A ship closing method based on analog assembly

Abstract

The application provides a ship closing method based on simulation assembly, comprising the following steps: S1. making a simulation assembly scheme and an implementation plan, the implementation plan implements the simulation assembly scheme to perform closing assembly; S2. analyzing improvement points according to problems found in the implementation process; S3. promoting segmented construction data simulation control according to the closing assembly situation; S4. perfecting assembly data simulation control and raw material cutting size making according to the segmented construction data requirement; S5. continuously improving, and reversely pushing the simulation assembly to be successfully implemented and the original bevel retention rate to be continuously improved. The ship closing method based on simulation assembly can achieve the purposes of quickly loosening hooks and quickly welding, effectively improves the on-site construction efficiency, shortens the dock period and improves the on-site environment.

Description

Technical Field

[0001] This invention belongs to the field of shipbuilding technology, specifically relating to a ship assembly method based on simulated assembly. Background Technology

[0002] Traditional ship assembly simulation aims to meet the dimensional accuracy requirements of the hull after hoisting and achieve rapid assembly. However, during the implementation of traditional simulation assembly, some aspects are not executed properly due to various factors. The gaps between the joints after the sections are hoisted cannot fully meet the requirements for direct assembly and welding. This necessitates cutting, grinding, or even excavating and replacing the original bevels of the main board and components. Cutting and grinding in high-altitude areas pose safety hazards, and some plug-in corner joint structures are located in narrow areas of the hull, resulting in harsh construction environments and reduced work efficiency.

[0003] How to ensure the dimensional accuracy of the hull while achieving the required gaps in the closure joints for direct assembly and welding, thereby improving closure efficiency, shortening the dock cycle, and improving the working environment, is an urgent problem to be solved. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a ship assembly method based on simulated assembly, which achieves both rapid hook release and rapid welding, effectively improving on-site construction efficiency, shortening dock cycle, and improving the on-site environment.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A ship assembly method based on simulation includes the following steps:

[0007] S1. Develop a simulation assembly plan and implementation plan, and implement the simulation assembly plan to perform assembly.

[0008] S2. Analyze the areas for improvement based on the problems identified during the implementation process.

[0009] S3. Based on the above assembly and joining situation, promote the simulation control of segmented construction data;

[0010] S4. Based on the above segmented construction data requirements, improve the assembly data simulation control and raw material cutting dimensions formulation;

[0011] S5. Continuous improvement, reverse simulation assembly was successfully implemented, and the original bevel retention rate continued to increase.

[0012] Furthermore, step S1 specifically includes the following steps:

[0013] S11. Based on the production plan, create a simulated assembly positioning scheme, and specify the positioning detection points, the installation position of the limit blocks, and their thickness in the scheme;

[0014] S12. Design and formulate a simulated assembly implementation schedule. Based on the control and precautions required for the simulated assembly implementation, compile the contents of the simulated assembly implementation schedule. The contents of the simulated assembly implementation schedule specifically include: the time of formulation of the simulated assembly positioning plan, the time of issuance of the plan, the ship name and section name of the merging section, the merging stage, the margin marking, the inspection line, the margin cutting, the limit block, the target pre-attachment, the dimensions after positioning, the gap, the secondary cutting length, the end face trimming, the positioning personnel information, and the positioning conclusion.

[0015] S13. Implement the simulated assembly plan at the construction site, verify and confirm the implementation status on site, and record the information in the simulated assembly progress implementation table;

[0016] S14. Implementation analysis and summary: The implementation of the simulated assembly will be tracked and fed back in the form of daily reports, and analyzed, improved and perfected in the form of weekly and monthly summaries to ensure the implementation effect of the simulated assembly.

[0017] Furthermore, in step 11, the simulated assembly positioning scheme calculates the difference by comparing and analyzing the actual three-dimensional coordinate data of adjacent section closures, and analyzes the data deviations in the ship's length, width, and height directions based on the difference. Finally, based on the coordinate position, it is determined whether the calculated difference is a gap or a deviation, to ensure that the main dimensions of the closure section meet the ship's precision requirements, while the closure gap can meet the requirements for direct welding. The positioning detection point is located at the intersection of the strong structure of the closure and the theoretical line of the main board, preferably at the center of the section closure, the maximum half-width of the theoretical line of the platform and the outer plate, the intersection of the strong rib frame and the theoretical line of the main board platform, and the intersection of the longitudinal wall panel and the theoretical line of the main board platform. The principle for selecting these positions is determined based on the positioning and layout benchmarks of the previous process, reducing the occurrence of cumulative tolerance problems while ensuring the accuracy of the main dimensions. The strong structure of the section closure position is determined according to the section structure diagram, and the strong structure position is used as the installation position of the limit block. Two limit blocks are installed for one closure. To avoid the limit blocks falling or deforming due to collisions between adjacent sections during hoisting, which would affect the limit accuracy, it is chosen to install them in advance at locations with strong structural features.

[0018] Furthermore, the gap size of the closure joint at the strong structure location was analyzed, and the plate thickness of the limiting block was set according to the gap size. Before hoisting, the limiting block was installed at the strong structure location to control the closure joint gap. The plate thickness of the limiting block was set according to the gap size, and the plate thickness of the limiting block was equal to the closure joint gap size, with the error controlled within 2mm. Before the segmented hoisting, according to the positioning detection points in the simulated assembly positioning scheme, the target pieces were pre-attached at the positioning detection point positions in advance, and the angle of the target pieces was set for direct detection during segmented positioning. The principle for setting the angle of the target pieces was that the front of the target piece was at a 90-degree angle to the laser beam emitted by the aiming lens of the total station, and the angle placement error was controlled within ±30 degrees to reduce the measurement error caused by the angle deviation.

[0019] Furthermore, in step 13, the information recording content includes the on-site implementation of allowance marking, inspection lines, allowance cutting, setting of limit blocks, and target pre-attachment implementation. The allowance marking is used to draw the allowance lines on-site to guide the cutting according to the lines and ensure the cutting accuracy. The inspection line adopts a 100mm or 200mm inspection line to check the accuracy of the allowance cutting, and at the same time serves as the closing positioning inspection baseline.

[0020] Furthermore, step S2 specifically includes the following steps:

[0021] S21. Data acquisition of the closure segment: Before the closure segment is hoisted together, the three-dimensional coordinate data of the closure joint is acquired.

[0022] S22. Adjacent segment data acquisition: Acquire three-dimensional coordinate data of adjacent closure joints of the closure segment;

[0023] S23. Simulation Analysis: Based on the data collected from the closure section and adjacent closure joints, a simulation analysis is conducted, comprehensively considering the accuracy requirements of the ship's main dimensions, the accuracy requirements of special positions, and the requirements for the closure gap. A data report is provided after the overall analysis. Based on the data report, the allowance size and positioning scheme for the butt joint or corner joint area of ​​the closure section are determined, guiding the on-site construction of the closure. The simulation analysis method involves using simulation analysis software to calculate the difference between the three-dimensional coordinates of corresponding positions of adjacent closure joints, analyzing the data deviations in the ship's length, height, and beam directions, and determining the size of the gap or the size of the structural misalignment based on the coordinate location.

[0024] S24. Segment Optimization: For issues such as segment allowance and end face difference discovered during simulated assembly in the closure stage, segment control and reminder points are added to optimize segment control measures and allowance compensation schemes, thereby improving the accuracy and quality of segment construction. The segment control and reminder points refer to the dimensional information of the main board or components extending out and retracting into the closure joint of the segment. The dimensional information is marked and clarified in the two-dimensional accuracy control inspection table to guide standardized construction on site. At the same time, information feedback is provided for locations where the design drawing information standards are unclear, and the drawing dimensional information is added.

[0025] The purpose of S21-S23 is to determine the allowance size and positioning scheme of the butt joint and corner joint areas of the closure section. By determining the scheme, the gap size of the butt joint or corner joint area can be improved, thereby meeting the requirements of direct assembly and welding.

[0026] The special locations mentioned are positions with high precision requirements, such as the hull shaft and rudder system position, the engine room main engine seat position, the hatch coaming plate, the container ship guide rail, the folding support position of the heavy-lift ship, and the pressure groove position of the movable ramp of the roll-on / roll-off ship.

[0027] Furthermore, S3 specifically includes the following steps:

[0028] S31. S31. Segmental Stage Completion Accuracy Inspection: After the three-dimensional data of the segment joint is collected after the segment construction is completed, the segment simulation analysis software in the PACM precision control system program is used to perform three-dimensional coordinate simulation analysis with adjacent segments. This ensures that the segment construction data meets both the hull accuracy dimensional requirements and the butt joint gap standard, generating a data report. Based on the report, on-site adjustments and corrections are made to ensure that the segment accuracy meets the requirements for subsequent assembly and use.

[0029] S32. Segmented plug-in corner joint area control: For plug-in corner joint structures, add three-dimensional detection coordinate values ​​for their protruding or retracted closing positions, and detect their three-dimensional coordinates during the segmented positioning and completion stages; through segmented simulation analysis software, simulate with adjacent segment data to ensure that the segmented construction data meets both the hull precision dimensional requirements and the diagonal joint gap standards, generate data reports, and guide on-site adjustments and corrections;

[0030] S33. Analyze and summarize, identify the reasons for the positioning and assembly process control, and formulate control improvement measures to provide high-quality segments for assembly.

[0031] Furthermore, S4 specifically includes the following steps:

[0032] S41. Theoretical simulation analysis: Before assembly, based on the theoretical model data, simulate and analyze the protruding structural dimensions of the construction section and the recessed closing dimensions of adjacent sections to analyze whether the design model is accurate and whether the gaps between butt joints or corner joints meet the standards. If there are deviations, the model will be adjusted in advance before construction. At the same time, the CNC cutting program will be corrected to correct the customization of raw material dimensions, ensure the accuracy of cutting dimensions and the quality of hull construction, and promote the effective utilization rate of steel plates.

[0033] S42. Assembly Dimension Control: During the assembly stage, based on the dimensional information in the assembly positioning drawings, install and position the dimensions of the extended or retracted closing structure to ensure that the positioning error is controlled within -2~0mm. If the positioning error deviation is -5~-2mm or 0~+3mm, then through simulation analysis, adjust the dimensions and structure of the unbuilt segments to ensure that the gap between the two meets the requirements.

[0034] S43. Final dimension confirmation: After the assembled structure is welded, check and confirm the dimensions of the extended or retracted closing structure according to the dimension information in the drawings to ensure accurate installation of the structure position and provide high-precision products for segmented completion.

[0035] Traditional simulated assembly aims to meet the dimensional accuracy requirements of the hull after hoisting, involving pre-hoisting planning, measurement, and trimming to achieve rapid loosening. This invention's simulated assembly, based on simulated assembly technology, promotes more demanding control methods. To reduce and avoid trimming issues during the closure phase of the structure and mainboard, the closure simulation assembly process is advanced to segmented simulation, and then from segmented simulation to assembly. During the structural assembly and positioning phase, issues of cross-sectional differences are addressed in advance through control of the extension and retraction of the closure opening dimensions, end-face difference control, and simulation analysis of adjacent segment data. Simultaneously, during the closure positioning phase, while meeting the main hull dimensions, adjustments and controls are effectively made using hull tolerances, butt joint gap standards, and allowable error ranges. This ensures that the mainboard and structure require little or no cutting after positioning, allowing for direct assembly and welding of the hull segments after hoisting. This reduces and avoids safety hazards associated with high-altitude operations and construction in confined areas, achieving both rapid hook loosening and rapid welding, effectively improving on-site construction efficiency, shortening dock cycle, and improving the site environment.

[0036] For the hull assembly joints, in accordance with the Chinese Shipbuilding Quality Standard (GB / T34000-2016), if the gap is greater than 1.5 times the plate thickness or 25mm (the minimum value), the plate needs to be replaced and reassembled. If the gap is less than the standard range, cutting and grinding are required. The gap of general corner joints is in accordance with the Chinese Shipbuilding Quality Standard (GB / T34000-2016). The allowable tolerances for hull assembly are in accordance with the Chinese Shipbuilding Quality Standard (GB / T34000-2016).

[0037] The simulated mounting to simulated assembly propulsion control method of the present invention has the following characteristics:

[0038] From data acquisition based on equipment to more comprehensive data acquisition of assembly requirements, combined with master dimension data requirements and reasonable use of tolerances, under the condition of segmented data forming and solidification, the gap of the closure weld is maximized to meet the dimensional requirements for direct welding.

[0039] By collecting data on assembly requirements, some difficult and blind spots in the original simulation assembly, such as plug-in and corner joint areas, were resolved, greatly reducing on-site trimming after hoisting in similar areas;

[0040] By simulating assembly control requirements, the problem of positioning measurement during the segmented lifting process was solved by pre-attaching measurement target pieces before segmented turning and hoisting, thus avoiding the dangers of high-altitude target swing measurement and measurement waiting.

[0041] By implementing simulated assembly control, before the segmented lifting, limit blocks are preset according to the simulated assembly gap control requirements, which effectively ensures that the gap size of the closing joint meets the requirements and achieves the effect of rapid hook delivery.

[0042] By simulating the implementation of each assembly step and following the PDCA cycle, the original bevel retention rate of each segment is promoted as a starting point. The data for segmentation, assembly, and material cutting are accurately deduced from the assembly requirements, thereby improving the utilization rate of steel plates and reducing construction waste such as weld repair and long material removal during the later assembly process. Attached Figure Description

[0043] Figure 1 This is a comparison chart of the retention rate of the positioning bevel during assembly using the method of this invention and the traditional simulation assembly method;

[0044] Figure 2 This is a comparison chart of the original bevel retention rates of insert rib structures using the method of this invention and those using the traditional simulation mounting method;

[0045] Figure 3 This is a comparison chart of the hoisting time of the large-scale assembly using the method of this invention and the traditional simulated mounting method;

[0046] Figure 4 This is a comparison chart of the gantry crane lifting time using the method of this invention and the traditional simulation loading method. Implementation

[0047] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0048] A ship assembly method based on simulation includes the following steps:

[0049] S1. Develop a simulation assembly plan and implementation plan, and implement the simulation assembly plan to perform assembly.

[0050] S2. Analyze the areas for improvement based on the problems identified during the implementation process.

[0051] S3. Based on the above assembly and joining situation, promote the simulation control of segmented construction data;

[0052] S4. Based on the above segmented construction data requirements, improve the assembly data simulation control and raw material cutting dimensions formulation;

[0053] S5. Continuous improvement, reverse simulation assembly was successfully implemented, and the original bevel retention rate continued to increase.

[0054] Step S1 specifically includes the following steps:

[0055] S11. Based on the production plan, create a simulated assembly positioning scheme, and specify the positioning detection points, the installation position of the limit blocks, and their thickness in the scheme;

[0056] S12. Design and formulate a simulated assembly implementation schedule. Based on the control and precautions required for the simulated assembly implementation, compile the contents of the simulated assembly implementation schedule. The contents of the simulated assembly implementation schedule specifically include: the time of formulation of the simulated assembly positioning plan, the time of issuance of the plan, the ship name and section name of the merging section, the merging stage, the margin marking, the inspection line, the margin cutting, the limit block, the target pre-attachment, the dimensions after positioning, the gap, the secondary cutting length, the end face trimming, the positioning personnel information, and the positioning conclusion.

[0057] S13. Implement the simulated assembly plan at the construction site, verify and confirm the implementation status on site, and record the information in the simulated assembly progress implementation table;

[0058] S14. Implementation analysis and summary: The implementation of the simulated assembly will be tracked and fed back in the form of daily reports, and analyzed, improved and perfected in the form of weekly and monthly summaries to ensure the implementation effect of the simulated assembly.

[0059] In step 11, the simulated assembly positioning scheme calculates the difference by comparing and analyzing the actual three-dimensional coordinate data of adjacent section closures. The difference analysis reveals deviations in the ship's length, width, and height. Finally, based on the coordinate positions, it determines whether the calculated difference is a gap or a deviation, ensuring that the main dimensions of the closure section meet the ship's precision requirements, while the closure gap meets the requirements for direct welding. The positioning detection point is located at the intersection of the strong structure and the theoretical line of the main board at the closure, preferably at the center of the section closure, the maximum half-width of the theoretical line of the platform and the outer plate, the intersection of the strong rib frame and the theoretical line of the main board platform, and the intersection of the longitudinal wall panel and the theoretical line of the main board platform. The selection of these locations is based on the positioning and layout references of the previous process, reducing cumulative tolerance issues while ensuring the accuracy of the main dimensions. The strong structure at the section closure location is determined according to the section structure diagram, and the strong structure location serves as the installation position for the limit blocks; two limit blocks are installed at each closure. To avoid the limit blocks falling or deforming due to collisions between adjacent sections during hoisting, which would affect the limit accuracy, it is chosen to install them in advance at locations with strong structural features.

[0060] Analyze the gap size of the closure joint at the strong structure location, and set the plate thickness of the limiting block according to the gap size. Before hoisting, install the limiting block at the strong structure location to control the closure joint gap. The plate thickness of the limiting block is set according to the gap size, and the plate thickness of the limiting block is equal to the closure joint gap size, with the error controlled within 2mm. Before the segmented hoisting, according to the positioning detection points in the simulated assembly positioning scheme, pre-attach target pieces at the positioning detection point positions and set the target piece angle for direct detection during segmented positioning. The principle for setting the target piece angle is that the front of the target piece is at a 90-degree angle to the laser beam emitted by the aiming lens of the total station, and the angle placement error is controlled within ±30 degrees to reduce measurement errors caused by angle deviation.

[0061] In step 13, the information recorded includes the on-site implementation of margin marking, inspection lines, margin cutting, setting of limit blocks, and target pre-attachment implementation. The margin marking is used to draw the margin lines on-site to guide the cutting according to the lines and ensure the cutting accuracy. The inspection lines are 100mm or 200mm inspection lines used to check the accuracy of margin cutting and also serve as the alignment and positioning inspection baseline.

[0062] Step S2 specifically includes the following steps:

[0063] S21. Data acquisition of the closure segment: Before the closure segment is hoisted together, the three-dimensional coordinate data of the closure joint is acquired.

[0064] S22. Adjacent segment data acquisition: Acquire three-dimensional coordinate data of adjacent closure joints of the closure segment;

[0065] S23. Simulation Analysis: Based on the data collected from the closure section and adjacent closure joints, a simulation analysis is conducted, comprehensively considering the accuracy requirements of the ship's main dimensions, the accuracy requirements of special positions, and the requirements for the closure gap. A data report is provided after the overall analysis. Based on the data report, the allowance size and positioning scheme for the butt joint or corner joint area of ​​the closure section are determined, guiding the on-site construction of the closure. The simulation analysis method involves using simulation analysis software to calculate the difference between the three-dimensional coordinates of corresponding positions of adjacent closure joints, analyzing the data deviations in the ship's length, height, and beam directions, and determining the size of the gap or the size of the structural misalignment based on the coordinate location.

[0066] S24. Segment Optimization: For issues such as segment allowance and end face difference discovered during simulated assembly in the closure stage, segment control and reminder points are added to optimize segment control measures and allowance compensation schemes, thereby improving the accuracy and quality of segment construction. The segment control and reminder points refer to the dimensional information of the main board or components extending out and retracting into the closure joint of the segment. The dimensional information is marked and clarified in the two-dimensional accuracy control inspection table to guide standardized construction on site. At the same time, information feedback is provided for locations where the design drawing information standards are unclear, and the drawing dimensional information is added.

[0067] The special locations mentioned are positions with high precision requirements, such as the hull shaft and rudder system, engine room main engine seat, hatch coaming, container ship guide rails, heavy-lift ship folding support positions, and roll-on / roll-off ship ramp pressure groove positions.

[0068] S3 specifically includes the following steps:

[0069] S31. Segmental Stage Completion Accuracy Inspection: After the three-dimensional data of the segment joint is collected after the segment construction is completed, the segment simulation analysis software in the PACM program of the accuracy control system is used to perform three-dimensional coordinate simulation analysis with adjacent segments. This ensures that the segment construction data meets both the hull accuracy dimensional requirements and the butt joint gap standard, generating a data report. Based on the report, on-site adjustments and corrections are made to ensure that the segment accuracy meets the requirements for subsequent assembly and use.

[0070] S32. Segmented plug-in corner joint area control: For plug-in corner joint structures, add three-dimensional detection coordinate values ​​for their protruding or retracted closing positions, and detect their three-dimensional coordinates during the segmented positioning and completion stages; through segmented simulation analysis software, simulate with adjacent segment data to ensure that the segmented construction data meets both the hull precision dimensional requirements and the diagonal joint gap standards, generate data reports, and guide on-site adjustments and corrections;

[0071] S33. Analyze and summarize, identify the reasons for the positioning and assembly process control, and formulate control improvement measures to provide high-quality segments for assembly.

[0072] S4 specifically includes the following steps:

[0073] S41. Theoretical simulation analysis: Before assembly, based on the theoretical model data, simulate and analyze the protruding structural dimensions of the construction section and the recessed closing dimensions of adjacent sections to analyze whether the design model is accurate and whether the gaps between butt joints or corner joints meet the standards. If there are deviations, the model will be adjusted in advance before construction. At the same time, the CNC cutting program will be corrected to correct the customization of raw material dimensions, ensure the accuracy of cutting dimensions and the quality of hull construction, and promote the effective utilization rate of steel plates.

[0074] S42. Assembly Dimension Control: During the assembly stage, based on the dimensional information in the assembly positioning drawings, install and position the dimensions of the extended or retracted closing structure to ensure that the positioning error is controlled within -2~0mm. If the positioning error deviation is -5~-2mm or 0~+3mm, then through simulation analysis, adjust the dimensions and structure of the unbuilt segments to ensure that the gap between the two meets the requirements.

[0075] S43. Final dimension confirmation: After the assembled structure is welded, check and confirm the dimensions of the extended or retracted closing structure according to the dimension information in the drawings to ensure accurate installation of the structure position and provide high-precision products for segmented completion.

[0076] The roll-on / roll-off (Ro-Ro) vessel (FL5800-1) uses a traditional assembly method. A comparison of the assembly and positioning bevel retention rates between this vessel and the same type of Ro-Ro vessel (FL5800-3) assembled using the invented method is as follows: Figure 1 As shown, the retention rate of the positioning bevel during assembly increased from 80.70% to 88.31%.

[0077] After adopting the closure method of this invention, the retention rate of the original bevel of the segmented insert rib structure is increased from 63.9% (for ship types FL5800-1, GR7800-6, TL866-1) using the traditional method to 90% (for ship types GR7800-7 / 8, TL866-2, FL5800-2 / 3). Figure 2 As shown.

[0078] The FL5800-3 and FL5800-1 are of the same type. The FL5800-3 was assembled using the method of this invention, while the FL5800-1 was assembled using a hull simulation method. Results show that the large-scale assembly and hoisting time of the FL5800-3 was reduced by 2.4 hours and the medium-scale assembly and hoisting time was reduced by 0.17 hours compared to the FL5800-1. Figure 3 and Figure 4 As shown.

[0079] In 2021, the company implemented a shift from simulated loading to simulated assembly control on the passenger ro-ro ship TL866-2, cargo ro-ro ships GR7800-7 / 8, cargo ro-ro ships FL5800 series, and heavy-lift ships. This reduced the number of meters to be cut by approximately 16,958 meters and saved a total of 472 hours of crane time. Compared to the previous method, this resulted in direct economic savings of approximately RMB 1.28 million (excluding the ancillary value generated by the shortened dock cycle, crane reuse, and high-altitude operations).

[0080] Those skilled in the art should understand that the above description is merely a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A ship assembly method based on simulated assembly, characterized in that, Includes the following steps: S1. Develop a simulated assembly plan and implementation plan, implement the simulated assembly plan and implementation plan at the construction site to perform assembly, verify and confirm the on-site implementation, and record the information in the simulated assembly progress table. S2. Analyze the areas for improvement based on the problems identified during the implementation process. S3. Based on the above assembly and joining situation, promote the simulation control of segmented construction data; S4. Based on the above-mentioned segmented construction data requirements, improve the assembly data simulation control and raw material cutting dimensions; specifically including the following steps: S41. Theoretical simulation analysis: Before assembly, based on the theoretical model data, the extended structural dimensions of the construction section and the recessed closing dimensions of adjacent sections are simulated and analyzed to determine whether the design model is accurate and whether the gaps between butt joints or corner joints meet the standards. If there are deviations, the model is adjusted in advance before construction. At the same time, the CNC cutting program is corrected to rectify the customization of raw material dimensions, ensuring the accuracy of cutting dimensions and the quality of hull construction, and promoting the effective utilization rate of steel plates. S42. Assembly Dimension Control: During the assembly stage, based on the dimensional information in the assembly positioning drawings, install and position the extended or retracted closing structure dimensions to ensure that the positioning error is controlled within -2~0mm. If the positioning error deviation is within -5~-2mm or 0~+3mm, then through simulation analysis, adjust the dimensions and structure of the unbuilt segments to ensure that the gap between the two meets the requirements. S43. Final dimension confirmation: After the assembled structure is welded, the dimensions of the extended or retracted closing structure are checked and confirmed according to the dimension information in the drawings to ensure that the structure position is installed accurately and to provide high-precision products for segmented completion. S5. Continuous improvement, reverse simulation assembly was successfully implemented, and the original bevel retention rate continued to increase.

2. The ship assembly method based on simulated assembly according to claim 1, characterized in that, S1 specifically includes the following steps: S11. Based on the production plan, create a simulated assembly positioning scheme, and specify the positioning detection points, the installation position of the limit blocks, and their thickness in the scheme; S12. Design and formulate a simulated assembly implementation schedule. Based on the control and precautions required for the simulated assembly implementation, compile the contents of the simulated assembly implementation schedule. The contents of the simulated assembly implementation schedule specifically include: the time of formulation of the simulated assembly positioning plan, the time of issuance of the plan, the ship name and section name of the merging section, the merging stage, the margin marking, the inspection line, the margin cutting, the limit block, the target pre-attachment, the dimensions after positioning, the gap, the length of the secondary cutting, the end face trimming, the positioning personnel information, and the positioning conclusion. S13. After the simulated assembly is completed at the construction site according to the simulated assembly plan and implementation schedule, an implementation analysis and summary shall be conducted. The implementation progress report shall be tracked and fed back in the form of daily reports, and the simulation assembly implementation effect shall be analyzed, improved and perfected in the form of weekly and monthly summaries to ensure the implementation effect of the simulation assembly.

3. The ship assembly method based on simulated assembly according to claim 2, characterized in that, In S11, the simulated assembly positioning scheme is the difference in three-dimensional coordinate data of adjacent section closures, presented in a graphical form. The simulated assembly positioning scheme is formulated by comparing and analyzing the actual three-dimensional coordinate data of adjacent section closures, calculating the difference, and analyzing the data deviations in the ship's length, width, and height directions. Finally, based on the coordinate position, the gap size or structural misalignment size is determined to ensure that the main dimensions of the closure section meet the ship's precision requirements, while the closure gap can meet the requirements for direct welding. The positioning detection point is located at the intersection of the strong structure of the closure and the theoretical line of the main board. The strong structure of the closure position is determined according to the segmented structure diagram, and the strong structure position is used as the installation position of the limit block. Two limit blocks are installed for each closure.

4. The ship assembly method based on simulated assembly according to claim 3, characterized in that, The positioning detection points are located at the center of the segment closure, at the maximum half-width of the theoretical line between the platform and the outer plate, at the intersection of the strong rib frame and the theoretical line of the main board platform, and at the intersection of the longitudinal wall panel and the theoretical line of the main board platform.

5. The ship assembly method based on simulated assembly according to claim 3, characterized in that, Analyze the gap size of the closure joint at the strong structure location, and set the plate thickness of the limiting block according to the gap size. Before hoisting, install the limiting block at the strong structure location to control the closure joint gap. The plate thickness of the limiting block is set according to the gap size, and the plate thickness of the limiting block is equal to the closure joint gap size, with the error controlled within 2mm. Before the segmented hoisting, according to the positioning detection points in the simulated assembly positioning scheme, pre-attach target pieces at the positioning detection point positions and set the target piece angle for direct detection during segmented positioning. The principle for setting the target piece angle is that the front of the target piece is at a 90-degree angle to the laser beam emitted by the aiming lens of the total station, and the angle placement error is controlled within ±30 degrees to reduce measurement errors caused by angle deviation.

6. The ship assembly method based on simulated assembly according to claim 2, characterized in that, In S1, the information recorded includes the on-site implementation of allowance marking, inspection lines, allowance cutting, setting of limit blocks, and target pre-attachment implementation. The allowance marking is used to draw the allowance lines on-site to guide the cutting according to the lines and ensure the cutting accuracy. The inspection line is a 100mm or 200mm inspection line used to check the accuracy of the allowance cutting and also serves as a reference line for the closing and positioning inspection.

7. The ship assembly method based on simulated assembly according to claim 1, characterized in that, Step S2 specifically includes the following steps: S21. Data acquisition of the closure segment: Before the closure segment is hoisted together, the three-dimensional coordinate data of the closure joint are acquired. S22. Adjacent segment data acquisition: Acquire three-dimensional coordinate data of adjacent closure joints of the closure segment; S23. Simulation Analysis: Based on the data collected from the closure section and adjacent closure joints, a simulation analysis is conducted, taking into account the accuracy of the main dimensions of the hull, the accuracy requirements of special positions, and the requirements for the closure gap. After the overall analysis, a data report is given. Based on the data report, the allowance size and positioning scheme of the butt joint or corner joint area of ​​the closure section are determined to guide the on-site construction of the closure. The simulation analysis method is to use simulation analysis software to calculate the difference through the three-dimensional coordinates of the corresponding positions of adjacent closure joints, analyze the data deviation in the directions of ship length, height, and width, and determine the size of the gap or the size of the structural misalignment based on the location of the coordinates. S24. Segment optimization: For issues such as segment allowance and end face difference discovered during simulated assembly in the closure stage, segment control and reminder points are added to optimize segment control measures and allowance compensation schemes, thereby improving the accuracy and quality of segment construction. The segment control and reminder points refer to the dimensional information of the main board or component extending out of or retracting into the closure joint of the segment. The dimensional information is marked and clarified in the two-dimensional accuracy control inspection table to guide standardized construction on site.

8. The ship assembly method based on simulated assembly according to claim 1, characterized in that, S3 specifically includes the following steps: S31. Segmental Stage Completion Accuracy Inspection: After the three-dimensional data of the segment joint is collected after the segment construction is completed, the segment simulation analysis software in the PACM program of the accuracy control system is used to perform three-dimensional coordinate simulation analysis with adjacent segments. This ensures that the segment construction data meets both the hull accuracy dimensional requirements and the butt joint gap standard, generating a data report. Based on the report, on-site adjustments and corrections are made to ensure that the segment accuracy meets the requirements for subsequent assembly and use. S32. Segmented plug-in corner joint area control: For plug-in corner joint structures, add three-dimensional detection coordinate values ​​for the protruding or retracted closing positions, and detect the three-dimensional coordinates during the segmented positioning and completion stages; through segmented simulation analysis software, simulate with adjacent segment data to ensure that the segmented construction data meets both the hull precision dimensional requirements and the diagonal joint gap standards, generate data reports, and guide on-site adjustments and corrections; S33. Analyze and summarize, identify the reasons for the positioning and assembly process control, and formulate control improvement measures to provide high-quality segments for assembly.

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