Bridge protection device optimization design method, system and computer program product

Abstract

The application discloses a kind of bridge protection device optimization design method, system and computer program product, belong to bridge protection device performance optimization technical field, including the following steps: establishing design parameter and design target;Design the initial structure of protection device;Ship, protection device and bridge are simplified into corresponding ship macro module, protection device macro module and bridge macro module respectively, and ship-protection device-bridge simplified dynamics model is established;The impact force borne by bridge is calculated using ship-protection device-bridge simplified dynamics model;Whether the impact force borne by bridge meets the design target is judged, if not satisfied, then modify protection device structure, if satisfied, then output final parameter combination, complete optimization design.The simplified dynamics calculation process and optimization parameterization analysis are realized, the calculation time consumption and hardware requirement are reduced, and the design efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of bridge protection device performance optimization technology, and in particular to bridge protection device optimization design methods, systems and computer program products. Background Technology

[0002] In bridge engineering, ship collisions pose a serious threat to bridge structural safety, and existing protective technologies are insufficient to meet the comprehensive requirements of protective performance, computational efficiency, and design accuracy in engineering practice. The performance of protective devices includes their protective performance under ship collision conditions and their crushability under impact tests. Protective performance mainly manifests as the device's ability to reduce the impact force of the ship, its energy absorption capacity, and its ability to protect both the ship and the bridge. From a bridge design perspective, the peak impact force during a collision is the primary evaluation indicator. However, laboratory studies often focus on the crushability of protective devices. One end of the device is fixed to a rigid reaction wall, and a rigid impactor of a certain mass impacts the device. The impact force transmitted to the rigid wall, along with parameters such as the device's energy absorption and deformation, characterizes its dynamic crushability. The crushability of a protective device is primarily determined by its material, structure, and dimensions, and is an important indicator for measuring structural stiffness and energy absorption capacity. The crushability of a protective device has a significant impact on its protective performance under ship collisions, but the protective performance must also consider the influence of the ship's bow stiffness. Therefore, the interaction mechanism between crushability and protective performance remains unclear.

[0003] Currently, the design of ship collision protection devices primarily relies on finite element analysis (FEA). This involves verifying the finite element analysis model through small-scale impact tests, then establishing a more accurate ship-protective device finite element analysis model and defining the contact relationships between components. Because both the protective device and the bow may experience extensive plastic deformation or even failure during a collision, simulation calculations are time-consuming and demand high-performance computer hardware. Furthermore, protective devices are often made of composite materials, and the model structures of different materials differ significantly under impact, involving damage and failure. These factors all affect simulation accuracy and computational efficiency, thus limiting their application in engineering practice. Simultaneously, the complex simulation calculation models also hinder the optimized design of protective structures. Existing technologies suffer from a trade-off between accuracy and efficiency, resulting in defects such as low energy absorption efficiency and poor bridge stress control in current protective devices, failing to fully meet the engineering requirements for bridge collision safety. Therefore, a method that simplifies dynamic calculations and optimizes parametric analysis is urgently needed. Summary of the Invention

[0004] The present invention aims to provide a method, system and computer program product for optimizing the design of bridge protection devices, thereby simplifying dynamic calculations and parametric analysis, reducing calculation time and hardware requirements, and improving the design efficiency of protection devices.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a method for optimizing the design of bridge protection devices, comprising the following steps: Step S1: Establish design parameters and design objectives; Step S2: Design the initial structure of the protective device; Step S3: Simplify the ship, protective device, and bridge into corresponding macroscopic modules for the ship, protective device, and bridge, respectively, and establish a simplified dynamic model of the ship-protective device-bridge. Step S4: Calculate the impact force on the bridge using a simplified dynamic model of ship-protective device-bridge; Step S5: Determine whether the impact force that the bridge can withstand meets the design target. If it does not, modify the structure of the protective device. If it meets the design target, output the final parameter combination to complete the optimization design.

[0006] Optionally, in step S1, the design parameters include the protective vessel type, bridge structure, pile foundation, and soil data; the design objective includes the target impact force that the bridge can withstand.

[0007] Optionally, in step S2, the initial structure of the protective device includes the outer shell thickness, keel density, keel specifications, and filling material.

[0008] Optionally, in step S3, the macroscopic module includes a mass block unit, a nonlinear spring unit, and a damping unit; the ship macroscopic module includes a ship mass block unit, a ship nonlinear spring unit, and a ship damping unit; the protective device macroscopic module includes a protective device mass block unit, a protective device nonlinear spring unit, and a protective device damping unit; and the bridge macroscopic module includes a bridge mass block unit, a bridge nonlinear spring unit, and a bridge damping unit.

[0009] Optionally, in step S3, the dynamic parameters of the ship, protective device, and bridge include the stiffness of the nonlinear spring unit and the damping coefficient of the damping unit; the stiffness is the ratio of elastoplastic force to deformation, and the damping coefficient is the ratio of damping force to velocity.

[0010] Optionally, in step S5, the collision process is divided into two stages based on the force angle: the first stage is when the protective device is compressed, and the second stage is when the protective device is completely crushed; in the first stage, the deformation of the protective device is less than the critical deformation when the protective device is completely crushed, which is represented as a coupled system of ship, protective device and bridge connected in series; in the second stage, the deformation of the protective device is greater than the critical deformation when the protective device is completely crushed, which simplifies the coupled system of ship, protective device and bridge to a coupled system of ship and bridge.

[0011] Optionally, the motion law of the entire coupled system of the ship, protective device, and bridge is expressed as follows: in, , , These are the deformations of ships, protective devices, and bridges, respectively. , , These refer to the stiffness of ships, protective devices, and bridges, respectively. , , The masses of ships, protective devices, and bridges are respectively. , , These are the accelerations of the bridge, protective devices, and the ship, respectively.

[0012] Optionally, in the bridge protection device optimization design method, the overall motion law of the coupling system between the ship and the bridge is expressed as: in, , The masses of ships and bridges, respectively. , These are the accelerations of the bridge and the ship, respectively. , These are the stiffnesses of ships and bridges, respectively. This refers to the amount of deformation of the ship. This represents the deformation of the bridge.

[0013] Secondly, this application also provides a bridge protection device optimization design system, comprising: one or more processors; a storage device for storing 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 bridge protection device optimization design method as described in any one aspect.

[0014] Thirdly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the bridge protection device optimization design method as described in any one of the first aspects.

[0015] The bridge protection device optimization design method proposed in this invention equates the ship-protection device-bridge system to a macroscopic unit composed of crushable capacity and mass blocks, and the collision process to a dynamic calculation model between different macroscopic units. Based on the protection device under ship impact, it performs rapid iterative optimization design, which significantly reduces the calculation time and hardware requirements, and improves design efficiency. Furthermore, by dividing the collision into different stages, simplified dynamic models are established for different states of the protection device (incomplete crushing and complete crushing). Combined with corresponding parameter settings and iterative calculations, the collision response under different parameters is simulated, enhancing the energy absorption and buffering capacity of the protection device and reducing the transmission of ship impact force to the bridge, thereby simplifying the dynamic calculation process and optimizing parameterized analysis.

[0016] To make the above-mentioned features and advantages of the invention more apparent and understandable, specific embodiments are described below, and detailed descriptions are provided in conjunction with the accompanying drawings. Attached Figure Description

[0017] Figure 1 This is a flowchart of an optimized design method for a bridge protection device provided in one embodiment of the present invention.

[0018] Figure 2 A simplified dynamic model diagram of a ship-protection device-bridge.

[0019] Figure 3 Impact force time history curve for a simplified dynamic model of a ship.

[0020] Figure 4 A crush curve diagram for a simplified dynamic model of a ship.

[0021] Figure 5 Deformation curves for a simplified dynamic model of a ship.

[0022] Figure 6 A velocity curve diagram for a simplified dynamic model of a ship.

[0023] Figure 7 Impact force time history curve for simplifying the dynamic model of the protective device.

[0024] Figure 8 A crush curve diagram for a simplified dynamic model of the protective device.

[0025] Figure 9 Deformation curves of a simplified dynamic model for the protective device.

[0026] Figure 10 A velocity curve diagram for a simplified dynamic model of the protective device.

[0027] Figure 11 A comparison of the impact force time history curves of a bridge subjected to impact force calculated using discrete macroscopic elements and finite element analysis.

[0028] Figure 12 A comparison of the crushing curves of a bridge subjected to impact force, calculated using discrete macroscopic elements and modeled using finite element analysis.

[0029] Figure 13 The crush curve was optimized to improve the calculation results.

[0030] Figure 14 To optimize the energy absorption curve of the calculation results. Detailed Implementation

[0031] To make the objectives and technical solutions of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0032] This invention proposes an optimized design method for bridge protection devices. Please refer to [link / reference]. Figure 1 , Figure 1 The flowchart of a bridge protection device optimization design method with a simplified dynamic model provided by the present invention includes: steps S1 to S6.

[0033] Step S1: Establish design parameters and design objectives.

[0034] Step S2: Design the initial structure of the protective device.

[0035] Step S3: Simplify the ship, protective device, and bridge into corresponding macroscopic modules and establish a simplified dynamic model of ship-protective device-bridge.

[0036] Step S4: Calculate the impact force on the bridge using a simplified dynamic model of ship-protection device-bridge.

[0037] Step S5: Determine whether the impact force that the bridge can withstand meets the design target. If it does not, modify the structure of the protective device. If it meets the design target, output the final parameter combination to complete the optimization design.

[0038] The bridge protection device optimization design method of this application simplifies the ship, protection device and bridge into macroscopic modules composed of crushable performance and mass blocks, and equates the collision process to the dynamic calculation model between different macroscopic modules. This enables rapid iterative optimization design of the protection device based on ship impact, which greatly reduces the calculation time and hardware requirements and improves design efficiency.

[0039] In step S1, please refer to Figure 1 Step S1 in the process involves establishing design parameters and design objectives.

[0040] As an example, design parameters are determined based on actual needs. These parameters include: the type of protective vessel, bridge structure, pile foundation, and soil data. Among these, the bridge structure, pile foundation, and soil data reflect the bridge's inherent collision resistance.

[0041] As an example, design objectives are determined based on the bridge's own impact resistance, including the target impact force that the bridge can withstand.

[0042] In step S2, please refer to Figure 1 In step S2, the initial structure of the protective device is designed.

[0043] Specifically, the initial structure of the protective device includes: the design shell thickness, the keel density, the keel specifications, and the filling material. The design shell thickness determines the initial impact stiffness and resistance to local damage of the protective device; the keel density determines the deformation capacity of the protective device; the keel specifications determine the load-bearing limit and elastic-plastic response characteristics of the frame; and the filling material determines the energy absorption efficiency and damping characteristics of the protective device.

[0044] In step S3, please refer to Figure 1 In step S3, the ship, protective device, and bridge are simplified into corresponding macroscopic modules for the ship, protective device, and bridge, respectively, and a simplified dynamic model of ship-protective device-bridge is established.

[0045] As an example, the simplified dynamic model is a single-degree-of-freedom spring-damper model (SDOF), which can quantitatively analyze the motion of objects after a collision, including amplitude decay, the motion process, and the final equilibrium state reached by the system. In the SDOF model, the objects in the collision are treated as macroscopic modules, and the effects of elastoplastic forces and damping forces during the collision are considered. Elastoplastic forces describe the elastic interaction between objects during the collision, while damping forces simulate the energy loss during the collision. Specifically, ships, protective devices, and bridges are equivalent to macroscopic modules that characterize their crushing performance, resulting in a simplified dynamic model of ship-protective device-bridge. This simplifies the collision process into a series calculation model of three units, enabling rapid evaluation of the performance of protective devices under ship collision conditions.

[0046] For example, please refer to Figure 2 , Figure 2 This is a simplified dynamic model diagram of a ship-protection device-bridge system, including a macroscopic module for the ship, a macroscopic module for the protection device, and a macroscopic module for the bridge. The macroscopic module for the ship includes ship mass block elements, ship nonlinear spring elements, and ship damping elements. The ship mass block elements include the ship's mass... The ship nonlinear spring unit includes the ship nonlinear spring stiffness. The ship damping unit includes the ship damping coefficient. The macroscopic module of the protective device includes a protective device mass block unit, a protective device nonlinear spring unit, and a protective device damping unit. The protective device mass block unit includes the protective device mass... The nonlinear spring unit of the protective device includes the nonlinear spring stiffness of the protective device. The damping unit of the protective device includes the damping coefficient of the protective device. The bridge macroscopic module includes bridge mass block elements, bridge nonlinear spring elements, and bridge damping elements. The bridge mass block elements include bridge mass... The nonlinear spring element of the bridge includes the nonlinear spring stiffness of the bridge. The bridge damping unit includes the bridge damping coefficient. .

[0047] Specifically, a ship can be described as its bow.

[0048] Specifically, the displacement of the ship is The displacement of the protective device is The displacement of the bridge is .

[0049] Specifically, displacement represents the amount of deformation during the collision process.

[0050] As an example, the superposition of nonlinear spring elements and damping elements can be used to simulate the crushing performance of a simplified dynamic model structure of a ship-protection device-bridge.

[0051] As an example, crush curves characterizing the crush performance of ships, protective devices, and bridges can be obtained through horizontal impact tests on ships, protective devices, and bridges.

[0052] Furthermore, the impact force when a ship-protective device collides with a bridge. It can be equivalent to elastoplastic force. and damping force The superposition of elastic and plastic forces; due to the superposition of elastic and plastic forces The simplified dynamic model of a ship-protection device-bridge structure was characterized by the reaction force under quasi-static compression, thus the elastic-plastic force was determined. It can be equivalent to the stiffness of a nonlinear spring. With deformation The product of; damping force This represents a simplified dynamic model of a ship-protective device-bridge structure under different impact velocities. Due to the influence of factors such as strain rate on the impact force, the damping force is... It can be equivalent to the damping coefficient. With speed The product of these factors allows for a simplified dynamic model of the ship-protective device-bridge system to consider the dynamic response of the structure to different impact velocities. The impact force when the ship-protective device collides with the bridge... The expression is: (1) in, This represents the stiffness of a nonlinear spring element. Indicates the damping coefficient. Indicates the amount of deformation. Indicates speed, Indicates time. The introduction of damping force allows the simplified dynamic model of the ship-protection device-bridge to consider the dynamic response of the structure to different impact velocities.

[0053] As an example, the parameters of the simplified dynamic model of a ship-protection device-bridge include the stiffness of the nonlinear spring element. and damping coefficient .

[0054] Optionally, the stiffness of the nonlinear spring element Including the stiffness of the ship's nonlinear spring unit Stiffness of the nonlinear spring unit of the protective device Stiffness of nonlinear springs in bridges Damping coefficient Including ship damping coefficient Damping coefficient of protective device and bridge damping coefficient .

[0055] As an example, the impact force experienced by a ship The stiffness of the ship's nonlinear spring unit can be substituted into the equation. and ship damping coefficient The impact force received by the protective device. The stiffness of the nonlinear spring unit of the protective device can be substituted. and the damping coefficient of the protective device The impact force received by the bridge was obtained. The stiffness can be obtained by substituting the stiffness of the nonlinear spring element of the bridge. and bridge damping coefficient get.

[0056] As an example, the stiffness of a nonlinear spring element The structure is determined by the simplified dynamic model of ship-protection device-bridge, influenced by factors such as the mechanical properties of materials, the dimensions and characteristics of the structure.

[0057] As an example, ship protection systems are typically made of low-carbon steel, conforming to the Cowper-Symonds strain rate model. This reflects the strain rate. The expression for the effect on the mechanical properties of the material is: (2) in, For strain rate, For dynamic stress, It is the static yield stress. A and D This is a material constant (related to material properties).

[0058] Furthermore, establish impact force With strain rate The association is expressed as: (3) in, For dynamic impact force, It is an elastic-plastic force. For dynamic stress, It is the static yield stress. A and D is a material constant.

[0059] As an example, strain rate It is a strain Regarding time The partial derivative of is expressed as: (4) Among them, strain rate It describes the degree of deformation of an object. This represents the initial length of the protective device along the impact direction. For speed, The rate of change of length is the velocity of an object during dynamic processes such as collisions between ships, collision avoidance devices, and bridges. It can be approximated as equal to the rate of change of length. .

[0060] Furthermore, it can be determined by elastoplastic forces. ,speed Initial length of the protective device along the impact direction The damping force was derived from the material constants. The expression is: (5) in, It is an elastic-plastic force. For speed, This represents the initial length of the protective device along the impact direction. A and D is a material constant.

[0061] As an example, speed The expression is: (6) in, The initial velocity, The change in velocity, It is acceleration.

[0062] As an example, acceleration can be determined based on Newton's second law. The expression is: (7) in, For dynamic impact force, The mass corresponding to a ship, protective device, or bridge.

[0063] Furthermore, by speed The integral over time can be transformed. The expression is: (8).

[0064] Furthermore, it can be determined by dynamic impact force. With damping force The relationship leads to the derivation of elastic-plastic force The expression is: (9) in, For speed, This represents the initial length of the protective device along the impact direction. A and D is a material constant.

[0065] Furthermore, damping force This can be represented as dynamic impact force. With elastic-plastic force The difference is expressed as: (10).

[0066] As an example, the stiffness of a nonlinear spring Elastic-plastic force With deformation The ratio, expressed as: (11).

[0067] As an example, damping coefficient For damping force With speed The ratio, expressed as: (12).

[0068] In step S4, please refer to Figure 1 In step S4, the impact force borne by the bridge is calculated using a simplified dynamic model of ship-protection device-bridge.

[0069] Specifically, the collision between a ship, a protective device, and a bridge is essentially a crushing process of three objects. The physical quantities such as force, energy, and deformation during the collision process are determined by the coupled superposition of the crushing performance of the ship and the protective device, which involves physical principles such as energy conversion and momentum conservation.

[0070] Specifically, based on the angle of force, the collision process can be divided into two stages: the first stage is when the protective device is compressed; the second stage is when the protective device is completely crushed.

[0071] Specifically, the deformation of the protective device in the first stage Less than the critical deformation amount when the protective device is completely crushed ,Right now This manifests as a coupled system of ship, protective device, and bridge, consisting of three macroscopic units connected in series. The overall stiffness of this coupled system is... The expression is: (13) in, For the rigidity of the ship, For the rigidity of the protective device.

[0072] Specifically, the deformation of the protective device in the second stage Greater than the critical deformation amount when the protective device is completely crushed ,Right now At this point, the stiffness of the protective device can be considered infinitely large, and can be equivalent to a coupled system of ship and bridge, consisting of two macroscopic modules connected in series. The overall stiffness of the coupled system of ship and bridge is... The expression is: (14) in, This refers to the stiffness of the ship.

[0073] Furthermore, the impact force borne by a bridge can be divided into two stages. The first stage is the impact force transmitted to the bridge by the deformation of the protective devices. The expression is: (15) in, For the rigidity of the protective device, This refers to the deformation of the protective device.

[0074] As an example, the second stage is the impact force on the bow of the ship after the protective devices have been crushed. Acting directly on the bridge, the expression is: (16) in, For the rigidity of the ship, This refers to the amount of deformation of the ship.

[0075] Furthermore, the impact process can be simplified into a macroscopic module model consisting of a mass-spring-damped model composed of a single-degree-of-freedom spring-damped model connected in series with the ship, protective devices, and bridge.

[0076] Furthermore, the mass-spring-damping macroscopic module model includes mass block elements, nonlinear spring elements, and damping elements. Through the series iterative calculation of mass block elements, nonlinear spring elements, and damping elements, the interaction of energy and impact force between ships and bridges during collision can be quickly simulated. It captures key information such as deformation, velocity, and force of ships, protective devices, and bridges during collision, and provides the possibility for rapid calculation of the performance of protective devices based on ship impact conditions.

[0077] As an example, the elastoplastic forces in the mass-spring-damped macroscopic modular model. and damping force The expression is: (17) in, The equivalent stiffness of the mass-spring-damped macroscopic module model. The damping coefficient is the macroscopic module model of mass-spring-damped structure. This represents the deformation of the macroscopic module model of mass-spring-damping.

[0078] Furthermore, the first stage is when the protective device is completely crushed, that is... At that time, the expressions for the elastoplastic force and damping force of the protective device and the ship are: (18) Where t represents time. The amount of deformation of the protective device, This is the critical deformation amount when the protective device completely collapses. , These are the ship's elastoplastic forces and damping forces, respectively. , These are the elastic-plastic force and damping force of the protective device, respectively. , The elastic-plastic forces and damping forces of the bridge are respectively... , , These are the deformations of ships, protective devices, and bridges, respectively. , , These refer to the stiffness of ships, protective devices, and bridges, respectively. , , These are the damping coefficients for ships, protective devices, and bridges, respectively.

[0079] Furthermore, the dynamic relationship between the acceleration and deformation of the ship, protective device, and bridge during the collision process is described in matrix form, reflecting the coupling effect of their mass and stiffness, and illustrating the overall motion law of the ship-protective device-bridge coupled system. The expression is as follows: (19) in, , , These are the deformations of ships, protective devices, and bridges, respectively. , , These refer to the stiffness of ships, protective devices, and bridges, respectively. , , The masses of ships, protective devices, and bridges are respectively. , , These are the accelerations of the bridge, protective devices, and the ship, respectively.

[0080] Furthermore, the relationship between the forces acting on a ship and its state of motion follows Newton's second law, expressed as: (20) in, For the quality of the ship, For the ship's acceleration, For the elastoplastic forces of ships, This refers to the damping force of the ship.

[0081] As an example, the forces and motion of a bridge under the action of protective devices are expressed as the forces exerted on it by the protective devices, as follows: (twenty one) in, For the quality of the protective device, For the acceleration of the protective device, For the elastoplastic forces of ships, For the damping force of the ship, For the elastoplastic force of the protective device, This refers to the damping force of the protective device.

[0082] As an example, the force and motion transmission of the protective device between the ship and the bridge is manifested as the force exerted by the ship on it, expressed as: (twenty two) in, For the quality of the bridge, The acceleration of the bridge, For the elastoplastic force of the protective device, For the damping force of the protective device, For the elastic-plastic forces of bridges, Damping force of a bridge.

[0083] Furthermore, the second stage occurs when the protective device is completely crushed, i.e. The expressions for the elastoplastic force and damping force of the protective device and the ship are as follows: (twenty three) in, The amount of deformation of the protective device, This is the critical deformation amount when the protective device completely collapses. , These are the elastoplastic forces of ships and bridges, respectively. , The damping forces are for ships and bridges, respectively. , These are the damping coefficients for ships and bridges, respectively. , These are the stiffnesses of ships and bridges, respectively. , These represent the deformation of ships and bridges, respectively.

[0084] Furthermore, after the protective device is completely crushed, its stiffness can be considered infinite. The ship-protective device-bridge system can be simplified into a coupled system of ship and bridge. The coupled dynamic relationship between the mass and stiffness of the protective device and the ship can be described by a matrix, expressed as: (twenty four) in, , The masses of ships and bridges, respectively. , These are the accelerations of the bridge and the ship, respectively. , These are the stiffnesses of ships and bridges, respectively. , These represent the deformation of ships and bridges, respectively.

[0085] Furthermore, consistent with the formula for ship acceleration in the uncrushed stage, the force logic at this point remains that the ship experiences the reverse action of the resultant force of its own elastic-plastic forces and damping forces, expressed as: (25) in, , The masses of ships and bridges, respectively. For the elastoplastic forces of ships, This refers to the damping force of the ship.

[0086] Furthermore, when the protective device completely collapses, the force exerted by the ship is directly transferred to the bridge, reflecting the force and motion transmission between the ship and the bridge, expressed as: (26) in, For the quality of the bridge, The acceleration of the bridge, , , respectively, represent the elastoplastic forces of ships and bridges. , These are the damping forces for ships and bridges, respectively.

[0087] Furthermore, the impact force borne by a bridge is the sum of its own elastic-plastic forces and damping forces, and is a key indicator for assessing the bridge's impact safety. The expression is: (27) in, The impact force that the bridge can withstand. For the elastic-plastic forces of the bridge, This refers to the damping force of the bridge.

[0088] In step S5, please refer to Figure 1 In step S5, it is determined whether the impact force borne by the bridge meets the design target. If it does not meet the target, the structure of the protective device is modified. If the target is met, the final parameter combination is output to complete the optimization design.

[0089] As an example, in step S1, a design target is set based on the impact resistance of the bridge piers themselves, i.e., a preset impact force target, which determines the impact force that the bridge will withstand. Compared with the design goals, if the bridge withstands the impact force If the impact force is less than the design target, it is considered to meet the requirements, and the structure of the protective device at this time is output; if the bridge is subjected to impact force... If the impact force exceeds the design target, return to step S2, modify the structure of the protective device, and continue optimization until the bridge can withstand the impact force. If the design target is exceeded, output the current structure of the protective device to complete the optimization design.

[0090] In one example, the protective device can be discretized into multiple macroscopic modules, establishing a Discrete Macroscopic Element Computation (DME) method to accurately simulate the contact between the bow and the protective device. Specifically, the ship's impact force is decomposed into nonlinear spring forces and damping forces, creating spring and damping force elements in a simplified ship dynamics model. The calculation results of the simplified ship dynamics model are then compared and verified with the results obtained from the Finite Element Analysis (FEA) model. Figure 3 The time history curve of the impact force for a simplified dynamic model of the ship. Figure 4 A crush curve diagram for a simplified ship dynamics model. Figure 5 Deformation curves for a simplified ship dynamics model. Figure 6 A velocity curve diagram for a simplified ship dynamics model. From... Figures 3-6 It can be seen that the single-degree-of-freedom spring-damped model exhibits extremely high accuracy in estimating the ship crush curve, and the deformation time history curves and velocity time history curves of the discrete macroscopic element calculation and the finite element analysis calculation model show a high degree of agreement.

[0091] Furthermore, finite element analysis can establish and solve mechanical equations by discretizing structural elements, accurately simulating complex nonlinear behavior, and is used to verify and calibrate single-degree-of-freedom spring-damped models to ensure the accuracy of the models. Discrete macroscopic elements, based on the single-degree-of-freedom spring-damped model, consider the local deformation and discrete characteristics of the collision avoidance device, and simulate the overall force and local deformation during collision through sub-module combination, providing a basis for the design optimization of collision avoidance devices and balancing computational efficiency and result accuracy.

[0092] Further, please refer to Figures 7-10 , Figure 7 The impact force time history curve is used to simplify the dynamic model of the protective device. Figure 8 A crush curve diagram for a simplified dynamic model of the protective device. Figure 9 Deformation curves for a simplified dynamic model of the protective device. Figure 10 A velocity curve diagram for a simplified dynamic model of the protective device. From... Figures 7-10 It can be seen that the deformation time history curves and velocity time history curves of the simplified dynamic model and the finite element analysis model show a high degree of agreement, further verifying the reliability and effectiveness of the single-degree-of-freedom spring damping model in predicting the dynamic characteristics of the protective device.

[0093] Specifically, the simplified dynamic model of the protective device is established in the same way as the simplified dynamic model of the ship.

[0094] Further, please refer to Figure 11 , Figure 11 This is a comparison of the impact force time history curves of a bridge subjected to impact force calculated using discrete macroscopic element methods and finite element analysis. Figure 12 A comparison of the crushing curves of bridges subjected to impact forces calculated using discrete macroscopic element methods and finite element analysis. From... Figure 11 and Figure 12 It can be seen that during the initial impact, the peak force measured by the discrete macroscopic element method is less than that measured by the finite element analysis method; at the end of the impact, the peak force measured by the discrete macroscopic element method is greater than that measured by the finite element analysis method; and the permanent deformation of the discrete macroscopic element is less than that measured by the finite element analysis method. Analysis of the impact force and deformation reveals that the discrete macroscopic element method has good accuracy in calculating the performance of protective devices under ship collision conditions and can significantly reduce computation time.

[0095] Further, please refer to Figure 13 , Figure 13 To optimize the crush curve plot of the calculation results, Figure 14 To optimize the energy absorption curve of the calculation results. From Figure 13 and Figure 14It can be seen that as the similarity ratio coefficient increases, the geometric dimensions and stiffness of the protective device structure also increase, thereby improving its structural stiffness and energy absorption capacity. However, the increase in the structural dimensions and stiffness of the protective device also leads to an increase in the peak impact force. Therefore, for a specific ship, there exists an optimal structural dimension for the protective device, at which the peak impact force is lowest. In addition, the energy absorption rate of the protective device is basically consistent with the trend of impact force reduction, that is, the increase in energy absorption is usually accompanied by a decrease in the peak impact force. In the design of the protective device, the structural stiffness and energy absorption capacity must be balanced within a certain range to obtain the best deformation protection effect.

[0096] In summary, the bridge protection device optimization design method based on a simplified dynamic model proposed in this invention provides a more fundamental understanding of the physical principles involved in collision phenomena, such as energy conversion and momentum conservation. A simplified dynamic model of ship-protection device-bridge is constructed, treating the objects in the collision as macroscopic modules and considering the effects of elastoplastic and damping forces during the collision. Elastoplastic forces describe the elastic interaction between objects during the collision, while damping forces simulate the energy loss during the collision. The simplified dynamic model of ship-protection device-bridge allows for quantitative analysis of the motion of objects after the collision, including amplitude decay, the motion process, and the final equilibrium state reached by the system. This simplified model provides a clear and effective framework for studying the collision process, facilitating a deeper exploration of the various physical phenomena and laws involved in collisions. In establishing the simplified dynamic model of ship-protection device-bridge, the crushing curve of the protection device is obtained, and a single-degree-of-freedom spring-damping model is used to simplify the impact process between the ship and the anti-collision device, integrating elastoplastic springs and damping units, and considering the influence of strain rate. The ship-protection device-bridge system is simplified into a series mass-spring-damping model. The deformation and dynamic behavior of the collision protection device in stages are simulated in stages. By iteratively calculating the deformation and velocity, the force and deformation in the collision are accurately simulated. Furthermore, a discrete macroscopic element calculation (DME) model is established to simplify the dynamic calculation and optimize the parameters.

[0097] It should be understood that although the steps in the flowcharts of the accompanying drawings are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some of the steps in the accompanying drawings may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0098] In yet another embodiment, this application also provides a bridge protection device optimization design system, comprising: one or more processors; a storage device for storing one or more programs; and when the one or more programs are executed by the one or more processors, causing the one or more processors to implement the bridge protection device optimization design method as described in any of the above embodiments.

[0099] In yet another embodiment, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the bridge protection device optimization design method as described in any of the above embodiments.

[0100] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0101] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention.

Claims

1. A method for optimizing the design of bridge protection devices, characterized in that, Includes the following steps: Step S1: Establish design parameters and design objectives; Step S2: Design the initial structure of the protective device; Step S3: Equip the ship, protective device, and bridge with equivalent macroscopic modules representing their crushing performance, and establish a simplified dynamic model of ship-protective device-bridge. The ship, protective device, and bridge macroscopic modules are obtained by treating the ship, protective device, and bridge in the collision as macroscopic modules and considering the effects of elastoplastic and damping forces during the collision. The elastoplastic forces represent the elastic interaction between objects during the collision, and the damping forces represent the energy loss during the collision. Step S4: Calculate the impact force borne by the bridge using the simplified dynamic model of the ship-protective device-bridge; Step S5: Determine whether the impact force borne by the bridge meets the design target. If not, modify the structure of the protective device. If the design target is met, output the final parameter combination to complete the optimization design. In step S5, the collision process is divided into two stages based on the force angle: the first stage is when the protective device is compressed, and the second stage is when the protective device is completely crushed. In the first stage, the deformation of the protective device is less than the critical deformation when the protective device is completely crushed, which is represented as a coupled system of ship, protective device and bridge connected in series. In the second stage, the deformation of the protective device is greater than the critical deformation when the protective device is completely crushed, which simplifies the coupled system of ship, protective device and bridge to a coupled system of ship and bridge.

2. The bridge protection device optimization design method as described in claim 1, characterized in that, In step S1, the design parameters include the protective vessel type, bridge structure, pile foundation, and soil data; the design objective includes the target impact force that the bridge can withstand.

3. The bridge protection device optimization design method as described in claim 1, characterized in that, In step S2, the initial structure of the protective device includes the outer shell thickness, keel density, keel specifications, and filling material.

4. The bridge protection device optimization design method as described in claim 1, characterized in that, In step S3, the ship macro module includes a ship mass block unit, a ship nonlinear spring unit, and a ship damping unit; the protective device macro module includes a protective device mass block unit, a protective device nonlinear spring unit, and a protective device damping unit; and the bridge macro module includes a bridge mass block unit, a bridge nonlinear spring unit, and a bridge damping unit.

5. The bridge protection device optimization design method as described in claim 1, characterized in that, In step S3, the dynamic parameters of the ship, protective device and bridge include the stiffness of the nonlinear spring unit and the damping coefficient of the damping unit; the stiffness of the nonlinear spring unit is the ratio of elastic-plastic force to deformation, and the damping coefficient of the damping unit is the ratio of damping force to velocity.

6. The bridge protection device optimization design method as described in claim 1, characterized in that, The motion law of the entire coupled system of the ship, protective device, and bridge is expressed as follows: in, , , These are the deformations of ships, protective devices, and bridges, respectively. , , These refer to the stiffness of ships, protective devices, and bridges, respectively. , , The masses of ships, protective devices, and bridges are respectively. , , These are the accelerations of the bridge, protective devices, and the ship, respectively.

7. The bridge protection device optimization design method as described in claim 1, characterized in that, The motion law of the entire coupling system of the ship and the bridge is expressed as follows: in, , The masses of ships and bridges, respectively. , These are the accelerations of the bridge and the ship, respectively. , These are the stiffnesses of ships and bridges, respectively. , Deformation of ships and bridges respectively.

8. A bridge protection device optimization design system, characterized in that, The bridge protection device optimization design system includes: one or more processors; a storage device for storing 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 bridge protection device optimization design method as described in any one of claims 1 to 7.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the bridge protection device optimization design method according to any one of claims 1 to 7.

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