571results about "Vessel designing" patented technology

The invention relates to the technical field of ship design optimization, and discloses a hull shape optimization method based on neural network modeling. In the data acquisition stage of the method, initial appearance parameters and hydrodynamic performance data of a ship body are obtained, the appearance parameters comprise geometric dimensions and shape features, and the performance data comprise resistance coefficients and wave-making resistance values. In the neural network construction stage, a neural network model with a multi-layer perceptron structure is trained by using collected data, weights are updated through a back propagation algorithm, and a nonlinear mapping relation between appearance parameters and hydrodynamic performance indexes is established. In the shape optimization stage, the trained neural network model is used for carrying out iterative adjustment on the shape of the ship body, fluid dynamic performance indexes are recalculated through the model after each adjustment until preset convergence conditions are met, and finally optimized ship body shape data are output. According to the method, partial complex calculation is replaced by the neural network, and intelligent optimization of the hull appearance is realized.

The invention discloses a ship equipment vibration test method and system based on frequency domain kurtosis mapping and non-Gaussian signal generation. The ship equipment vibration test method comprises the following steps: collecting an actual ship impact vibration signal and extracting a target power spectral density curve; the method comprises the following steps: identifying an impact energy concentration frequency band based on spectrum energy distribution, carrying out frequency band division by adopting an elliptical filter bank with a second-order section structure, and calculating an envelope kurtosis value of each frequency band to establish a kurtosis-frequency mapping model; after the initial Gaussian driving signal is generated, a non-Gaussian driving signal is generated through a phase randomization and amplitude dynamic scaling algorithm based on a mapping model; a multi-target optimization controller based on Pareto leading edge search is adopted, a power spectral density error and a kurtosis error are taken as optimization targets, synchronous optimization is carried out through fast non-dominated sorting and an adaptive hybrid variation strategy, and a driving signal is output. According to the invention, the broadband and non-Gaussian impact vibration environment of the ship equipment in the actual severe sea condition can be reproduced in a high-fidelity manner, and the authenticity of the test and the fault mode coverage capability are remarkably improved.

The invention provides an LSTM underwater robot modeling method based on TPE hyper-parameter optimization, and relates to the technical field of underwater robot modeling, and the method comprises the steps: carrying out the time sequence feature extraction through a memory unit comprising a forgetting gate, an input gate and an output gate, and predicting the state change amount delta Yt'at a t + 1 moment through an output layer; performing iterative optimization on the number of layers and the number of units of the LSTM network and training the model to obtain an optimized LSTM model; evaluating the optimized LSTM model through a multi-step cumulative prediction error, inputting an initial real state into the model to carry out T-step recursive prediction, updating a current state by utilizing a prediction state increment in each step, and finally calculating an average position error and an attitude error in a T-step window on a verification set; and selecting the hyper-parameter combination with the minimum comprehensive error of the verification set as a final model parameter, and completing the dynamic modeling of the underwater robot. According to the method, the problem that the model is inaccurate due to excessive parameterization in a nonlinear dynamic model can be solved.

The invention discloses a test verification platform and a test verification method for a motion compensation gangway ladder of an offshore wind power operation and maintenance ship. The platform comprises a system calculation and control center, an environment simulation vibration platform, an active motion compensation execution mechanism, a high-precision sensing and sensing module, a multi-channel data acquisition and storage system, an offshore wind turbine target platform module and an optical motion capture module. The platform reproduces six-degree-of-freedom motion of the operation and maintenance ship through integrated cooperation and high fidelity, simulates active compensation of a gangway ladder and dynamic characteristics of a hydraulic system, and accurately measures key parameters such as poses, forces / torques and the like by using multiple sensors and an optical capture technology. The method comprises the steps of motion instruction synthesis, platform motion reproduction, compensation action simulation, data synchronous acquisition and performance evaluation. According to the invention, high-precision land simulation verification of ship-gangway ladder-fan dynamic coupling is realized, the problems of high cost, high risk and poor repeatability of offshore actual measurement are effectively solved, and a reliable and efficient solution is provided for performance verification of a motion compensation system.

The invention discloses a ship viscous flow numerical simulation method based on a hybrid Cartesian grid, and relates to the technical field of ship CFD. The method comprises the steps that after a computational domain is constructed, a body-fitted grid is generated at the object plane boundary of a ship model; then, on the basis of the outermost-layer body-fitted grid, a full-thread tree is used for carrying out space division on a computational domain to generate a Cartesian grid, and the full-thread tree is output as Cartesian grid topological information matched with the data structure of the target viscous flow solver; and finally, assembling and coupling the body-fitted grid and the Cartesian grid by using an overlapping grid technology to obtain a mixed partition grid unit, and applying the mixed partition grid unit to a solving process of a target viscous flow solver. Therefore, the accuracy and robustness of viscous flow numerical simulation of the ship with the complex geometry are improved, and the method can be well applied to resistance and flow field numerical simulation scenes in underwater and water surface ship body motion states.

The invention relates to the technical field of underwater propeller modeling, and discloses an underwater propeller annular propeller modeling method based on analog simulation. The method comprises the following steps: constructing an initial blade fluid domain grid model by using a discrete element simulation algorithm based on three-dimensional geometric parameters and material attribute data of an annular propeller; after multiphase flow coupling boundary conditions are applied to the initial model, fluid dynamic load distribution data are obtained through a transient flow field solver; generating a blade deformation characteristic value according to the load data, and if the blade deformation characteristic value exceeds a preset tolerance interval, activating a dynamic grid reconstruction instruction; fluid-structure interaction interface pressure pulsation data is extracted based on the instruction, a stress concentration coefficient is calculated in combination with material attributes, and an abnormal signal is generated when a safety threshold value is exceeded; and when the signal is triggered, the vortex field tracking module is called to update the fluid domain grid model.

The invention relates to an intelligent space layout method and system based on ship internal design, and relates to the technical field of ship design, and the method comprises the steps: obtaining an initial layout map, an actual furniture type and actual furniture parameters of a living room; defining a layout existence type, a priority processing type and an accident existence type; determining a preliminary adding scheme according to the layout existence type; and determining a reasonable placement scheme according to the priority processing type and the accident existence type, and combining the reasonable placement scheme with the preliminary addition scheme to construct an internal layout scheme to output the internal layout scheme to a preset management end. The method has the effect of improving the design convenience of the accommodation space layout in the ship.

The invention discloses a dynamic power management method for an all-electric ship hybrid energy storage system. The method comprises the following steps: S1, establishing a direct-current voltage dynamic model and a ship hybrid energy storage system model based on a ship micro-grid structure of a ship; s2, establishing a multi-working-condition propulsion power model based on the movement mechanism of the ship; s3, establishing a joint SOC-SOP estimation model based on the nonlinear relationship among the state of charge, the battery power characteristics and the ambient temperature; s4, on the basis of the direct-current voltage dynamic model, the ship hybrid energy storage system model and the multi-working-condition propulsion power model, establishing a dynamic power distribution model; and S5, estimating an available power range of the battery through a combined SOC-SOP estimation model, inputting the available power range into the dynamic power distribution model, obtaining a dynamic power distribution strategy, and realizing dynamic power distribution of the ship hybrid energy storage system. According to the method, the dynamic power management of the hybrid energy storage system of the all-electric ship under the uncertain navigation condition is optimized, and the stability and the economical efficiency of a ship power system are improved.

The invention discloses a variant reconstruction AUV (Autonomous Underwater Vehicle) shape optimization method based on proxy-assisted multi-starting-point space reduction. The variant reconstruction AUV shape optimization method comprises the following steps: establishing a parameterized model of a variant reconstruction AUV; constructing a variant reconstruction AUV shape modeling-grid division-performance simulation automation framework, realizing input of design variables, and automatically performing variant reconstruction AUV shape modeling and watershed grid division; a variant reconstruction AUV shape hydrodynamic force simulation calculation framework is built, and assessment of variant reconstruction AUV hydrodynamic force performance is achieved; generating a plurality of groups of initial samples for a design space of design variables, calculating target function values corresponding to the samples by utilizing the simulation automation framework and the simulation calculation framework, and importing the samples and corresponding sailing resistance into a sample library; and performing optimization in the design space of the design variables by utilizing an agent-assisted multi-starting-point space reduction method to obtain an optimal solution of the variant reconstruction AUV shape design problem. According to the method, the reliability of an optimization result and the design efficiency can be improved, and the optimization time is shortened.

The application relates to the technical field of calculation simulation of ship hull propulsion research, in particular to a simulation model convenient for hydrodynamic calculation of a full-rotation double-propeller ship, which comprises a plurality of groups of water pressure sensors arranged on the circular arc outer wall of a detection column and facing openings, a drainage long groove arranged on the circular arc outer wall of the detection column and located at the openings, a water inlet pipe of an external water pump assembly arranged in the detection column, and a lifting port arranged at one end of the water inlet pipe and capable of sliding along the drainage long groove to adjust the height, wherein the beneficial effects are that the water flow direction and flow rate in the pool model are accurately controlled through water pumping and high-pressure water inflow in the symmetrical direction, the data detection range of the test is improved, the simulation equipment provided with the water pressure sensors and the displacement sensors is arranged, so that the data in the test process can be conveniently collected, the position of the simulation small ship can be accurately collected through the coordinates established by the transparent grid plates, and the test accuracy is greatly improved.

The invention discloses a model intelligent verification and parameter correction method, which comprises the following steps of 1, building an unmanned ship task high-value verification point set based on expert experience and a large model collaboratively, screening boundary points and extreme points, and performing simulation-actual measurement data consistency verification; if the normalization error of the simulation data and the actual measurement data exceeds a threshold value, triggering correction; step 2, constructing a sensitive factor set according to global sensitivity analysis and a parameter association relationship mining result, screening high-sensitivity parameters as a priority correction target, and avoiding redundancy optimization; and step 3, optimizing the high-sensitivity parameters, and forming a verification-correction-update closed loop by verifying and iteratively updating the priority of the factors to realize the intelligent correction of the parameters of the unmanned ship model.

The invention relates to the technical field of ocean engineering operation motion modeling and control, and particularly discloses a method and a system for calculating influence of dynamic response of a separation supporting device and a buffer coupling device on a ship pose in a floating support installation process. The method comprises the following steps: acquiring initial position information of a separation support device and a buffer coupling device at a previous moment; acquiring vertical position and attitude information of the dynamic positioning ship and the upper module; calculating the supporting force of the separation supporting device and the buffer coupling device at the current moment; calculating the vertical position and attitude information of the upper module and the dynamic positioning ship at the current moment based on the supporting force and the external ballast water load; outputting relevant parameters and judging whether the installation is completed or not. According to the method, a multi-degree-of-freedom coupling dynamic model is constructed, high-precision real-time simulation of device dynamic response and ship motion attitude in the continuous unsteady-state load transfer process is realized, key parameter monitoring and risk early warning are provided for floating mounting operation, and the operation safety and efficiency are improved.

The invention belongs to the technical field of ship block two-dimensional irregular layout, and discloses a ship block layout method based on a critical polygon and a dynamic niche. The method comprises the following steps: constructing an NFP solving method based on an edge-vertex contact point convex hull to obtain a critical polygon, constructing a BL positioning stacking strategy on the basis to determine a feasible region, realizing accurate positioning of the irregular polygon, and calculating the fitness; designing a multi-stage adaptive genetic algorithm parameter collaborative optimization method, and dynamically adjusting genetic algorithm parameters based on population diversity and fitness variance; a dynamic niche management and crowding punishment mechanism is introduced, premature convergence of populations is avoided, and diversity of solutions is maintained; and carrying out refined optimization on the polygon rotation angle through genetic post-processing, and preferentially selecting a layout scheme. According to the method, the space utilization rate of the two-dimensional irregular layout can be effectively increased, the complex shape characteristic of the segments is fully reserved in the stacking process, and the method is suitable for the segmented stacking scene of ship construction.

The invention discloses an ice load calculation method suitable for upward-floating icebreaking of an ultra-large vehicle in a layer ice environment, and the method comprises the steps: carrying out the grid division of a layer ice environment and an ultra-large UUV geometric model, and obtaining an ultra-large UUV upward-floating icebreaking calculation model; the floating icebreaking calculation model comprises a layer ice rink geometric model after grid division and an ultra-large UUV model after grid division; fluid-solid coupling relation definition is carried out on the floating icebreaking calculation model, multiphase fluid-solid coupling unified solution of a water area, an air area, an ice layer and a boat body is achieved, identification, separation and calculation of ice loads in the floating icebreaking process are completed under a unified solution framework, and therefore the stability, precision and engineering applicability of load results are remarkably improved; and performing simulation calculation on floating icebreaking of the ultra-large UUV under each working condition by using the floating icebreaking calculation model to obtain the ice load borne by the ultra-large UUV at each moment.

The invention discloses an aerodynamic load loading method, device and equipment and a medium, relates to the technical field of ocean engineering, is applied to a processor, and comprises the following steps: receiving scale motion data currently acquired by a scaling model of a floating wind turbine generator, and amplifying the scale motion data to obtain full-scale motion data; determining a first expected aerodynamic load borne by the floating wind turbine generator based on the full-size motion data; reducing the first expected aerodynamic load to obtain a second expected aerodynamic load borne by the scaling model; decomposing the second expected aerodynamic load into output thrust of each propeller in the loading device, and converting the output thrust into a PWM control signal; the loading device regulates and controls the rotating speed of each propeller based on the PWM control signal, and loads a target aerodynamic load generated by rotation to the scaling model; and skipping to the step of receiving the scale motion data again until a preset stop condition is met. And the loading of the aerodynamic load on the scale model is accurately realized.

The invention discloses a ship pipeline leakage detecting and positioning method based on an optimization algorithm, and belongs to the technical field of thermal power generating unit monitoring. In the ship pipeline leakage detecting and positioning method, various data acquisition modules are arranged, and an infrared thermal imager can also be used for measuring the temperature of a working medium pipeline of a ship pipeline and serves as a basis for judging whether heat preservation reaches a specified effect or not; the sealing position of the flange is prone to leakage, the thermal infrared imager can be used for monitoring heat preservation of the boiler shell so as to reduce heat dissipation loss, a high-temperature point on the outer wall of the boiler can be found, the high-temperature point indicates the failure position of the refractory layer, and therefore the situation that the process efficiency is reduced due to heat loss is avoided. The alarm module is arranged, when the information acquisition module monitors that the working medium of the ship pipeline leaks, the multiple alarm modules in the alarm module can send out broadcast voice through the broadcast voice alarm module to remind more workers to pay attention to maintenance, and the overall safety and reliability of the system are improved.

The invention discloses an offshore floating body FSI forecasting method and system based on bidirectional coupling of FVM and MBD. The method comprises the steps that a numerical pool model containing a floating body and surrounding fluid is established in a CFD solver; establishing a floating body structure finite element model in the MBD solver; constructing a bidirectional coupling mapping relation between a fluid grid and a structural grid based on a preCICE open source library to realize real-time transmission of data; calculating a floating body surface fluid load time calendar value through a CFD solver, and transmitting the floating body surface fluid load time calendar value to the structure model; the MBD solver calculates structural dynamic response and feeds back a deformation time calendar value to a fluid domain; fluid grid deformation is dynamically updated based on a Laplace solver; iteratively executing a load transfer-structure response-grid updating process until the pressure and displacement residual error meet a convergence condition; and outputting a coupling forecast result of the fluid load and the structural deformation. High-precision two-way coupling is achieved through the open source coupling library, and the accuracy of floating body structure dynamic response forecasting in the complex wave environment is remarkably improved.

The invention belongs to the technical field of deep sea equipment, and particularly relates to a deep sea plugging device and a floating base radial pressing force adjusting method thereof. The device is located in a water injection type pressurization cabin, and a driving sliding table mechanism and a floating base are sequentially arranged along the same axis; the driving sliding table mechanism comprises a sliding rail, a sliding rail cabin, a lead screw assembly, a driving motor, a tension and compression sensor and a displacement sensor, the motor drives a lead screw to enable the sliding rail to do reciprocating linear motion through sealing, the two ends of the sliding rail cabin are sealed, and plugging force and displacement data are collected through the sensor; the floating base is composed of a fixing plate, a floating positioning sleeve, a pressing disc and circumferentially distributed elastic adjusting assemblies, the connector female end is installed in the floating positioning sleeve, the elastic adjusting assemblies are distributed along the periphery of the floating positioning sleeve, when axial eccentricity exists in plugging of the connector male end and the connector female end, the floating positioning sleeve is automatically centered under the elastic effect, and interference of eccentric force is eliminated. According to the invention, high-precision, repeatable and controllable testing of the plugging performance of the connector in a high-pressure, high-salt and high-corrosion environment is realized.

The invention discloses a ship vertical stress prediction method based on POD modal decomposition, and aims to solve the problems that a traditional CFD method is high in calculation cost and low in solving efficiency and a pure data driving method lacks physical constraints. The method comprises the following steps: modeling discrete slices of a ship body, simulating different pitching and heaving working conditions through CFD software, and collecting vertical stress data; preprocessing and separating an average field and a pulsating field, and extracting a core characteristic mode and a time coefficient through POD mode decomposition; amplitude-coefficient mapping is established for time coefficient fitting, and target working condition parameters are input to obtain a corresponding time coefficient function; and reconstructing the pulsating field and superposing the average field, and integrating to obtain the total vertical stress. According to the method, calculation is simplified through modal dimension reduction, physical characteristics are reserved, rapid and accurate prediction of multiple working conditions is achieved, the method is suitable for ship seakeeping analysis and hydrodynamic performance calculation, and the engineering application efficiency is remarkably improved.

This invention discloses a ship hull simulation test device and method, belonging to the field of ship testing technology. The ship hull simulation test device includes a support frame, and further includes: a rotating ratchet, the rotating ratchet being placed on the upper side of the support frame, with a rotating shaft rotatably connected to the rotating ratchet on the support frame; a placement seat, the placement seat being disposed on the rotating ratchet for placing a ship hull model; and a rotating impact mechanism, the rotating impact mechanism including a rotating component for driving the rotating ratchet to rotate intermittently and an impact component for impacting the ship hull model. In this invention, the rotating component drives the ship hull model on the rotating ratchet to rotate, causing the impact component to impact the rotated ship hull model. The rotating component and the impact component alternately operate intermittently, allowing for rapid adjustment of the impact position and angle of the ship hull model according to test needs, simplifying the adjustment steps, increasing the diversity of tests, and thus making the test results more comprehensive.

The invention discloses a ship parameterization geometric reconstruction method and system based on a Lackenby method, and the method comprises the steps: inputting a three-dimensional mother type ship body model, setting target ship type parameters, and obtaining the geometric basic data of a three-dimensional mother type ship and a target ship type parameter set meeting the demands; judging a specific ship type transformation type according to the target ship type parameters, iteratively solving a proportional transformation coefficient by using a dichotomy according to the ship type transformation type, executing ship surface coordinate transformation according to the transformation type, and judging whether the transformed target parameters meet the requirements of the target ship type or not; if the requirements are met, ship type proportion transformation is carried out according to the transformed target parameters, and a transformation path matched with the design target and a ship body geometric shape preliminarily conforming to the core target parameters are obtained; performing topological transformation on the mother ship type value table, and generating and outputting a type value table conforming to the target ship type; according to the method, the ship type transformation under the preset target parameters can be realized on the premise of ensuring the geometric fairness.

This invention discloses a test device for simulating different water accumulation levels on a floating thin-film photovoltaic platform model, relating to the field of offshore photovoltaic power generation technology. It includes a fluid diverter, a jet head array, and a thin-film photovoltaic platform model. The thin-film photovoltaic platform model is fixed in a water tank, and the jet head array is installed above the model. The fluid diverter is connected to the jet head array and can adjust the water flow distribution of the jet head array. This invention, through the coordinated operation of a wave generator and a rainfall system, can simulate complex dynamic responses under extreme environments, such as floating state, motion characteristics, and mooring forces. It provides high-precision test data for platform design, not only enabling timely identification of potential design problems and optimization of structural performance, but also improving the safety and reliability of floating photovoltaic power generation platforms in extreme environments, and further promoting the development of photovoltaic power generation technology.

The invention provides a parametric modeling and drawing automatic generation method and device for a ship driving shafting, equipment and a medium, and the method comprises the steps: calculating contract parameters through employing a preset formula contained in a parametric modeling rule, obtaining the nominal diameters of parts of the ship driving shafting, and calculating the nominal diameters of the parts of the ship driving shafting; according to the empirical rule of each shaft section in the ship driving shafting part, the nominal diameter is adjusted to be the actual diameter, meeting the machining and matching requirements, of each shaft section; modifying corresponding parameters in the parameterized three-dimensional model template based on the actual diameter of each shaft section and the default length parameter of each shaft section so as to automatically reconstruct and generate a corresponding ship driving shafting part three-dimensional model; and based on the generated three-dimensional model of the ship driving shafting part, adjusting the two-dimensional engineering drawing template according to a two-dimensional drawing rule, and generating a two-dimensional engineering drawing conforming to the two-dimensional drawing rule. Through the method, the generation efficiency and accuracy of the three-dimensional model and the two-dimensional engineering drawing of the ship driving shafting are improved.

The invention provides a forecasting system and method for forecasting underwater radiation noise after ship equipment replacement. The system comprises a data acquisition module, a data processing module and a noise forecasting module, and the data acquisition module acquires various related data before and after equipment replacement to provide comprehensive support for subsequent calculation; the data processing module performs a series of calculation processing on the acquired data to ensure that the data is accurate and available; the ship underwater radiation noise prediction system is compact and reasonable in structure, and the existing technical problems can be effectively solved. According to the method, through the steps of experimental testing before equipment replacement, transfer function construction, acceleration admittance matrix acquisition and the like, the influence of various factors on noise after equipment replacement is comprehensively considered, and specific operations of each step, such as construction of a base-underwater noise transfer function, construction of an equipment-base transfer function and the like, are explained in details, so that the noise level can be accurately forecasted, and the noise level can be accurately predicted. And powerful support is provided for making a ship equipment replacement scheme.

A server device (40) is provided with: an acquisition means (412) for acquiring the degree of fouling in a plurality of regions on the hull surface of a ship; and a calculation means (415) for calculating the frictional resistance of the entire hull using frictional resistance coefficients corresponding to the degree of fouling of the plurality of regions.

The invention discloses a parametric modeling method for a shell structure of an auxiliary propulsion section of an AUV (Autonomous Underwater Vehicle). The parametric modeling method comprises the following steps: constructing an auxiliary propeller model of the AUV; parameterization definition is carried out on the shell structure model of the AUV auxiliary propulsion section; determining key parameters of an AUV auxiliary propulsion section according to task requirements of the AUV; based on the key parameters and the parameterized definition, calculating component feature modeling data of the shell structure; modeling each component of the shell structure through a modeling function and the component feature modeling data; assembling each component model of the shell structure and the auxiliary propeller model to obtain an AUV auxiliary propelling section assembly body model; key parameters are modified, and the AUV auxiliary propulsion section assembly model is iteratively updated until the design requirement is met. According to the method, rapid modeling of the AUV auxiliary propulsion section shell structure is realized, so that the modeling speed and the modeling efficiency can be effectively improved.

The invention discloses an automatic modeling and separating method for self-made parts of a ship. The method comprises the steps that S1, data of the self-made parts of the ship are filled in a customized table; s2, selecting a proper programming language to read a table containing the data of the ship self-made parts; s3, establishing a modeling rule according to the characteristics and design requirements of the self-made parts of the ship; s4, compiling codes by utilizing the selected programming language and tool to realize automatic modeling; and S5, after modeling is completed, the whole model is separated into independent parts according to needs. Through automatic modeling and part separation, the tedious degree of manual operation is reduced, and the labor intensity is reduced.

A segmented trimaran model and a wave load measurement method, characterized in that: comprising a main hull and a piece body located on both sides of the main hull, the main hull is divided into N segments along the length direction, N is greater than or equal to four, each segment of the main hull is connected through the longitudinal measuring beam arranged along the length direction, the longitudinal measuring beam is provided with a first transverse measuring beam and a second transverse measuring beam; each piece body is divided into two segments; the two ends of the first transverse measuring beam are respectively connected with the front piece body; the two ends of the second transverse measuring beam are respectively connected with the rear piece body; the main hull, the connecting bridge and the piece body between the first transverse measuring beam and the second transverse measuring beam are segmented at the same station; the connecting bridge between the piece body and the main hull is segmented, and the segmented position is the longitudinal segmented position and penetrates through the whole connecting bridge along the length direction. Thus, the load borne by the main hull and the connecting bridge can be accurately measured simultaneously during the wave load test.

The invention discloses a design method of a self-elevating ocean platform, which comprises the following steps: inserting a lifting type supporting device into a seabed, and mounting a deck on the lifting type supporting device; manufacturing a three-dimensional concave reinforced structure base by using the negative Poisson's ratio concave cell element structure; mounting a three-dimensional concave reinforcing structure base at a preset position on the deck; power equipment is mounted on the three-dimensional concave reinforcing structure base; the negative Poisson's ratio concave cell structure comprises a concave hexagonal structure which comprises a first horizontal cell wall, a second horizontal cell wall, a first concave bending structure and a second concave bending structure; each of the first rhombus structure and the second rhombus structure is composed of four inclined cell walls; the connecting point of the bottom inclined cell wall of the first rhombic structure is connected with the connecting point of the top inclined cell wall of the second rhombic structure; the double-rhombus structure is embedded in the concave hexagonal structure, the top end point of the double-rhombus structure is connected with the first horizontal cell wall, and the bottom end point of the double-rhombus structure is connected with the second horizontal cell wall.

The invention belongs to the technical field of lifeboats, discloses a free-falling lifeboat model test method, and effectively solves the problem that the result is inaccurate when a wooden model is used for testing. Comprising the following steps: manufacturing a lifeboat model by glass fiber reinforced plastic according to a selected scale ratio; performing static calibration and dynamic calibration on the lifeboat model; carrying out a free falling test on the lifeboat model, measuring the impact acceleration of the lifeboat model falling into water, and measuring the water entering distance and the forward rushing distance of the lifeboat model; the method comprises the following steps: firstly, determining the angle of a landing slide way, preliminarily selecting an approved landing height and the length of the landing slide way, then respectively combining the weight distribution state and the initial landing state of a lifeboat model, then carrying out a free landing test, and finally determining the landing approved height, the landing slide way angle and the landing slide way length of the lifeboat. The acceleration test result is closer to the real boat test, and the accuracy is higher.