Simulation and verification optimization method, storage medium and equipment for ship launching process in dock

Abstract

The present application relates to the field of shipbuilding technology, and more specifically, to a method, storage medium, and device for simulating and verifying the launching process of a ship in a dock. The present application establishes a three-dimensional finite element model of the entire ship, and according to the weight distribution of the calculation station and the arrangement of the dock piers, calculates the structural strength of the hull before loading, after loading, in the critical floating state, and in the full floating state, and calculates the stress state of the dock piers before loading, after loading, and in the critical floating state. When the calculation results do not meet the requirements, targeted measures such as strengthening the structural strength of the ship, adjusting the dock pier arrangement, and changing the dock pier structural parameters are adopted to ensure that the calculation results in each step meet the requirements, obtain a more reasonable dock pier arrangement plan and launching plan, estimate the critical floating state of the entire launching process in advance, and verify the local strength of the hull during the entire launching process.

Description

Technical Field

[0001] The present application relates to the technical field of shipbuilding, and in particular to a method, storage medium and equipment for simulating and verifying the optimization of a ship launching process in a dock. Background Art

[0002] The description in this section merely provides background information related to the present disclosure and may not constitute prior art.

[0003] There are many ways to launch ships, depending on the shipyard and the type of ship. For ships built in a dock, dock launching is a common, simple, and safe method of launching. However, for ships with large linear loads, there is a risk of exceeding the local strength of the dock piers and hull structure during the entire process of launching, from the pier state to the loading state, to the critical floating state, and then to the fully floating state. It is necessary to ensure the safety of the hull structure and the dock pier strength throughout the entire process. Launching calculations are usually performed before the ship is launched, and the launch of the ship is macroscopically predicted through hydrostatic calculations. In order to simplify the model, the hull is generally regarded as an elastic beam with a variable cross-section, and the dock piers are regarded as elastic supports for the bottom of the ship. A finite element model of the hull beam is established, and the hull deformation and dock pier support reaction forces are calculated. However, this equivalent and simplified treatment method cannot verify the local structure of the hull, and the local structure of the hull is often damaged to varying degrees. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a simulation verification and optimization method for the launching process of a ship in a dock, which is used to more accurately simulate the stress conditions of the hull and the dock pier during the launching process of the ship.

[0005] Another object of the embodiments of the present application is to provide a computer storage medium and a computer device for implementing the above method.

[0006] In a first aspect, a method for simulating and optimizing a ship launching process in a dock is provided, comprising the following steps:

[0007] 1) Establish a 3D finite element model of the entire ship, divide the 3D finite element model into several calculation stations according to the corresponding rib position numbers, and calculate the distribution of the entire ship weight at each calculation station before loading; establish a dock support system model based on the layout of the dock piers;

[0008] 2) Calculate the ship's structural strength and dock support reaction force when the ship is in the dry dock, based on the distribution of the ship's weight before loading at each calculation station and the dock pier layout. Determine whether the calculation results meet the requirements. If not, adopt at least one of the following methods: strengthening the ship's structural strength, adjusting the dock pier layout, or changing the dock pier structural parameters until the calculation results of this step meet the requirements.

[0009] 3) Input launching control parameters and ship loading conditions, calculate and analyze the ship structural strength in the loaded state, critical floating state, and fully floating state, calculate and analyze the dock pier support reaction in the loaded state and critical floating state, and judge whether the calculation results in this step meet the requirements. If not, adjust the loading form in the cabin, adjust the dock pier layout form, and adjust the dock pier structural parameters until the calculation results in this step meet the requirements.

[0010] In one possible implementation scheme, step 1) includes: according to the weight of the hull before launching and its distribution, statistically calculating the weight distribution of each computing station on the entire ship, redistributing the weight center of the computing station, and drawing a weight distribution curve of the entire ship.

[0011] In one possible implementation, step 2) includes:

[0012] 21) Based on the finite element model of the entire ship and according to the weight distribution of each calculation station before loading, adjust the weight center of the calculation station to be consistent with the actual ship;

[0013] 22) Calculate the stiffness coefficient of the entire dock pier;

[0014] 23) Input the constraint conditions and load parameters to calculate the ship's structural strength and dock support reaction force when the ship is in the dry dock;

[0015] 24) Compare the calculated results of the ship structure strength with the allowable stress of the structure, and compare the dock support reaction with the maximum load-bearing capacity of the dock to determine whether the calculated results meet the requirements. If not, adopt at least one of the following methods: strengthening the ship structure strength, adjusting the dock layout, or changing the dock structure parameters, until the calculated results of this step meet the requirements.

[0016] In one possible implementation, in step 24), the ship's structural strength is strengthened at locations where the structural stress in local areas of the bottom exceeds the allowable stress, and the stiffness coefficient of the dock is reduced by arranging cork or increasing the contact area between the dock and the bottom.

[0017] In one possible implementation, step 3) includes:

[0018] Calculate and analyze the bow structural strength and dock support reaction force when all loading in the cabin is completed. If the calculation results do not meet the requirements, adjust the cabin loading plan and dock layout until the calculation results meet the requirements.

[0019] In one possible implementation, step 3) includes:

[0020] The calculation method for the stern structural strength and dock pier strength when the ship is critically floating is:

[0021] By creating a new coordinate system under the condition of longitudinal inclination of the hull caused by the center of gravity shift, the stress of the stern structure and the load of the dock pier under the critical floating state are calculated and analyzed; if the calculation results do not meet the requirements, the loading plan in the cabin is adjusted until the calculation results meet the requirements;

[0022] In one possible implementation, step 3) includes:

[0023] The calculation method for the structural strength and deformation of the ship in the fully floating state is:

[0024] When the ship is floating upright in the harbor, the structural strength and hull deflection under the force of gravity and outboard hydrostatic pressure are analyzed. If the calculated results do not meet the requirements, the loading plan in the cabin is adjusted until the calculated results meet the requirements.

[0025] In one possible implementation, the calculation method for the stern structural strength and dock pier strength during critical floating of the ship includes:

[0026] 321) Based on the finite element model of the entire ship, the weight center of the calculation station is adjusted according to the weight distribution of each station on the entire ship after loading to be consistent with the actual ship;

[0027] 322) Calculate the stiffness coefficient of the entire dock pier;

[0028] 323) The trim angle is obtained based on the difference in draft height between the bow and stern of the ship after the center of gravity is shifted, and a new coordinate system under the trim angle is created at the center of gravity position in the three-dimensional finite element model of the entire ship;

[0029] 324) The average draft value at the center of gravity of the three-dimensional finite element model of the entire ship is converted according to the bow and stern draft, and the hydrostatic pressure value is applied accordingly;

[0030] 325) Input the constraint conditions and load parameters. When the calculated dock support reaction is negative, it means that the dock has been separated from the pier at this point on the hull and is in a tension state. The tensioned dock needs to be deleted from the three-dimensional finite element model of the entire ship and the iterative calculation is continued until the remaining docks are in a compression state. This is used to verify the maximum dock support reaction at the stern during the bow floating process.

[0031] In a second aspect, a computer storage medium is also provided, which stores a computer program, and when the program is executed by a processor, it implements the simulation verification and optimization method of the launching process of a ship in the dock as described in any possible embodiment scheme of the first aspect.

[0032] In a third aspect, a computer device is also provided, comprising a memory and a processor, wherein the memory stores a computer program, which, when executed by the processor, implements the simulation, verification and optimization method for the launching process of a ship in a dock as described in any possible embodiment scheme of the first aspect.

[0033] The beneficial effects of the present application are as follows: the present application establishes a three-dimensional finite element model of the entire ship, and according to the weight distribution of the calculation station and the arrangement of the dock piers, calculates the structural strength of the hull before loading, after loading, in the critical floating state and in the full floating state respectively; calculates the stress state of the dock piers before loading, after loading and in the critical floating state respectively; when the calculation results do not meet the requirements, targeted measures such as strengthening the structural strength of the ship, adjusting the dock pier arrangement form, and changing the dock pier structural parameters are adopted, so that the calculation results in each step meet the requirements, and a more reasonable dock pier arrangement plan and launching plan are obtained, the critical floating state of the entire launching process is estimated in advance, and the local strength of the hull during the entire launching process is verified. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 Schematic diagram of a flow chart of a method for simulating, verifying and optimizing a ship launching process in a dock according to an embodiment of the present application;

[0036] Figure 2 Schematic diagram of a cross-sectional view of a bow portion of a ship dock arrangement according to an embodiment of the present application;

[0037] Figure 3 Schematic diagram of a typical cross-section of a ship dock arrangement amidships according to an embodiment of the present application;

[0038] Figure 4 Schematic diagram of hydrostatic pressure distribution on a bow cross section according to an embodiment of the present application;

[0039] Explanation of the accompanying reference numerals: 1. launching beam; 2. dock pier; 3. hardwood; 4. engineering plastic; 5. ribbed timber; 6. hull. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0042] In the description of this application, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as limiting this application. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0044] According to the first aspect of the present application, a method for simulating and optimizing the launching process of a ship in a dock is first provided. Figure 1 The present invention is a flowchart of a method for simulating, verifying and optimizing the launching process of a ship in a dock according to an embodiment of the present application.

[0045] During the launch process, due to the uneven weight distribution of the entire ship, the bow and stern float at different times before the buoyancy is leveled. This can cause the bow or stern plating and internal structure to deform due to the large support reaction force from the dock piers, which can easily cause damage to the hull structure. This requires an early safety assessment of the ship's launching process. By predicting risks in advance, measures such as optimizing the dock layout for areas with insufficient structural strength can be implemented to prevent excessive structural stress or even damage.

[0046] This application establishes a full-scale 3D finite element model of the ship and numerically simulates the entire launching process, from dry docking, stowage, critical flotation, to full flotation. This iterative optimization approach selects a suitable docking pier layout and pre-stowage scheme within the hold. This approach also estimates the critical flotation state throughout the launching process and verifies the local strength of the hull and the docking pier strength throughout the launching process, ensuring structural safety. The following details the verification and optimization methods.

[0047] The simulation and verification optimization method for the ship launching process in the dock includes the following steps:

[0048] 1) Establish a three-dimensional finite element model of the entire ship, divide the three-dimensional finite element model of the entire ship into several calculation stations according to the corresponding rib position numbers, and calculate the distribution of the entire ship weight at each calculation station before loading; establish a dock support system model based on the layout of the dock piers.

[0049] Specifically, according to the hull weight and its distribution before launching, the weight distribution of each calculation station on the whole ship is statistically calculated, the weight center of the calculation station is redistributed, and the weight distribution curve of the whole ship is drawn.

[0050] The finite element modeling scope covers the entire ship structure, primarily including the main hull, superstructure, shafting, stern support system, and other components. Due to modeling workload and other factors, some minor factors that have little impact on the hull structure deformation, such as smaller brackets and openings, can be ignored in the calculation model.

[0051] According to the dock pier layout diagram, the dock pier support system model is established. The specific method is as follows: the dock pier support system can be divided into the following types:

[0052] like Figure 2 As shown in FIG, the bow launching beam 1 is provided with a rib 5. Figure 3 As shown, the stern and midship dock piers 2 are constructed with either engineering plastic 3 or hardwood 4. The dock support system is simulated using multi-point constraints (MPC) combined with spring elements. The calculation assumes that the dock pier 2 and bow crossbeam 1 are rigid and will not deform. Only the engineering plastic 3, hardwood 4, and crossbeam upper bracing 5 are simulated using MPC combined with spring elements. To accurately simulate the forces and deformations of the support system and the hull, the spring element stiffness coefficient K is calculated and assigned to the corresponding spring element. The calculation formula is K = EA / H, where E is the elastic modulus of the dock, A is the actual vertical contact area of the dock, and H is the height of the dock. The dimensions of the hardwood 4 are 1800mm*400mm, and the dimensions of the engineering plastic 3 are 1000mm*400mm. In particular, for the linearly tapered stern area, the dock's projected area must be calculated based on the actual contact area with the hull structure.

[0053] 2) Based on the distribution of the full ship weight before loading at each calculation station and the docking pier layout, calculate the ship's structural strength and docking pier support reaction when the ship is in the dry dock. Determine whether the calculation results meet the requirements. If not, adopt at least one of the following measures: strengthening the ship's structural strength, adjusting the docking pier layout, or changing the docking pier structural parameters until the calculation results of this step meet the requirements. In this state, all stern support systems used during the construction process should be removed.

[0054] Step 2) includes:

[0055] 21) Based on the finite element model of the entire ship and according to the weight distribution of each calculation station before loading, adjust the weight center of the calculation station to be consistent with the actual ship;

[0056] 22) Calculate the stiffness coefficient of the entire dock pier;

[0057] 23) Input the constraint conditions and load parameters to calculate the ship's structural strength and dock support reaction force when the ship is in the dry dock;

[0058] 24) Compare the calculated results of the ship structure strength with the allowable stress of the structure, and compare the dock support reaction with the maximum load-bearing capacity of the dock to determine whether the calculated results meet the requirements. If not, adopt at least one of the following methods: strengthening the ship structure strength, adjusting the dock layout, or changing the dock structure parameters, until the calculated results of this step meet the requirements.

[0059] In step 24), where the structural stress in the localized area of the ship's bottom exceeds the allowable stress, the ship's structural strength is strengthened. At the same time, the stiffness coefficient of the dock is reduced by installing cork or increasing the contact area between the dock and the ship's bottom, thereby reducing the structural stress in the localized area of the ship's bottom. If the dock strength does not meet the requirements, the number of docks can be increased, or the size of the docks can be increased.

[0060] 3) Input launching control parameters and ship loading conditions, calculate and analyze the ship structural strength in the loaded state, critical floating state, and fully floating state, calculate and analyze the dock pier support reaction in the loaded state and critical floating state, and judge whether the calculation results in this step meet the requirements. If not, adjust the loading form in the cabin, adjust the dock pier layout form, and adjust the dock pier structural parameters until the calculation results in this step meet the requirements.

[0061] Specifically, according to the requirements of the undocking process, the ship needs to be leveled by ballast water to float, or the interior of the ship needs to be partially loaded in advance in the dry dock state. During the water release process, the water release in the dock and the loading in the cabin are carried out simultaneously. Step 3) includes:

[0062] 31) Calculate and analyze the bow structural strength and dock support reaction force when all loading in the cabin is completed. If the calculation results do not meet the requirements, adjust the cabin loading plan and dock layout until the calculation results meet the requirements.

[0063] Step 31) includes: 311) based on the finite element model of the entire ship, according to the weight distribution of each calculation station of the entire ship before loading, adjusting the weight center of gravity of the calculation station to be consistent with the actual ship;

[0064] 312) Calculate the stiffness coefficient of the entire dock pier;

[0065] 313) The compartment to be loaded is the ballast tank. Based on the capacity and center of gravity of each compartment in the overall ballast tank loading plan, it is proposed to use multi-point constraint MPC and mass points to distribute the loading on the ballast tank boundary. That is, the weight of the loading in the ballast tank is loaded at the centroid of the ballast tank, and then the multi-point constraint is used to apply the loading to the entire ballast tank boundary.

[0066] 314) Figure 4 As shown, according to the overall input, when the water filling in the dock is suspended and the ballast tank is loaded, the ship's attitude has been basically adjusted to a flat floating state. According to the average draft value at this time, the hydrostatic pressure value is applied to the two-dimensional unit of the hull shell 6 in the form of surface pressure;

[0067] 315) Add constraints and loads and submit the calculation;

[0068] 316) Compare the calculated results with the allowable structural stress, mainly considering the structural strength of the bow ballast tank area, and compare the bow dock support reaction with the maximum load-bearing capacity of the dock to meet the dock strength verification. In particular, for the structural stress in the bow area or the position where the dock support reaction exceeds the load, the loading scheme is adjusted to meet the structural strength requirements. In other embodiments, the dock arrangement can also be adjusted, such as adding docks or changing the size of the docks. The loading scheme can be adjusted by distributing the load in one compartment to multiple compartments to disperse the range of the load gravity.

[0069] 32) The calculation method for the stern structural strength and dock pier strength when the ship is critically floating is:

[0070] The different times at which the bow and stern of a ship are floated cause the stern structure to experience significant support reactions from the dock. By creating a new coordinate system for the ship's longitudinal tilt caused by a center of gravity offset, the stern structural stresses and dock loads under the critical floatation state are calculated and analyzed. If the calculated results do not meet the requirements, the internal loading plan is adjusted until the results meet the requirements. The critical floatation state refers to a situation in which the bow of a large stern-engined ship is already floated, but only the stern is partially anchored, leaving the entire ship in a state of near-floating.

[0071] The specific steps are as follows:

[0072] 321) Based on the finite element model of the entire ship, the weight center of the calculation station is adjusted according to the weight distribution of each station on the entire ship after loading to be consistent with the actual ship;

[0073] 322) Calculate the stiffness coefficient of the entire dock pier;

[0074] 323) The trim angle is obtained based on the difference in draft height between the bow and stern of the ship after the center of gravity is shifted, and a new coordinate system under the trim angle is created at the center of gravity position in the three-dimensional finite element model of the entire ship;

[0075] 324) The average draft value at the center of gravity of the three-dimensional finite element model of the entire ship is converted according to the bow and stern draft, and the hydrostatic pressure value is applied accordingly;

[0076] 325) Input the constraint conditions and load parameters. When the calculated dock support reaction is negative, it means that the dock has been separated from the pier at this point on the hull and is in a tension state. The tensioned dock needs to be deleted from the three-dimensional finite element model of the entire ship and the iterative calculation is continued until the remaining docks are in a compression state. This is used to verify the maximum dock support reaction at the stern during the bow floating process.

[0077] 33) The calculation method for the structural strength and deformation of the ship in the fully floating state is:

[0078] When the ship is floating upright in the harbor, the structural strength and hull deflection under the force of gravity and outboard hydrostatic pressure are analyzed. If the calculated results do not meet the requirements, the loading plan in the cabin is adjusted until the calculated results meet the requirements.

[0079] The specific steps are as follows: 331) Based on the finite element model of the entire ship, adjust the center of gravity to be consistent with the actual ship according to the weight distribution of each station on the entire ship after loading. 332) Delete the dock support system from the model. 333) Based on the overall input, the average draft of the ship at this time is applied accordingly. 334) Add constraints and loads and submit the calculation. In particular, the boundary conditions can use the inertia release method to use the inertia (mass) force of the structure to balance the external forces. 335) At this point, the hull is in a cambered state, with the bow and stern drooping at the bow and stern, forming a deflection curve for the entire ship and predicting the local strength stress value of the hull structure. If the local strength stress value of the hull structure does not meet the requirements, adjust the loading to change the deflection curve of the entire ship until the calculation results meet the requirements.

[0080] The results of actual ship monitoring show that this calculation method is scientific and reliable, providing technical support for early risk prediction and effectively ensuring the safety of ship launching structures:

[0081] (1) During the entire launching process, the reaction force of the stern pier reached a maximum value of 170t in the dry dock state, which did not exceed the maximum load-bearing capacity of 200t, meeting the pier strength verification. After the local structure of the bottom was strengthened, the overall structural stress was 193MPa, which was less than the allowable stress.

[0082] (2) During the advance loading and synchronous loading process in the cabin, the overall structural stress of the bow bottom after the local structure was strengthened was 90 MPa, the structural stress was less than the allowable stress, and the dock pier support reaction force did not exceed the maximum bearing capacity of 200t.

[0083] (3) During critical buoyancy, the reaction force of the stern dock pier did not exceed the maximum load-bearing capacity of the dock pier. The structural stress was 184 MPa, which was less than the allowable stress. The maximum dock pier reaction force was 119 t. The order in which the dock piers detached from the hull was that the dock pier at the midship pier detached first, and then gradually detached towards the bow and stern.

[0084] (4) The numerical calculation shows that the maximum flexural deformation value at the midship under static floating state is 200.3 mm, which is very close to the maximum camber flexural deformation value of 206 mm at the midship during actual launching monitoring.

[0085] According to the second aspect of the present application, a computer storage medium is also provided, which stores a computer program. When the program is executed by a processor, it implements the simulation verification and optimization method for the launching process of a ship in the dock described in the above embodiment.

[0086] Preferably, the storage medium includes: ROM, RAM, magnetic disk, USB flash drive, memory card or optical disk, etc., various media that can store program codes.

[0087] According to the third aspect of the present application, the present application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the program is executed by the processor, it implements the simulation verification and optimization method of the launching process of a ship in the dock as described in any one of the embodiments of the first aspect.

[0088] The memory includes various media that can store program codes, such as ROM, RAM, magnetic disk, USB flash drive, memory card or optical disk. The processor is connected to the memory and is used to execute the computer program stored in the memory.

[0089] Preferably, the processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0090] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A method for simulating and optimizing the launching process of a ship in a dock, characterized in that: The following steps are involved: 1) Establish a 3D finite element model of the entire ship, divide the 3D finite element model into several calculation stations according to the corresponding rib position numbers, and calculate the distribution of the entire ship weight at each calculation station before loading; establish a dock support system model based on the layout of the dock piers. The dock support system can be divided into the following types: The bow launching beam is equipped with slats, and the stern and midship dock piers are equipped with engineering plastics or hardwood. Multi-point constraints (MPC) combined with spring elements are used to simulate the dock pier support system. During the calculation, the dock pier and bow beam are assumed to be rigid structures and will not deform. Only the engineering plastics, hardwood, and the slats on the beam are simulated using MPC combined with spring elements. 2) Calculate the ship's structural strength and dock support reaction force when the ship is in the dry dock, based on the distribution of the ship's weight before loading at each calculation station and the dock pier layout. Determine whether the calculation results meet the requirements. If not, adopt at least one of the following methods: strengthening the ship's structural strength, adjusting the dock pier layout, or changing the dock pier structural parameters until the calculation results of this step meet the requirements. 3) Input launching control parameters and ship loading conditions, calculate and analyze the ship structural strength in the loaded state, critical floating state, and fully floating state, calculate and analyze the dock support reaction in the loaded state and critical floating state, and determine whether the calculation results in this step meet the requirements. If not, adjust at least one of the following methods: adjust the loading form in the cabin, adjust the dock arrangement form, or adjust the dock structural parameters until all the calculation results in this step meet the requirements; The calculation methods for the stern structural strength and dock pier strength of the ship during critical floating include: 321) Based on the finite element model of the entire ship, the weight center of the calculation station is adjusted according to the weight distribution of each station on the entire ship after loading to be consistent with the actual ship; 322) Calculate the stiffness coefficient of the entire dock pier; 323) The trim angle is obtained based on the difference in draft height between the bow and stern of the ship after the center of gravity is shifted, and a new coordinate system under the trim angle is created at the center of gravity position in the three-dimensional finite element model of the entire ship; 324) The average draft value at the center of gravity of the three-dimensional finite element model of the entire ship is converted according to the bow and stern draft, and the hydrostatic pressure value is applied accordingly; 325) Input the constraint conditions and load parameters. When the calculated dock support reaction is negative, it means that the dock has been separated from the pier at this point on the hull and is in a tension state. The tensioned dock needs to be deleted from the three-dimensional finite element model of the entire ship and the iterative calculation is continued until the remaining docks are in a compression state. This is used to verify the maximum dock support reaction at the stern during the bow floating process.

2. The method for simulating and optimizing the launching process of a ship in a dock according to claim 1, characterized in that: Step 1) includes: according to the weight of the hull before launching and its distribution, statistically calculating the weight distribution of each calculation station of the whole ship, redistributing the weight center of gravity of the calculation station, and drawing a weight distribution curve of the whole ship.

3. The method for simulating, verifying and optimizing the launching process of a ship in a dock according to claim 1, characterized in that: Step 2) includes: 21) Based on the finite element model of the entire ship and according to the weight distribution of each calculation station before loading, adjust the weight center of the calculation station to be consistent with the actual ship; 22) Calculate the stiffness coefficient of the entire dock pier; 23) Input the constraint conditions and load parameters to calculate the ship's structural strength and dock support reaction force when the ship is in the dry dock; 24) Compare the calculated results of the ship structure strength with the allowable stress of the structure, and compare the dock support reaction with the maximum load-bearing capacity of the dock to determine whether the calculated results meet the requirements. If not, adopt at least one of the following methods: strengthening the ship structure strength, adjusting the dock layout, or changing the dock structure parameters, until the calculated results of this step meet the requirements.

4. The method for simulating, verifying and optimizing the launching process of a ship in a dock according to claim 3, characterized in that: In step 24), the ship's structural strength is strengthened at locations where the structural stress in the local area of the bottom exceeds the allowable stress, and the stiffness coefficient of the dock is reduced by arranging cork or increasing the contact area between the dock and the bottom.

5. The method for simulating, verifying and optimizing the launching process of a ship in a dock according to claim 1, characterized in that: Step 3) includes: Calculate and analyze the bow structural strength and dock support reaction force when all loading in the cabin is completed. If the calculation results do not meet the requirements, adjust the cabin loading plan and dock layout until the calculation results meet the requirements.

6. The method for simulating, verifying and optimizing the launching process of a ship in a dock according to claim 1, characterized in that: Step 3) includes: The calculation method for the stern structural strength and dock pier strength when the ship is critically floating is: By establishing a new coordinate system under the longitudinal inclination of the hull caused by the center of gravity offset, the stern structural stress and the dock pier load-bearing conditions under the critical floating state are calculated and analyzed; if the calculation results do not meet the requirements, the loading plan in the cabin is adjusted until the calculation results meet the requirements.

7. The method for simulating, verifying and optimizing the launching process of a ship in a dock according to claim 1, characterized in that: Step 3) includes: The calculation method for the structural strength and deformation of the ship in the fully floating state is: When the ship is floating upright in the harbor, the structural strength and hull deflection under the force of gravity and outboard hydrostatic pressure are analyzed. If the calculated results do not meet the requirements, the loading plan in the cabin is adjusted until the calculated results meet the requirements.

8. A computer storage medium, characterized in that It stores a computer program, which, when executed by a processor, implements the simulation, verification and optimization method for the launching process of a ship in a dock as claimed in any one of claims 1 to 7.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory stores a computer program, and when the program is executed by the processor, the simulation, verification and optimization method for the launching process of a ship in a dock described in any one of 1 to 7 is implemented.

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