Tolerance simulation analysis-based sealing plate mounting structure improvement method

Abstract

The invention belongs to the field of aeronautical manufacturing, and relates to a tolerance simulation analysis-based sealing plate mounting structure improvement method, which comprises the following steps of S1, establishing a rear platform tolerance model and setting an input tolerance; s2, establishing a rudder local tolerance model and setting an input tolerance; s3, the rear platform tolerance model and the rudder local tolerance model are combined to establish a butt joint tolerance model, and measurement data are set; s4, setting simulation times N and a calculation result output mode to perform assembly simulation calculation; s5, performing statistical analysis on simulation results; and if the simulation result does not meet the requirement, performing simulation again on the adjusted platform tolerance model.

Description

Technical Field

[0001] The invention belongs to the field of aviation manufacturing and relates to a method for improving a sealing plate installation structure based on tolerance simulation analysis. Background Art

[0002] In the process of structural design, the coordination between different structures and how to better optimize the structure to ensure that the design requirements are met while reducing the difficulty of assembly often troubles designers and process personnel. The sealing plate is located on the outer surface of the structure, and its front and rear ends are coordinated with the locking mechanism and the vertical tail structure respectively. In order for the locking mechanism to work properly and not affect the movement of the rear end structure, the structural distance between the sealing plate and the front and rear ends must be kept within a fixed size. In the design process of the sealing plate, it is generally difficult for designers and process personnel to directly and accurately calculate the most suitable position of the sealing plate, and it is also difficult to ensure that there are no problems in the coordination between the designed products. It is always necessary to try many times during the structural assembly process to complete the final design of the sealing plate. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that it is impossible to directly and accurately complete the position determination and judge whether the structure is reasonable during the design process of the sealing plate structure.

[0004] Technical Solution

[0005] A method for improving a sealing plate installation structure based on tolerance simulation analysis comprises the following steps:

[0006] S1: Establish the rear platform tolerance model and set the input tolerance;

[0007] S2: Establish the rudder local tolerance model and set the input tolerance;

[0008] S3: Combine the rear platform tolerance model and the rudder local tolerance model to establish a docking tolerance model, and set measurement data;

[0009] S4: Set the simulation times N and the calculation result output mode to perform assembly simulation calculation;

[0010] S5: Perform statistical analysis on the simulation results; if the simulation results do not meet the requirements, adjust the platform tolerance model and re-simulate.

[0011] Furthermore, in S1, the tolerance model of the rear platform includes: vertical tail joint, sealing plate, rudder lock, web and T-section;

[0012] Determine the installation position of the web according to the vertical tail joint;

[0013] The rudder lock is installed under the belly plate.

[0014] The horizontal plate of the T-profile is connected to the web plate, and the vertical plate is connected to the sealing plate.

[0015] Furthermore, in S1, the input tolerances of the rear platform tolerance model include:

[0016] Tolerance L1 of the gap between the rudder lock and the sealing plate;

[0017] Angle tolerance of T-profiles;

[0018] Sealing plate positioning tolerance.

[0019] Rudder lock installation hole position;

[0020] Sealing plate profile

[0021] Further, in S2, the rudder local tolerance model includes the rudder;

[0022] The input tolerances include: the distance tolerance between the rudder and the rudder lock, L2;

[0023] The clearance tolerance between the rudder and the sealing plate is L3.

[0024] Further, in S3, the position of the rudder local tolerance model is determined according to the clearance between the vertical tail joint and the rudder and the sealing plate to achieve combination with the rear platform tolerance model.

[0025] Furthermore, the docking tolerance model sets the measurement data as follows:

[0026] The gap between the rudder lock and the sealing plate is D1.

[0027] Further, in S4, each time a simulation is performed, a set of parameters is randomly selected from the seven input tolerances for simulation, and the measurement data is output after the simulation.

[0028] Furthermore, normal statistics were performed on each measurement data;

[0029] Calculate the qualified rate of N simulation results of the measurement data according to the preset value of the measurement data;

[0030] According to the results of N simulations, the influence of the parameters in the input tolerance on the change of the measurement results is calculated, and then the total change of the measurement results is calculated. Finally, the influence of each parameter is compared with the total change in proportion to determine the influence of the input tolerance.

[0031] Furthermore, if the qualified rate exceeds the set value, the set input tolerance meets the production requirements;

[0032] Otherwise, adjust the input tolerance with the greatest influence according to the influence of each parameter, and re-simulate; and analyze the results of the re-simulation until they meet the product qualification rate requirements.

[0033] Beneficial effects: This method has low cost, simple tools, easy use, high accuracy, improves assembly quality, and reduces the occurrence of problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention includes 5 drawings, and the drawings and the descriptions of the drawings are as follows:

[0035] Figure 1 It is a schematic diagram after the rear platform tolerance model is connected with the rudder local tolerance model;

[0036] 1- web, 2- joint, 3- rudder lock, 4- T-profile, 5- sealing plate, 6- rudder;

[0037] Figure 2 It is a schematic diagram of simulation calculation results before optimization;

[0038] Figure 3 It is a schematic diagram of simulation calculation results after angle tolerance optimization;

[0039] Figure 4 It is a schematic diagram of simulation results after the sealing plate structure is optimized;

[0040] Figure 5 This is a schematic diagram of the normal distribution of simulation results;

[0041] In the figure, the horizontal axis is the measured value, the vertical axis is the number of times the corresponding measured value occurs, the LSL line is the lower limit qualified line, and the mean line is the average line;

[0042] In the simulation result data table, Nominal is the theoretical value of the measurement, Mean is the average value of the measurement, LSL is the qualified value of the lower limit of the measurement, USL is the qualified value of the upper limit of the measurement, Est.Low is the minimum value of the measurement, Est.High is the maximum value of the measurement, Est.Range is the range of the measurement value, and Est.Tot-OUT% is the unqualified rate of the measurement value;

[0043] In the statistical table of the impact of each link, Index is the serial number, Contributor is the parameter that affects the calculation result, Part is the structure where the affected parameter is located, Range is the range of parameter value variation, and Contribution is the influence of the parameter on the calculation result. DETAILED DESCRIPTION

[0044] In order to solve the background technical problem, the present invention provides a method for improving the sealing plate installation structure based on tolerance simulation analysis, using 3DCS three-dimensional dimension chain analysis, using Monte Carlo simulation method to calculate the gap between structures, and at the same time obtain the contribution rate and sensitivity of each component ring, and then optimize the relevant dimensional tolerance and structure; the method comprises the following steps:

[0045] Step 1: Analyze the assembly positioning relationship, use the AUTO BEND assembly command of 3DCS to combine the structures and establish the sealing plate structure tolerance model;

[0046] Step 2: Based on the design technical requirements as the basis for tolerance input, a local tolerance model of the heading rear end with a coordinated relationship is established in the 3DCS software;

[0047] Step 3: assemble the two tolerance models according to the technical requirements of the design docking;

[0048] Step 4: Use 3DCS software and Monte Carlo method to calculate tolerances, and output simulation results of gap / interference measurement values ​​and analysis of the impact of each tolerance;

[0049] Step 5: Based on the simulation results and the impact analysis of each tolerance, sort out the factors that have the greatest impact on the structure and determine the targets that need to be optimized and improved.

[0050] Step 6: Improve the product structure according to the simulation results, simulate and analyze the improved tolerance and structure again, determine the optimization effect according to the simulation results, and analyze the product qualification rate;

[0051] Step 7: Conduct actual production assembly verification, verify multiple times and record actual clearance data.

[0052] Embodiment 1

[0053] A method for improving the sealing plate installation structure based on tolerance simulation analysis, which imports the structural digital model, dimensional tolerance and design requirements into 3DCS, uses 3DCS three-dimensional dimension chain analysis, calculates the gap between structures by Monte Carlo simulation method, and obtains the contribution rate and sensitivity of each component ring, thereby optimizing the relevant dimensional tolerance and structure; the method includes the following steps:

[0054] Step 1. Establish the tolerance simulation model of the rear platform. The simulation target of this paper is the heading clearance between the rudder lock and the sealing plate. The dimensional influence in the wingspan direction is not considered. Therefore, the original digital model of the design can be cut along the symmetry center, and the tolerance simulation digital model including the sealing plate, rudder lock, web and T-profile structure can be established according to the symmetry plane; the rudder lock is installed under the web of the rear platform of the dorsal fin, the web is positioned according to the intersection of the vertical tail, and the rear end is controlled in height according to the vertical rib surface of the T-profile, which belongs to multi-point surface contact. Due to the angle deviation of the T-profile, the web may bend during installation. For this reason, the AUTO BEND assembly command of 3DCS is used to combine the sealing plate, web and T-profile according to the assembly relationship to form the tolerance model of the rear platform;

[0055] Step 2: Establish the local tolerance model of the rudder. In the actual manufacturing process of this component, the stabilizer and rudder components are assembled on the jig and docked outside the jig. There are many factors that affect the installation accuracy of the rudder and the assembly process is complicated.

[0056] Since the rationality and accuracy of the vertical tail assembly are not the research purpose of this case, the design clearance requirement between the leading edge of the rudder and the vertical tail stabilizer sealing plate is used as the basis for tolerance input, the tolerance of the clearance is created, and the rudder local tolerance model including the rudder structure and clearance requirements is established in the 3DCS software;

[0057] Step 3: Establish the docking tolerance model, such as Figure 1 As shown in the figure, the tolerance model of the rear platform of the tail section and the local tolerance model of the vertical tail rudder are positioned according to the vertical tail joint when docking. This paper ignores the influence of factors such as the manufacturing error of the vertical tail joint, assembly error and gravity deformation of the components, and docks the tail section and the vertical tail according to theory; after the docking of the tail section components and the vertical tail components is completed, in order to ensure the clearance requirement between the rudder lock body and the lock slot, the rudder lock installation model is installed with the rudder lock as the reference, and the rudder lock installation hole is made on the sealing plate using the drill template hole of the rudder lock installation model. In the actual assembly process, due to the size fluctuation of the belly plate surface, the drill template cannot fit with the belly plate surface, so the heading direction and span direction of the rudder lock hole are controlled by the drill template, and the horizontal direction position of the rudder lock installation hole is controlled by the lower surface of the belly plate.

[0058] In order to realistically simulate the above operation process, the rudder lock installation hole position is established in the 3DCS rear platform tolerance model. The Iteration Move is used to fix the first installation hole, rotate around the fixed point to reach the second installation hole, and complete the iteration process step by step; the installation hole is made consistent with the drilling hole of the installation model in the heading direction and the wingspan direction, and the installation hole is made consistent with the belly plate surface in the horizontal direction.

[0059] Step 4: Perform assembly simulation calculation. Click the Run Analysis button to set the number of assembly simulations to 5000. Use the Monte Carlo method to calculate the tolerance. The quality requirement is controlled within the range of ±3σ. The product qualification rate is controlled at 99.73%. Set the calculation results to be expressed in normal distribution.

[0060] Step 5: Analyze the simulation results. According to the simulation results of the gap / interference measurement between the rudder lock and the sealing plate, Figure 2As shown, the influence of the input tolerance on the measurement result change is calculated, and the total change of the measurement result is calculated. Finally, the influence of each parameter is compared with the total change in proportion to determine the influence of the input tolerance. The influence analysis of each tolerance is shown in Table 1. It can be seen that the result is normally distributed, the left extreme value is -2.84mm, the right limit is 3.80mm, and the left limit is a negative value, which has interference problems. The unqualified rate reaches 33.21%, which does not meet the production requirements. The first two tolerances directly affect the target size and need to be strictly controlled.

[0061] Table 1 Influence of each link

[0062] Index Contributor Part Range Contribution 1 Installation position Rudder 5.000(mm) 56.51％ 2 Angle tolerance T-profile 2.000(mm) 42.87％ 3 Positioning tolerance Sealing plate 0.500(mm) 0.45％ 4 Mounting hole position Rudder lock 0.200(mm) 0.1％ 7 Outer contour Sealing plate 0.500(mm) 0.06％

[0063] Step 6. Based on the analysis results, the structure is optimized and improved, and the optimization results are checked again by simulation. The two factors with the greatest impact are analyzed. The installation accuracy of the rudder is related to its own weight sinking and the assembly accuracy of the components. It is difficult to make more stringent requirements and controls. Therefore, only the angle tolerance of the T-profile is controlled.

[0064] Compress the angle tolerance of the T profile, reduce the current tolerance to one-half, modify the angle tolerance of the T profile in the GD&T tolerance setting command, and perform simulation calculation again after the modification. The optimized result is as follows Figure 3 As shown;

[0065] Table 2 Influence of each link after angle tolerance optimization

[0066] Index Contributor Part Range Contribution 1 Installation position Rudder 5.000(mm) 98.94％ 2 Angle tolerance T-profile 2.000(mm) 0.45％ 3 Positioning tolerance Sealing plate 0.500(mm) 0.45％ 4 Mounting hole position Rudder lock 0.200(mm) 0.1％ 7 Outer contour Sealing plate 0.500(mm) 0.06％

[0067] According to Table 2, the influence of the optimized T-profile angle tolerance on the product failure rate is less than 0.5%. Therefore, it can be considered that the angle tolerance optimization has reached its limit, and the product failure rate is still 15.23%. Therefore, other parts still need to be optimized.

[0068] In order to further reduce the risk of interference between the sealing plate and the rudder lock, after technical discussions with the design, the existing sealing plate structure was optimized under the premise of meeting the aerodynamic and strength requirements. A protrusion was added at the corresponding position of the rudder lock to increase the installation space of the rudder lock and reduce the probability of interference between the sealing plate and the rudder lock after installation. The sealing plate structure in the modified platform tolerance model added a protrusion, and the other parameters remained unchanged except that the T-profile angle tolerance was adjusted to the optimized value. The optimized results were obtained by simulation again. Figure 4 As shown;

[0069] According to the simulation optimization results, after the T-profile angle tolerance is optimized, the unqualified rate of the sealing edge plate structure improved product is reduced to 0.25%, which meets the product qualification rate control requirements, can better solve the interference problem between the rudder lock and the sealing edge plate, and can be carried out in actual production verification tests.

[0070] Step seven: Implement the virtual simulation optimization work into the actual process and design documents, conduct actual production and assembly verification, control the parts manufacturing accuracy and component assembly accuracy based on the previous simulation results and optimization results, optimize the sealing plate design structure, perform assembly verification on the new sealing plate and record the gap data. After multiple verifications, the problem did not recur in the structure. The optimization effect was effective and reliable, successfully reducing the problem failure rate and improving the assembly quality.

[0071] Index Contributor Part Range Contribution 1 Installation position Rudder 5.000(mm) 56.51％ 2 Angle tolerance T-profile 2.000(mm) 42.87％ 3 Positioning tolerance Sealing plate 0.500(mm) 0.45％ 4 Mounting hole position Rudder lock 0.200(mm) 0.1％ 5 Outer contour Sealing plate 0.500(mm) 0.06％

Claims

1. A method for improving the sealing plate installation structure based on tolerance simulation analysis, characterized in that: The following steps are involved: S1: Establish the rear platform tolerance model and set the input tolerance; S2: Establish the rudder local tolerance model and set the input tolerance; S3: Combine the rear platform tolerance model and the rudder local tolerance model to establish a docking tolerance model, and set measurement data; S4: Set the simulation times N and the calculation result output mode to perform assembly simulation calculation; S5: Perform statistical analysis on the simulation results; if the simulation results do not meet the requirements, adjust the platform tolerance model and re-simulate.

2. The method according to claim 1, characterized in that: In S1, the tolerance model of the rear platform includes: vertical tail joint, sealing plate, rudder lock, web and T-section; Determine the installation position of the web according to the vertical tail joint; The rudder lock is installed under the belly plate. The horizontal plate of the T-profile is connected to the web plate, and the vertical plate is connected to the sealing plate.

3. The method according to claim 2, characterized in that: In S1, the input tolerances of the rear platform tolerance model include: Tolerance of the gap between the rudder lock and the sealing plate L1; Angle tolerance of T-profiles; Sealing plate positioning tolerance. Rudder lock installation hole position; The contour of the sealing plate.

4. The method according to claim 3, characterized in that: In S2, the rudder local tolerance model includes the rudder; The input tolerances include: the distance tolerance between the rudder and the rudder lock, L2; The clearance tolerance between the rudder and the sealing plate is L3.

5. The method according to claim 4, characterized in that: In S3, the position of the rudder local tolerance model is determined according to the clearance between the vertical tail joint and the rudder and the sealing plate to realize the combination with the rear platform tolerance model.

6. The method according to claim 5, characterized in that: The measurement data for the docking tolerance model setting is: The gap between the rudder lock and the sealing plate is D1.

7. The method according to claim 6, characterized in that: In S4, each time a simulation is performed, a set of parameters is randomly selected from the seven input tolerances for simulation, and the measured data is output after the simulation.

8. The method according to claim 7, characterized in that: Normal statistics were performed on each measurement data; Calculate the qualified rate of N simulation results of the measurement data according to the preset value of the measurement data; According to the results of N simulations, the influence of the parameters in the input tolerance on the change of the measurement results is calculated, and then the total change of the measurement results is calculated. Finally, the influence of each parameter is compared with the total change in proportion to determine the influence of the input tolerance.

9. The method according to claim 8, characterized in that: If the qualified rate exceeds the set value, the set input tolerance meets the production requirements; Otherwise, adjust the input tolerance with the greatest influence according to the influence of each parameter and re-simulate; The results of the re-simulation are analyzed until they meet the product qualification rate requirements.

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