Bridge anti-ship-collision fortification ship type parameter determination method, equipment and medium

Abstract

The embodiment of the invention discloses a method and equipment for determining ship-collision-resistant fortification ship type parameters of a bridge and a medium, and relates to the technical field of bridge risk assessment. The method comprises the steps that a ship-to-bridge collision model is constructed, and the ship-to-bridge collision model is used for reflecting the relation among ship-to-bridge displacement, mass and rigidity; determining a calculation formula of a net displacement ratio and an energy ratio of the ship and the bridge according to the ship-bridge collision model; according to the calculation formula and the law of conservation of energy, determining an expression of the initial navigational speed of the ship about the energy absorbed by the pier; determining a navigational speed threshold expression for preventing the bridge from collapsing under different ship tonnages according to the expression and the maximum threshold of the bridge pier displacement; and according to the ship speed threshold expression, determining fortification ship type parameters of the bridge pier. According to the embodiment, fortification ship type parameters can be determined according to bridge pier structure characteristics and service stages.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the technical field of bridge risk assessment, and particularly relates to a bridge ship collision resistance ship type parameter determination method, equipment and medium. BACKGROUND

[0002] At present, with the increasing number of long-span bridges across the sea and the development of large-scale ships, combined with the continuous change of the water environment in the bridge area, ship-bridge collision accidents occur frequently. In the collision moment, a huge impact load will act on the bridge structure, the impact energy will diffuse along the force transmission path of the structure, which is easy to cause the resistance attenuation of the weak components of the bridge, local damage or even overall fracture. In extreme cases, such collisions may cause the bridge to collapse, and then cause safety accidents. Therefore, it is necessary for bridge engineers to deeply explore the action mechanism of ship-bridge collision and develop effective ship collision bridge risk assessment methods to improve the overall safety performance of the bridge.

[0003] The risk assessment of long-span bridges across the sea under ship collision in the prior art is still insufficient, and at present, it mainly focuses on the design of ship collision prevention devices, damage identification and early warning systems, and pays less attention to the dynamic response of the bridge. For example, patent CN103966980B designs a steel-concrete combined bridge ship collision prevention device and a ship collision prevention bridge. The ship collision prevention device includes an energy dissipation component and a force transmission component which are fixedly connected with the bridge pier or the pile cap. The energy dissipation component is arranged in a grid structure, and mainly realizes energy dissipation through progressive compression in the direction of the ship collision. The force transmission path of the ship collision prevention device is clear, the energy dissipation mode is stable, the energy dissipation efficiency is high, the corrosion resistance is good, the safety is high, and the construction is simple. Patent CN115326260B discloses a real-time identification method and a health detection system for ship collision pier load. Once the pier is impacted by the ship collision, the impact load time history is inverted based on the collected data and the load identification algorithm. The identified impact load time history can be used as a reference for simulation of the ship collision pier, and can also be used for performance evaluation of the pier after being hit, to provide a theoretical evaluation index for the overall safety performance of the bridge. Patent CN115346399B discloses a bridge ship collision early warning system based on a phased array radar, an AIS and an LSTM network, which includes a collection system and an analysis system connected with the collection system and used for predicting the information collected by the collection system. The ship collision bridge risk early warning unit can accurately warn the risk of bridge collision and alarm in time. The overall system is easy to implement and suitable for the water area of the bridge. Patent CN116467776B discloses a bridge collision multi-damage mode resistance calculation method based on energy equivalence. The relationship between the nonlinear response of ship-bridge collision and the equivalent static ship collision resistance is established from the energy angle, so that the dynamic nature of the ship-bridge collision problem is reflected, and the calculated bridge ship collision resistance result is more scientific and accurate, which has more guiding significance for the design and protection and reinforcement of actual bridge ship collision prevention.

[0004] For ship-bridge collision risk assessment, early qualitative methods are mainly used for analysis according to experience and intuition. In recent years, quantitative methods for navigation risk assessment are increasingly widely used, and specific parameters of representative ship types are important data in ship-bridge collision risk assessment. Specifically, the representative ship type refers to a ship type with a design load that can reach the corresponding tonnage, which is selected through technical demonstration and optimization to adapt to the navigation scale, and can provide data basis for risk assessment work. Because the collapse risk of long and large bridges of different span types and different service times in the same channel is different, even there can be a big difference, so the same ship may pose a fatal threat to short-span or high-life bridge segments, but the risk of large-span or low-life segments is controllable. However, the determination of the traditional ship collision representative ship type is only based on static channel ship data (that is, the most common ship type in this environment is counted as the representative ship type, and the most common speed of the ship type is taken as the speed of the representative ship type), which cannot determine the representative ship type and its specific parameters according to the structure characteristics and service stage of the pier, so that the bridge collapse risk cannot reflect the changes of different span types and different service times.

[0005] Therefore, how to determine the ship type parameters according to the structure characteristics and service stage of the pier is a problem to be solved. SUMMARY

[0006] The embodiment of the present application provides a bridge anti-ship collision ship type parameter determination method, device and medium to solve the above technical problems.

[0007] In a first aspect, the embodiment of the present application provides a bridge anti-ship collision ship type parameter determination method, comprising:

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

[0009] According to the ship-bridge collision model, a calculation formula of ship-bridge net displacement ratio and energy ratio is determined;

[0010] According to the calculation formula and the law of conservation of energy, an expression of the initial speed of the ship about the energy absorbed by the pier is determined;

[0011] According to the expression and the maximum threshold value of the pier displacement, an expression of the speed threshold value for preventing the bridge from collapsing under different ship tonnages is determined;

[0012] According to the ship speed threshold value expression, the ship type parameters of the pier are determined.

[0013] In a second aspect, the embodiment of the present application provides an electronic device, comprising:

[0014] One or more processors;

[0015] a memory for storing 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 bridge anti-ship collision ship type parameter determination method described in any embodiment.

[0017] To sum up, the present application provides a bridge anti-ship collision ship type parameter determination method, which can realize rapid calculation of the ship speed threshold of the displacement overrun of a specific pier caused by the impact of a ship of different tonnage. The method considers the bridge structure characteristics and pier stiffness degradation, establishes the quantitative relationship between the pier ultimate lateral resistance and the key parameters of the collapse prevention ship type based on bridge collapse risk analysis, and deduces the calculation formula of the pier energy dissipation ratio and the critical speed of the ship. It is helpful to provide dynamic design basis for ship collision risk assessment and protective measures for long and large bridges, thereby reducing the probability of bridge collapse. Specifically:

[0018] 1) The embodiment establishes a quantitative relationship model between the pier energy dissipation ratio and the ship speed threshold, realizes rapid calculation of the key parameters of the ship type, and can efficiently output the tonnage and critical speed threshold of the ship type under different stiffness degradation stages, significantly improving the timeliness of the ship collision safety assessment of the in-service bridge, and providing a quantifiable technical basis for operation and maintenance decision-making.

[0019] 2) The embodiment breaks through the traditional ship type determination method which only relies on static channel data, innovatively introduces the dynamic time-varying characteristics of the bridge structure, comprehensively considers the pier stiffness degradation and the structural differences of different spans, realizes dynamic ship type determination based on actual collapse risk, and significantly improves the applicability and risk assessment accuracy of the method. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the following will briefly introduce the drawings needed to be used in the description of the specific embodiments or prior art. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0021] Figure 1 is a flowchart of a bridge anti-ship collision ship type parameter determination method provided by an embodiment of the present application;

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

[0023] Figure 3 is a structural schematic diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work belong to the scope of protection of the present application.

[0025] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0026] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] Figure 1 It is a flow chart of a bridge anti-ship collision defense ship type parameter determination method provided by an embodiment of the present application. The method is executed by an electronic device, as shown in Figure 1 The method specifically comprises the following steps.

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

[0029] When the ship contacts the pier, the contact surface is simplified as an elastic interaction mechanism starting and stopping dynamically, and the joint stiffness of the ship body and the pier can be used to simulate the elastic response of the two to resist the collision caused by the collision. As shown in Figure 2 The ship-bridge collision process can be simplified as a spring-mass interaction model to capture the basic characteristics of the ship-bridge collision.

[0030] Specifically, in the past ship-bridge collision test, it is found that the direct influence of damping on the system response is relatively small. The possible reason is that the impact energy is released rapidly, and the proportion of damping in the overall energy dissipation is low. Therefore, in the present model, the damping effect is ignored to simplify the analysis process and focus on the key parameters. Secondly, the model assumes a small-angle head-on collision situation, and the ship impacts the target bridge pier without passive anti-collision facilities. In addition, in order to make the calculation results of the defended ship type have better safety redundancy and facilitate calculation, it is assumed that the ship bow deformation is always in the elastic stage.

[0031] Further, as shown in Figure 2 , the impact ship can be equivalent to a mass block with mass m1 and motion speed V0, and the ship bow stiffness is equivalent to a spring with stiffness k1; the bridge pier is equivalent to a mass block with mass m2, and the bridge pier stiffness can be regarded as the stiffness k 2-1 superimposed after the stiffness k 2-2 superimposed after the stiffness k 1= ; the ship movement distance is represented by x1, and the bridge pier movement distance is represented by x2. Then, for the motion system shown in Figure 2 , there is the following dynamic equation, that is:

[0032]

[0033] Wherein, m1, k1 and x1 are the mass, equivalent stiffness and displacement of the impact ship, and m2, k2 and x2 represent the mass, equivalent stiffness and displacement of the impacted bridge pier.

[0034] S120, according to the ship-bridge model, determining the calculation formula of the ship-bridge net displacement ratio and the energy ratio.

[0035] Based on equation (1), first, the ship-bridge displacement in the ship-bridge model can be expressed as a complex number, and the amplitude ratio of the ship-bridge displacement is solved. Specifically, in order to obtain the ship bow displacement value x1 and the bridge pier displacement value 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, and s is the conjugate complex root of the coefficient matrix on the left side of equation (2). The general solution of equation (2) is x 1= A1e st , x 2= A2e st , t represents time. To make the characteristic vector have a non-zero solution, the conjugate complex root s in the determinant of the coefficient matrix on the left side is i n (w ndenotes the imaginary part), so that s 2 = -λ (λ denotes the eigenvalue), and the characteristic equation (3) is obtained by expanding and arranging:

[0038]

[0039] Substituting equation (2) to solve the expression (4) of the corresponding eigenvalues λ1 and λ2:

[0040]

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

[0042]

[0043] Then, the calculation formula of the ship-bridge net displacement ratio and the energy ratio can be determined according to the amplitude ratio. Specifically, each eigenvalue λ corresponds to an eigenvector {A}, which represents the amplitude corresponding to the first-order mode. However, here we only care about the eigenvector when x1 / x2>0, so we substitute λ1 into equation (5), and the net displacement ratio of m1 and m2 can be expressed as Δ1 / Δ2, which can be calculated from the amplitude: Finally, equation (6) is obtained:

[0044]

[0045] where ξ and η are intermediate variables, ξ=k1 / k2; η=m1 / m2. Further, the energy ratio absorbed by the ship bow and the pier is expressed as follows:

[0046]

[0047] In the equation, Δ1 and Δ2 are the net displacement (i.e. deformation) of the impacted ship and pier, respectively; E1 is the impact energy absorbed by the ship; E2 is the impact energy absorbed by the pier.

[0048] S130, according to the calculation formula and the law of conservation of energy, determine the expression of the initial speed of the ship about the energy absorbed by the pier.

[0049] Here, the initial speed of the ship before it hits the pier is referred to as the impact speed.

[0050] In order to evaluate the crashworthiness and safety of the pier under the action of ship collision, the ratio of the impact energy absorbed by the pier to the initial total energy of the ship E2 / E0 needs to be obtained. To this end, first of all, the relationship equation among the initial total energy of the ship, the kinetic energy of the ship and the pier respectively, and the impact energy absorbed during the process of the ship colliding with the bridge can be constructed according to the law of conservation of energy:

[0051]

[0052] In the formula, E0 is the initial total energy of the ship; V0 is the initial speed of the ship; E b is the total energy of the ship; E s is the total energy of the pier; T is the total duration of the ship-bridge collision, t∈(0, T); E * 1(t) is the kinetic energy of the ship at t; E1(t) is the impact energy absorbed by the ship at t; E * 2(t) is the kinetic energy of the pier at t; E2(t) is the impact energy absorbed by the pier at t; is the net displacement of the ship at t, is the net displacement of the pier at t; V1(t) is the speed of the ship during the collision process, and V1(t)=0 is the most unfavorable case (the compression depth of the ship to the bridge is the deepest); V2(t) is the speed of the pier at t during the collision process, and V2(t)=0 is the most unfavorable case.

[0053] Then, according to the relationship equation and the calculation formula (7), the expression of the initial speed of the ship about the energy absorbed by the pier is constructed. Specifically, set c as the ratio of E * 2 to E2, then the value of c decreases with the increase of the tonnage of the ship, and c=0 is the most unfavorable case, then the energy conservation formula of the simplified motion system shown in formula (8) can be transformed as:

[0054]

[0055] The recovery coefficient e is introduced as a ship speed index for measuring the ship-bridge collision, and the recovery coefficient e is expressed as the ratio between the speed of the ship approaching the bridge at a certain time and the initial speed, as shown in formula (10):

[0056]

[0057] For a completely elastic collision and a completely inelastic collision, e is equal to 1 and 0 respectively.

[0058] The expression of the ratio of the energy consumption of the pier E2 / E0 can be obtained by integrating formula (7)~(10), as shown in formula (11):

[0059]

[0060] Let E0= 1 / 2m1V0 2 Substitute into the formula (11) after deformation, the expression (12) of the initial speed V0 of the ship can be obtained:

[0061]

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

[0063] S140, according to the expression and the maximum threshold value of pier displacement, the speed threshold expression of preventing bridge collapse under different ship tonnage is determined.

[0064] In formula (12), take (I.e. the most unfavorable case, when the ship compresses the bridge the deepest), take = the impact energy absorbed by the pier when the pier displacement takes the maximum threshold value, substitute into formula (12), and formula (12) can be converted into the speed threshold expression of preventing bridge collapse under different ship tonnage.

[0065] Optionally, in the "Highway Bridge and Culvert Maintenance Specification" and "Railway Bridge and Culvert Design Basic Specification", the horizontal allowable displacement value of the pier top of the simply supported beam bridge is mm, wherein L is the minimum span between adjacent piers. The displacement limit considers the influence of vehicle, water flow, temperature and wind, etc. The ship collision belongs to short duration dynamic load, if E2 reaches the threshold value, i.e. when the target pier top displacement reaches mm, the energy size absorbed by the pier can be considered as the bridge collapse, and formula (12) becomes the speed threshold calculation formula.

[0066] S150, according to the ship speed threshold expression, the pier defense ship type parameters are determined.

[0067] The defense ship type parameters include ship tonnage and speed threshold, which correspond to and in formula (12) respectively. In the case of known pier energy consumption threshold, the speed threshold formula can be used to calculate the speed threshold of different tonnage ships when the target pier is hit by the ship to reach the specified allowable displacement value.

[0068] Optionally, the pier energy consumption threshold can be obtained by numerical simulation method, and the ship-bridge collision process is simulated and modeled. When the target pier top displacement reaches mm, the energy size absorbed by the pier is the threshold value of E2, and the threshold value and V1(t)=0 are substituted into the speed threshold calculation formula, and the speed threshold (i.e. the maximum threshold value). Exemplarily, LS-DYNA finite element software can be used for numerical calculation of ship-bridge pier collision, a ship model with the same tonnage is established, the bridge pier with a bottom fixed or elastic pile is established, a downward beam body gravity is applied to the upper part, and then the process of ship collision with the bridge pier is simulated. In the simulation, the pier top displacement and the energy absorbed by the bridge pier can be obtained in real time, and the energy absorbed by the bridge pier when the pier top displacement reaches 0.5 m is taken as E2, which is involved in the calculation of the ship speed threshold value.

[0069] In the risk assessment of long-span bridges across the sea under the action of ship collision, for each bridge pier, the current mass and equivalent stiffness of the bridge pier can be determined according to the structural characteristics and service stage of the bridge pier; at the same time, according to the navigation data, the tonnages of different ships passing through the bridge pier can be determined. For each ship tonnage, according to the ship mass and equivalent stiffness, and the current mass and equivalent stiffness of the bridge pier, the ship speed threshold value of each ship tonnage corresponding to the bridge pier can be determined from the ship speed threshold value expression, and the case of exceeding the ship speed threshold value is the case of bridge collapse risk, so that the collapse risk of each bridge pier at each service stage can be evaluated, and the dynamic risk assessment of the bridge can be realized.

[0070] At the same time, in order to ensure the safety of the bridge against ship collision in the operation period, the ship type parameters should be calculated and adjusted in real time according to the specific bridge pier structural characteristics and the update of the bridge navigation data.

[0071] In addition, according to the formula provided by the AASHTO specification, the limit lateral resistance of the bridge pier causing the bridge to collapse can also be calculated, as shown in formula (13), which will provide more accurate data reference for the design of ship collision prevention:

[0072]

[0073] In the formula, V is the ship collision speed (m / s); DWT is the ship tonnage (t).

[0074] In summary, the embodiment provides a method for determining ship type parameters for bridge anti-ship collision, which can quickly calculate the ship speed threshold value of a specific bridge pier under the impact of different tonnage ships, and the pier top displacement is out of limit. The method considers the bridge structural characteristics and pier stiffness degradation, establishes the quantitative relationship between the pier limit lateral resistance and the key parameters of the collapse prevention ship type, deduces the calculation formula of the pier energy dissipation ratio and the critical ship speed, and helps to provide dynamic design basis for long-span bridge ship collision risk assessment and development of protection measures, thereby reducing the probability of bridge collapse. Specifically:

[0075] ​1) This embodiment realizes the rapid calculation of the key parameters of the designed ship type by establishing the quantitative relationship model between the pier energy consumption ratio and the ship speed threshold, can efficiently output the tonnage and critical speed threshold of the designed ship type under different stiffness degradation stages, significantly improves the timeliness of the in-service bridge ship collision safety evaluation, and provides a quantifiable technical basis for operation and maintenance decision-making;

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

[0077] Figure 3 A structural schematic diagram of an electronic device provided by the embodiment of the present application is shown in Figure 3 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 and an example of one processor 60 is taken; the processor 60, the memory 61, the input device 62 and the output device 63 in the device can be connected through a bus or other means, Figure 3 and an example of connection through a bus is taken.

[0078] The memory 61, as a kind of 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 anti-ship collision designed ship type parameter determination method in the embodiment of the present application. The processor 60 executes the software programs, instructions and modules stored in the memory 61, thereby performing various functional applications and data processing of the device, i.e. realizing the bridge anti-ship collision designed ship type parameter determination method described above.

[0079] The memory 61 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, at least one application program required by a function; the data storage area can store data created according to the use of the terminal and the like. In addition, the memory 61 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some examples, the memory 61 can further include a memory remotely arranged with respect to the processor 60, which can be connected to the device through a network. Examples of the above-mentioned network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network and a combination thereof.

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

[0081] The embodiment of the present application also provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor to realize the bridge anti-ship collision ship type parameter determination method of any embodiment.

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

[0083] The computer readable signal medium can include a data signal propagating in baseband or propagating as a carrier wave in a propagated data signal, in which computer readable program code is embodied. Such a propagated data signal can take many forms, including but not limited to electro-magnetic, optical, or any suitable combination thereof. The computer readable signal medium can also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate or transport program for use by or in connection with an instruction execution system, apparatus, or device.

[0084] The program code contained on the computer readable medium can be transmitted by any suitable medium, including but not limited to wireless, wire, cable, optical fiber, RF, etc., or any suitable combination thereof.

[0085] Computer program code for carrying out operations of the present application can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0086] Finally, it should be noted that the above-described embodiments are merely intended to illustrate the technical solutions of the present application, and are not intended to limit the present application; even though the present application has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the above-described embodiments, or make equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present application.

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; Based on the ship-bridge collision model, the calculation formulas for the ship-bridge net displacement ratio and energy ratio 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 aforementioned ship speed threshold expression, the design ship type parameters of 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 calculation formulas for determining the net displacement ratio and energy ratio of the ship and bridge based on the ship-bridge collision model include: 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 bridge and the ship are determined.

4. The method according to claim 3, 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.

5. The method according to claim 4, 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.

6. 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.

7. The method according to claim 6, 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.

8. The method according to claim 7, characterized in that, The 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.

9. The method according to claim 8, 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.

10. 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.

Images