Load collaborative design and hull safety verification method for vacuum adsorption type mooring system

Abstract

The invention provides a load collaborative design and hull safety verification method for a vacuum adsorption type mooring system, and belongs to the technical field of ship mooring safety design and automatic control. Comprising the following steps: acquiring target ship parameters and extreme environmental conditions, and acquiring a ship loading state and a tidal water level as dynamic coupling variables; modeling and analyzing a multi-source load model to obtain a reference load, a wave load and a yawing moment, and determining a standard value of a limit load combination; constructing a parameterized simulation model to obtain an initial limit load, and determining a simulation value and standard value decision logic to obtain a final limit load; a mooring force distribution model is established, iterative optimization of the number of the vacuum adsorption type mooring devices is carried out, and the number of the vacuum adsorption type mooring devices and the maximum allowable adsorption force of the single vacuum adsorption type mooring device are output; and carrying out compatibility verification with the ship body structure, determining whether the safety boundary is matched or not, and obtaining the number of the vacuum adsorption type mooring devices and the maximum allowable adsorption force.

Description

Technical Field

[0001] This invention relates to the field of ship mooring safety design and automatic control technology, and in particular to a method for load coordination design and hull safety verification of a vacuum adsorption mooring system. Background Technology

[0002] Ship mooring is a crucial link in ensuring port operation safety. Traditional mooring relies on manual operation of cables, which has drawbacks such as low efficiency, high risk, and significant susceptibility to environmental influences. As the global shipping industry transforms towards high efficiency, safety, and intelligence, vacuum adsorption mooring systems are gradually replacing traditional methods. However, the design and application of existing domestic vacuum adsorption mooring systems face the following core challenges: 1. Incomplete environmental load analysis dimensions: Current international standards and design specifications are significantly inadequate in environmental load analysis, lacking a systematic quantitative method for wave forces and generally neglecting the yaw moment generated by the ship's turning motion. Furthermore, key parameters such as the dynamic changes in the ship's actual loading state and water level fluctuations caused by tides are not included in a unified analysis framework, leading to significant deviations between design loads and actual port operating conditions. 2. Insufficient confidence in the design verification process: Traditional design processes rely excessively on theoretical formulas and lack the crucial verification step of high-fidelity digital simulation. 1. The inability to simulate the complex environmental coupling effects under multiple directions and operating conditions results in a lack of data support for setting safety thresholds, making it impossible to accurately define safety boundaries in the design results; 2. The lack of algorithmic basis for the coordinated output allocation of the system: Faced with the need for coordinated operation of multiple vacuum adsorption mooring devices, existing methods lack scientific allocation algorithms based on force system balance. The number and layout of devices largely rely on engineering experience, making it impossible to achieve optimal allocation of system resources and difficult to balance operational safety and economy; 3. The neglect of ship-shore structural compatibility: The existing design process completely severs the connection between the output of the mooring system and the load-bearing capacity of the hull structure. The force generated by vacuum adsorption acts directly on the hull plates, but the strength and deformation limits are not verified during the design process, posing a potential risk of damage to the hull structure.

[0003] In existing technologies, environmental load calculation, simulation verification, device allocation, and hull calibration are all isolated technical points. For example, the Chinese patent application with application number 202310404240.7 only focuses on mooring stability and has not formed a systematic design method covering the entire process "from environmental input to structural safety," resulting in data disconnect between various stages. The above-mentioned technical defects have led to significant commercial consequences: on the one hand, over-design has generally inflated the manufacturing cost of mooring systems by 15%-30%; on the other hand, insufficient design confidence has created huge safety hazards for port operations.

[0004] Therefore, it is essential to provide a load-coordinated design and hull safety verification method for vacuum adsorption mooring systems. This method involves constructing a complete environmental load model, forming a load decision-making process that integrates simulation and standards, proposing a calculation scheme for multi-machine load distribution and quantity optimization, and introducing a systematic safety load definition method for the pillowcase system in the compatibility verification of hull structural strength. This provides a decision-making basis for the design of vacuum adsorption mooring devices and the feasibility analysis of port safety upgrades. The aim is to significantly reduce the R&D and manufacturing costs of high-end mooring equipment, enhance my country's core competitiveness in the field of port automation equipment, and foster new business models for safety assessment services based on high-confidence simulation analysis. Summary of the Invention

[0005] In view of this, the present invention proposes a limit load determination process that integrates standard calculation, multi-factor coupled analysis and hydrodynamic simulation verification, and realizes the limit load determination method for the design of automatic mooring devices, which realizes parallel analysis and verification of multi-source loads, limit load determination, mooring force distribution and hull structure safety verification.

[0006] This invention provides a method for load coordination design and hull safety verification of a vacuum adsorption mooring system, comprising the following steps: The target ship parameters and extreme environmental conditions are obtained, and the ship loading status and tidal level are obtained as dynamic coupling variables. Based on the target ship parameters, extreme environmental conditions and dynamic coupling variables, a multi-source load model is modeled and analyzed to obtain the reference load, wave load and yaw moment, and the ultimate load combination is determined to obtain the specification value of the ultimate load. Construct a parametric simulation model and set dynamic boundary conditions to obtain the initial ultimate load; based on the initial ultimate load and the specification values ​​of the ultimate load, determine the decision logic and output the final ultimate load; Multi-dimensional working condition scanning and final ultimate load extraction are performed to establish a mooring force distribution model, iterative optimization of the number of vacuum adsorption mooring devices is carried out, and the number of vacuum adsorption mooring devices and the maximum allowable adsorption force of a single vacuum adsorption mooring device are output. Based on the obtained number of vacuum adsorption mooring devices and the maximum allowable adsorption force of a single vacuum adsorption mooring device, a compatibility check is performed with the hull structure to determine whether the safety boundaries match. If they match, the number of vacuum adsorption mooring devices and the maximum allowable adsorption force of a single vacuum adsorption mooring device are output. If they do not match, the iterative optimization step for the number of vacuum adsorption mooring devices is returned, and the iterative optimization of the number and placement of vacuum adsorption mooring devices is repeated.

[0007] Based on the above technical solutions, preferably, the acquisition of target ship parameters and extreme environmental conditions includes the target ship parameters such as the overall length, beam, depth, and draft of the target ship; and the extreme environmental conditions such as wind speed, significant wave height, wave period, current velocity, water depth, and seawater density.

[0008] Based on the above technical solutions, the preferred approach involves modeling and analyzing a multi-source load model based on target ship parameters, extreme environmental conditions, and dynamic coupling variables. This yields the reference load, wave load, and yaw moment, and determines the ultimate load combination to obtain the specified values ​​for the ultimate load. Specifically, this includes the following: S11: Calculate wind load and current load, and further calculate the resultant force of ship sway, the resultant force of ship roll, and the unbalanced bending moment of bow roll based on wind load and current load. Lateral wind force related to wind load in attached coordinate system Longitudinal wind force Yaw torque caused by wind Lateral flow forces related to flow load Longitudinal water flow force Yaw torque caused by water flow The resultant force of the ship's swaying The combined force of ship swaying Unbalanced bending moment of bow roll for: ; S12: Introduce wave loads and perform a wave direction angle scan from 0° to 180°; S13: Perform bow roll moment calculation; S14: Determine the ultimate load combination; select the maximum transverse mooring force load and the maximum longitudinal mooring force load corresponding to different wind direction angles and flow direction angles, and select the maximum transverse wave force, yaw torque and the maximum longitudinal wave force corresponding to different wave incidence angles as the standard values ​​for the ultimate load combination.

[0009] Preferably, the construction of the parameterized simulation model, setting dynamic boundary conditions, and obtaining the preliminary ultimate load; based on the preliminary ultimate load and the specification values ​​of the ultimate load, determining the decision logic and outputting the final ultimate load, specifically includes the following: S21: Establish a parametric model; based on the ship's width between perpendiculars, beam, draft, mass inertia, and windward area, establish a frequency response model for the ship, defining the key degrees of freedom of the ship in hydrodynamics, including the resultant force of sway, the resultant force of roll, and bow roll; import a domain file containing the berth and breakwater structure, use a local coordinate system, divide the grid to a specified size, and cover the area around the ship; set the bathymetry data according to the actual terrain to ensure that the water depth at the wharf front matches the tidal level parameters; based on the actual mooring arrangement, define nonlinear mooring cables and fender units, and establish a mooring system model to simulate the constraint and energy dissipation of the hull by the vacuum adsorption mooring device; S22: Set dynamic boundary conditions; input the environmental load spectrum corresponding to the limit parameters of wind load, current load, and wave load; the ship's load capacity is discretely set as empty, ballast, or fully loaded, and the simulation model automatically associates the ship's draft, displacement, center position, and underwater wetted surface area corresponding to each load capacity, dynamically correcting the ship's hydrodynamic coefficient and windward and current-receiving areas; based on the actual tidal characteristics of the port area, set the tidal water level status including three types of water levels: lowest low tide, average tide, and highest high tide. S23: Multi-dimensional operating condition scanning and ultimate load extraction; Based on the established ship frequency response model, perform omnidirectional environmental scanning, systematically changing the wind direction angle at 22.5° intervals within the range of 0° to 180°. α Flow angle β The system response under each combination of wave direction angles is calculated. The results of the omnidirectional environmental scan are orthogonally combined with the preset ship load and tidal level to form an environmental direction-load-tidal level coupled working condition matrix. The time domain results of all simulation working conditions are post-processed to select the maximum load values ​​in the resultant force of sway, resultant force of roll, and bow roll degrees of freedom within the parameter range. The maximum load values ​​in each degree of freedom are combined as the preliminary limit load. S24: Verify and correct based on the standard model to determine the decision logic; compare the obtained preliminary limit load with the standard value of the obtained limit load combination, and give the following decision logic: if the preliminary limit load obtained by simulation is greater than the standard value and the difference does not exceed 20%, directly use the preliminary limit load as the final limit load; if the preliminary limit load obtained by simulation is greater than the standard value and the difference exceeds 20%, check whether the ship's frequency response model and input parameters are correct. After confirming that the frequency response model and input parameters are correct, use the envelope value of the simulation value and the standard value as the final limit load. If there are errors in the frequency response model and input parameters, correct the errors and re-simulate the preliminary limit load, and compare it with the standard value again; when the preliminary limit load obtained by simulation is less than the standard value, use the standard value as the final limit load.

[0010] More preferably, the process of performing multi-dimensional working condition scanning and ultimate load extraction, establishing a mooring force distribution model, iteratively optimizing the number of vacuum adsorption mooring devices, and outputting the number of vacuum adsorption mooring devices and the maximum allowable adsorption force of a single vacuum adsorption mooring device specifically includes the following: S31: Establish a mooring force distribution model to account for the resultant force of the ship's sway. The combined force of ship swaying According to the number of vacuum adsorption mooring devices n Evenly distributed unbalanced bending moment of the bow. According to the distance of each vacuum adsorption mooring device from the center of the mooring system model d i Allocation, number i Longitudinal driving force of a vacuum adsorption mooring device F yi and lateral driving force F xi for: , ;in i ∈ n , k 1 and k 2 represents the gain coefficient; S32: Perform iterative optimization of the number of vacuum adsorption mooring devices, given constraints, determine the number of vacuum adsorption mooring devices; S33: Construct an iterative algorithm for solving vacuum adsorption mooring devices and determine the number of vacuum adsorption mooring devices. n Equidistant spacing from adjacent vacuum adsorption mooring units .

[0011] Furthermore, the gain coefficient is preferred. k 1 and k The value of 2 is related to the water area, and is relevant in areas where the water depth is greater than twice the ship's waterline length. k 2 represents 0.1-1.0. k 1 represents 0.07-0.10; in areas where the water depth does not exceed twice the ship's waterline length. k 2 represents 1.0-3.0. k 1 represents 0.1-0.3.

[0012] More preferably, the iterative algorithm for constructing the vacuum adsorption mooring device is based on obtaining the resultant force of the ship's sway. The combined force of ship swaying Subsequently, based on the resultant force of ship swaying Determine the current number of vacuum adsorption mooring devices. n 0, determine if it satisfies If the conditions are met, then the current number of vacuum adsorption mooring devices will be used. n 0 represents the required number of vacuum adsorption mooring units; if this requirement is not met, the current number of vacuum adsorption mooring units will be used. n Add 1 to the base value of 0, and re-evaluate whether the inequality is satisfied. The process continues until the desired number of vacuum adsorption mooring devices is achieved. The number of devices required for each cycle is then output as the total number of vacuum adsorption mooring devices needed. After determining the required number of devices, the equidistant spacing between adjacent vacuum adsorption mooring devices is further determined. .

[0013] More preferably, the step of verifying the compatibility between the obtained number of vacuum adsorption mooring devices and the maximum allowable adsorption force of a single vacuum adsorption mooring device and the hull structure to determine whether the safety boundaries match includes the following: S41: Determine the verification area; select the outer side plate as the area with the weakest vacuum adsorption force under the vacuum adsorption mooring device; obtain the structural parameters of the outer side plate, including the nominal thickness of the outer plate, the spacing between longitudinal ribs, and the spacing between strong ribs, and establish a parametric finite element reference model. S42: Define dual structural safety limit criteria; simultaneously satisfy both strength safety criteria and stiffness safety criteria. The strength safety criterion is that the maximum equivalent stress of the side outer plate must not exceed the design allowable stress; the stiffness safety criterion is that the maximum deflection of the side outer plate under the adsorption force of the vacuum adsorption mooring device must not exceed the preset percentage of the support rib spacing. S43: Perform iterative finite element analysis to determine the safety boundary; in the central region of the parameterized finite element reference model, apply an adsorption pressure load equivalent to the design area of ​​the vacuum suction cup of the vacuum adsorption mooring device. Increase the adsorption pressure load and perform static iterative analysis. When the maximum equivalent stress of the side outer plate first reaches the design allowable stress, or the maximum deflection of the side outer plate under the adsorption force of the vacuum adsorption mooring device first reaches the maximum allowable limit, it is determined that the critical safety state has been reached. At this time, the adsorption force under the critical safety state is recorded and output as the maximum allowable adsorption force of a single vacuum adsorption mooring device. ; S44: Establish a design closed loop and mandatory safety constraints; apply the contents of steps S42 and S43 as mandatory constraints to ensure that the overall mooring load is distributed to the adsorption force requirements of a single vacuum adsorption mooring device. The maximum allowable adsorption force of a single vacuum adsorption mooring unit shall not exceed the maximum allowable adsorption force of a single vacuum adsorption mooring unit. .

[0014] In a further preferred embodiment, the allowable design stress mentioned in step S42 is obtained by dividing the yield strength of the material of the side outer plate by a preset safety factor.

[0015] In a further preferred embodiment, the stiffness safety criterion mentioned in step S42 is that the maximum deflection of the outer side plate under the adsorption force of the vacuum adsorption mooring device shall not exceed 6% of the support rib spacing.

[0016] The load coordination design and hull safety verification method for vacuum adsorption mooring systems provided by this invention has the following advantages compared to existing technologies: 1. Construct a complete environmental load model: By establishing calculation models for wind- and current-induced yaw moments and supplementing the parameterized wave load model, gaps in the specifications are filled, achieving comprehensive quantification of environmental loads for the three degrees of freedom: pitch, sway, and yaw. Ship loading and port tidal levels are systematically incorporated into the analysis to ensure that the ultimate load accurately reflects the dynamic changes throughout the entire operational cycle.

[0017] 2. Establish a load decision-making process that integrates simulation and standards. Through high-fidelity hydrodynamic simulation, conduct a systematic scan of all directions and multiple working conditions, compare and integrate the results with the calculation results of the standard formulas, and form a set of load envelope value determination methods verified by virtual experiments, providing a reliable basis for system output design. 3. Propose a calculation scheme for multi-machine load distribution and quantity optimization: Establish a load distribution algorithm based on mechanical balance, and match iterative solution strategy for the number of devices, so as to scientifically determine the minimum number of vacuum adsorption mooring devices required to meet the operation requirements and the theoretical output value of each unit. 4. Introduce a compatibility verification step for the hull structure strength, and take the finite element analysis of the hull outer plate as a necessary step in the design. Through simulation calculation, determine the maximum allowable adsorption force of a single vacuum adsorption mooring device, and use this as a rigid constraint condition to ensure that mooring operations will not cause irreversible damage to the ship structure. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of a method for load coordination design and hull safety verification of a vacuum adsorption mooring system according to the present invention; Figure 2 This is a schematic diagram of environmental load decomposition for a load collaborative design and hull safety verification method for a vacuum adsorption mooring system according to the present invention. Figure 3This is a schematic diagram of the mooring position for a load coordination design and hull safety verification method for a vacuum adsorption mooring system according to the present invention. Figure 4 This invention provides the iterative process of the solution iterative algorithm for the vacuum adsorption mooring device in a load collaborative design and hull safety verification method for a vacuum adsorption mooring system. Figure 5 This is a schematic diagram of the stress distribution results of the outer plate of the hull side in the load-coordinated design and hull safety verification method of the vacuum adsorption mooring system of the present invention. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] The design and application of existing automated mooring systems face the following challenges: 1. How to accurately and comprehensively determine the ultimate loads that the system needs to withstand; 2. The calculation of wave loads is lacking and the calculation of environmental loads is not comprehensive; the influence of load capacity and tides on loads is ignored, which are two parameters that play a decisive role in the ultimate load of the ship's hydrodynamic performance; 3. The simplification of the ultimate load direction is too idealistic and fails to reflect the real and ever-changing marine environment; 4. The verification methods are limited, and the traditional design process relies on standard formulas for calculation, lacking simulation verification through high-fidelity hydrodynamic simulation software for multiple working conditions and multiple degrees of freedom; 5. The number and arrangement of vacuum adsorption mooring devices rely on experience, and the allocation method is unscientific; 6. The allowable adsorption force of vacuum adsorption mooring devices is not verified in conjunction with the stress of the ship's hull structure.

[0022] In view of this, such as Figure 1 As shown, this invention provides a method for load coordination design and hull safety verification of a vacuum adsorption mooring system, comprising the following steps: S1: Obtain the target ship parameters and extreme environmental conditions, and obtain the ship loading status and tidal level as dynamic coupling variables; based on the target ship parameters, extreme environmental conditions and dynamic coupling variables, perform multi-source load modeling and analysis to obtain the reference load, wave load, and bow roll moment, and determine the ultimate load combination to obtain the specification value of the ultimate load.

[0023] In this step, the target vessel parameters mainly include the overall length, beam, depth, and draft of the target vessel; the extreme environmental conditions include the wind speed, significant wave height, wave period, current velocity, water depth, and seawater density at the wharf; the dynamic coupling variables are defined as the vessel's loading status: 100% DWT fully loaded, 50% DWT ballasted, and 0% DWT unloaded, where DWT is an abbreviation for deadweight tons; and the tidal levels: the lowest tide level: the lowest water level in the port area during the tidal cycle; the average tide level: the statistical average water level in the port area during the tidal cycle; and the highest tide level: the highest water level in the port area during the tidal cycle.

[0024] Taking a 3000T oil tanker as an example, the ship is 97m long, 95m between perpendiculars, 15.2m wide, and has a full-load draft of 5.9m. At a certain chemical terminal, the wind speed is 20m / s, the significant wave height is 0.7m, the wave period is 3.3s, and the current speed is 0.51m / s. The lowest tide level is 12.86m, the average tide level is 15.0m, and the highest tide level is 16.9m.

[0025] Based on the above parameters, a multi-source load model is constructed and analyzed to obtain the reference load, wave load, and yaw moment, and to determine the specification values ​​of the ultimate load combination. Specifically, this includes the following: S11: Calculate wind load and current load, and further calculate the resultant force of ship sway, the resultant force of ship roll, and the unbalanced bending moment of bow roll based on wind load and current load. like Figure 2 As shown, in the attached coordinate system, the lateral wind force related to the wind load. Longitudinal wind force Yaw torque caused by wind Lateral flow forces related to flow load Longitudinal water flow force Yaw torque caused by water flow The resultant force of the ship's swaying The combined force of ship swaying Unbalanced bending moment of bow roll for: It should be noted that the calculation of wind load and flow load is a common technique in this field, and will not be elaborated here. For example, the calculation can be performed directly using the OCIMF standard and port engineering specifications.

[0026] S12: Introduce wave loads and perform a wave direction angle scan from 0° to 180°; The transverse wave force along the longitudinal axis of the ship is: The longitudinal wave force along the ship's longitudinal axis is: ,in, , , H For the incident wave height, θ The angle of incidence of the wave.L pp For the length between the ship's perpendiculars, D For the ship's draft, B For the ship's beam, g It is the acceleration due to gravity. T x For the ship's rolling period, T y For the ship's pitching period, T For wave cycles, W This refers to the ship's current displacement. W t This refers to the ship's full-load displacement.

[0027] S13: Perform bow roll moment calculation; The yaw moment caused by wind load is: The yaw moment caused by the flow load is: ,in This is the longitudinal distance from the point of application of the longitudinal wind force to the ship's center of gravity. This is the lateral distance from the point of application of the lateral wind force to the ship's center of gravity. This is the longitudinal distance from the point of application of the longitudinal water flow force to the ship's center of gravity. This is the lateral distance from the point of application of the lateral water flow force to the ship's center of gravity; Both the formulas for the bow roll moment caused by wind load and the formulas for the bow roll moment caused by current load are based on the vector cross product principle of moments. Bow roll is the rotation of the ship about its vertical z-axis, and moment calculations need to consider the vector relationship between force and lever arm. Furthermore, considering that the effects of wind and current forces on the ship are not uniformly distributed, and that the location of their point of application is affected by the ship's structure, a lever arm correction factor is introduced. η 0.7 ≤ η ≤ 0.8, the lever arm correction factor is an empirical value derived from statistical analysis of a large amount of ship hull wind tunnel and water tank test data, used to compensate for the offset between the actual pressure center and the geometric centroid. For wind loads... , , L pp For the hull length; for the current load, since its point of application is closer to the bow, then... In this embodiment, a 3000T oil tanker is used as an example, and the lever arm correction factor is... η It is 0.75.

[0028] S14: Determine the ultimate load combination; select the maximum transverse mooring force and maximum longitudinal mooring force corresponding to different wind and flow angles, and select the maximum transverse wave force, yaw torque, and maximum longitudinal wave force corresponding to different wave incidence angles as the standard values ​​for the ultimate load combination. Here, the OCIMF standard calculation model or the port engineering load code calculation model can be used to calculate the mooring force load under ultimate conditions.

[0029] Taking a 3000T oil tanker as an example, the maximum transverse mooring force is selected with a wind direction and flow angle of 0 degrees, the maximum longitudinal mooring force with a wind direction and flow angle of 90 degrees, and the maximum bow torque with a wind direction and flow angle of 135 degrees. For wave-induced loads, the maximum transverse wave force and bow torque are selected when the wave incidence angle is 67.5 degrees, and the maximum longitudinal wave force is selected when the wave incidence angle is 90 degrees. This step is to calculate different ultimate load combinations as the standard values ​​for theoretical calculations.

[0030] S2: Construct a parametric simulation model and set dynamic boundary conditions to obtain the initial ultimate load; based on the initial ultimate load and the specification value of the ultimate load, determine the decision logic and output the final ultimate load.

[0031] See attached document Figure 2 Step S2 constructs a parallel verification of the ship's ultimate load. Using hydrodynamic simulation software such as MIKE21, a multi-condition, multi-factor coupled simulation verification platform, the most unfavorable load combination is extracted from a massive dataset of operating conditions through systematic parametric scanning and coupled analysis. Step S3 includes the following:

[0032] S21: Establish a parametric model; First, establish a parametric simulation model that can accurately reflect the interaction between the ship, mooring system, and environment. Ship and hydrodynamic model: Based on the main dimensions of the target ship type, such as beam between perpendiculars, beam, draft, mass inertia and windward area, establish the frequency response model of the ship and define the key degrees of freedom of the ship in hydrodynamics. The key degrees of freedom usually include at least the resultant force of sway, the resultant force of roll and bow roll. Computational Domain and Mesh Import: Import the domain file containing the berth and breakwater structure, use a local coordinate system, divide the grid into grids of a specified size, and cover the area around the ship; the bathymetry data is set according to the actual terrain to ensure that the water depth and tidal level parameters at the wharf front match; in this embodiment, the grid size is 0.5m × 0.5m, covering a range of ±160m around the ship.

[0033] Mooring System Establishment: Based on the actual mooring arrangement, define nonlinear mooring cables and fender units to establish a mooring system model for simulating the constraint and energy dissipation of the hull by the vacuum adsorption mooring device. The nonlinear mooring cables are specified with material, breaking strength, stiffness curve, and damping parameters. The fender units include force-deformation characteristics and friction coefficients. Taking a 3000T oil tanker as an example, the mooring system model is as follows: Figure 3 As shown.

[0034] S22: Set dynamic boundary conditions; Environmental load spectrum: Input the environmental load spectrum corresponding to the limit parameters of wind load, flow load and wave load, such as the JONSWAP wave spectrum for simulation; Integrated loading conditions: The ship's load capacity is set discretely as empty, ballasted, or fully loaded; when the ship is sailing in ballast condition, the draft should reach 50% of the full load draft in summer, and 55% to 60% of the full load draft in winter.

[0035] Integration of tidal water level conditions: The parametric simulation model automatically associates the ship's draft, displacement, center position, and underwater wetted surface area for each loading capacity, and dynamically corrects the ship's hydrodynamic coefficient and windward and current-receiving areas; Based on the actual tidal characteristics of the port area, the tidal water level states are set to include three water levels: lowest low tide, average tide, and highest high tide; The ship's hydrodynamic coefficient is a conventional technical means in this field, which can be obtained through experiments or simulation.

[0036] S23: Multi-dimensional working condition scanning and ultimate load extraction; Perform an omnidirectional environmental scan: Based on the established frequency response model of the ship, perform an omnidirectional environmental scan, systematically changing the wind direction angle at 22.5° intervals within the range of 0° to 180°. α Flow angle β Calculate the system response for each combination of wave angles; Perform multi-factor coupling analysis: The results of the omnidirectional environmental scan are orthogonally combined with the preset ship loading capacity and tidal level status to form an environmental direction-loading capacity-tidal level coupled working condition matrix; this ensures that the analysis covers the entire operational parameter space. Synthetic envelope limit load: Post-process the time-domain results of all simulation conditions, and select the maximum load values ​​that appear in the resultant force of sway, the resultant force of roll, and the degree of freedom of yaw within the parameter range. Combine the maximum load values ​​in each degree of freedom as the preliminary limit load. S24: Verify and correct based on the standard model to determine the decision logic; compare the obtained preliminary limit load with the standard value of the limit load combination obtained in step S2, and give the following decision logic: If the preliminary limit load obtained by simulation is greater than the standard value and the difference does not exceed 20%, directly use the preliminary limit load as the final limit load; if the preliminary limit load obtained by simulation is greater than the standard value and the difference exceeds 20%, check whether the ship's frequency response model and input parameters are correct. After confirming that the frequency response model and input parameters are correct, use the envelope value of the simulation value and the standard value as the final limit load. If there are errors in the frequency response model and input parameters, correct the errors and re-simulate the preliminary limit load, and compare it with the standard value again; when the preliminary limit load obtained by simulation is less than the standard value, use the standard value as the final limit load. Table 1 shows the collaborative decision logic, and Table 2 shows the mooring force load under the limit conditions.

[0037] Table 1 Collaborative Decision-Making Logic

[0038] This invention establishes a clear collaborative decision-making logic to handle the discrepancies between simulation results and standard calculation results. Taking the 3000T oil tanker as an example, the final ultimate environmental mooring force results are shown in Table 2. The simulation value or the calculated value based on the standard can be directly adopted according to the specific content of the decision-making rules, following the decision-making logic in Table 1 as the final ultimate load.

[0039] Table 2. Mooring force loads under limit conditions

[0040] S3: Perform multi-dimensional working condition scanning and final ultimate load extraction, establish a mooring force distribution model, iteratively optimize the number of vacuum adsorption mooring devices, and output the number of vacuum adsorption mooring devices and the maximum allowable adsorption force of a single vacuum adsorption mooring device.

[0041] Existing technologies lack a systematic approach to determining the required number of automated mooring devices and how to rationally distribute loads among them. This invention proposes an optimized configuration method based on mechanical allocation and iterative verification, specifically including the following:

[0042] S31: Establish a mooring force distribution model to account for the resultant force of the ship's sway. The combined force of ship swaying According to the number of vacuum adsorption mooring devices n Evenly distributed unbalanced bending moment of the bow. According to the distance of each vacuum adsorption mooring device from the center of the mooring system model d i distribute; No.i Longitudinal driving force of a vacuum adsorption mooring device F yi and lateral driving force F xi for: , ;in i ∈ n , k 1 and k 2 represents the gain coefficient; gain coefficient k 1 and k The value of 2 is related to the water area, and is relevant in areas where the water depth is greater than twice the ship's waterline length. k 2 represents 0.1-1.0. k 1 represents 0.07-0.10; in areas where the water depth does not exceed twice the ship's waterline length. k 2 represents 1.0-3.0. k 1 represents 0.1-0.3.

[0043] S32: Perform iterative optimization of the number of vacuum adsorption mooring devices. Given constraints, determine the number of vacuum adsorption mooring devices. The constraints are: 1) , , and These are the maximum longitudinal force and maximum lateral force that the vacuum adsorption mooring device can output, respectively. 2) Number of vacuum adsorption mooring devices , ,in The equidistant interval between adjacent vacuum adsorption mooring units; S33: As Figure 4 As shown, an iterative algorithm for solving the vacuum adsorption mooring device is constructed to determine the number of vacuum adsorption mooring devices. n Equidistant spacing from adjacent vacuum adsorption mooring units .

[0044] Specifically, this involves obtaining the resultant force of the ship's heave. The combined force of ship swaying Subsequently, based on the resultant force of ship swaying , the formula Rewritten as Determine the current number of vacuum adsorption mooring devices. n 0, determine if it satisfies If the conditions are met, then the current number of vacuum adsorption mooring devices will be used. n 0 represents the required number of vacuum adsorption mooring units; if this requirement is not met, the current number of vacuum adsorption mooring units will be used. nAdd 1 to the base value of 0, and re-evaluate whether the inequality is satisfied. This process continues until the desired result is achieved. The number of vacuum adsorption mooring devices corresponding to the number of cycles is then output as the required number of vacuum adsorption mooring devices. After determining the required number of vacuum adsorption mooring devices, the equidistant spacing between adjacent vacuum adsorption mooring devices is further determined. .

[0045] Taking the aforementioned 3000T oil tanker as an example, calculations show that under the set extreme conditions, this 3000T oil tanker requires at least two devices, spaced 50 meters apart, with each device bearing the force of device 1. F x =50KN, F y =180KN; Device 2: F x =50KN F y =70KN, therefore the maximum output force of a single unit is set to F x =50KN F y =180KN.

[0046] S4: Based on the number of vacuum adsorption mooring devices and the maximum output of a single vacuum adsorption mooring device output in the previous step, perform a compatibility check with the hull structure to determine whether the safety boundaries match. If they match, output the number of vacuum adsorption mooring devices and the maximum allowable adsorption force of a single vacuum adsorption mooring device. If they do not match, return to the iterative optimization step of the number of vacuum adsorption mooring devices in the previous step and re-perform iterative optimization of the number and placement of vacuum adsorption mooring devices.

[0047] The specific content includes: S41: Determine the verification area; select the outer side plate as the area with the weakest vacuum adsorption force under the vacuum adsorption mooring device; obtain the structural parameters of the outer side plate, including the nominal thickness of the outer plate, the spacing between longitudinal ribs, and the spacing between strong ribs, and establish a parametric finite element reference model. Based on the general principles of ship structural design, the outer plating on the side of the ship is identified as the weakest area subjected to vacuum adsorption forces. The identification of this area comprehensively considers factors such as plating thickness, rib arrangement, and local curvature. Key structural parameters of the outer plating on the side of the target ship in typical weak areas, such as midship or fore and aft peaks, including nominal plating thickness, longitudinal rib spacing, and strong rib spacing, are extracted to establish a parametric finite element baseline model for further analysis.

[0048] Taking a 3000T oil tanker as an example, based on standard calculations, its side outer plate reference thickness is determined to be 10mm, the longitudinal girder spacing is 0.65m, and the strong rib spacing is 3.6m.

[0049] S42: Defines a dual structural safety constraint criterion; simultaneously satisfying both the strength safety criterion and the stiffness safety criterion. The strength safety criterion stipulates that the maximum equivalent stress of the outer side plating must not exceed the design allowable stress, which is the yield strength of the outer side plating material divided by a preset safety factor. γ In this embodiment, the result is... γ =1.25; The stiffness safety criterion is that the maximum deflection of the outer side plate under the adsorption force of the vacuum adsorption mooring device shall not exceed the preset percentage of the support rib spacing, such as not exceeding 6%.

[0050] For a 3000T oil tanker, under the stiffness safety criterion, the maximum deflection shall not exceed 6% of the preset percentage of the support rib spacing. For a longitudinal rib spacing of 0.65m, the maximum allowable deflection is 39mm.

[0051] S43: Perform iterative finite element analysis to determine the safety boundary; in the central region of the parameterized finite element reference model, apply an adsorption pressure load equivalent to the design area of ​​the vacuum suction cup of the vacuum adsorption mooring device. Increase the adsorption pressure load and perform static iterative analysis. When the maximum equivalent stress of the side outer plate first reaches the design allowable stress, or the maximum deflection of the side outer plate under the adsorption force of the vacuum adsorption mooring device first reaches the maximum allowable limit, it is determined that the critical safety state has been reached. At this time, the adsorption force under the critical safety state is recorded and output as the maximum allowable adsorption force of a single vacuum adsorption mooring device. ; Taking a 3000T oil tanker as an example, a finite element model of the weakest area of ​​the hull was established using ANSYS software. The model dimensions were 7200mm × 1950mm × 8mm, covering two strong ribs spaced 3.6m apart and three longitudinal ribs spaced 650mm apart. The outer plating used shell elements S4R, and the longitudinal ribs / strong ribs used beam elements B31, with a mesh size of 50mm. A vacuum adsorption pressure was applied to the center of the model, with an adsorption area of ​​2m². Through iterative calculation, when the adsorption force was 204.8KN, the maximum equivalent stress of the outer plating was 176N / mm², which was equal to the design allowable stress. Figure 5 As shown, the maximum deformation is 13.71 mm, which is far lower than the allowable deflection of 39 mm. Therefore, the maximum allowable adsorption force of a single vacuum adsorption mooring device is set at 204.8 KN.

[0052] S44: Establish a design closed loop and mandatory safety constraints; apply the contents of steps S42 and S43 as mandatory constraints to ensure that the overall mooring load is distributed to the adsorption force requirements of a single vacuum adsorption mooring device. The maximum allowable adsorption force of a single vacuum adsorption mooring unit shall not exceed the maximum allowable adsorption force of a single vacuum adsorption mooring unit. .

[0053] This step employs a closed-loop feedback mechanism: if the aforementioned mandatory safety constraints are not met, the design process must return to the previous steps, such as step S3, which optimizes mooring force distribution and the number of devices. This is done by increasing the number of devices or adjusting their arrangement to reduce the adsorption force requirement of a single vacuum adsorption mooring device. Then, re-verify until the security constraint is met.

[0054] Verification through the examples shows that this solution is suitable for high-risk vessel types such as liquid chemical carriers, bulk carriers and LNG carriers with a capacity of 3000DWT and above, and its design process covers typical wharf operation scenarios such as coastal deep water and inland river shoals.

[0055] The above description is only a preferred 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 method for load coordination design and hull safety verification of a vacuum adsorption mooring system, characterized in that, Includes the following steps: The target ship parameters and extreme environmental conditions are obtained, and the ship loading status and tidal level are obtained as dynamic coupling variables. Based on the target ship parameters, extreme environmental conditions and dynamic coupling variables, a multi-source load model is modeled and analyzed to obtain the reference load, wave load and yaw moment, and the ultimate load combination is determined to obtain the specification value of the ultimate load. Construct a parametric simulation model and set dynamic boundary conditions to obtain the initial ultimate load; Based on the preliminary ultimate load and the specification value of the ultimate load, the decision logic is determined and the final ultimate load is output. Multi-dimensional working condition scanning and final ultimate load extraction are performed to establish a mooring force distribution model, iterative optimization of the number of vacuum adsorption mooring devices is carried out, and the number of vacuum adsorption mooring devices and the maximum allowable adsorption force of a single vacuum adsorption mooring device are output. Based on the obtained number of vacuum adsorption mooring devices and the maximum allowable adsorption force of a single vacuum adsorption mooring device, a compatibility check is performed with the hull structure to determine whether the safety boundaries match. If they match, the number of vacuum adsorption mooring devices and the maximum allowable adsorption force of a single vacuum adsorption mooring device are output. If they do not match, the iterative optimization step for the number of vacuum adsorption mooring devices is returned, and the iterative optimization of the number and placement of vacuum adsorption mooring devices is repeated.

2. The method for load coordination design and hull safety verification of a vacuum adsorption mooring system according to claim 1, characterized in that, The acquisition of target ship parameters and extreme environmental conditions includes the target ship parameters such as overall length, beam, depth, and draft; and extreme environmental conditions such as wind speed, significant wave height, wave period, current velocity, water depth, and seawater density.

3. The method for load coordination design and hull safety verification of a vacuum adsorption mooring system according to claim 1, characterized in that, Based on the target ship parameters, extreme environmental conditions, and dynamic coupling variables, a multi-source load model is constructed and analyzed to obtain the reference load, wave load, and yaw moment. The ultimate load combination is then determined, and the specification values ​​of the ultimate loads are obtained. Specifically, this includes the following: S11: Calculate wind load and current load, and further calculate the resultant force of ship sway, the resultant force of ship roll, and the unbalanced bending moment of bow roll based on wind load and current load. Lateral wind force related to wind load in attached coordinate system Longitudinal wind force Yaw torque caused by wind Lateral flow forces related to flow load Longitudinal water flow force Yaw torque caused by water flow The resultant force of the ship's swaying The combined force of ship swaying Unbalanced bending moment of bow roll for: ; S12: Introduce wave loads and perform a wave direction angle scan from 0° to 180°; S13: Perform bow roll moment calculation; S14: Determine the ultimate load combination; select the maximum transverse mooring force load and the maximum longitudinal mooring force load corresponding to different wind direction angles and flow direction angles, and select the maximum transverse wave force, yaw torque and the maximum longitudinal wave force corresponding to different wave incidence angles as the standard values ​​for the ultimate load combination.

4. The method for load coordination design and hull safety verification of a vacuum adsorption mooring system according to claim 3, characterized in that, The process of constructing a parameterized simulation model, setting dynamic boundary conditions, and obtaining the initial ultimate load; based on the initial ultimate load and the specification values ​​of the ultimate load, determining the decision logic and outputting the final ultimate load, specifically includes the following: S21: Establish a parametric model; based on the ship's width between perpendiculars, beam, draft, mass inertia, and windward area, establish a frequency response model for the ship, defining the key degrees of freedom of the ship in hydrodynamics, including the resultant force of sway, the resultant force of roll, and bow roll; import a domain file containing the berth and breakwater structure, use a local coordinate system, divide the grid to a specified size, and cover the area around the ship; set the bathymetry data according to the actual terrain to ensure that the water depth at the wharf front matches the tidal level parameters; based on the actual mooring arrangement, define nonlinear mooring cables and fender units, and establish a mooring system model to simulate the constraint and energy dissipation of the hull by the vacuum adsorption mooring device; S22: Set dynamic boundary conditions; input the environmental load spectrum corresponding to the limit parameters of wind load, current load, and wave load; the ship's load capacity is discretely set as empty, ballast, or fully loaded, and the simulation model automatically associates the ship's draft, displacement, center position, and underwater wetted surface area corresponding to each load capacity, dynamically correcting the ship's hydrodynamic coefficient and windward and current-receiving areas; based on the actual tidal characteristics of the port area, set the tidal water level status including three types of water levels: lowest low tide, average tide, and highest high tide. S23: Multi-dimensional operating condition scanning and ultimate load extraction; Based on the established ship frequency response model, perform omnidirectional environmental scanning, systematically changing the wind direction angle at 22.5° intervals within the range of 0° to 180°. α Flow angle β The system response under each combination of wave direction angles is calculated. The results of the omnidirectional environmental scan are orthogonally combined with the preset ship load and tidal level to form an environmental direction-load-tidal level coupled working condition matrix. The time domain results of all simulation working conditions are post-processed to select the maximum load values ​​in the resultant force of sway, resultant force of roll, and bow roll degrees of freedom within the parameter range. The maximum load values ​​in each degree of freedom are combined as the preliminary limit load. S24: Verify and correct based on the standard model to determine the decision logic; compare the obtained preliminary limit load with the standard value of the obtained limit load combination, and give the following decision logic: if the preliminary limit load obtained by simulation is greater than the standard value and the difference does not exceed 20%, directly use the preliminary limit load as the final limit load; if the preliminary limit load obtained by simulation is greater than the standard value and the difference exceeds 20%, check whether the ship's frequency response model and input parameters are correct. After confirming that the frequency response model and input parameters are correct, use the envelope value of the simulation value and the standard value as the final limit load. If there are errors in the frequency response model and input parameters, correct the errors and re-simulate the preliminary limit load, and compare it with the standard value again; when the preliminary limit load obtained by simulation is less than the standard value, use the standard value as the final limit load.

5. The method for load coordination design and hull safety verification of a vacuum adsorption mooring system according to claim 4, characterized in that, The process involves multi-dimensional working condition scanning and ultimate load extraction, establishing a mooring force distribution model, iteratively optimizing the number of vacuum adsorption mooring devices, and outputting the number of vacuum adsorption mooring devices and the maximum allowable adsorption force of a single vacuum adsorption mooring device. Specifically, this includes the following: S31: Establish a mooring force distribution model to account for the resultant force of ship sway. The combined force of ship swaying According to the number of vacuum adsorption mooring devices n Evenly distributed unbalanced bending moment of the bow. According to the distance of each vacuum adsorption mooring device from the center of the mooring system model d i Allocation, number i Longitudinal driving force of a vacuum adsorption mooring device F yi and lateral driving force F xi for: , ;in i ∈ n , k 1 and k 2 represents the gain coefficient; S32: Perform iterative optimization of the number of vacuum adsorption mooring devices, given constraints, determine the number of vacuum adsorption mooring devices; S33: Construct an iterative algorithm for solving vacuum adsorption mooring devices and determine the number of vacuum adsorption mooring devices. n Equidistant spacing from adjacent vacuum adsorption mooring units .

6. The method for load coordination design and hull safety verification of a vacuum adsorption mooring system according to claim 5, characterized in that, Gain coefficient k 1 and k The value of 2 is related to the water area, and is relevant in areas where the water depth is greater than twice the ship's waterline length. k 2 represents 0.1-1.

0. k 1 represents 0.07-0.10; in areas where the water depth does not exceed twice the ship's waterline length. k 2 represents 1.0-3.

0. k 1 represents 0.1-0.

3.

7. The method for load coordination design and hull safety verification of a vacuum adsorption mooring system according to claim 5, characterized in that, The iterative algorithm for constructing the vacuum adsorption mooring device is based on obtaining the resultant force of the ship's sway. The combined force of ship swaying Subsequently, based on the resultant force of ship swaying Determine the current number of vacuum adsorption mooring devices. n 0, determine if it satisfies If the conditions are met, then the current number of vacuum adsorption mooring devices will be used. n 0 represents the required number of vacuum adsorption mooring units; if this requirement is not met, the current number of vacuum adsorption mooring units will be used. n Add 1 to the base value of 0, and re-evaluate whether the inequality is satisfied. The process continues until the desired number of vacuum adsorption mooring devices is achieved. The number of devices required for each cycle is then output as the total number of vacuum adsorption mooring devices needed. After determining the required number of devices, the equidistant spacing between adjacent vacuum adsorption mooring devices is further determined. .

8. The method for load coordination design and hull safety verification of a vacuum adsorption mooring system according to claim 5, characterized in that, The process involves verifying the compatibility of the vacuum adsorption mooring devices with the ship's structure based on the number of devices and the maximum allowable adsorption force of each device, to determine if the safety boundaries are met. This includes the following: S41: Determine the verification area; select the outer side plate as the area with the weakest vacuum adsorption force under the vacuum adsorption mooring device; obtain the structural parameters of the outer side plate, including the nominal thickness of the outer plate, the spacing between longitudinal ribs, and the spacing between strong ribs, and establish a parametric finite element reference model. S42: Defines a dual structural safety limit criterion; simultaneously satisfying both the strength safety criterion and the stiffness safety criterion. The strength safety criterion stipulates that the maximum equivalent stress of the outer side plating must not exceed the design allowable stress. The stiffness safety criterion is that the maximum deflection of the outer side plate under the adsorption force of the vacuum adsorption mooring device shall not exceed the preset percentage of the support rib spacing. S43: Perform iterative finite element analysis to determine the safety boundary; in the central region of the parameterized finite element reference model, apply an adsorption pressure load equivalent to the design area of ​​the vacuum suction cup of the vacuum adsorption mooring device. Increase the adsorption pressure load and perform static iterative analysis. When the maximum equivalent stress of the side outer plate first reaches the design allowable stress, or the maximum deflection of the side outer plate under the adsorption force of the vacuum adsorption mooring device first reaches the maximum allowable limit, it is determined that the critical safety state has been reached. At this time, the adsorption force under the critical safety state is recorded and output as the maximum allowable adsorption force of a single vacuum adsorption mooring device. ; S44: Establish a design closed loop and mandatory safety constraints; apply the contents of steps S42 and S43 as mandatory constraints to ensure that the overall mooring load is distributed to the adsorption force requirements of a single vacuum adsorption mooring device. The maximum allowable adsorption force of a single vacuum adsorption mooring unit shall not exceed the maximum allowable adsorption force of a single vacuum adsorption mooring unit. .

9. The method for load coordination design and hull safety verification of a vacuum adsorption mooring system according to claim 8, characterized in that, The allowable design stress mentioned in step S42 is obtained by dividing the yield strength of the material of the outer side plate by a preset safety factor.

10. The method for load coordination design and hull safety verification of a vacuum adsorption mooring system according to claim 8, characterized in that, The stiffness safety criterion mentioned in step S42 is that the maximum deflection of the outer side plate under the adsorption force of the vacuum adsorption mooring device shall not exceed 6% of the support rib spacing.

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