An assembly characteristic simulation analysis method based on surface feature topography

Abstract

The application provides a kind of simulation analysis method of assembly characteristic based on surface feature topography, the surface topography of each part is digitally modeled, the surface topography of digital part is superimposed system error and random error, and meets the design tolerance band;Three-dimensional assembly model is constructed, the surface topography of part with error is stitched with the surface topography of error-free part;The assembly key characteristics and manufacturing cost model of three-dimensional assembly model are constructed;Through simulation analysis on three-dimensional assembly model, a plurality of three-dimensional assembly models and the surface topography and tolerance value of its parts meeting design requirements are obtained;Based on the simulation analysis result, the part tolerance is optimized, and the manufacturing cost is reduced.The application takes the real surface model as input to carry out simulation analysis, analyzes the rationality of actual assembly key size or tolerance, guides product tolerance design and manufacturing process, reduces manufacturing cost, and provides a set of feasible method for quantifying assembly key characteristics.

Description

Technical Field

[0001] This invention belongs to the field of aerospace product structural design optimization technology, specifically involving a simulation analysis method for assembly characteristics based on surface feature morphology. Background Technology

[0002] As aircraft speeds continue to increase, the requirements for their aerodynamic shape become increasingly stringent, ultimately necessitating strict control over structural surface steps during the structural design process. To ensure that these structural surface steps meet flight requirements, stringent tolerances must be designed during the structural design phase. These stringent tolerances ultimately lead to difficulties in product assembly and increased manufacturing costs. Therefore, it is necessary to propose a method for pre-simulating and analyzing the key characteristics of aircraft assembly. The premise of this method is the ability to simulate the surface morphology actually produced.

[0003] How to conduct pre-simulation analysis of surface assembly characteristics during the design phase, to achieve technical support, evaluate the rationality of tolerance design, select the optimal manufacturing solution, reduce manufacturing costs while meeting aircraft performance requirements, ensure reasonable and controllable aircraft assembly characteristics, and adopt quantitative methods to control product quality, has important guiding significance. Summary of the Invention

[0004] To address the technical problems in existing aircraft structures, such as difficulties in product assembly and increased manufacturing costs due to strict tolerances, this invention provides a simulation analysis method for assembly characteristics based on surface feature morphology. This method performs simulation analysis based on the actual surface of the part, primarily by constructing a model of the actual surface forming process. The simulation analysis is conducted using this model as input to analyze the rationality of key dimensions or tolerances in actual assembly, guiding the product tolerance design and manufacturing processes, reducing manufacturing costs, and providing a feasible method for quantifying key assembly characteristics.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0006] A simulation analysis method for assembly characteristics based on surface feature morphology includes the following steps.

[0007] The surface morphology of each part is digitally modeled, and systematic and random errors are superimposed on the digital part surface morphology to meet the design tolerance zone;

[0008] A three-dimensional assembly model is constructed based on the surface morphology of digital parts, and the surface morphology of parts with errors is stitched together with the surface morphology of parts without errors.

[0009] Construct a three-dimensional assembly model that includes key assembly characteristics and manufacturing cost.

[0010] By performing simulation analysis on the three-dimensional assembly model, several three-dimensional assembly models and their parts that meet the design requirements are obtained, along with their surface morphology and tolerance values.

[0011] Based on the simulation analysis results, the tolerances of parts are optimized and the manufacturing costs are reduced.

[0012] Furthermore, the assembly key characteristics and manufacturing cost model of the three-dimensional assembly model are as follows:

[0013]

[0014]

[0015]

[0016] Where Ti is the tolerance of the i-th part, i = 1, 2...n, n represents the number of parts to be assembled, f(KC,Ti) is the influence weight of each part tolerance Ti on the assembly key characteristic KC, and g(MC,Ti) is the influence weight between each part tolerance Ti and the manufacturing cost MC.

[0017] Furthermore, the part tolerances are optimized to ensure that the 3D assembly model meets the following requirements:

[0018]

[0019] By optimizing part tolerances, the lowest manufacturing cost can be achieved.

[0020] Furthermore, the optimization target value of H(KC,MC) is set in advance.

[0021] Furthermore, the systematic error is determined based on the feature point data of the actual surface obtained by actual measurement during the part processing, and the random error is obtained through a random error function.

[0022] Furthermore, by superimposing systematic errors and random errors, multiple digital part surface morphologies are obtained for each part, and the digital part surface morphologies that meet the tolerance zones of each part are selected.

[0023] Furthermore, when stitching the surface morphology of a part with errors to the surface morphology of a part without errors, the common edge of the two surfaces is fitted into a straight line or curve.

[0024] Furthermore, the simulation analysis includes contact analysis, assembly performance analysis, and evaluation of key assembly characteristics.

[0025] Furthermore, the contact analysis includes at least stress and strain analysis, the assembly performance analysis includes at least friction performance and sealing performance analysis, and the assembly key characteristic assessment includes at least distance and clearance assessment.

[0026] The beneficial effects of this invention compared to the prior art are as follows:

[0027] This invention uses mathematical methods to simulate the actual surface morphology of machined parts, and uses a digital surface model as input to conduct simulation analysis. It analyzes key characteristics of aircraft assembly (such as step differences), and by performing pre-analysis of key assembly characteristics in the design stage, it evaluates the rationality of tolerance design and the feasibility and improvement measures of the parts manufacturing and assembly process. This improves product performance while reducing aircraft manufacturing costs, quantifies key assembly characteristics, and provides an effective solution.

[0028] This method decomposes the deviation of the feature surface into systematic error and random error to simulate the real machined surface. By constructing the surface feature morphology, simulation analysis is performed to simulate the actual assembly state of the surface, making the analysis results more realistic and more instructive. Attached Figure Description

[0029] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0030] Figure 1 A flowchart illustrating a simulation analysis method for assembly characteristics based on surface feature morphology, provided for a specific embodiment of the present invention;

[0031] Figure 2 This is a three-dimensional assembly model provided for a specific embodiment of the present invention. Detailed Implementation

[0032] Specific embodiments of the present invention will now be described in detail. In the following description, specific details are set forth for purposes of explanation and not limitation, in order to aid in a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced in other embodiments departing from these specific details.

[0033] It should be noted that, in order to avoid obscuring the invention with unnecessary details, only the device structure and / or processing steps closely related to the solution of the invention are shown in the accompanying drawings, while other details that are not closely related to the invention are omitted.

[0034] This invention proposes a simulation analysis method for assembly characteristics based on surface feature morphology. This method decomposes surface errors into systematic and random errors, and uses numerical methods to simulate both types of errors, constructing a feature morphology that conforms to the real surface. By constructing a model of the relationship between tolerances and key assembly characteristics, as well as between tolerances and manufacturing costs, the rationality of tolerance design is evaluated, thereby improving aircraft assembly performance while reducing manufacturing costs.

[0035] like Figure 1 As shown, a simulation analysis method for assembly characteristics based on surface feature morphology includes the following steps:

[0036] S1: Digitally model the surface morphology of each part.

[0037] Based on the actual machining method of the part, analyze the systematic errors that may occur during the machining process, and generate a digital part surface morphology by superimposing random errors. At the same time, the digital part surface morphology must be within the design tolerance zone.

[0038] The ideal assembly model is set to include n parts to be assembled. Based on the dimensional parameters of the ideal assembly model, the tolerance zone of each part is preset.

[0039] Different machining methods for parts will produce specific systematic errors, which can be determined based on the feature point data of the actual surface obtained by actual measurement during the machining process. However, the random errors in the machining process are uncertain and can be obtained through a random error function. By superimposing systematic and random errors, multiple digital part surface morphologies for each part can be obtained, and the digital part surface morphologies that meet the tolerance zones of each part can be selected.

[0040] S2: Construct the 3D assembly model of each part.

[0041] Based on the generated digital surface morphology of each part, a three-dimensional assembly model is constructed to achieve the stitching of the surface morphology of the part with errors with the surface morphology of the part without errors.

[0042] The three-dimensional assembly model of each part includes relative contact surfaces and adjacent non-contact surfaces. The contact surfaces adopt the surface morphology with errors obtained in step S1, and the non-contact surfaces adopt the surface morphology without errors.

[0043] When stitching the surface morphology of a part with errors to that of a part without errors, the common edge of the two surfaces can be fitted into a straight line or curve using a fitting method.

[0044] Since the digital surface morphology of each part is not unique, this step can obtain multiple three-dimensional assembly models.

[0045] S3: Constructing a 3D assembly model including key assembly characteristics and manufacturing cost.

[0046] Based on the influence relationship f(KC, Ti) of each part tolerance Ti (i = 1, 2…n) on the critical assembly characteristic KC and the evaluation relationship g(MC, Ti) between each part tolerance Ti (i = 1, 2…n) and the manufacturing cost MC, the influence weights of each part tolerance on the critical assembly characteristic KC and the manufacturing cost MC are assigned, and a model H(KC, MC) between the critical assembly characteristic and the manufacturing cost is constructed.

[0047] Using multiple 3D assembly models from step S2 as input, a model relating assembly key characteristics and manufacturing costs is constructed. The weights of each part's tolerances on assembly key characteristic KC and manufacturing cost MC are determined through simulation calculations combined with empirical knowledge data.

[0048] Based on past design experience, the following settings are made:

[0049]

[0050]

[0051] At this point, the corresponding situation is:

[0052]

[0053] Where n represents the number of parts to be assembled, i = 1, 2...n, f(KC,Ti) is the influence weight of each part's tolerance Ti on the assembly key characteristic KC, and g(MC,Ti) is the influence weight between each part's tolerance Ti and the manufacturing cost MC.

[0054] The relationship f(KC, Ti) between the tolerances Ti (i = 1, 2, ..., n) of each part and the critical assembly characteristic KC always satisfies The evaluation relationship between the tolerances Ti (i = 1, 2, ..., n) of each part and the manufacturing cost MC is g(MC, Ti). The higher the machining accuracy, the smaller the tolerance, and the higher the cost.

[0055] S4: Simulation Analysis

[0056] Simulation analysis is performed using a 3D assembly model as input, including contact analysis (stress, strain), assembly performance analysis (friction performance, sealing performance), and evaluation of key assembly characteristics (distance, gap).

[0057] Taking contact analysis as an example, multiple three-dimensional assembly models are subjected to contact analysis to obtain multiple sets of analysis results, such as stress-strain cloud maps. From multiple sets of stress-strain cloud maps, parts that are close to the design requirements can be extracted, thereby obtaining the corresponding part surface morphology and tolerance values.

[0058] By performing simulation analysis on the three-dimensional assembly model, one or more three-dimensional assembly models that meet the design requirements are obtained, along with the surface morphology and tolerance values ​​of the corresponding parts.

[0059] S5: Surface Tolerance Optimization

[0060] By comparing and analyzing the simulation results with the key characteristics required by the design, we can evaluate whether the tolerance design of the parts is reasonable. Based on the analysis results, we can optimize the tolerance of the parts, allocate the tolerance reasonably, and reduce the manufacturing cost to the greatest extent.

[0061] That is, the tolerances of the several three-dimensional assembly models obtained in step S4 are adjusted to satisfy the following formula:

[0062]

[0063] Select the tolerance allocation with the lowest manufacturing cost.

[0064] By properly allocating tolerances, H(KC,MC) should be minimized while ensuring that H(KC,MC) < 1. Furthermore, to improve design efficiency, an optimization target value for H(KC,MC) can be set according to actual needs, such as 0.9. The design can then be adjusted using tolerance zones to obtain the required assembly characteristics.

[0065] The following is a detailed description using a specific embodiment:

[0066] like Figure 2 As shown, an assembly consists of three parts. The tolerance requirements for each part and the key characteristics of the assembly are as follows: Figure 2 As shown.

[0067] After completing the digital modeling of the machined surface of the part and the construction of the three-dimensional model of the part, the influence relationship f(KC, Ti) of each part tolerance Ti (i = 1, 2…n) on the assembly key characteristic KC and the relationship g(MC, Ti) between each part tolerance Ti (i = 1, 2…n) and the manufacturing cost MC are set.

[0068] The tolerances of each part are

[0069] T1±0.1

[0070] T2±0.2

[0071] T3±0.2

[0072] Based on simulation calculations and historical experience data, we set the current time...

[0073] f(KC,T1)=0.2

[0074] f(KC,T2)=0.4

[0075] f(KC,T3)=0.4

[0076] g(MC,T1)=5

[0077] g(MC,T2)=3

[0078] g(MC,T3)=2

[0079] at this time,

[0080] H(KC,MC)=1

[0081] After simulation analysis, the tolerance values ​​of each part were adjusted and changed as follows:

[0082] T1±0.2

[0083] T2±0.1

[0084] T3±0.2

[0085] Then the corresponding:

[0086] f(KC,T1)=0.2

[0087] f(KC,T2)=0.4

[0088] f(KC,T3)=0.4

[0089] g(MC,T1)=2

[0090] g(MC,T2)=4

[0091] g(MC,T3)=2

[0092] at this time:

[0093]

[0094] This invention conducts pre-simulation analysis of surface assembly characteristics during the design phase to evaluate the rationality of tolerance design, and selects the optimal manufacturing scheme to reduce manufacturing costs while meeting aircraft performance requirements and ensuring that aircraft assembly characteristics are reasonable and controllable. At the same time, it adopts quantitative methods to control product quality.

[0095] The features described and / or illustrated above with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, and / or in combination with or in lieu of features in other embodiments.

[0096] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, whole, step, or component, but does not exclude the presence or addition of one or more other features, wholes, steps, components, or combinations thereof.

[0097] Many features and advantages of these embodiments are apparent from this detailed description, and therefore the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since many modifications and alterations will readily occur to those skilled in the art, the embodiments of the invention are not intended to be limited to the precise structures and operations illustrated and described, but rather to encompass all suitable modifications and equivalents falling within their scope.

[0098] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0099] The parts of this invention not described in detail are techniques known to those skilled in the art.

Claims

1. A simulation analysis method for assembly characteristics based on surface feature morphology, characterized in that, Includes the following steps The surface morphology of each part is digitally modeled, and systematic and random errors are superimposed on the digital part surface morphology to meet the design tolerance zone; A three-dimensional assembly model is constructed based on the surface morphology of digital parts, and the surface morphology of parts with errors is stitched together with the surface morphology of parts without errors. Construct a three-dimensional assembly model that includes key assembly characteristics and manufacturing cost. By performing simulation analysis on the three-dimensional assembly model, several three-dimensional assembly models and their parts that meet the design requirements are obtained, along with their surface morphology and tolerance values. Based on the simulation analysis results, optimize part tolerances and reduce manufacturing costs; The assembly key characteristics and manufacturing cost model of the three-dimensional assembly model are as follows: ,in, For the first Tolerances of individual parts n represents the number of parts to be assembled. For the tolerance of each part Key characteristics of assembly Influence weight, For the tolerance of each part With manufacturing costs The influence weights between them; Optimize part tolerances to meet the following requirements: By optimizing part tolerances, the lowest manufacturing cost can be achieved.

2. The assembly characteristic simulation analysis method according to claim 1, characterized in that, The optimization target value is set in advance.

3. The assembly characteristic simulation analysis method according to claim 1, characterized in that, The systematic error is determined based on the feature point data of the actual surface obtained by actual measurement during the part processing, and the random error is obtained through a random error function.

4. The assembly characteristic simulation analysis method according to claim 1, characterized in that, By superimposing systematic errors and random errors, multiple digital part surface morphologies are obtained for each part, and the digital part surface morphologies that meet the tolerance zones of each part are selected.

5. The assembly characteristic simulation analysis method according to claim 1, characterized in that, When stitching the surface morphology of a part with errors to that of a part without errors, the common edge of the two surfaces is fitted into a straight line or a curve.

6. The assembly characteristic simulation analysis method according to claim 1, characterized in that, The simulation analysis includes contact analysis, assembly performance analysis, and evaluation of key assembly characteristics.

7. The assembly characteristic simulation analysis method according to claim 6, characterized in that, The contact analysis includes at least stress and strain analysis, the assembly performance analysis includes at least friction performance and sealing performance analysis, and the assembly key characteristic assessment includes at least distance and gap assessment.

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