Method, device and medium for determining ship type parameters for bridge ship collision prevention

Abstract

Embodiments of the present application disclose a bridge anti-ship collision defense ship type parameter determination method, equipment and medium, and relate to the technical field of bridge risk assessment. The method comprises: constructing a ship-bridge model, wherein the ship-bridge model is used to reflect the relationship among ship displacement, mass and stiffness; determining a calculation formula of a ship-bridge net displacement ratio and an energy ratio according to the ship-bridge model; determining an expression of a ship initial speed about bridge pier absorbed energy according to the calculation formula and the law of conservation of energy; determining a ship speed threshold expression for preventing bridge collapse under different ship tonnages according to the expression and a maximum threshold value of bridge pier displacement; and determining the defense ship type parameters of the bridge pier according to the ship speed threshold expression. The embodiments can determine the defense ship type parameters according to the structural characteristics and service stage of the bridge pier.

Description

Technical Field

[0001] This invention relates to the field of bridge risk assessment technology, and in particular to a method, equipment and medium for determining the ship type parameters of bridge anti-ship collision design. Background Technology

[0002] Currently, with the increasing number of long-span sea-crossing bridges and the large-scale development of navigation vessels, coupled with the constantly changing water environment in bridge areas, ship-bridge collisions are occurring frequently. At the moment of collision, a massive impact load acts on the bridge structure, and the impact energy spreads along the structural force transmission path, easily leading to attenuation of the bridge's weak components, localized damage, or even overall fracture. In extreme cases, such collisions may cause bridge collapse, resulting in a safety accident. Therefore, it is necessary for bridge engineers to thoroughly explore the mechanisms of ship-bridge collisions and develop practical and effective methods for assessing the risk of ship-bridge collisions to improve the overall safety performance of bridges.

[0003] Current technologies for risk assessment of long-span sea-crossing bridges under ship collisions are insufficient, primarily focusing on the design of anti-ship collision devices, damage identification, and early warning systems, with less attention paid to the bridge's dynamic response. For example, patent CN103966980B designs a steel-concrete composite bridge anti-ship collision device and an anti-ship collision bridge. The device includes energy-dissipating components fixed to the bridge piers or abutments, as well as force-transmitting components. The energy-dissipating components are designed as a grid structure, primarily dissipating energy through progressive compression in the direction of the ship collision. The anti-ship collision device features a clear force transmission path, stable energy dissipation mode, high energy efficiency, good corrosion resistance, high safety, and simple construction. Patent CN115326260B discloses a real-time identification method and health monitoring system for ship-collision pier loads. Once a pier is impacted by a ship, the impact load time history is inverted based on the collected data and load identification algorithm. The identified impact load time histories can serve as a simulation reference for ship-to-bridge pier collisions and can also be used for performance evaluation of piers after impact, providing theoretical evaluation indicators for the overall safety performance of bridges. Patent CN115346399B discloses a bridge anti-ship collision early warning system based on phased array radar, AIS, and LSTM networks, including a data acquisition system and an analysis system connected to the acquisition system for predicting the information acquired. The ship-to-bridge collision risk early warning unit can accurately predict bridge collision risks and provide timely alarms. The overall system of this invention is easy to implement and applicable to bridge-area waterways. Patent CN116467776B discloses a bridge impact multi-failure mode resistance calculation method based on energy equivalence. It establishes the relationship between the nonlinear response of ship-to-bridge collisions and the equivalent static ship-to-bridge collision resistance from an energy perspective, allowing the dynamic nature of ship-to-bridge collision problems to be reflected. The calculated bridge ship-to-bridge collision resistance results are more scientific and accurate, providing greater guidance for actual bridge anti-ship collision design and reinforcement.

[0004] Early risk assessments of ship-bridge collisions largely employed qualitative methods, relying primarily on experience and intuitive judgment. In recent years, quantitative methods for navigation risk assessment have become increasingly prevalent. Specific parameters of representative vessel types are crucial data in this assessment. Specifically, a representative vessel type refers to a vessel whose design load capacity, determined through technical validation, meets the required navigation standards and can reach the corresponding tonnage, providing a data foundation for risk assessment. Because the collapse risk of long bridges with different span types and at different service stages within the same waterway varies significantly, the same vessel may pose a fatal threat to short-span or long-life bridge sections while posing a manageable risk to large-span or short-life sections. However, traditional methods for determining the representative vessel type in ship-bridge collision assessments rely solely on static waterway vessel data (statistically, identifying the most frequently used vessel type and its most common speed in the environment). This fails to consider the structural characteristics of bridge piers and their specific parameters, resulting in a failure to reflect variations in bridge collapse risk across different span types and service stages.

[0005] Therefore, determining the design parameters of the ship type based on the structural characteristics of the bridge piers and the service stage is an urgent problem to be solved. Summary of the Invention

[0006] This invention provides a method, equipment, and medium for determining the ship type parameters of bridge anti-ship collision design to solve the above-mentioned technical problems.

[0007] In a first aspect, embodiments of the present invention provide a method for determining the hull type parameters for bridge collision resistance, including:

[0008] A ship-bridge collision model is constructed, wherein the ship-bridge collision model is used to reflect the relationship between ship-bridge displacement, mass, and stiffness;

[0009] Based on the ship-bridge collision model, the calculation formulas for the ship-bridge net displacement ratio and energy ratio are determined.

[0010] Based on the aforementioned calculation formula and the law of conservation of energy, the expression for the initial speed of the ship with respect to the energy absorbed by the bridge pier is determined;

[0011] Based on the aforementioned expression and the maximum threshold for pier displacement, determine the speed threshold expression for preventing bridge collapse under different ship tonnages;

[0012] Based on the aforementioned ship speed threshold expression, the design ship type parameters of the bridge piers are determined.

[0013] In a second aspect, embodiments of the present invention provide an electronic device, the electronic device comprising:

[0014] One or more processors;

[0015] Memory, used to store one or more programs.

[0016] When the one or more programs are executed by the one or more processors, the one or more processors implement the method for determining bridge collision-resistant ship type parameters as described in any embodiment.

[0017] In summary, this invention provides a method for determining the parameters of the vessel type for bridge collision resistance, enabling rapid calculation of the ship speed threshold at which the displacement of the pier top exceeds the limit due to impacts from ships of different tonnages. This method considers the structural characteristics of the bridge and the stiffness degradation of the pier. Based on bridge collapse risk analysis, it establishes a quantitative relationship between the ultimate lateral resistance of the pier and key parameters of the collapse-resistant vessel type, and derives the calculation formulas for the pier energy consumption ratio and the critical ship speed. This helps provide a dynamic design basis for the collision risk assessment of long bridges and the formulation of protective measures, thereby reducing the probability of bridge collapse. Specifically:

[0018] 1) This embodiment establishes a quantitative relationship model between the energy consumption ratio of bridge piers and the ship speed threshold, realizes the rapid calculation of key parameters of the fortified ship type, and can efficiently output the tonnage and critical speed threshold of the fortified ship type under different stiffness degradation stages, which significantly improves the timeliness of the safety assessment of in-service bridge collisions and provides a quantifiable technical basis for operation and maintenance decisions.

[0019] 2) This embodiment breaks through the traditional method of determining ship type that only relies on static waterway data. It innovatively introduces the dynamic time-varying characteristics of bridge structure, comprehensively considers the stiffness degradation of bridge piers and the structural differences of different spans, and realizes dynamic defense ship type determination based on actual collapse risk, which significantly improves the applicability of the method and the accuracy of risk assessment. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a method for determining the hull type parameters for bridge collision resistance provided by an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of a simplified spring-mass interaction model for a ship-bridge collision provided in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0025] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for 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 the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] Figure 1 This is a flowchart illustrating a method for determining the hull type parameters for bridge collision resistance according to an embodiment of the present invention. The method is executed by electronic equipment, such as... Figure 1 As shown, the method specifically includes:

[0028] S110. Construct a ship-bridge collision model, wherein the ship-bridge collision model is used to reflect the relationship between ship-bridge displacement, mass, and stiffness.

[0029] When a ship contacts a bridge pier, the contact surface is simplified as a dynamically starting and stopping elastic interaction mechanism. This can be simulated by the combined stiffness of the hull and the pier, demonstrating how they jointly resist the elastic response caused by the collision. For example... Figure 2 As shown, the ship-bridge collision process can be simplified into a spring-mass interaction model to capture the basic characteristics of ship-bridge collisions.

[0030] Specifically, previous ship-bridge collision tests have shown that damping has a relatively small direct impact on the system response. This may be because the impact energy is released rapidly, and damping accounts for a low proportion of the overall energy dissipation. Therefore, the damping effect is ignored in this model to simplify the analysis process and focus on key parameters. Secondly, this model assumes a small-angle frontal impact and that the ship's impact target is a bridge pier without passive collision protection. Furthermore, to ensure good safety redundancy and ease of calculation for the designed ship type, it is assumed that the bow deformation remains in the elastic stage.

[0031] Furthermore, such as Figure 2 As shown, the impacting ship can be equivalently represented as a mass block of mass m1 moving at velocity V0, and the bow stiffness can be equivalently represented as a spring with stiffness k1; the bridge pier can be equivalently represented as a mass block of mass m2, and the pier stiffness can be considered as the stiffness k caused by the pier's own flexibility. 2-1 and the stiffness k caused by the earth pressure of the pile foundation 2-2 The equivalent stiffness after superposition is k2; the ship's motion distance is represented by x1, and the bridge pier's motion distance is represented by x2. Then for... Figure 2 The shown motion system has the following dynamic equations:

[0032]

[0033] Where m1, k1, and x1 represent the mass, equivalent stiffness, and displacement of the colliding vessel, respectively, and m2, k2, and x2 represent the mass, equivalent stiffness, and displacement of the bridge pier that was collided with.

[0034] S120. Based on the ship-bridge collision model, determine the calculation formulas for the ship-bridge net displacement ratio and energy ratio.

[0035] Based on equation (1), the ship-bridge displacement in the ship-bridge collision model can first be expressed as a complex number, and the amplitude ratio of the ship-bridge displacement can be solved. Specifically, in order to obtain the ship bow displacement x1 and the bridge pier displacement x2, the motion equation shown in equation (1) is transformed to obtain equation (2):

[0036]

[0037] In the formula, A1 and A2 are the amplitudes corresponding to m1 and m2, respectively, s is the conjugate complex root of the coefficient row and column on the left side of equation (2), and the general solution of equation (2) is x. 1= A1e st x 2= A2e st t represents time. To make the eigenvectors... It has a non-zero solution, and the conjugate complex root s=iw in the left-hand side coefficient determinant. n (w) n(representing the imaginary part), therefore we have s 2 =-λ (λ represents the eigenvalue), expand and rearrange to obtain the characteristic equation (3):

[0038]

[0039] Substituting into equation (2) and solving, we can obtain the expressions (4) for the corresponding eigenvalues ​​λ1 and λ2:

[0040]

[0041] Therefore, the expression for the amplitude ratio A1 / A2 can be rewritten as equation (5):

[0042]

[0043] Then, the calculation formulas for the net displacement ratio and energy ratio of the bridge can be determined based on the amplitude ratio. Specifically, each eigenvalue λ corresponds to an eigenvector {A}, representing the amplitude of the corresponding first mode. However, here we only care about the eigenvector when x1 / x2>0, so we take λ1 and substitute it into equation (5). The net displacement ratio of m1 and m2 can be expressed as Δ1 / Δ2, which can be calculated from the amplitude. Finally, we obtain equation (6):

[0044]

[0045] Where ξ and η are intermediate variables, ξ = k1 / k2; η = m1 / m2. Furthermore, the ratio of energy absorbed by the bow to that absorbed by the bridge pier is... It is expressed as follows:

[0046]

[0047] In the formula, Δ1 and Δ2 are the net displacements (i.e., deformations) of the impacting ship and the bridge pier, respectively; E1 is the impact energy absorbed by the ship; and E2 is the impact energy absorbed by the bridge pier.

[0048] S130. Based on the calculation formula and the law of conservation of energy, determine the expression for the initial speed of the ship with respect to the energy absorbed by the bridge pier.

[0049] Here, the initial speed refers to the ship's speed before it hits the bridge pier, also known as the impact speed.

[0050] To assess the impact resistance and safety of bridge piers under ship collision, it is necessary to obtain the ratio of the impact energy absorbed by the pier to the initial total energy of the ship, E2 / E0. Therefore, based on the law of conservation of energy, we can first construct the following equations relating the initial total energy of the ship, the kinetic energy of both the ship and the pier, and the absorbed impact energy during the ship-bridge collision process:

[0051]

[0052] In the formula, E0 is the initial total energy of the ship; V0 is the initial speed of the ship; E b E represents the total energy of the ship. s E represents the total energy of the bridge pier; T represents the total duration of the ship-bridge collision, t∈(0,T); * E1(t) represents the kinetic energy of the ship at time t; E1(t) represents the impact energy absorbed by the ship at time t; E * E2(t) represents the kinetic energy of the pier at time t; E2(t) represents the impact energy absorbed by the pier at time t. Let be the net displacement of the ship at time t. V1(t) is the net displacement of the bridge pier at time t; V1(t) is the speed of the ship during the impact, and V1(t)=0 is the most unfavorable situation (the ship compresses the bridge to the greatest depth); V2(t) is the speed of the bridge pier at time t during the impact, and V2(t)=0 is the most unfavorable situation.

[0053] Then, based on the aforementioned relational equation and calculation formula (7), an expression for the initial ship speed with respect to the energy absorbed by the pier is constructed. Specifically, c is set to E. * The ratio of 2 to E2 means that the value of c decreases as the ship's tonnage increases. When c=0, it is the most unfavorable situation. Therefore, the energy conservation formula of the simplified motion system shown in formula (8) can be transformed into:

[0054]

[0055] The coefficient of restitution, e, is introduced as a speed index to measure ship-bridge collisions. The coefficient of restitution, e, is expressed as the ratio between the ship's speed at a certain moment of approaching the bridge and its initial speed, as shown in formula (10):

[0056]

[0057] For perfectly elastic and perfectly inelastic collisions, e equals 1 and 0, respectively.

[0058] By combining formulas (7) to (10), the expression for the energy consumption ratio of bridge piers, E2 / E0, can be obtained, as shown in formula (11):

[0059]

[0060] Let E0 = 1 / 2m1V0 2 Substituting into formula (11) and transforming it, we can obtain the expression (12) for the initial speed V0 of the ship:

[0061]

[0062] When V1(t)=0, the ship impact depth is at its maximum, and E2 is at its maximum value at this time.

[0063] S140. Based on the expression and the maximum threshold of pier displacement, determine the speed threshold expression for preventing bridge collapse under different ship tonnages.

[0064] In equation (12), take (That is, the worst-case scenario, where the ship compresses the bridge to the greatest extent), take =The impact energy absorbed by the pier when the pier displacement is taken as the maximum threshold. Substituting into equation (12), equation (12) can be transformed into the speed threshold expression for preventing bridge collapse under different ship tonnages.

[0065] Optionally, the "Specifications for Maintenance of Highway Bridges and Culverts" and the "Basic Specifications for Design of Railway Bridges and Culverts" stipulate that the allowable horizontal displacement of the top surface of the piers and abutments of simply supported beam bridges is [value missing]. mm, where L is the minimum span between adjacent piers. This displacement limit takes into account the effects of dynamic loads such as vehicles, water flow, temperature, and wind. Both vehicle and ship collision loads are short-duration dynamic loads. If E2 reaches this threshold, that is, when the displacement of the target pier top reaches... The amount of energy absorbed by the pier when the bridge collapses is mm can be considered as the bridge collapsing. At this time, equation (12) becomes the formula for calculating the speed threshold.

[0066] S150. Determine the ship type parameters for the bridge piers based on the aforementioned ship speed threshold expression.

[0067] The ship type parameters for defense include ship tonnage and speed thresholds, which correspond to the values ​​in equation (12) respectively. and Given the energy consumption threshold of the bridge pier, the speed threshold formula can be used to calculate the speed threshold of ships of different tonnages when the target bridge pier is impacted by a ship and reaches the specified allowable displacement value.

[0068] Optionally, the energy consumption threshold of the bridge pier can be obtained through numerical simulation. This involves simulating and modeling the ship-bridge collision process, and determining the threshold when the displacement of the target pier top reaches a certain value. When the pier absorbs energy at a certain value (mm), the energy threshold of E2 is obtained. Substituting this threshold and V1(t)=0 into the formula for calculating the ship speed threshold, the ship speed threshold can be obtained (i.e., ...). (Maximum threshold). For example, LS-DYNA finite element software can be used to perform numerical calculations of ship collisions with bridge piers. A ship model with the same tonnage and a bridge pier with either fixed or elastic piles at the bottom are established. A downward beam weight is applied to the upper part, and then the process of the ship colliding with the bridge pier is simulated. During the simulation, the pier top displacement and the energy absorbed by the pier can be obtained in real time. The maximum threshold is taken as the pier top displacement reaches... The energy absorbed by the pier at a speed of mm is used as E2 and is included in the calculation of the ship speed threshold.

[0069] In the risk assessment of long-span sea-crossing bridges under ship collisions, for each pier, the current mass and equivalent stiffness of the pier can be determined based on its structural characteristics and service stage. Simultaneously, based on navigation data, the tonnage of different vessels passing through the pier can be determined. For each vessel tonnage, based on the vessel's mass and equivalent stiffness, and the current mass and equivalent stiffness of the pier, a speed threshold for each vessel tonnage corresponding to that pier can be determined using a speed threshold expression. Exceeding the speed threshold indicates a risk of bridge collapse, thus enabling the assessment of the collapse risk of each pier at each service stage, achieving dynamic risk assessment of the bridge.

[0070] Meanwhile, to ensure the safety of bridges against ship collisions during operation, the parameters of the protected vessels should be calculated and adjusted in real time according to the specific structural characteristics of the bridge piers and the updated navigation data of the bridge area, based on this determination method.

[0071] Furthermore, the ultimate lateral resistance of the piers that would cause the bridge to collapse can be calculated using the formulas provided by the AASHTO standard, as shown in equation (13). This will provide more accurate data references for anti-ship collision design.

[0072]

[0073] In the formula, V is the ship's impact speed (m / s); DWT is the ship's tonnage (t).

[0074] In summary, this embodiment provides a method for determining the parameters of the vessel type for bridge collision resistance, enabling rapid calculation of the ship speed threshold at which the displacement of the pier top exceeds the limit due to impacts from ships of different tonnages. This method considers the structural characteristics of the bridge and the stiffness degradation of the pier. Based on bridge collapse risk analysis, it establishes a quantitative relationship between the ultimate lateral resistance of the pier and key parameters of the collapse-resistant vessel type, and derives the calculation formulas for the pier energy consumption ratio and the critical ship speed. This helps provide a dynamic design basis for the collision risk assessment of long bridges and the formulation of protective measures, thereby reducing the probability of bridge collapse. Specifically:

[0075] 1) This embodiment establishes a quantitative relationship model between the energy consumption ratio of bridge piers and the ship speed threshold, realizes the rapid calculation of key parameters of the fortified ship type, and can efficiently output the tonnage and critical speed threshold of the fortified ship type under different stiffness degradation stages, which significantly improves the timeliness of the safety assessment of in-service bridge collisions and provides a quantifiable technical basis for operation and maintenance decisions.

[0076] 2) This embodiment breaks through the traditional method of determining ship type that only relies on static waterway data. It innovatively introduces the dynamic time-varying characteristics of bridge structure, comprehensively considers the stiffness degradation of bridge piers and the structural differences of different spans, and realizes dynamic defense ship type determination based on actual collapse risk, which significantly improves the applicability of the method and the accuracy of risk assessment.

[0077] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention, such as... Figure 3 As shown, the device includes a processor 60, a memory 61, an input device 62, and an output device 63; the number of processors 60 in the device can be one or more. Figure 3 Taking a processor 60 as an example; the processor 60, memory 61, input device 62, and output device 63 in the device can be connected via a bus or other means. Figure 3 Taking the example of a connection between China and Israel via a bus.

[0078] The memory 61, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the bridge collision-resistant hull type parameter determination method in this embodiment of the invention. The processor 60 executes various functional applications and data processing of the device by running the software programs, instructions, and modules stored in the memory 61, thereby realizing the aforementioned bridge collision-resistant hull type parameter determination method.

[0079] The memory 61 may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a given function; the data storage area may store data created based on terminal usage. Furthermore, the memory 61 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory, or other non-volatile solid-state storage device. In some instances, the memory 61 may further include memory remotely located relative to the processor 60, which can be connected to the device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0080] Input device 62 can be used to receive input digital or character information, and to generate key signal inputs related to user settings and function control of the device. Output device 63 may include display devices such as a display screen.

[0081] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the bridge collision-resistant hull type parameter determination method of any embodiment.

[0082] The computer storage medium of this invention can be any combination of one or more computer-readable media. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0083] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0084] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0085] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof. Programming languages ​​include object-oriented programming languages—such as Java, Smalltalk, and C++—as well as conventional procedural programming languages—such as C or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining the hull type parameters for bridge collision resistance, characterized in that, include: A ship-bridge collision model is constructed, wherein the ship-bridge collision model is used to reflect the relationship between ship-bridge displacement, mass, and stiffness; The ship-bridge displacement in the ship-bridge collision model is expressed as a complex number, and the amplitude ratio of the ship-bridge displacement is solved. Based on the amplitude ratio, the calculation formulas for the net displacement ratio and energy ratio of the ship-bridge are determined; Based on the aforementioned calculation formula and the law of conservation of energy, the expression for the initial speed of the ship with respect to the energy absorbed by the bridge pier is determined; Based on the aforementioned expression and the maximum threshold for pier displacement, determine the speed threshold expression for preventing bridge collapse under different ship tonnages; Based on the speed threshold expression, the ship type parameters for the bridge piers are determined.

2. The method according to claim 1, characterized in that, The ship-bridge collision model is as follows: , Where m1, k1 and x1 represent the mass, equivalent stiffness and displacement of the ship, respectively, and m2, k2 and x2 represent the mass, equivalent stiffness and displacement of the bridge pier.

3. The method according to claim 1, characterized in that, The step of expressing the ship-bridge displacement in the ship-bridge collision model as a complex number and solving for the amplitude ratio of the ship-bridge displacement includes: The displacement of the ship in the ship-bridge collision model. and the displacement of bridge piers , respectively expressed in complex form x 1= A1e st and x 2= A2e st Thus, the ship-bridge collision model is transformed into: （2） in, and They represent amplitudes, Indicates conjugate complex roots, Indicates time; Based on equation (2), the following amplitude ratio of the bridge displacement is obtained. : , , Where m1 and k1 represent the mass and equivalent stiffness of the ship, respectively, and m2 and k2 represent the mass and equivalent stiffness of the bridge pier, respectively. Represents the eigenvalue.

4. The method according to claim 3, characterized in that, The calculation formula for determining the net displacement ratio and energy ratio of the ship-bridge based on the amplitude ratio includes: Based on the amplitude ratio, it is the net displacement ratio of the bridge. Energy ratio of bridge The following calculation formula is determined: , , Where Δ1 and Δ2 represent the net displacements of the ship and the pier, respectively; E1 represents the impact energy absorbed by the ship; and E2 represents the impact energy absorbed by the pier. ξ and η are intermediate variables, respectively, where ξ = k1 / k2 and η = m1 / m2.

5. The method according to claim 1, characterized in that, The process of determining the expression for the initial speed of the ship with respect to the energy absorbed by the bridge pier, based on the aforementioned calculation formula and the law of conservation of energy, includes: Based on the law of conservation of energy, we construct an equation relating the initial total energy of the ship, the kinetic energy of both the ship and the bridge pier, and the energy absorbed during the ship-bridge collision process. Based on the aforementioned relational equation and calculation formula, an expression for the initial speed of the ship with respect to the energy absorbed by the bridge pier is constructed.

6. The method according to claim 5, characterized in that, Based on the law of conservation of energy, the equations relating the initial total energy of the ship, the kinetic energy of both the ship and the bridge pier, and the absorbed impact energy during the ship-bridge collision process are constructed, including: Based on the law of conservation of energy, the following relational equation can be constructed: （8） In the formula, E0 is the initial total energy of the ship; V0 is the initial speed of the ship; E b E represents the total energy of the ship. s E represents the total energy of the bridge; T represents the total duration of the ship-bridge collision, t∈(0,T); * E1(t) represents the kinetic energy of the ship at time t; E1(t) represents the impact energy absorbed by the ship at time t; E * E2(t) is the kinetic energy of the pier at time t; E2(t) is the impact energy absorbed by the pier at time t; V1(t) is the ship speed at time t during the impact, and V2(t) is the pier speed at time t during the impact. Let be the net displacement of the ship at time t. Let m1 be the net displacement of the pier at time t; m1 and k1 represent the mass and equivalent stiffness of the ship, respectively, and m2 and k2 represent the mass and equivalent stiffness of the pier, respectively.

7. The method according to claim 6, characterized in that, Bridge energy ratio The calculation formula is: （7） Accordingly, constructing the expression for the initial ship speed with respect to the energy absorbed by the bridge pier based on the relational equation and the calculation formula includes: Introducing energy ratio The relational equation (8) can be expressed as: （9） Introducing the coefficient of recovery As the ratio between the ship's speed at a certain moment of approaching the bridge and its initial speed: （10） Combining equations (7) and (10), we obtain the following expression for the initial speed of the ship: （12） Where ξ and η are intermediate variables, ξ=k1 / k2, η=m1 / m2, E1 represents the impact energy absorbed by the ship, and E2 represents the impact energy absorbed by the bridge pier. This is the kinetic energy of the bridge pier.

8. The method according to claim 7, characterized in that, The process of determining the speed threshold expression for preventing bridge collapse under different ship tonnages based on the aforementioned expression and the maximum threshold of pier displacement includes: In equation (12), take ,Pick =The impact energy absorbed by the pier when the pier displacement is taken as the maximum threshold, and Equation (12) is transformed into the speed threshold expression for preventing bridge collapse under different ship tonnages.

9. An electronic device, characterized in that, include: One or more processors; Memory, used to store one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement the method for determining bridge collision-resistant ship type parameters as described in any one of claims 1-8.

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