A kind of stiffened plate testing device and stiffened plate testing method

Abstract

The application discloses a stiffened plate testing device and a stiffened plate testing method. The stiffened plate testing method comprises the following steps: configuring the mass of a lateral counterweight assembly according to a lateral pressure parameter, and placing the configured lateral counterweight assembly on the upper surface of a stiffened plate model; determining the lifting height and the counterweight mass of an axial impact assembly according to an axial impact parameter; adjusting the counterweight of the axial impact assembly to the counterweight mass, releasing the axial impact assembly after being lifted to the lifting height, and making the axial impact assembly slide along the vertical section of the guide rail to the horizontal section to impact the stiffened plate model; and obtaining the deformation data, buckling mode data and damage data of the stiffened plate model after the impact. The testing method can simultaneously provide lateral pressure and axial impact load for the stiffened plate, simulates the real stress state of the ship bottom or deck in the slamming process, and makes the deformation data, buckling mode data and damage data of the stiffened plate model obtained by the test have a small deviation from the actual working condition and have high reliability.

Description

Technical Field

[0001] This application relates to the field of structural strength technology in marine engineering, and in particular to a stiffening plate testing device and a stiffening plate testing method. Background Technology

[0002] During ship navigation, the hull beams generate significant impact bending moments under wave slamming loads. According to simple beam theory, these bending moments induce strong axial in-plane impact loads at the deck and bottom of the hull. Simultaneously, the bottom is subjected to a uniformly distributed lateral pressure load from hydrostatic pressure, while the deck experiences a similar uniformly distributed lateral load under cargo stacking conditions. When the hull experiences wave slamming flutter, the axial impact load and lateral pressure load act simultaneously on the stiffened plate structures of the bottom and deck, creating a typical complex load condition.

[0003] Related studies have shown that such composite loading significantly alters the buckling path, ultimate bearing capacity, and failure mode of stiffened plates, and its deformation response differs from that under single load. However, current stiffened plate testing equipment is mostly designed for single load conditions, such as applying only axial impact loads or only lateral compressive loads. It cannot achieve synchronous and stable coupling of two loads, resulting in a large deviation between the test conditions and the actual stress state of the ship hull, making it difficult to accurately assess the structural safety of stiffened plates under composite loading. Summary of the Invention

[0004] This application aims to at least solve one of the aforementioned technical problems existing in the prior art. Therefore, the purpose of this application is to provide a testing method for stiffened plates capable of simulating the combined load conditions of a stiffened plate model subjected to axial impact and lateral compressive loads.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: A stiffening plate testing apparatus according to a first aspect of this application includes: A frame, the frame being provided with guide rails, the guide rails having vertical sections and horizontal sections connected in sequence, the vertical sections extending in a vertical direction and the horizontal sections extending in a horizontal direction; A stiffened plate model is horizontally positioned within the horizontal segment and connected to the horizontal segment. An axial impact assembly is slidably connected to the guide rail and configured to impact the stiffened plate model to apply an axial impact load to the stiffened plate model. A lateral counterweight assembly is disposed on the upper surface of the stiffened plate model and is configured to apply a lateral impact load to the stiffened plate model.

[0006] A stiffening plate testing device according to an embodiment of this application has at least the following beneficial effects: The stiffened plate testing device in this application embodiment is suitable for conducting the above-mentioned stiffened plate testing method. The lateral counterweight assembly is placed on the upper surface of the stiffened plate model to apply lateral pressure. The axial impact assembly falls along the vertical section, turns to the horizontal section, and then impacts the end face of the stiffened plate model. The axial impact assembly can provide dynamic axial impact loads to the stiffened plate model, thereby simultaneously providing lateral pressure and axial impact loads to the stiffened plate, simulating the actual stress state of the ship's bottom or deck during slamming and fluttering. This results in small deviations between the deformation data, buckling morphology data, and damage data of the stiffened plate model obtained from the test and the actual working conditions, ensuring high reliability.

[0007] According to some embodiments of this application, the lateral counterweight assembly includes a plurality of flexible counterweight bags and a plurality of first counterweight blocks; the flexible counterweight bags are evenly distributed on the upper surface of the stiffening plate model, and the first counterweight blocks are disposed on the upper surface of the flexible counterweight bags.

[0008] According to some embodiments of this application, the axial impact assembly includes a counterweight box and a plurality of second counterweight blocks, the counterweight box being slidably connected to the guide rail, and the second counterweight blocks being disposed inside the counterweight box.

[0009] A method for testing stiffened plates according to a second aspect of this application includes: Configure the mass of the lateral counterweight assembly according to the lateral pressure parameters, and place the configured lateral counterweight assembly on the upper surface of the stiffened plate model; The lifting height and counterweight mass of the axial impact assembly are determined based on the axial impact parameters. Adjust the counterweight of the axial impact assembly to the counterweight mass, lift the axial impact assembly to the lifting height and then release it, so that the axial impact assembly slides along the vertical section of the guide rail to the horizontal section and impacts the stiffened plate model; Obtain deformation data, buckling morphology data, and damage data of the stiffened plate model after impact.

[0010] The test method for a stiffened plate according to an embodiment of this application has at least the following beneficial effects: In the test method of the stiffened plate in this application embodiment, the lateral counterweight assembly is placed on the upper surface of the stiffened plate model to apply lateral pressure to it; the axial impact assembly falls along the vertical section and turns to the horizontal section before impacting the end face of the stiffened plate model. The axial impact assembly can provide axial impact load to the stiffened plate model, thereby providing both lateral pressure and axial impact load to the stiffened plate, simulating the real stress state of the ship bottom or deck during the slamming and fluttering process. This makes the deformation data, buckling morphology data and damage data of the stiffened plate model obtained by the test have small deviations from the actual working conditions and high reliability.

[0011] According to some embodiments of this application, configuring the mass of the lateral counterweight assembly according to the lateral pressure parameters and placing the configured lateral counterweight assembly on the upper surface of the stiffened plate model includes: The lateral counterweight assembly includes multiple flexible counterweight bags and multiple first counterweight blocks. The total mass of the flexible counterweight bags and the total mass of the first counterweight blocks are determined according to the lateral pressure parameters. The flexible counterweight bags are evenly laid on the upper surface of the stiffened plate model, and then the first counterweight blocks are placed on top of the flexible counterweight bags.

[0012] According to some embodiments of this application, determining the total mass of the flexible counterweight bag and the total mass of the first counterweight block based on lateral pressure parameters includes: The total mass of the flexible counterweight bag and the total mass of the first counterweight block are calculated using the following formulas: ; in, P The lateral pressure parameter is expressed in Pa. m s The total mass of the flexible counterweight bag is expressed in kg. m c The total mass of the first counterweight is expressed in kg. g It is the acceleration due to gravity; A The effective bearing area of ​​the stiffened plate model is expressed in m². 2 .

[0013] According to some embodiments of this application, determining the lifting height and counterweight mass of the axial impact assembly based on axial impact parameters includes: The axial impact parameters include impact velocity and impact mass; the lifting height of the axial impact assembly is determined based on the impact velocity. The counterweight mass of the axial impact assembly is determined based on the impact mass.

[0014] According to some embodiments of this application, determining the lifting height of the axial impact assembly based on the impact velocity includes: The lifting height of the axial impact assembly is calculated using the following formula: ; in, v The impact velocity is expressed in m / s. g It is the acceleration due to gravity; h The elevation is given in meters (m).

[0015] According to some embodiments of this application, before configuring the mass of the lateral counterweight assembly according to the lateral pressure parameters and placing the configured lateral counterweight assembly on the upper surface of the stiffened plate model, the method further includes: Obtain the material mechanical parameters of the stiffened plate model, and perform numerical simulation analysis based on the material mechanical parameters; The axial impact parameters are determined based on the results of numerical simulation analysis. The lateral pressure parameters are determined based on the ship's draft.

[0016] According to some embodiments of this application, obtaining the material mechanical parameters of the stiffened plate model and performing numerical simulation analysis based on the material mechanical parameters includes: The material mechanical parameters include static mechanical parameters and dynamic mechanical parameters; the static mechanical parameters and dynamic mechanical parameters of the stiffened plate models in the same batch are obtained, and the dynamic constitutive model of the stiffened plate model is fitted according to the static mechanical parameters and the dynamic mechanical parameters for numerical simulation analysis. Attached Figure Description

[0017] The accompanying drawings are used to provide a further understanding of the technical solutions disclosed in this application and form part of the specification. They are used together with the embodiments disclosed in this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions disclosed in this application.

[0018] Figure 1 This is a structural schematic diagram of the stiffened plate model in the embodiments of this application; Figure 2 This is one of the structural schematic diagrams of the stiffened plate test device in the embodiments of this application; Figure 3 This is the second schematic diagram of the stiffened plate test device in the embodiments of this application; Figure 4 This is a flowchart of the test method for the stiffening plate in the embodiments of this application.

[0019] Figure descriptions: 100, frame; 200, guide rail; 210, vertical section; 220, transition section; 230, horizontal section; 300, axial impact assembly; 400, stiffening plate model; 500, lateral counterweight assembly; 600, lifting mechanism; 700, baffle. Detailed Implementation

[0020] The following specific embodiments will further illustrate the content of this application in detail.

[0021] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0022] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0024] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0025] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0026] like Figures 1 to 3 As shown, the stiffened plate testing apparatus according to the first aspect of this application includes: The frame 100 is provided with a guide rail 200, which has a vertical section 210 and a horizontal section 230 connected in sequence. The vertical section 210 extends in the vertical direction and the horizontal section 230 extends in the horizontal direction. A stiffening plate model 400 is horizontally positioned within a horizontal section 230 and connected to the horizontal section 230. Axial impact assembly 300 is slidably connected to guide rail 200 and is configured to impact stiffened plate model 400 to apply axial impact load to stiffened plate model 400. A lateral counterweight assembly 500 is disposed on the upper surface of the stiffened plate model 400 and is configured to apply a lateral impact load to the stiffened plate model 400.

[0027] The stiffened plate testing device in this application embodiment is suitable for conducting the above-mentioned stiffened plate testing method. The lateral counterweight component 500 is placed on the upper surface of the stiffened plate model 400 to apply lateral pressure. The axial impact component 300 falls along the vertical section 210, turns to the horizontal section 230, and then impacts the stiffened plate model 400. The axial impact component 300 can provide dynamic axial impact loads to the stiffened plate model 400, thereby simultaneously providing lateral pressure and axial impact loads to the stiffened plate model 400, simulating the actual stress state of the ship's bottom or deck during slamming and fluttering. This results in small deviations between the deformation data, buckling morphology data, and damage data of the stiffened plate model 400 obtained from the test and the actual working conditions, ensuring high reliability.

[0028] In this embodiment of the application, at least two guide rails 200 are provided. For example... Figure 2 As shown, two guide rails 200 are provided, each with a guide groove. The axial impact component 300 is provided with multiple pulleys, which are embedded in the guide grooves of the corresponding guide rails 200 and slide in cooperation with them. The two guide rails 200 are arranged in parallel, and the axial impact component 300 is slidably connected to the guide grooves of the corresponding guide rails 200 through the pulleys, preventing the axial impact component 300 from shifting or jamming during sliding.

[0029] According to some embodiments of this application, the horizontal segment 230 is provided with a baffle 700, and the end of the stiffening plate model 400 away from the vertical segment 210 is detachably connected to the baffle 700. Specifically, the stiffening plate model 400 and the baffle 700 are connected by bolts. The end of the stiffening plate model 400 near the vertical segment 210 is a free end, used to receive the impact of the axial impact assembly 300.

[0030] According to some embodiments of this application, such as Figure 2 and Figure 3 As shown, the frame 100 also includes a lifting mechanism 600 and a release locking mechanism (not shown in the figure). Both the lifting mechanism 600 and the release locking mechanism are connected to the axial impact assembly 300. The lifting mechanism 600 is used to drive the axial impact assembly 300 to be lifted along the guide rail 200, and the release locking mechanism is used to lock or release the axial impact assembly 300 on the guide rail 200.

[0031] like Figures 1 to 4As shown, a method for testing stiffened plates based on the above-mentioned stiffened plate testing device includes: S100: Configure the mass of the lateral counterweight component 500 according to the lateral pressure parameters, and place the configured lateral counterweight component 500 on the upper surface of the stiffened plate model 400. S200: Determine the lifting height and counterweight mass of the axial impact assembly 300 based on the axial impact parameters; S300: Adjust the counterweight of the axial impact assembly 300 to the counterweight mass, lift the axial impact assembly 300 to the lifting height and then release it, so that the axial impact assembly 300 slides along the vertical section 210 of the guide rail 200 to the horizontal section 230 and impacts the stiffened plate model 400. S400: Acquire deformation data, buckling morphology data, and damage data of stiffened plate model 400 after impact.

[0032] like Figure 1 As shown, Figure 1 The diagram shows a horizontally placed stiffened plate model 400, with the x-direction representing the lateral pressure direction and the y-direction representing the axial impact load direction. It can be understood that by applying lateral pressure to the stiffened plate model 400 along the x-direction, the condition of the stiffened plate being subjected to a uniformly distributed lateral pressure load can be simulated; by impacting the stiffened plate model 400 along the y-direction, the condition of the stiffened plate being subjected to an axial impact load can be simulated.

[0033] In the test method of the stiffened plate in this embodiment, the lateral counterweight assembly 500 is placed on the upper surface of the stiffened plate model 400 to apply lateral pressure to it; the axial impact assembly 300 falls along the vertical section 210 and turns to the horizontal section 230 before impacting the end face of the stiffened plate model 400. The axial impact assembly 300 can provide dynamic axial impact load to the stiffened plate model 400, thereby providing both lateral pressure and axial impact load to the stiffened plate model 400 at the same time, simulating the real stress state of the bottom or deck during the slamming and fluttering process, so that the deformation data, buckling morphology data and damage data of the stiffened plate model 400 obtained by the test have small deviations from the actual working conditions and high reliability.

[0034] According to some embodiments of this application, such as Figure 3 As shown, the guide rail 200 also has a transition section 220, which connects the vertical section 210 and the horizontal section 230. The transition section 220 is set in an arc shape to realize the smooth conversion of the kinetic energy of the vertical axial impact component 300 to the horizontal axial impact, avoid the jamming, deflection and energy loss of the axial impact component 300 during the reversal process, improve the stability and controllability of the impact loading, and achieve high test repeatability.

[0035] According to some embodiments of this application, the axial impact assembly 300 includes a counterweight box and a plurality of second counterweight blocks (not shown in the figure). The counterweight box is slidably connected to the guide rail 200, and the second counterweight blocks are disposed inside the counterweight box.

[0036] The total mass of the axial impact assembly 300 can be independently adjusted by increasing or decreasing the number of second counterweights in the counterweight box. At the same time, the sliding connection between the counterweight box and the guide rail 200 ensures that the movement path of the impact assembly is consistent under different counterweight conditions, thus ensuring the repeatability of the test.

[0037] Accordingly, in step S300, the counterweight of the axial impact assembly 300 is adjusted to the counterweight mass, the axial impact assembly 300 is lifted to the lifting height and then released, so that the axial impact assembly 300 slides along the vertical section 210 of the guide rail 200 to the horizontal section 230 and impacts the stiffened plate model 400, specifically including: S310: Determine the number of second counterweights based on the counterweight mass; S320: Place the corresponding number of second counterweights into the counterweight box, lift the axial impact component 300 to the lifting height and then release it, so that the axial impact component 300 falls along the vertical section 210 of the guide rail 200, turns to the horizontal section 230 after passing through the transition section 220 and then impacts the stiffened plate model 400.

[0038] Furthermore, the lateral counterweight assembly 500 includes multiple flexible counterweight bags and multiple first counterweight blocks; the flexible counterweight bags are evenly distributed on the upper surface of the stiffening plate model 400, and the first counterweight blocks are disposed on the upper surface of the flexible counterweight bags.

[0039] According to some embodiments of this application, step S100: configuring the mass of the lateral counterweight assembly 500 according to the lateral pressure parameters, and placing the configured lateral counterweight assembly 500 on the upper surface of the stiffened plate model 400, includes: S110: The lateral counterweight assembly 500 includes multiple flexible counterweight bags and multiple first counterweight blocks; the total mass of the flexible counterweight bags and the total mass of the first counterweight blocks are determined according to the lateral pressure parameters. S120: Spread the flexible counterweight bag evenly on the upper surface of the stiffened plate model 400, and then place the first counterweight block on top of the flexible counterweight bag.

[0040] The flexible counterweight bag is a counterweight, such as a sandbag, filled with contents inside a flexible bag. In this embodiment, the flexible counterweight bag, after being filled with its contents, has a certain mass and, when evenly laid on the upper surface of the stiffened plate model 400, can provide uniform lateral pressure to the stiffened plate model 400. The first counterweight block can be a standard counterweight block or a weight, placed on top of the flexible counterweight bag. The lateral pressure value can be changed by replacing or adding / removing the first counterweight block, without the need to re-lay the flexible counterweight bag.

[0041] According to some embodiments of this application, step S110: determining the total mass of the flexible counterweight bag and the total mass of the first counterweight block based on the lateral pressure parameters, includes: Calculate the total mass of the flexible counterweight bag and the total mass of the first counterweight block using the following formulas: ; in, P This is a lateral pressure parameter, in Pa. m s The total mass of the flexible counterweight bag is expressed in kg. m c The total mass of the first counterweight is expressed in kg. g It is the acceleration due to gravity; A The effective bearing area of ​​the stiffened slab model 400 is expressed in m². 2 .

[0042] Specifically, before the flexible counterweight bags are evenly laid on the upper surface of the stiffened plate model 400, the total mass of the flexible counterweight bags is measured, and the effective bearing area of ​​the stiffened plate model 400 is pre-measured. The total mass of the first counterweight block can then be calculated using the aforementioned formula. Based on the mass of each first counterweight block, the required number of first counterweight blocks is calculated. By changing the number of first counterweight blocks, the lateral pressure on the stiffened plate model 400 is altered, thus achieving independent adjustment of the lateral pressure.

[0043] According to some embodiments of this application, the axial impact parameters include impact velocity and impact mass; step S200: determining the lifting height and counterweight mass of the axial impact assembly 300 based on the axial impact parameters, including: S210: Determine the lifting height of the axial impact assembly 300 based on the impact velocity; S220: Determine the counterweight mass of the axial impact assembly 300 based on the impact mass.

[0044] In related technologies, it is often possible to apply both static axial load and lateral pressure load simultaneously to the stiffened plate model 400, while dynamic axial impact load is prone to interference with lateral pressure load. This embodiment addresses this by assigning impact velocity and impact mass to the lifting height and counterweight mass, two independently adjustable variables, respectively. This allows the axial impact parameters to be adjusted independently under the condition of simultaneous application of lateral pressure, thereby enabling the simulation of composite load conditions under different impact energies and impact momentum.

[0045] According to some embodiments of this application, step S220: determining the lifting height of the axial impact assembly 300 based on the impact velocity includes: The lifting height of the axial impact assembly 300 is calculated using the following formula: ; in, v Impact velocity, in m / s; g It is the acceleration due to gravity; h To indicate the height, the unit is meters (m).

[0046] Specifically, the axial impact assembly 300, after being counterweighted, is lifted to the lifting height and then released, causing it to fall along the vertical section 210 of the guide rail 200. After passing through the transition section 220 and turning to the horizontal section 230, it impacts the end face of the stiffened plate model 400. The height of the axial impact assembly 300 is converted into impact velocity. With friction negligible, the correspondence between the impact velocity and the lifting height of the axial impact assembly 300 is achieved, ensuring that the impact velocity is controllable and the test repeatability is high.

[0047] According to some embodiments of this application, before configuring the mass of the lateral counterweight assembly 500 according to the lateral pressure parameters and determining the lifting height and counterweight mass of the axial impact assembly 300 according to the axial impact parameters, step S100 further includes: S510: Obtain the material mechanical parameters of stiffened plate model 400, and perform numerical simulation analysis based on the material mechanical parameters; S520: Determine the axial impact parameters based on the results of numerical simulation analysis; S530: Determine lateral pressure parameters based on the ship's draft.

[0048] In this embodiment, the lateral pressure parameter is directly calculated based on the ship's draft, simulating the hydrostatic pressure at the ship's bottom under real-world conditions by applying lateral pressure to the stiffened plate model 400. The axial impact parameter is determined by acquiring material mechanical parameters and performing numerical simulation analysis. This allows for obtaining the axial impact parameter that causes the stiffened plate model 400 to undergo ultimate collapse before the formal test, and for determining a reasonable gradient range of the axial impact parameter in subsequent sets of tests, avoiding unreasonable settings of the axial impact parameter during the test. Unreasonable settings of the axial impact parameter may lead to the stiffened plate model 400 being directly punctured, or the axial impact component 300 failing to effectively damage the stiffened plate model 400. Therefore, determining the axial impact parameter based on the numerical simulation analysis results ensures that multiple sets of tests can fully cover the response process of the stiffened plate model 400 from elastic deformation to ultimate collapse.

[0049] According to some embodiments of this application, the material mechanical parameters include static mechanical parameters and dynamic mechanical parameters; Step S510: Obtain the material mechanical parameters of the stiffened plate model 400, and perform numerical simulation analysis based on the material mechanical parameters, specifically including: S511: Obtain the static and dynamic mechanical parameters of the stiffened plate model 400 in the same batch, and fit the dynamic constitutive model of the stiffened plate model 400 based on the static and dynamic mechanical parameters for numerical simulation analysis.

[0050] Specifically, step S511 includes the following steps: S501: Select materials from the same batch as stiffened plate model 400 to make material samples.

[0051] S502: Perform a static tensile test on the material specimen to obtain the static mechanical parameters of the material specimen, including the material's elastic modulus, static yield strength, ultimate strength, and static stress-strain curve.

[0052] S503: Perform a dynamic compression test on the material specimen to obtain the dynamic mechanical parameters of the material specimen, including the dynamic yield strength and dynamic stress-strain relationship of the material.

[0053] S504: Fitting the Cowper-Symonds dynamic constitutive equations of stiffened plate model 400 based on static and dynamic mechanical parameters. ; in, σ d This refers to the dynamic yield strength, expressed in Pa. σ s This is the static yield strength, expressed in Pa. The strain rate of the material is expressed in seconds (s). - ¹; D , p The strain rate of the material is an undetermined parameter. D The unit is s - ¹.

[0054] S505: Dynamic material testing is performed on material samples using a split Hopkinson pressure bar to obtain measured reflected strain signals and the material strain rate is calculated according to the following formula. ,strain ε and stress σ : ; in, C 0 represents the wave velocity of the elastic stress wave in the split Hopkinson column, in m / s; l s The initial length of the material sample is in meters (m). A s This represents the initial cross-sectional area of ​​the material sample, in m². Ab The cross-sectional area of ​​the split Hopkinson column is in m². E The elastic modulus of the split Hopkinson column material is expressed in Pa. ε R This is the measured reflected strain signal; ε T This is the measured reflected strain signal; t and τ Time, in seconds; The strain rate of the material is expressed in seconds (s). - ¹; ε In response to the situation; σ Stress is expressed in Pa.

[0055] S506: Based on material strain rate ,strain ε and stress σ Plot the stress-strain curve and obtain different strain rates based on the stress-strain curve. Dynamic yield strength σ d Based on static yield strength σ s Different strain rates Dynamic yield strength σ d Construct the objective function of sum of squared errors: ; in, D , p The strain rate of the material is an undetermined parameter; σ si This is the static yield strength. σ si subscript i These are the serial numbers corresponding to different strain rates; σ di For dynamic yield strength, σ di subscript i These are the serial numbers corresponding to different strain rates; i For strain rate, i subscript i These are the serial numbers corresponding to different strain rates.

[0056] S507: The objective function is iteratively optimized using the nonlinear least squares method to obtain the undetermined material strain rate parameters that minimize the error. D and p .

[0057] Specifically, the numerical simulation analysis is a finite element analysis. It is based on the material's elastic modulus, static yield strength, dynamic yield strength, and undetermined strain rate parameters. D and p Finite element analysis was conducted using static stress-strain curves and dynamic stress-strain curves.

[0058] Further, step S520: Determine the axial impact parameters based on the numerical simulation analysis results, specifically including: The lateral pressure parameters and axial impact parameters are determined based on the results of finite element analysis.

[0059] Specifically, axial impact parameters include impact velocity and impact mass. Impact velocity includes initial velocity. v 0 and multiple velocity gradient values, impact mass including critical mass m 0 and multiple quality gradient values.

[0060] initial velocity v 0 is set to a strain rate of 1.0 s. - The impact velocity corresponding to ¹ v 0 =L*1.0s -1 ,in, L The length of the stiffened plate model is 400, in meters.

[0061] Using finite element method (FEM) software and employing dynamic display analysis, the loading mass was adjusted to simulate the process of stiffened plate model 400 undergoing elastic deformation to ultimate collapse under impact load, thereby obtaining the critical mass. m 0, specifically, critical mass m 0 is set to finite element analysis 1.0 P The mass of the structure that collapses at the corresponding velocity is obtained at 0.

[0062] Furthermore, S530: based on the ship's draft. h Determining lateral pressure parameters specifically includes: The lateral pressure parameters are calculated using the following formula: ; in, ρ This refers to the fluid density, expressed in kg / m³. g It is the acceleration due to gravity; h The draft of a ship is expressed in meters (m).

[0063] According to some embodiments of this application, step S510: obtaining the material mechanical parameters of the stiffened plate model 400, and before performing numerical simulation analysis based on the material mechanical parameters, further includes: S610: Design and fabricate a stiffened plate model 400 that is geometrically similar to the stiffened plate prototype based on similarity theory; S620: Use a three-dimensional laser to scan the stiffened plate model 400 to obtain the reference state data of the stiffened plate model 400. The reference state data includes initial deformation data, flatness data and geometric defect data.

[0064] In steps S610 to S620, a three-dimensional laser scanner is used to record the data of the stiffened plate model 400 before and after the test. The baseline state data of the stiffened plate model 400 is compared with the deformation data, buckling morphology data and damage data obtained after the test. This can effectively analyze the influence of lateral pressure and axial impact on the stiffened plate model 400, simulate the real stress state of the stiffened plate of the ship bottom or deck during the slamming and fluttering process, and the test data has high reliability and repeatability.

[0065] According to some embodiments of this application, S400: After acquiring the deformation data, buckling morphology data, and damage data of the stiffened plate model 400 after impact, the method further includes: S700: Keep any two of the lateral pressure parameters, impact velocity, and impact mass fixed, change the third parameter, and repeat the above steps to conduct multiple sets of tests to obtain the influence of lateral pressure, impact velocity, and impact mass on the deformation, buckling morphology, and damage degree of the stiffened plate model 400.

[0066] In this embodiment, the lateral pressure parameter, impact velocity, and impact mass are adjusted independently. By keeping any two parameters fixed and changing the third parameter, multiple sets of working condition tests are conducted. This allows for the systematic acquisition of the influence of each parameter on the deformation, buckling morphology, and damage degree of the stiffened plate model 400, thereby improving the efficiency and data validity of the multi-working condition comparison test.

[0067] Because the lateral counterweight assembly 500 and the axial impact assembly 300 are structurally independent in this test method, the lateral pressure is directly applied by the lateral counterweight assembly 500, and the axial impact is applied by the axial impact assembly 300 after turning along the guide rail 200. The loading paths of the two do not interfere with each other, and the adjustment of each load parameter does not affect each other. Therefore, it can efficiently complete multi-parameter tests.

[0068] According to some embodiments of this application, the lateral pressure parameter includes a lateral pressure reference value. P 0 and multiple lateral pressure gradient values, impact velocity including initial velocity v 0 and multiple velocity gradient values, impact mass including critical mass m 0 and multiple quality gradient values; In step S700, keeping any two of the lateral pressure parameter, impact velocity, and impact mass fixed, and changing the third parameter, the above steps are repeated for multiple sets of tests, specifically including: S710: Determine the reference value for lateral pressure. P 0. Initial velocityv 0 and critical mass m 0; S720: Based on lateral pressure reference value P 0. Design multiple lateral pressure gradient values ​​based on the initial velocity. v 0. Design multiple velocity gradient values ​​based on critical mass. m 0. Design multiple quality gradient values; S730: Maintain initial speed v 0 and critical mass m Keeping 0 constant, select multiple lateral pressure gradient values ​​and repeat the above steps to conduct multiple sets of tests; Alternatively, maintain the lateral pressure reference value. P 0 and critical mass m Keeping 0 constant, select multiple velocity gradient values ​​and repeat the above steps to conduct multiple sets of experiments; Alternatively, maintain the lateral pressure reference value. P 0 and initial velocity v Keeping 0 constant, select multiple quality gradient values ​​and repeat the above steps to conduct multiple sets of experiments.

[0069] As an example, the lateral pressure reference value P The lateral pressure gradient is set to 1.0 based on the hydrostatic pressure at the hull corresponding to the ship's design draft. Considering that when the ship is sailing in severe sea conditions, the wave height increases significantly, and the local water pressure at the hull may far exceed the design draft pressure. P 0, 2.0 P 0 and 3.0 P 0.

[0070] initial velocity v 0 is set to a strain rate of 1.0 s. - The initial velocity corresponding to time ¹ is given by setting the velocity gradient to 0.5. v 0, 1.0 v 0, 2.0 v 0, 3.0 v 0 and 5.0 v 0.

[0071] critical mass m 0 is set to finite element analysis 1.0 P The critical mass for structural collapse at velocity 0 is obtained, and the mass gradient value is preferably set to 0.8. m 0, 1.0 m 0, 1.2 m 0 and 1.5 m 0, which is determined by the actual mass of the counterweight box and the second counterweight of the axial impact assembly 300. If it cannot be precisely met, the number of the second counterweight is selected based on the nearest preferred mass gradient value.

[0072] The lateral pressure parameters, impact velocity, and impact mass determined above can ensure that multiple sets of tests can fully cover the response process of the stiffened plate model 400 from elastic deformation to ultimate collapse.

[0073] In some alternative embodiments, the functions / operations mentioned in the block diagrams may not occur in the order shown in the operation diagrams. For example, depending on the functions / operations involved, two consecutively shown blocks may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order. Furthermore, the embodiments presented and described in the flowcharts of this application are provided by way of example to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and sub-operations described as part of a larger operation are executed independently.

[0074] The above embodiments are preferred embodiments of this application, but the implementation of this application is not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of this application shall be considered equivalent substitutions and shall be included within the protection scope of this application.

Claims

1. A test apparatus for stiffened plates, characterized in that, include: A frame, the frame being provided with guide rails, the guide rails having vertical sections and horizontal sections connected in sequence, the vertical sections extending in a vertical direction and the horizontal sections extending in a horizontal direction; A stiffened plate model is horizontally positioned within the horizontal segment and connected to the horizontal segment. An axial impact assembly is slidably connected to the guide rail and configured to impact the stiffened plate model to apply an axial impact load to the stiffened plate model. A lateral counterweight assembly is disposed on the upper surface of the stiffened plate model and is configured to apply a lateral impact load to the stiffened plate model.

2. The stiffened plate testing device according to claim 1, characterized in that, The lateral counterweight assembly includes multiple flexible counterweight bags and multiple first counterweight blocks; the flexible counterweight bags are evenly distributed on the upper surface of the stiffened plate model, and the first counterweight blocks are disposed on the upper surface of the flexible counterweight bags.

3. The stiffened plate testing device according to claim 1, characterized in that, The axial impact assembly includes a counterweight box and several second counterweight blocks. The counterweight box is slidably connected to the guide rail, and the second counterweight blocks are disposed inside the counterweight box.

4. A method for testing stiffened plates based on the stiffened plate testing apparatus according to any one of claims 1 to 3, characterized in that, include: Configure the mass of the lateral counterweight assembly according to the lateral pressure parameters, and place the configured lateral counterweight assembly on the upper surface of the stiffened plate model; The lifting height and counterweight mass of the axial impact assembly are determined based on the axial impact parameters. Adjust the counterweight of the axial impact assembly to the counterweight mass, lift the axial impact assembly to the lifting height and then release it, so that the axial impact assembly slides along the vertical section of the guide rail to the horizontal section and impacts the stiffened plate model; Obtain deformation data, buckling morphology data, and damage data of the stiffened plate model after impact.

5. The test method for stiffened plates according to claim 4, characterized in that, The step of configuring the mass of the lateral counterweight assembly according to the lateral pressure parameters and placing the configured lateral counterweight assembly on the upper surface of the stiffened plate model includes: The lateral counterweight assembly includes multiple flexible counterweight bags and multiple first counterweight blocks. The total mass of the flexible counterweight bags and the total mass of the first counterweight blocks are determined according to the lateral pressure parameters. The flexible counterweight bags are evenly laid on the upper surface of the stiffened plate model, and then the first counterweight blocks are placed on top of the flexible counterweight bags.

6. The test method for stiffened plates according to claim 5, characterized in that, The step of determining the total mass of the flexible counterweight bag and the total mass of the first counterweight block based on the lateral pressure parameters includes: The total mass of the flexible counterweight bag and the total mass of the first counterweight block are calculated using the following formulas: ； in, P The lateral pressure parameter is expressed in Pa. m s The total mass of the flexible counterweight bag is expressed in kg. m c The total mass of the first counterweight is expressed in kg. g It is the acceleration due to gravity; A The effective bearing area of ​​the stiffened plate model is expressed in m². 2 .

7. The test method for stiffened plates according to claim 4, characterized in that, The process of determining the lifting height and counterweight mass of the axial impact assembly based on axial impact parameters includes: The axial impact parameters include impact velocity and impact mass; the lifting height of the axial impact assembly is determined based on the impact velocity. The counterweight mass of the axial impact assembly is determined based on the impact mass.

8. The test method for stiffened plates according to claim 7, characterized in that, Determining the lifting height of the axial impact assembly based on the impact velocity includes: The lifting height of the axial impact assembly is calculated using the following formula: ； in, v The impact velocity is expressed in m / s. g It is the acceleration due to gravity; h The elevation is given in meters (m).

9. The test method for stiffened plates according to claim 4, characterized in that, Before configuring the mass of the lateral counterweight assembly according to the lateral pressure parameters and placing the configured lateral counterweight assembly on the upper surface of the stiffened plate model, the method further includes: Obtain the material mechanical parameters of the stiffened plate model, and perform numerical simulation analysis based on the material mechanical parameters; The axial impact parameters are determined based on the results of numerical simulation analysis. The lateral pressure parameters are determined based on the ship's draft.

10. The test method for stiffened plates according to claim 9, characterized in that, The process of obtaining the material mechanics parameters of the stiffened plate model and performing numerical simulation analysis based on these parameters includes: The material mechanical parameters include static mechanical parameters and dynamic mechanical parameters; the static mechanical parameters and dynamic mechanical parameters of the stiffened plate models in the same batch are obtained; A dynamic constitutive model of the stiffened plate model is fitted based on the static mechanical parameters and the dynamic mechanical parameters for numerical simulation analysis.

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