Airborne external store static strength evaluation virtual test method and system

Abstract

The invention relates to the technical field of virtual-real combined simulation tests, and discloses an airborne external store static strength evaluation virtual test method and system to replace a real object static test to realize efficient, low-cost and reliable static strength evaluation. The method comprises the following steps: trimming an ideal finite element model according to deviation information to obtain an airborne external store finite element model for a virtual static test system; carrying out equivalence on the contact rigidity between the airborne external store finite element model and the test fixture finite element model by using a virtual material method; sampling points of a virtual static test are selected in the gap range, and a three-dimensional mapping relation among the sleeving depth gap, the load and the maximum strain or the maximum displacement is obtained through fitting according to sampling data of virtual simulation; and carrying out an actual static test, and checking the three-dimensional mapping relationship to obtain a sleeving depth gap of an actual measurement environment, so as to obtain a final virtual parameter of the equivalent assembly error of the thin-layer unit in the virtual material method for a subsequent virtual static test system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of virtual-real combined simulation test, in particular to a virtual test method and system for static strength evaluation of airborne external stores. BACKGROUND

[0002] Airborne external stores refer to objects hung on aircraft, which play a very important role in various mission profiles of the carrier aircraft. With the upgrading of modern mission scenarios, higher requirements are put forward for the functional diversity and rapid development iteration of airborne external store products. In response to the requirements of the times, modularization and serialization have become one of the mainstream trends in the development of modern airborne external stores. Modularized and serialized airborne external store products have the need to be assembled with multiple models, so the products need to face more complex and diversified service task load environments. In order to ensure the structural safety and reliability of the products under various complex load conditions, multiple static tests are usually required to verify the structural static strength reliability of the products under different models and load conditions.

[0003] However, the traditional physical static test method has two defects: first, during the static test process, only a limited number of strain and displacement sensors can be used to obtain the local mechanical response of the product, and the full-field mechanical response of the tested product cannot be obtained in real time. For the positions where the product sensor installation is limited, the response information cannot be obtained, which may lead to the failure to collect the mechanical response of the high-risk area (high strain and high displacement area) of the product, resulting in the failure to timely discover the local failure of the product; second, due to the complex and diverse load conditions of modularized and serialized products, the number of static test rounds of the products is significantly increased, leading to long test cycle and high test cost of the physical static test, which seriously affects the product development efficiency.

[0004] With the development of new generation information technology and the improvement of virtual simulation modeling technology, virtual test technology and virtual-real combined test technology have been developed and have become an important static test verification tool. However, the existing virtual test technology focuses on improving the refinement and intelligence of physical static test, mainly applied to checking whether the physical static test tool design is reasonable, and visualizing the test mechanical response and other auxiliary functions, lacking research and methods for improving the fidelity and accuracy of the virtual test system itself. It also cannot replace the physical static test to perform high-fidelity static strength evaluation of the product, and cannot truly and effectively reduce the static test amount of modularized and serialized products. SUMMARY

[0005] The present application aims to disclose a virtual test method and system for static strength evaluation of airborne external stores to replace physical static test and achieve efficient, low-cost and reliable static strength evaluation.

[0006] To achieve the above-mentioned purpose, the virtual test method and system for static strength evaluation of airborne external stores disclosed by the present application comprises: Step S1, a topography scanning is performed on the airborne external store test product to obtain source point cloud data after noise reduction, a three-dimensional rigid body transformation matrix is used to align the source point cloud data with the target point cloud of the ideal finite element model of the airborne external store, the deviation information of the airborne external store test product in the manufacturing process is determined by comparing the aligned source point cloud data and the target point cloud data, and then the ideal finite element model is modified according to the deviation information to obtain the finite element model of the airborne external store for the virtual static test system; Step S2, in the virtual static test system constructed according to the actual static test system, the contact stiffness between the finite element model of the airborne external store and the finite element model of the test fixture is equivalent by the virtual material method, and the first virtual material parameters of the thin layer element between the finite element model of the airborne external store and the finite element model of the test fixture under ideal assembly condition are calculated; Step S3, under the condition that no load is applied to the actual static test system, the gap range caused by the assembly error of the fitting depth between the airborne external store and the test fixture is measured; Step S4, the sampling points of the virtual static test are selected within the gap range, the first virtual material parameters of each sampling point are corrected according to the ratio between the actual fitting depth and the ideal fitting depth to obtain the second virtual parameters, and then the virtual static test is performed based on each second virtual parameter to obtain the maximum strain or maximum displacement of the airborne external store under different loads, and then a three-dimensional mapping relationship between the fitting depth gap, the load and the maximum strain or the maximum displacement is fitted according to the sampling data; the actual fitting depth is the difference between the ideal fitting depth and the assembly gap; Step S5, an actual static test is performed, the difference between the measured mechanical response data of the measurement point and the virtual test data is used to correct the virtual mechanical response by RBF interpolation to obtain the maximum strain or maximum displacement of the measured environment under a specific load; Step S6, according to the three-dimensional mapping relationship, the fitting depth gap corresponding to the maximum strain or maximum displacement of the measured environment under a specific load is found, and then the first virtual material parameters of each sampling point are corrected according to the ratio between the actual fitting depth corresponding to the finding result and the ideal fitting depth to obtain the final virtual parameters of the equivalent assembly error of the thin layer element for the subsequent virtual static test system.

[0007] Preferably, after step S6, it further comprises: Step S7, a second actual static test is performed, whether the difference between the measured mechanical response data of the measurement point and the test data obtained by the virtual static test system considering the equivalent assembly error of the thin layer element is within the preset error range, if yes, it is confirmed that the reliability of the virtual static test system meets the requirements; if no, a notification of returning to step S4 after adjustment is output to the user.

[0008] Preferably, the virtual static test system further comprises: The manufacturing tolerance of the airborne external store product is analyzed, and the finite element model is adjusted based on the upper limit or lower limit value of the tolerance to minimize the static strength.

[0009] Preferably, the adjusting the finite element model based on the upper limit or lower limit value of the tolerance to minimize the static strength comprises reducing the wall thickness of the finite element model to the lower limit value of the tolerance and / or reducing the size of the inspection window in the finite element model to the upper limit value of the tolerance.

[0010] Preferably, the virtual material parameters of the thin layer unit include thickness, area, elastic modulus and shear modulus, and the formula for correcting the ideal virtual material parameters of each sampling point according to the ratio between the actual fitting depth and the ideal fitting depth is: The thickness remains unchanged, and the area is times of the ideal case, wherein, is the ideal fitting depth, is the gap caused by the assembly error, and the elastic modulus and the shear modulus are times of the ideal case.

[0011] To achieve the above purpose, the present application further discloses a virtual test system for static strength evaluation of airborne external stores, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements the above method when executing the computer program.

[0012] The present application has the following beneficial effects: The high-fidelity manufacturing deviation information is recorded in the finite element model of the airborne external store, and on the basis of the existing virtual material method, the sampling points of the virtual static test are selected within the gap range, and then the first virtual material parameters of each sampling point are corrected according to the ratio between the actual fitting depth and the ideal fitting depth corresponding to the sampling points within the gap range to obtain the second virtual parameters corresponding to each gap, and then a three-dimensional mapping relationship between the fitting depth gap, the load and the maximum strain or the maximum displacement is fitted according to the sampling data of the virtual simulation; finally, the actual static test is carried out, and the fitting depth gap of the measured environment is obtained by searching the three-dimensional mapping relationship, and then the final virtual parameters of the equivalent assembly error of the thin layer unit in the virtual material method are obtained for subsequent virtual static test system. The logic of each step is consistent and reliable, and the problems caused by inaccurate assembly error measurement in the virtual static test are solved, so that the static strength evaluation can be realized efficiently, reliably and at low cost by replacing the physical static test.

[0013] The present application will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0014] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The drawings illustrate embodiments of the present application and, together with the description, serve to explain the application. In the drawings: Figure 1 is a schematic diagram of the virtual test method for evaluating the static strength of airborne external stores disclosed in the embodiments of the present application. DETAILED DESCRIPTION

[0015] Embodiments of the present application will be described in detail below with reference to the accompanying drawings, but the present application can be implemented in various different ways limited and covered by the claims.

[0016] Embodiment 1 This embodiment takes a certain airborne external store using a cabin structure as an example for illustration, and discloses a virtual test method for evaluating the static strength of airborne external stores, comprising the following steps: Step one: Establish a high-fidelity digital model of the airborne external store.

[0017] The specific implementation of this step can be: first, calibrate the laser scanner to ensure that the laser scanner meets the accuracy requirements. Second, paste marker points on the structure to facilitate subsequent laser surface scanning. For such large structural parts, it is difficult to complete the test piece topography scanning at one time, so the same frequency laser is used to scan each piece area of the test piece respectively, and the point cloud of each piece area structure is spliced, the redundant point cloud after splicing is removed, and the point cloud is saved as a file for output. Then, the original point cloud is denoised. The scanned three-dimensional point cloud data is usually extremely large and discrete, and the hash function grid method is used to denoise the three-dimensional point cloud. In order to ensure that the scanned point cloud is consistent with the theoretical position, a registration method based on corresponding points is used to register the scanned point cloud and the theoretical position point cloud, and the matching pairs of each point in the source point cloud and the target point cloud are obtained. Based on the singular value decomposition solving method, the three-dimensional rigid body transformation matrix is solved by using the matching point pairs, so as to realize the conversion of the source data point cloud to the target point cloud. The manufacturing geometric deviation information can be determined by comparing the converted source data point cloud and the target point cloud, and the deviation introduction algorithm is used to adjust the finite element model, and a high-precision numerical model containing the measured geometric deviation is established.

[0018] Step two: Build a real static test system. According to the static test outline, build a static test system. The static test system is composed of the tested airborne external store product, test fixtures, loading tooling and test measurement devices (such as sensors, etc.), and the parts are assembled together to form an assembly according to the requirements of the test outline.

[0019] Step three: Establish a high-precision virtual static test system. The specific steps are as follows: 3.1, According to the ideal position relationship between the test product and each part of the test system (including test fixture, loading tool, etc.), an ideal assembly model of the virtual test system is established.

[0020] 3.2, The contact stiffness (i.e. constraint relationship) between the test product and the test fixture is accurately equivalent by using the virtual material method, that is, a thin layer of elements is established between the model and the test fixture, and the virtual material parameters are assigned to the thin layer of elements, and the contact stiffness between the test fixture and the test fixture is equivalent through the thin layer of elements. The parameters of the virtual material include: virtual material thickness h, virtual material area S, virtual material elastic modulus E, virtual material shear modulus G.

[0021] 3.3, Calculate the virtual material parameters under ideal assembly condition.

[0022] The calculation method of virtual material parameters between the test product and the test fixture under ideal assembly condition is mature, which can be referred to many existing technologies. For example, according to the technology disclosed in the paper "A virtual material modeling method based on interface damping characterization" published by Tianbiao et al. in the 42nd volume of the 7th issue of China Network in the mechanical design block, combined with the surface roughness scanning of the fixture, the thickness parameter, area parameter and elastic modulus parameter of the virtual material under ideal assembly condition are calculated respectively. The specific steps are as follows: 3.3.1, Fractal parameters are used to describe the profile characteristics of rough surfaces to characterize the roughness of the interface, including fractal dimension D and fractal roughness parameter G. Calculating fractal parameters is the cornerstone of calculating the parameters of virtual material method, therefore, first calculate the fractal parameter value of the connecting interface. Through the roughness of the test fixture and the two surfaces in contact, combined with electron microscope scanning, the fractal dimension D and fractal roughness parameter G of the test fixture and the two surfaces in contact can be obtained. This technology is relatively mature and will not be described here.

[0023] 3.3.2, Calculate the thickness parameter of the virtual material.

[0024] Through electron microscope scanning results of the surface of the test product and the surface of the test fixture, according to the thickness parameter calculation formula (wherein, is the average line height of the rough surface, is the height deviation of the rough surface, is the thickness of the virtual material), the thickness of the virtual material of the contact surface and the contact surface of the test fixture is calculated respectively, and the total thickness of the virtual material thin layer element is obtained by summing the two thicknesses.

[0025] 3.3.3, Calculate the area parameter of the virtual material.

[0026] The area of the virtual material is determined according to the effective contact area between the test fixture. According to the assembly relationship with the test fixture, the effective contact area with the fixture is S = πdL in the ideal assembly condition. Wherein, d is the diameter of the end face, and L is the sleeve joint depth of the outer hanging object and the test fixture in the ideal assembly.

[0027] 3.3.4, the elastic modulus and shear modulus of the virtual material are calculated according to the calculation formula of the elastic modulus and shear modulus of the virtual material respectively.

[0028] 3.4, analyze the assembly error of the real assembly body, and introduce the assembly error function. The assembly error of the test assembly body (that is, the test system) mainly refers to the deviation of the actual relative position between the test object and the test fixture from the ideal assembly condition. In the test assembly body, the assembly form of the outer hanging object and the fixture is sleeve joint, and the main assembly error is the assembly gap j with the fixture. For the assembly gap error, the assembly error function can be established: the sleeve joint depth is L in the ideal assembly condition, and the end face is in contact with the end face of the fixture. In the actual assembly condition, due to the influence of the screw pre-tightening force, the manufacturing deviation of the product itself, burr and other factors, there is a gap j between the end face and the fixture in the actual assembly. Therefore, the sleeve joint depth in the actual assembly environment is L-j, wherein j is the assembly gap length.

[0029] 3.5, analyze the influence of the assembly error on the parameters of the virtual material, and establish the calculation method of the virtual material parameters after introducing the assembly error. Through the analysis of the parameters of the virtual material, the parameters affected by the assembly error of the fixture are the area S of the virtual material, the elastic modulus E of the virtual material and the shear modulus G of the virtual material. After introducing the assembly error, the area of the virtual material is , the elastic modulus of the virtual material is , and the shear modulus of the virtual material is .

[0030] 3.6, adjust the parameters of the virtual material, and establish a high-precision virtual static test system. Measure the assembly error of the actual assembly body, adjust the parameters of the virtual material according to the established calculation method of the virtual material parameters after introducing the assembly error, and establish a high-precision virtual test system (that is, a virtual test assembly body) with contact equivalent after introducing the assembly error.

[0031] Note that the adjustment of this step is used to preliminarily determine the range of each virtual material parameter, and the parameters of the virtual material can be adjusted according to the manually measured assembly error. Since the assembly gap j will inevitably have errors due to many reasons by relying on measurement, therefore, the virtual material parameters of the virtual test system need to be further accurately valued according to the measured data of the physical test.

[0032] 3.7, Perform assembly error sensitivity analysis. Adjust the assembly gap j in a small range, and calculate the virtual material parameter values (S, E, G, where the thickness remains unchanged) under different assembly gaps. Then input different virtual material parameters into the assembly model and perform simulation tests, and the output is the simulation results such as the maximum displacement and maximum strain corresponding to a specific load.

[0033] The essence of this step is: select sampling points for virtual static tests within the gap range, and modify the ideal first virtual material parameters of each sampling point according to the ratio between the actual joint depth and the ideal joint depth to obtain the second virtual parameters considering the assembly gap (where the parameters of each sampling point under ideal conditions are consistent, but the modification calculations are independent of each other and differ from each other); then perform virtual static tests based on each second virtual parameter to obtain the maximum strain or maximum displacement of the airborne external stores under different loads, and then fit the three-dimensional mapping relationship between the joint depth gap, load, and maximum strain or maximum displacement based on the sampling data.

[0034] In this embodiment, the virtual material parameters are inherent characteristics of the virtual simulation system and do not change with external loads. However, the relationship between load and strain and displacement satisfies Hooke's law, so in this embodiment, only one of the maximum strain and maximum displacement needs to be selected during the fitting of the three-dimensional mapping relationship, and the corresponding results of the final virtual parameters tend to be consistent.

[0035] Step 4: Perform virtual test system static test simulation analysis. According to the load conditions in the static test outline, perform static test loading on the tested product in the virtual test system and perform simulation analysis to obtain the full-field virtual mechanics response under the test load. In the virtual test system, load is loaded step by step from 30% design load, and is loaded in turn to 100% according to 10% gradient, and simulation analysis is performed to obtain the full-field mechanics response (including displacement, strain cloud, stress cloud).

[0036] Step 5: Conduct static tests and achieve real-time monitoring. Following the static test outline, conduct static tests on the product, applying test loads in 10% increments, and collecting measured mechanical response data at test measurement points in real time using strain gauges and displacement sensors. Integrate the static test data and the full-field virtual mechanical response. Based on the difference between the measured response data and the virtual test data, use RBF (Radial Basis Function) interpolation to construct an additive bridge function to correct the virtual mechanical response, ensuring accurate matching of the test data at the measurement points and maintaining high precision in the full-field response, generating a high-fidelity real-time full-field mechanical response for the tested product. Monitor the full-field mechanical response (including the full-field strain cloud map of the tested product) of the tested product under the current load level in real time on a large screen at the test site, and detect high-strain and high-displacement areas of the tested product in real time. Achieve real-time display of static test results and real-time monitoring and early warning of high-risk areas of the tested product.

[0037] In this step, the additive bridge function, a type of bridge function, is a crucial step in fusing finite element and strain gauge data. Assume two sets of sample data are known, one of which contains... , The sample size is large and the acquisition cost is low, but the accuracy of this sample is relatively low, such as in finite element fields. Another set of samples ( , While limited in quantity and costly to acquire, these samples offer high precision, such as strain gauge data. Data fusion methods are employed to combine the strengths of both sets of data, resulting in a global response field that incorporates the advantages of both sets, such as a digital twin field. .

[0038] In this embodiment, as an equivalent replacement, the addition bridge function can also be replaced by the multiplication bridge function or the hybrid bridge function.

[0039] The multiplication bridge function was first proposed by Haftka and is based on the multiplication scaling factor. Establishing a digital twin , can be represented as: ;in, For sample points ( , The proxy model constructed by ) Based on variables Scaling factor The constructed proxy model, It can be represented as: .

[0040] When sample When the response approaches 0, the multiplication bridge function tends to fail, and the addition bridge function is developed based on the addition scaling factor. establishing a digital twin field , which can be expressed as: ; wherein, is a variable-based and an additive scaling factor constructed surrogate model, which can be expressed as: .

[0041] Further, Gano proposed a hybrid bridge function to establish a digital twin field , which can be expressed as: ; wherein, δ (0≤δ≤1) is a weight coefficient adjusting the contribution of the multiplicative bridge function and the additive bridge function. For different actual engineering problems, the determination of the δ coefficient is crucial to the accuracy of the digital twin field. When the weight coefficient δ=0, the hybrid bridge function method degenerates into the additive bridge function. When the weight coefficient δ=1, the hybrid bridge function method degenerates into the multiplicative bridge function.

[0042] The essence of this step is to perform a real static test, and according to the difference between the measured mechanical response data of the measuring point and the virtual test data, the RBF interpolation is used to correct the virtual mechanical response to obtain the maximum strain or maximum displacement of the measured environment under a specific load.

[0043] Step six: calibrate the virtual test system. The specific process is: according to the three-dimensional mapping relationship described above, find the corresponding sleeve joint depth gap of the maximum strain or maximum displacement of the measured environment under a specific load, and then according to the ratio between the actual sleeve joint depth corresponding to the search result and the ideal sleeve joint depth, the first virtual material parameter of each sampling point is corrected to obtain the final virtual parameter of the thin layer element equivalent assembly error for the subsequent virtual static test system; wherein, the specific correction formula is the same as the above step 3.5, that is: the thickness remains unchanged, the area is times the ideal situation, and the elastic modulus and shear modulus are

[0044] Step seven: perform product manufacturing tolerance analysis. Organize the structure tolerance of each place, and statistically analyze the common uncontrollable manufacturing deviations in the manufacturing process to obtain the structure geometric deviation information. Analyze the influence of each deviation on the static strength of the product.

[0045] Step eight: adjust the size parameters and shape parameters in the virtual test system, adjust the characteristic size beneficial to the structural static strength such as the wall thickness to the lower limit value of the tolerance, adjust the characteristic not beneficial to the structural static strength such as the size of the inspection window to the upper limit value of the tolerance, and make the static strength of the tested product in the virtual test system the lowest in the product, so as to form the final static strength evaluation virtual test system. Thus, the airborne external object product with qualified strength can be guaranteed in the virtual test system of the embodiment, and even if there are various deviations in the actual manufacturing of the product, the static strength can still be guaranteed.

[0046] Preferably, after step S6, the following step S7 can be further included.

[0047] Step S7, performing a secondary actual static force test, and determining whether the difference between the actually measured mechanical response data of the measuring point and the test data obtained from the virtual static force test system considering the equivalent assembly error of the thin layer element is within the preset error range. If yes, it is confirmed that the reliability of the virtual static force test system meets the requirements; if no, a notification of returning to step S4 after adjustment is output to the user.

[0048] In this step, the preset error range can be set to 5%.

[0049] Embodiment 2 Corresponding to the above embodiment, the embodiment discloses an airborne external object static strength evaluation virtual test system, including a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the method of the above embodiment when executing the computer program, which at least includes the following steps as shown in the figure. Figure 1

[0050] Step S1, obtaining source point cloud data by scanning the appearance of the airborne external object test product and denoising, aligning the source point cloud data with the target point cloud of the ideal finite element model of the airborne external object through a three-dimensional rigid body transformation matrix, determining the deviation information of the airborne external object test product in the manufacturing process by comparing the aligned source point cloud data and the target point cloud data, and then obtaining the finite element model of the airborne external object for the virtual static force test system by trimming the ideal finite element model according to the deviation information.

[0051] Step S2, in the virtual static force test system constructed according to the actual static force test system, the contact stiffness between the finite element model of the airborne external object and the finite element model of the test fixture is equivalent by the virtual material method, and the first virtual material parameter of the thin layer element between the finite element model of the airborne external object and the finite element model of the test fixture under ideal assembly condition is calculated.

[0052] Step S3, measuring the gap range caused by the assembly error of the depth of the sleeve joint between the airborne external object and the test fixture under the condition that no load is applied to the actual static force test system. ​

[0053] Step S4, selecting sampling points of the virtual static test in the gap range, correcting the first virtual material parameters of each sampling point according to the ratio between the actual jointing depth and the ideal jointing depth to obtain second virtual parameters, and then respectively performing virtual static tests based on each of the second virtual parameters to obtain the maximum strain or the maximum displacement of the airborne external stores under different loads, and then fitting the three-dimensional mapping relationship between the jointing depth gap, the load and the maximum strain or the maximum displacement according to the sampling data; the actual jointing depth is the difference between the ideal jointing depth and the assembly gap.

[0054] Step S5, performing an actual static test, correcting the virtual mechanical response by using RBF interpolation according to the difference between the measured mechanical response data of the measuring point and the virtual test data to obtain the maximum strain or the maximum displacement of the measured environment under a specific load.

[0055] Step S6, finding the jointing depth gap corresponding to the maximum strain or the maximum displacement of the measured environment under a specific load according to the three-dimensional mapping relationship, and then correcting the first virtual material parameters of each sampling point according to the ratio between the actual jointing depth corresponding to the finding result and the ideal jointing depth to obtain the final virtual parameters of the equivalent assembly error of the thin layer element for the subsequent virtual static test system.

[0056] Similarly, after step S6, the following step S7 can be further included.

[0057] Step S7, performing a second actual static test, and determining whether the difference between the measured mechanical response data of the measuring point and the test data obtained by the virtual static test system considering the equivalent assembly error of the thin layer element is within a preset error range, if yes, confirming that the reliability of the virtual static test system meets the requirements, and if no, outputting a notification to the user to return to step S4 after adjustment.

[0058] The specific implementation details of each step are described in the above embodiments, and will not be repeated here.

[0059] In summary, the methods and systems disclosed in the above two embodiments have at least the following beneficial effects: The high-fidelity manufacturing deviation information is recorded in the finite element model of the airborne external stores, and on the basis of the existing virtual material method, the sampling points of the virtual static test are selected in the gap range, then according to the ratio between the actual joint depth and the ideal joint depth corresponding to the sampling points in the gap range, the first virtual material parameters of each sampling point are corrected to obtain the corresponding second virtual parameters under each gap, and then the three-dimensional mapping relationship among the joint depth gap, load and maximum strain or maximum displacement is fitted according to the sampling data of the virtual simulation; finally, the actual static test is carried out and the joint depth gap of the measured environment is obtained by searching the three-dimensional mapping relationship, and then the final virtual parameters of the equivalent assembly error of the thin layer element in the virtual material method are obtained to be used for the subsequent virtual static test system. The logic of each step is echoed and the problems caused by the inaccurate assembly error measurement in the virtual static test are reliably solved, so that the static strength evaluation can be realized efficiently, at low cost and reliably by replacing the physical static test.

[0060] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. An airborne external store static strength evaluation virtual test method, characterized by, The method comprises the following steps: Step S1, scanning the appearance of the airborne external object test product and obtaining source point cloud data after noise reduction, aligning the source point cloud data with the target point cloud of the ideal finite element model of the airborne external object through a three-dimensional rigid body transformation matrix, comparing the aligned source point cloud data and the target point cloud data to determine the deviation information of the airborne external object test product in the manufacturing process, and then modifying the ideal finite element model according to the deviation information to obtain the finite element model of the airborne external object for the virtual static test system; Step S2, in the virtual static test system constructed according to the actual static test system, the contact stiffness between the finite element model of the airborne external object and the finite element model of the test fixture is equivalent by the virtual material method, and the first virtual material parameters of the thin layer element between the finite element model of the airborne external object and the finite element model of the test fixture under ideal assembly condition are calculated; Step S3, under the condition that the actual static test system does not apply load, the gap range caused by the assembly error of the fitting depth between the airborne external object and the test fixture is measured; Step S4, selecting sampling points for virtual static test in the gap range, correcting the first virtual material parameters of each sampling point according to the ratio between the actual fitting depth and the ideal fitting depth to obtain second virtual parameters, and then performing virtual static test based on each second virtual parameter to obtain the maximum strain or maximum displacement of the airborne external object under different loads, and then fitting the three-dimensional mapping relationship between the fitting depth gap, the load and the maximum strain or the maximum displacement according to the sampling data; the actual fitting depth is the difference between the ideal fitting depth and the assembly gap; Step S5, performing an actual static test, correcting the virtual mechanical response by RBF interpolation according to the difference between the measured mechanical response data of the measurement point and the virtual test data to obtain the maximum strain or maximum displacement of the measured environment under a specific load; Step S6, according to the three-dimensional mapping relationship, the fitting depth gap corresponding to the maximum strain or maximum displacement of the measured environment under a specific load is found, and then the first virtual material parameters of each sampling point are corrected according to the ratio between the actual fitting depth corresponding to the finding result and the ideal fitting depth to obtain the final virtual parameters of the equivalent assembly error of the thin layer element for subsequent virtual static test system.

2. The method of claim 1, wherein: After step S6, it further comprises: Step S7, performing a second actual static test, and determining whether the difference between the measured mechanical response data of the measurement point and the test data obtained by the virtual static test system considering the equivalent assembly error of the thin layer element is within the preset error range, if yes, confirming that the reliability of the virtual static test system meets the requirements; if no, outputting a notification to the user to return to step S4 after adjustment.

3. The method of claim 1, wherein: After the virtual static test system considers the equivalent assembly error of the thin layer element, it further comprises: The manufacturing tolerance of the airborne external object product is analyzed, and the finite element model is adjusted based on the upper limit or lower limit value of the tolerance to minimize the static strength.

4. The method of claim 3, wherein the method further comprises: Adjusting the finite element model based on the upper or lower limit value of the tolerance to minimize the static strength includes reducing the wall thickness of the finite element model to the lower limit value of the tolerance and / or reducing the size of the inspection window in the finite element model to the upper limit value of the tolerance.

5. The method of claim 1 to 4, wherein, The virtual material parameters of the thin layer unit include thickness, area, elastic modulus and shear modulus, and a formula for correcting the ideal virtual material parameters of each sampling point according to the ratio between the actual joint depth and the ideal joint depth is: The thickness remains unchanged, and the area is ideal times, wherein is the ideal socket depth, is the gap caused by assembly error, and the elastic modulus and shear modulus are ideal times.

6. An airborne stores static strength evaluation virtual test system comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein, The processor implements the method of any one of claims 1-5 when executing the computer program.

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