures is calculated and compared with the control spectrum of the thermal vibration test vibration table.

[0048] For the vibration differential equations of multi-degree-of-freedom systems: (1) in, , , They represent the mass matrix, damping matrix, and stiffness matrix of the system respectively; is the external load vector of the system; , , They represent the system acceleration response, velocity response, and displacement response respectively.

[0049] Assume that the load position is known, the number of loads is m, and the number of response points is n (n ≥ m). The relationship between the response x and the load f in the frequency domain is as follows: (2) in, It is the displacement frequency response function, velocity frequency response function and acceleration frequency response function.

[0050] When n=m, the frequency response function matrix is a square matrix, identifying the load It is expressed as: (3) Formula (3) is a load identification method that directly inverts. However, in the actual test process, signal acquisition cannot completely avoid the influence of various noise problems in the environment, so there are errors in the measured response x and frequency response function matrix H. According to Tikhonov regularization theory, when solving the optimization problem, the following objective function is established: (4) Among them, α is the regularization parameter.

[0051] The Tikhonov regularization method includes two major constraints: the bi-norm of the residual vector Constraints are used to ensure the accuracy of the solution, the bi-norm of the solution vector Constraints are used to ensure the stability of the solution.

[0052] Please refer to Figure 9 for the comparison results of the identified load spectrum and the actual test vibration table control spectrum. Figure 9 (a) is the load identification comparison when the heating temperature is 200°C, Figure 9 (b) is the load identification comparison when the heating temperature is 300°C, and Figure 9 (c) is the load identification comparison when the heating temperature is 500°C. From the comparison of the results, it can be seen that the load identification method proposed in the present invention can effectively identify the dynamic input load of the structure in a high temperature environment, and has important practical application value.

[0053] In another embodiment of the present invention, a load identification system for a typical rudder structure in a thermal field environment is provided. The system can be used to implement the load identification method for a typical rudder structure in the above-mentioned thermal field environment. Specifically, the load identification system for a typical rudder structure in the thermal field environment includes a correction module, a data module, a calculation module, an experimental module and an identification module.

[0054] Among them, the correction module establishes a structural finite element mesh model based on the rudder structure geometric model and material properties, and corrects the structural finite element mesh model based on the test mode; The data module builds and conducts normal temperature vibration table modal tests based on the modified structural finite element mesh model to obtain structural test modal information; The calculation module considers the quartz lamp heat flow model, combines the obtained structural test modal information, and uses finite element method to perform heat transfer simulation calculation to obtain the temperature distribution of the rudder structure; Experimental module: Based on the obtained temperature distribution of the rudder structure, the thermal vibration modal test of the structure is carried out. The quartz lamp radiates heating on both sides of the structure to obtain the modal frequency of the rudder structure at different temperatures. The identification module uses the finite element model combined with the Tikhonov regularized load identification method to calculate the input load of the rudder structure at different temperatures based on the modal frequencies of the rudder structure at different temperatures.

[0055] In another embodiment of the present invention, a terminal device is provided, the terminal device includes a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, and is specifically suitable for loading and executing one or more instructions to implement corresponding method processes or corresponding functions; the processor described in the embodiment of the present invention can be used for the operation of the load identification method of a typical rudder structure in a thermal field environment, including: Based on the geometric model and material properties of the rudder structure, a structural finite element mesh model is established, and the structural finite element mesh model is modified based on the experimental modal. Based on the modified structural finite element mesh model, a normal temperature vibration table modal test is built and carried out to obtain the structural experimental modal information. Considering the quartz lamp heat flow model and combining the obtained structural experimental modal information, the finite element method is used to perform heat transfer simulation calculations to obtain the temperature distribution of the rudder structure. Based on the obtained temperature distribution of the rudder structure, a structural thermal vibration modal test is carried out, and the quartz lamp radiates heating on both sides of the structure to obtain the modal frequencies of the rudder structure at different temperatures. The finite element model is combined with the Tikhonov regularized load identification method to calculate the input loads of the rudder structure at different temperatures based on the modal frequencies of the rudder structure at different temperatures.

[0056] See also Fig.10 , the terminal device is a computer device. The computer device 60 of this embodiment includes: a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61. When the computer program 63 is executed by the processor 61, the load identification method of the typical rudder structure under the thermal field environment of the embodiment is realized. To avoid repetition, it is not described one by one here. Alternatively, when the computer program 63 is executed by the processor 61, the functions of each model / unit in the load identification system of the typical rudder structure under the thermal field environment of the embodiment are realized. To avoid repetition, it is not described one by one here.

[0057] The computer device 60 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The computer device 60 may include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art will appreciate that Fig.10 This is only an example of the computer device 60 and does not constitute a limitation of the computer device 60. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the computer device may also include input and output devices, network access devices, buses, etc.

[0058] The processor 61 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0059] The memory 62 may be an internal storage unit of the computer device 60, such as a hard disk or memory of the computer device 60. The memory 62 may also be an external storage device of the computer device 60, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc., equipped on the computer device 60.

[0060] Furthermore, the memory 62 may include both an internal storage unit of the computer device 60 and an external storage device. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 may also be used to temporarily store data that has been output or is to be output.

[0061] See also Fig.11 , the terminal device is a chip, and the chip 600 of this embodiment includes a processor 622, which may be one or more, and a memory 632 for storing a computer program executable by the processor 622. The computer program stored in the memory 632 may include one or more modules, each corresponding to a set of instructions. In addition, the processor 622 may be configured to execute the computer program to execute the load identification method of a typical rudder structure in a thermal field environment.

[0062] In addition, the chip 600 may further include a power supply component 626 and a communication component 650, wherein the power supply component 626 may be configured to perform power management of the chip 600, and the communication component 650 may be configured to implement communication, for example, wired or wireless communication, of the chip 600. In addition, the chip 600 may further include an input / output interface 658. The chip 600 may operate based on an operating system stored in the memory 632.

[0063] In another embodiment of the present invention, the present invention also provides a storage medium, specifically a computer-readable storage medium, which is a memory device in a terminal device for storing programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and the extended storage medium supported by the terminal device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs. It should be noted that the computer-readable storage medium here can be a high-speed RAM memory, or a non-volatile memory (Non-VolatileMemory), such as at least one disk memory.

[0064] The processor may load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the load identification method for a typical rudder structure in a thermal field environment in the above embodiment; the processor may load and execute the following steps: Based on the geometric model and material properties of the rudder structure, a structural finite element mesh model is established, and the structural finite element mesh model is modified based on the experimental modal. Based on the modified structural finite element mesh model, a normal temperature vibration table modal test is built and carried out to obtain the structural experimental modal information. Considering the quartz lamp heat flow model and combining the obtained structural experimental modal information, the finite element method is used to perform heat transfer simulation calculations to obtain the temperature distribution of the rudder structure. Based on the obtained temperature distribution of the rudder structure, a structural thermal vibration modal test is carried out, and the quartz lamp radiates heating on both sides of the structure to obtain the modal frequencies of the rudder structure at different temperatures. The finite element model is combined with the Tikhonov regularized load identification method to calculate the input loads of the rudder structure at different temperatures based on the modal frequencies of the rudder structure at different temperatures.

[0065] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention described and shown in the drawings here can usually be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0066] Using the load spectrum identified by the present invention as the input parameter of the finite element model of the rudder surface under a thermal environment, a comparison result of the high temperature calculated response and the measured response of a certain measuring point on the structure is shown in Figure 12. Figure 12 (a) is the vibration response comparison when the heating temperature is 200°C, Figure 12 (b) is the vibration response comparison when the heating temperature is 300°C, and Figure 12 (c) is the vibration response comparison when the heating temperature is 500°C. It can be seen from the figure that the measured response under the high temperature test condition is basically the same as the structural vibration response with the identified control spectrum as the input condition, and the deviation between the measured value and the calculated value of the response of the typical rudder structure focus point is less than ±3dB.

[0067] The accuracy of the transfer function of the finite element model under high temperature conditions and the effectiveness of the identified loads are proved, so the structural vibration model constructed by the present invention can well reflect the real vibration characteristics of the structure.

[0068] In summary, the present invention provides a load identification method and system for a typical rudder structure under a thermal field environment, establishes a structural finite element model of a typical rudder structure, and builds a typical rudder structure inherent characteristic test platform, carries out a simulation study on the structural inherent characteristics of a typical rudder structure, and modifies the structural model of a typical rudder structure by comparing with the test results, further considers the influence of the thermal environment, uses a quartz lamp radiation heating method, carries out a simulation study on the thermal modal characteristics of a typical rudder structure and a test study on the thermal modal characteristics of a typical rudder structure, and finally, uses the control spectrum identification method of the Tikhonov regularization method to obtain a high-temperature excitation spectrum based on the calculated high-temperature transfer characteristics. The response of a typical rudder structure measurement point under the excitation of a high-temperature excitation spectrum of a vibration table is calculated by a response spectrum calculation program, which illustrates the effectiveness of the inventive method for load identification.

[0069] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0070] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0071] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in the present invention can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0072] In the embodiments provided by the present invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0073] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0074] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0075] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0076] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices, and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0077] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0078] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0079] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A load identification method for a typical rudder structure in a thermal field environment, characterized in that: The following steps are involved: Based on the rudder structure geometry model and material properties, a structural finite element mesh model is established, and the structural finite element mesh model is modified based on the test mode; Based on the modified structural finite element mesh model, a normal temperature vibration table modal test was built and carried out to obtain the structural test modal information; Considering the quartz lamp heat flow model and combining the obtained structural test modal information, the finite element method is used to perform heat transfer simulation calculation to obtain the temperature distribution of the rudder structure. Based on the obtained temperature distribution of the rudder structure, a structural thermal vibration modal test was carried out. The quartz lamp radiated heating on both sides of the structure to obtain the modal frequencies of the rudder structure at different temperatures. The finite element model combined with the Tikhonov regularized load identification method is used to calculate the input load of the rudder structure at different temperatures based on the modal frequencies of the rudder structure at different temperatures.

2. The load identification method for a typical rudder structure in a thermal environment according to claim 1, characterized in that: The modification of the structural finite element mesh model based on the experimental mode is as follows: For a typical rudder structure, the adapter and the mounting base plate are connected by bolts. The connection method has a great influence on the stiffness. By optimizing the connection and contact between the parts, the result of the finite element modal correction can meet the requirements.

3. The load identification method of a typical rudder structure in a thermal environment according to claim 2, characterized in that: The structural finite element mesh model is as follows: For the typical rudder solid structure, its geometric model is simplified and the structural finite element mesh model is established.

4. The load identification method for a typical rudder structure in a thermal environment according to claim 1, characterized in that: The structural test modal information specifically includes: The modal test measurement points are evenly arranged on the rudder surface of a typical rudder structure. The test uses the moving hammer method to obtain the modal frequency and modal vibration shape information of the structure.

5. The load identification method for a typical rudder structure in a thermal environment according to claim 1, characterized in that: The temperature distribution of the rudder structure is as follows: Finite element method is used to perform heat transfer calculation, and the quartz lamp temperature loading device is considered. A heat insulation board is installed between the heating device and the vibration table slide. The quartz lamp heating device uses 25 to 30 quartz lamps.

6. The load identification method for a typical rudder structure in a thermal environment according to claim 5, characterized in that: During the simulation, the emissivity of the quartz lamp is 1 and the ambient temperature is 18~22℃.

7. The load identification method for a typical rudder structure in a thermal environment according to claim 1, characterized in that: The specific steps of conducting structural thermal vibration modal test are as follows: The radiation heating method using a quartz lamp as the heating device simulates the aerodynamic heating state of the outer surface of the structure of the control surface during flight. The excitation methods such as rapid scanning and broadband random vibration are used to measure the vibration response of the structure, and the thermal modal parameters are obtained using the working modal analysis or transmissibility analysis method. The vibration table provides random excitation signals to simulate the working state and obtain the response signal data. The modal frequency and modal vibration shape are identified by correlation analysis and spectrum analysis.

8. The load identification method for a typical rudder structure in a thermal environment according to claim 1, characterized in that: The specific load identification method using the finite element model combined with Tikhonov regularization is: Assume that the load position is known, the number of loads is m, the number of response points is n (n ≥ m), and the relationship between the response x and the load f in the frequency domain is , is the displacement frequency response function, velocity frequency response function, and acceleration frequency response function; when n=m, the frequency response function matrix is a square matrix, and the identification load is ; Establish the objective function Used to solve optimization problems; the Tikhonov regularization method contains the following constraints: The second norm of the residual vector Constraint, the second norm of the solution vector constraint; The transfer function and response results at different temperatures are calculated using the finite element model, and the input load of the rudder structure at different temperatures is obtained.

9. The load identification method for a typical rudder structure in a thermal environment according to claim 8, characterized in that: The objective function is as follows: Among them, α is the regularization parameter.

10. A load identification system for a typical rudder structure in a thermal environment, characterized in that: include: A correction module is used to establish a structural finite element mesh model based on the rudder structure geometry model and material properties, and to correct the structural finite element mesh model based on the test mode; The data module builds and conducts normal temperature vibration table modal tests based on the modified structural finite element mesh model to obtain structural test modal information; The calculation module considers the quartz lamp heat flow model, combines the obtained structural test modal information, and uses finite element method to perform heat transfer simulation calculation to obtain the temperature distribution of the rudder structure; Experimental module: Based on the obtained temperature distribution of the rudder structure, the thermal vibration modal test of the structure is carried out. The quartz lamp radiates heating on both sides of the structure to obtain the modal frequency of the rudder structure at different temperatures. The identification module uses the finite element model combined with the Tikhonov regularized load identification method to calculate the input load of the rudder structure at different temperatures based on the modal frequencies of the rudder structure at different temperatures.

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