Method for dividing a passenger aircraft nose skin

Abstract

The application relates to the field of aircraft design, and provides a passenger plane nose skin blocking method for improving design efficiency, which comprises the following steps: step 1, obtaining overall input of skin blocking; step 2, determining size limitation of sheet metal parts; step 3, determining front and rear blocking lines of upper skin, lower boundary of the front side of the upper skin and lower boundary of the rear side of the upper skin; step 4, determining front and rear blocking lines of bottom skin, front heading blocking line of the front part of the bottom skin and rear longitudinal blocking line of the rear part of the bottom skin; and step 5, refining the skin blocking based on the size limitation of the sheet metal parts. The above method can reduce the number of modifications and improve the design efficiency.

Description

Technical Field

[0001] This invention relates to the field of aircraft design, specifically a method for segmenting the nose skin of a passenger aircraft. Background Technology

[0002] In the conceptual design phase of the structural system of civil transport aircraft, the skin needs to be processed and analyzed. After entering the scheme design phase, the segmented design of the nose structure skin is the overall input of the prototype model for subsequent structural design, electronic equipment layout, bird strike design, strength design, etc.

[0003] Currently, in the segmented design of the skin, the overall department first makes a preliminary division of the skin based on past experience. In the subsequent design phase, the main responsible designer provides feedback and requirements. After multiple refinements and iterations by the design department, it reaches the testing or prototype stage and is handed over to the process department and supplier units, whereby the relevant process engineers provide corresponding responses.

[0004] Existing methods often result in repeated iterations of the skin segmentation scheme due to multiple design feedbacks, and further changes to the skin segmentation due to feedback from process engineers regarding skin production and assembly issues, leading to adjustments across multiple disciplines, resulting in extremely low design efficiency. Summary of the Invention

[0005] To improve design efficiency, this application provides a method for segmenting the nose skin of a passenger aircraft.

[0006] The technical solution adopted by the present invention to solve the above problems is:

[0007] The method for segmenting the nose skin of a passenger aircraft includes:

[0008] Step 1: Obtain the overall input of the skin block. The overall input includes the nose shape, frame positioning surface, longitudinal component positioning surface and system-related opening curves. The system-related opening curves include: the view window area, landing gear openings, passenger passage opening curves and all system door openings located in the nose area.

[0009] Step 2: Determine the dimensional constraints of the sheet metal parts;

[0010] Step 3: Determine the front and rear segment lines of the upper skin, the lower front boundary of the upper skin, and the lower rear boundary of the upper skin based on the view window area and the passenger passage opening curve.

[0011] Step 4: Based on the front and rear segment lines of the upper skin, the landing gear openings, and the symmetry plane of the nose shape, determine the front and rear segment lines of the bottom skin, the forward directional segment line of the bottom skin, and the longitudinal segment line of the rear bottom skin.

[0012] Step 5: Refine the skin sections based on the size limitations of the sheet metal parts.

[0013] Furthermore, step 1 also includes preprocessing the overall input.

[0014] Furthermore, the preprocessing includes:

[0015] Check whether the quality of the graphics meets the requirements, and cut, repair and fill any graphics that do not meet the requirements;

[0016] Adjust the orientation of each component surface so that it faces inwards;

[0017] If there are overlapping areas between surfaces, then the corresponding surfaces are cut off from each other.

[0018] Furthermore, step 3 specifically includes:

[0019] Step 31: Use the frame station surface located in the middle between the rear boundary of the view window area and the front boundary of the passenger passage opening curve as the front and rear segment lines of the upper skin.

[0020] Step 32: Starting from the longitudinal component station surface closest to the lower boundary of the view window area, select the third longitudinal component station surface far away from the view window area as the lower boundary of the front side of the upper skin.

[0021] Step 33: Taking the longitudinal component station surface closest to the lower boundary of the passenger passage opening curve as the starting point, select the third longitudinal component station surface far away from the passenger passage opening curve as the lower boundary of the rear side of the upper skin.

[0022] Furthermore, step 4 specifically includes:

[0023] Step 41: Determine whether the front and rear segment lines of the upper skin are located within the two frame surfaces before and after the front or rear boundary of the landing gear opening. If not, use the extension line of the front and rear segment lines of the upper skin as the front and rear segment lines of the bottom skin. If so, move the front and rear segment lines of the upper skin away from this boundary to the frame position surface that meets the requirements, and use this frame position surface as the front and rear segment lines of the upper and bottom skins.

[0024] Step 42: Use the symmetry plane of the nose as the heading segment line of the front part of the bottom skin;

[0025] Step 43: Select the longitudinal component positioning surface that is furthest from the landing gear opening and meets the sheet metal size requirements as the longitudinal segmentation line of the rear part of the bottom skin.

[0026] Furthermore, the size limitations in step 2 include the maximum width, maximum length, and maximum chord height after molding.

[0027] Furthermore, step 5 specifically includes:

[0028] Step 51: Confirm that the distance between adjacent segment lines of the front and rear skin sections in the middle of the shape does not exceed the distance of 2 longitudinal component positioning surfaces. If the distance is greater than the distance of 2 longitudinal component positioning surfaces, adjust the corresponding segment lines.

[0029] Step 52: If the skin segmentation line crosses the relevant opening curve of the system, adjust it to the longitudinal component station surface adjacent to the curve;

[0030] Step 53: Refine and divide the remaining skin into blocks, retaining the largest skin while meeting the size constraints;

[0031] Step 54: If the chord height of a single skin after segmentation does not meet the requirements, increase the number of segments.

[0032] The advantages of this invention compared to the prior art are as follows: By adopting the block-based method of this application, technicians can quickly move from the conceptual design stage to the scheme design stage, clarify the primary and secondary relationships in the skin block design process, introduce process information in advance as the primary condition for refinement, provide some refinement criteria, reduce the number of iterations after entering the detailed design stage and the testing stage, avoid some block changes that may be caused by process problems, reduce repetitive modeling work, and thus improve design efficiency. Attached Figure Description

[0033] Figure 1 Flowchart of the method for segmenting the nose skin of a passenger aircraft;

[0034] Figure 2 A schematic diagram of the overall input for skin segmentation;

[0035] Figure 3 This is a schematic diagram of the first block;

[0036] Figure 4 This is a schematic diagram of the second block;

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. Nose shape; 2. Window area; 3. System door openings; 4. Passenger aisle opening curves; 5. Bottom door openings; 6. Landing gear openings. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0040] like Figure 1 As shown, the method for segmenting the nose skin of a passenger aircraft includes:

[0041] Step 1: Obtain the overall input for skinning blocks, such as... Figure 2 As shown, the overall input includes the nose shape 1, frame station surfaces (F1, F2, ..., F20), longitudinal component station surfaces (S0, S1, ..., S39) and system-related opening curves. The system-related opening curves include: the view window area 2, the landing gear opening 6, the passenger passage opening curve 4, and all system door openings 3 located in the nose area.

[0042] To ensure the accuracy of data input, preprocessing is performed after obtaining the overall input. This preprocessing includes: 1. Checking the graphic quality of the input shape, ensuring continuity and eliminating sharp corners, gaps, etc., and cutting, repairing, and filling any non-compliant graphics; 2. Highlighting each surface of the machine head shape and selecting the Extract command, then selecting Extract without Expansion in the pop-up dialog box, checking the direction of each surface to ensure all surfaces face inwards. If any surfaces face outwards, using the Reverse function under the Operation command to correct them until their direction is consistent; 3. Using the Trim command to confirm there are no overlapping areas between surfaces; 4. For all processed surfaces, selecting the Join command and checking the Continuity Check option to ensure shape quality.

[0043] Step 2: Determine the size limits of the sheet metal parts; the size limits mainly include the maximum width L1 and maximum length L2 of the sheet metal parts before forming, and the maximum chord height H after forming; the size limits mainly come from raw material procurement, production equipment and processing technology.

[0044] Step 3: Determine the front and rear segment lines of the upper skin, the lower front boundary of the upper skin, and the lower rear boundary of the upper skin based on the view window area 2 and the passenger passage opening curve 4.

[0045] The nose cone has a symmetrical structure; taking one half as an example, for instance... Figure 3 As shown, specifically: Step 31, use the frame surface located in the middle between the rear boundary of the view window area and the front boundary of the passenger passage opening curve as the front and rear segment lines of the upper skin, i.e., F10;

[0046] Step 32: Taking the longitudinal component station surface closest to the lower boundary of the view window area as the starting point, i.e., S14, select the third longitudinal component station surface far away from the view window area as the lower boundary of the front side of the upper skin, i.e., S17; at this time, the front upper skin surface a1 can be obtained.

[0047] Step 33: Taking the longitudinal component station surface closest to the lower boundary of the passenger passage opening curve as the starting point, select the third longitudinal component station surface far away from the passenger passage opening curve as the lower boundary of the upper skin, i.e., S25; at this time, the upper rear skin surface a2 can be obtained.

[0048] Step 4: Based on the front and rear segment lines of the upper skin, the landing gear openings, and the symmetry plane of the nose shape, determine the front and rear segment lines of the bottom skin, the forward directional segment line of the bottom skin, and the longitudinal segment line of the rear bottom skin.

[0049] Specifically: Step 41: Determine whether the front and rear segment lines of the upper skin are located within the two frame surfaces before and after the front or rear boundary of the landing gear opening. If not, use the extension line of the front and rear segment lines of the upper skin as the front and rear segment lines of the bottom skin, i.e., F10, to obtain the bottom skin surfaces b1 and b2. If yes, move the front and rear segment lines of the upper skin away from this boundary to a frame surface that meets the requirements, and use this frame surface as the front and rear segment lines of the upper and bottom skins.

[0050] Step 42: Using the nose section symmetry plane S0 as the forward heading segment line of the bottom skin, divide the bottom skin surface b1 into b1.1 and b1.2, as follows. Figure 4 As shown in Figure b1.2;

[0051] Step 43: Select the longitudinal component position surface that is farthest from the landing gear opening 6 and meets the sheet metal size requirements as the longitudinal segment line of the rear part of the bottom skin, i.e., S32, to obtain b2.1 and b2.2.

[0052] Step 5: Refine the skin sections based on the size limitations of the sheet metal parts;

[0053] Specifically: Step 51: Confirm that the distance between adjacent segment lines of the front and rear skin sections in the middle part of the shape does not exceed the distance of 2 longitudinal component positions. If the distance is greater than the distance of 2 longitudinal component positions, adjust the corresponding segment lines.

[0054] Step 52: If the skin segmentation line crosses the relevant opening curve of the system, adjust it to the longitudinal segmentation surface adjacent to the curve.

[0055] Step 53: Refine and divide the remaining skin into blocks, retaining the largest skin while meeting the size constraints;

[0056] Step 54: If the height H of a single skin string does not meet the requirements after segmentation, increase the number of segments.

[0057] In this embodiment, the only vertical dividing line between the front section and the middle section is S17, and the vertical dividing line between the middle section and the rear section is S25. According to step 51, the front section S17 is adjusted to S24. Therefore, the upper part of the front section a1 (S17, F10) area is adjusted to (S24, F10), and the corresponding surface b1.1 is adjusted to (S24, F10). After the adjustment, according to step S53, the skin width of a1 exceeds the size of L1 in step 2. L2 and H meet the requirements. A dividing line is added to a1 at (S10) to obtain surfaces a1.1 and a1.3.

[0058] According to step 53, the length of the skin of the upper part of the rear section a2 exceeds the size of L2, so the segment line S7 is added to refine it and is adjusted to face a2.1 and face a2.2.

[0059] According to steps 33 and 43, the lower rear section is divided into blocks S25 and S32. According to step 54, since the bottom hatch opening 5 is located between S32 and S33, the block lines are adjusted to S25 and S33, and the skin is divided into surface b2.1 and surface b2.2.

[0060] By adopting a top-down, large-to-small design sequence, and incorporating sheet metal part size constraints into the initial design, the design's skin sections are better suited to the needs of subsequent processes, thereby effectively reducing the number of changes and increasing design efficiency.

Claims

1. A method for segmenting the nose skin of a passenger aircraft, characterized in that, include: Step 1: Obtain the overall input of the skin block. The overall input includes the nose shape, frame positioning surface, longitudinal component positioning surface and system-related opening curves. The system-related opening curves include: the view window area, landing gear openings, passenger passage opening curves and all system door openings located in the nose area. Step 2: Determine the dimensional constraints of the sheet metal parts, including the maximum width, maximum length, and maximum chord height after forming; Step 3: Determine the front and rear segment lines of the upper skin, the lower front boundary of the upper skin, and the lower rear boundary of the upper skin based on the view window area and the passenger passage opening curve; specifically: Step 31: Use the frame station surface located in the middle between the rear boundary of the view window area and the front boundary of the passenger passage opening curve as the front and rear segment lines of the upper skin. Step 32: Starting from the longitudinal component station surface closest to the lower boundary of the view window area, select the third longitudinal component station surface far away from the view window area as the lower boundary of the front side of the upper skin. Step 33: Taking the longitudinal component station surface closest to the lower boundary of the passenger passage opening curve as the starting point, select the third longitudinal component station surface far away from the passenger passage opening curve as the lower boundary of the rear side of the upper skin. Step 4: Based on the front and rear segment lines of the upper skin, the landing gear openings, and the symmetry plane of the nose shape, determine the front and rear segment lines of the bottom skin, the forward directional segment line of the bottom skin, and the longitudinal segment line of the rear bottom skin; specifically: Step 41: Determine whether the front and rear segment lines of the upper skin are located within the two frame surfaces before and after the front or rear boundary of the landing gear opening. If not, use the extension line of the front and rear segment lines of the upper skin as the front and rear segment lines of the bottom skin. If so, move the front and rear segment lines of the upper skin away from this boundary to the frame position surface that meets the requirements, and use this frame position surface as the front and rear segment lines of the upper and bottom skins. Step 42: Use the symmetry plane of the nose as the heading segment line of the front part of the bottom skin; Step 43: Select the longitudinal component positioning surface that is furthest from the landing gear opening and meets the sheet metal size requirements as the longitudinal segmentation line of the rear part of the bottom skin; Step 5: Refine the skin sections based on the size limitations of the sheet metal parts, specifically as follows: Step 51: Confirm that the distance between adjacent segment lines of the front and rear skin sections in the middle of the shape does not exceed the distance of 2 longitudinal component positioning surfaces. If the distance is greater than the distance of 2 longitudinal component positioning surfaces, adjust the corresponding segment lines. Step 52: If the skin segmentation line crosses the relevant opening curve of the system, adjust it to the longitudinal component station surface adjacent to the curve; Step 53: Refine and divide the remaining skin into blocks, retaining the largest skin while meeting the size constraints; Step 54: If the chord height of a single skin after segmentation does not meet the requirements, increase the number of segments.

2. The method for segmenting the nose skin of a passenger aircraft according to claim 1, characterized in that, Step 1 also includes preprocessing the overall input.

3. The method for segmenting the nose skin of a passenger aircraft according to claim 2, characterized in that, The preprocessing includes: Check whether the quality of the graphics meets the requirements, and cut, repair and fill any graphics that do not meet the requirements; Adjust the orientation of each component surface so that it faces inwards; If there are overlapping areas between surfaces, then the corresponding surfaces are cut off from each other.

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