Stable progressive impact-resistant topological optimization method for ship anti-collision structure

Abstract

The invention relates to a ship anti-collision structure stability progressive impact-resistant topological optimization method, which relates to the field of ship structures, and comprises the following steps: establishing a finite element model and an optimization design domain, taking the minimum volume fraction as a constraint condition, and taking the maximum energy absorption capacity as a target function; adding elastic-plastic and limit plastic strain parameters of the material, and adding automatic single-side contact; constructing a unit energy absorption sensitivity integral relative difference algorithm, reading transient collision simulation structure impact force and collision displacement information, and calculating an energy absorption sensitivity value of each unit; calculating unit filtering sensitivity by utilizing a unit area sensitivity filtering technology; dynamically adjusting the volume deletion amount and the asymptotic evolution rate; and returning the optimization structure under the current iteration step again until convergence. The structure weight and the size are reduced, the energy absorption capacity and the impact resistance are improved, and meanwhile design automation and efficient engineering application are achieved.

Description

Technical Field

[0001] This invention relates to the field of ship structure optimization, and particularly to a side impact resistance topology optimization method that can improve multiple impact resistance properties of a structure and further reduce the overall weight of the structure in the design of ship collision protection and impact resistance structures. Background Technology

[0002] Due to the influence of various extreme environmental factors in the marine environment, such as wind, waves, and currents, ship collisions and impacts are frequent occurrences. If a ship's impact structure cannot effectively withstand the impact of a collision, it will cause extensive structural damage and may further lead to major safety accidents such as ship breakage and sinking. Therefore, to enhance the collision resistance of ship structures, designers have developed different types of side impact protection structures to absorb the impact energy generated by collisions and reduce the damage to the hull.

[0003] In existing ship collision protection designs, double-layer, X-shaped, and Y-shaped collision protection structures have been widely used in practical engineering. However, most of the previous ship collision protection structures were designed based on experience. Optimizing the impact resistance of the structure required designers to manually modify and repeatedly experiment with the existing structure. This made the optimization of traditional collision protection structures highly dependent on the designer's subjective experience and the referenced foundation structure. Consequently, the optimization results were often not the optimal solution, the improvement in impact resistance was very limited, and a large amount of manpower, time, and computational costs were required to complete the manual trial and error process.

[0004] Topology optimization methods for structures have been widely used in industrial product design because they can find material distribution locations based on the optimal mechanical transmission path within the design domain, thus reducing the reliance on designer experience and initial reference structures. Methods such as variable density topology optimization and evolutionary topology optimization are commonly applied. However, in collision-oriented ship design, impacts induce various complex nonlinear factors, including material elastic-plasticity and its failure nonlinearity, and surface contact nonlinearity, making traditional topology optimization techniques often inapplicable. Therefore, currently, there are no patents that apply topology optimization techniques to ship collision protection sides, enabling automated topology optimization to eliminate reliance on manual trial-and-error iterations, effectively improving the impact resistance of side structures, and further enhancing their lightweighting effect.

[0005] Furthermore, the high nonlinearity of the collision process and the uncertainty of the phase difference between the impact resistance sensitivity of elements during the collision process also have a significant impact on the convergence of the optimization iteration process. How to effectively and gradually approach the optimal solution during the design process, avoid numerical oscillations and non-convergence phenomena in transient dynamic topology optimization iteration during the collision process, and achieve stable and rapid convergence of the results has become an urgent problem to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide a stable, progressive, impact-resistant topology optimization method for ship collision protection structures, in order to solve the problems existing in the design of existing ship collision protection structures, including reliance on designer experience, limitations of the initial reference structure, and insufficient optimization effect and efficiency.

[0007] To achieve the above objectives, the present invention provides a progressive shock-resistant topology optimization method for stabilizing ship collision avoidance structures, comprising the following steps: Step 100: Establish a finite element model and an optimization design domain, using the lowest acceptable volume fraction as a constraint condition and maximizing the energy absorption of the structure during the collision as the objective function. Step 200: Add material elastic-plastic and ultimate plastic strain parameters in each optimization iteration, and add automatic single-sided contact in real time to complete transient collision simulation; Step 300: Construct the unit energy absorption sensitivity integral relative difference algorithm, read the impact force and collision displacement information of the transient collision simulation structure when each unit is present or absent, and calculate the energy absorption sensitivity value of each unit during the impact process. Step 400: The unit sensitivity adaptive stabilization algorithm is used to calculate the unit filtering sensitivity using the unit region sensitivity filtering technology to avoid the checkerboard phenomenon and adaptively balance and improve the drastic changes and numerical oscillations of the unit energy absorption sensitivity during the iteration process. Step 500: Employ an energy-maximizing, efficient, dynamic, and gradual strategy to dynamically adjust the volume deletion amount and the gradual evolution rate. Step 600: Return the optimized structure of the current iteration step to step 200 until convergence, and obtain the impact-resistant topology optimization design of the collision-resistant structure that satisfies the structural volume constraint conditions. Step 700: Conduct layout regularization interpretation work and set the main support components of the side profile on the center line of the main distribution area of ​​the topological material.

[0008] Preferably, in step 100, the entire area of ​​the ship's anti-collision structure is geometrically filled, a geometric mesh is divided using three-dimensional hexahedral elements, loads and boundary conditions are applied, and an initial finite element model is established.

[0009] Preferably, in step 200, the material is defined as ideal elastic-plastic steel, and parameters such as elastic modulus, yield stress, tangent modulus, and element ultimate plastic strain are added.

[0010] Preferably, in step 300, the energy absorption sensitivity information of the calculation unit is calculated using the following formula: (1) in, Let be the energy absorption sensitivity value of the i-th unit; Let F be the function of the impact force F on the original structure during the current optimization iteration as a function of the collision deformation displacement s, and d be its maximum collision deformation distance. It is the impact force F on the structure after the removal of the i-th unit in the current optimization iteration. i Displacement s with collision deformation i A function of change, d i It is its maximum collision deformation distance.

[0011] Preferably, in step 400, the element energy absorption sensitivity is converted into the node energy absorption sensitivity using the following formula: (2) in, The energy absorption sensitivity of the nth element containing the j-th node can be found in the element energy absorption sensitivity. The value is obtained from m, where m is the total number of units involved in the j-th node. The filter weighting value for nodal energy absorption sensitivity is calculated using the following formula: (3) in, It is the filtering weight value of the j-th node relative to the i-th unit. It is the weighted filtering radius. It is the distance between the j-th node and the center of the i-th cell.

[0012] Preferably, in step 400, when the energy absorption sensitivity of each node is obtained... With filter weights Then, the energy absorption and filtering sensitivity of the unit is further solved. As shown in the following formula, this avoids the occurrence of the checkerboard pattern: (4) in, It is the energy absorption sensitivity of each node. It is a filter weighted value. It refers to the energy absorption and filtering sensitivity of the unit.

[0013] Preferably, the energy absorption sensitivity of the unit in the k-th iteration step is constructed. The criterion for the change is as follows: (5) Identify the energy absorption sensitivity of the unit in the k-th iteration step based on the calculated value of the energy absorption sensitivity change criterion. Whether the value exhibits chaotic phenomena such as repeated numerical oscillations, as detailed below: (6).

[0014] Preferably, in step 400, the energy absorption sensitivity of the unit in the k-th iteration step is... Values ​​are balanced and improved: (7) Thus, the equilibrium energy absorption sensitivity of the unit is finally obtained in the k-th iteration step. .

[0015] Preferably, in step 500, the amount of stable volume to be removed in each previous iteration is determined using the following formula: (8) in, It is the volume deletion amount in each iteration step. It is an asymptotic volume fraction condition. It represents the number of approximation iterations in the early stages.

[0016] Preferably, in step 500, when the number of iterations... The asymptotic evolution rate expression is constructed using the following formula: (9) in, Let be the asymptotic evolution rate of the k-th iteration; The set initial evolution rate for the later stages; It is the structural volume fraction of the (k-1)th iteration; It is the set asymptotic volume fraction condition.

[0017] In summary, the present invention has the following beneficial technical effects: This invention achieves significant weight reduction in ship collision protection structures through a stable, progressive impact-resistant topology optimization method. Compared to traditional "X"-shaped collision protection side structures, the optimized new ship collision protection side structure reduces overall volume by 19.43% and weight by nearly 0.5 tons, demonstrating a significant weight reduction effect. Material distribution is more concentrated in key load-bearing areas, inefficient materials are eliminated, material utilization is greatly improved, ship construction costs and operating energy consumption are reduced, and the ship's economic and environmental performance is enhanced. The novel anti-collision structure designed in this invention achieves a 21.41% increase in maximum energy absorption capacity during a collision compared to traditional structures, and a 50.70% increase in energy absorption capacity per unit mass of material. By redistributing materials through topology optimization, the structure can more effectively dissipate energy upon impact, significantly enhancing the ship's impact resistance and safety. The optimized structure exhibits stronger energy absorption capacity in the most critical parts of a collision, providing reliable protection for the ship's structural safety under extreme conditions.

[0018] The impact-resistant topology optimization method of this invention can adopt an automated design process, reducing reliance on designer experience and initial reference structures. By combining finite element simulation with an adaptive stabilization algorithm, it can efficiently search for the optimal material layout, avoiding the limitations of manual design and tedious trial-and-error processes. The final design result is neat and concise, avoiding the checkerboard and irregular layout problems common in topology optimization, meeting the needs of practical engineering construction and mass production, and has significant promotion and application value. Attached Figure Description

[0019] Figure 1 A schematic diagram of the anti-collision side of an "X"-shaped vessel; Figure 2 A schematic diagram of the initial finite element model for topology optimization of the anti-collision side; Figure 3 This is a schematic diagram of the impact force-displacement curve of a structural collision. Figure 4 A schematic diagram of the progressive impact-resistant topology optimization results for side stabilization of the anti-collision hull; Figure 5 A schematic diagram illustrating the structural layout of the impact-resistant topology for the hull side; Figure 6 A schematic diagram of the optimized new ship anti-collision side structure. Detailed Implementation

[0020] 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 embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention discloses a stable progressive shock-resistant topology optimization method for ship collision avoidance structures, comprising the following steps: Step 100: Taking the ship's anti-collision structure as the object, establish a finite element model and an optimization design domain, and take the minimum acceptable volume fraction during structural design as its constraint condition, and take maximizing the energy absorption of the structure during the collision as its objective function to carry out optimization design. Step 200: Based on the current finite element model, the material elastic-plastic and ultimate plastic strain parameters are added to the finite element software in each optimization iteration by calling a self-written program, and automatic single-sided contact is added in real time, thereby completing the transient collision simulation of the structural iteration process. Step 300: Construct the unit energy absorption sensitivity integral relative difference algorithm, read the transient collision simulation structure impact force and collision displacement information when each unit is present and absent, and calculate the energy absorption sensitivity numerical information of each unit of the anti-collision side finite element model during the impact process. Step 400: Using the proposed unit sensitivity adaptive stabilization algorithm, the unit filtering sensitivity is first calculated using the unit region sensitivity filtering technology to avoid the occurrence of the checkerboard phenomenon; then, relying on the proposed adaptive stabilization algorithm, the chaotic phenomena such as drastic changes and numerical oscillations in the unit energy absorption sensitivity during the iteration process are adaptively balanced and improved. Step 500: The developed energy absorption maximization efficient dynamic asymptotic strategy is adopted to enable the topology iteration to be dynamically optimized in the early and late stages by using a stable volume deletion amount and an asymptotic evolution rate. This allows the iteration process to stably, efficiently and accurately approach the target value of maximizing energy absorption, avoiding the occurrence of slow or non-convergent iteration due to the uncertainty and uneven distribution of energy absorption sensitivity between units. Step 600: Return the optimization result of the current iteration step to step 200 until convergence, and finally obtain the impact-resistant topology optimization design of the collision-resistant structure that satisfies the structural volume constraint conditions. Step 700: Based on the obtained impact-resistant topology optimization design of the anti-collision structure, carry out the regularization interpretation of the layout, and set the main supporting components of the side profile on the center line of the main distribution area of ​​the topological material, so as to obtain a new type of ship anti-collision side that meets the requirements of structural impact resistance and lightweighting and is easy to produce.

[0022] In one embodiment of the present invention, a method for impact-resistant topology optimization of a ship's anti-collision structure is disclosed, the specific contents of which include: In step 100, taking the ship's collision avoidance structure as the object, the region containing the entire structure is geometrically filled to provide a larger optimization geometric space for topology optimization. Within the established optimization geometric space, a geometric mesh is generated using three-dimensional hexahedral elements, loads and boundary conditions are applied, and an initial finite element model is established. The lowest acceptable volume fraction during the initial finite element model design is used as its constraint condition, and maximizing the energy absorption of the structure during a collision is used as its objective function to carry out the structural impact resistance optimization design.

[0023] In step 200, based on the current finite element model, the material elastic-plastic and ultimate plastic strain parameters are added in each optimization iteration by calling the finite element software, and automatic single-sided contact is added in real time, thereby completing the transient collision simulation of the structural optimization iteration process. In step 300, the impact force and collision displacement of the transient collision simulation structure are read when each unit is present and absent, and the unit energy absorption sensitivity integral relative difference algorithm is constructed (as shown in equation (1) below) to calculate the energy absorption sensitivity numerical information of each unit in the anti-collision side finite element model during the impact process.

[0024] (1) In the formula, Let be the energy absorption sensitivity value of the i-th unit; Let F be the function of the impact force F on the original structure during the current optimization iteration as a function of the collision deformation displacement s, and d be its maximum collision deformation distance. It is the impact force F on the structure after the removal of the i-th unit in the current optimization iteration. i Displacement s with collision deformation i A function of change, d i It is its maximum collision deformation distance.

[0025] In step 400, the proposed unit sensitivity adaptive stabilization algorithm first uses the unit region sensitivity filtering technique to adjust the unit energy absorption sensitivity calculated by equation (1). Equation (2) is used to transform the nodal energy absorption sensitivity of the eight nodes of a three-dimensional hexahedral element. : (2) in, The energy absorption sensitivity of the nth element containing the j-th node can be found in the element energy absorption sensitivity. The value is obtained from m, where m is the total number of units involved in the j-th node.

[0026] Next, the filter weighting value of the energy absorption sensitivity of each node is calculated, as shown in equation (3) below: (3) In the formula, It is the filtering weight value of the j-th node relative to the i-th unit. It is the weighted filtering radius. It is the distance between the j-th node and the center of the i-th cell.

[0027] When the energy absorption sensitivity of each node is obtained With filter weights Then, the energy absorption and filtering sensitivity of the unit is further solved. As shown in the following formula, this avoids the occurrence of the checkerboard pattern: (4) The energy absorption and filtering sensitivity of the unit is obtained. Based on this, the proposed adaptive stabilization algorithm is used to construct the energy absorption sensitivity of the unit in the k-th iteration step. The criterion for the change is shown in equation (5).

[0028] (5) Based on the calculated value of the energy absorption sensitivity change criterion, the energy absorption sensitivity of the unit in the k-th iteration step can be effectively identified. Whether the value exhibits chaotic phenomena such as repeated numerical oscillations, as detailed below: (6) Furthermore, based on the identification results of the energy absorption sensitivity change criterion, different strategies are adaptively adopted (as shown in Equation (7)) to adjust the energy absorption sensitivity of the unit in the k-th iteration step. Values ​​are balanced and improved: (7) Thus, the equilibrium energy absorption sensitivity of the unit is finally obtained in the k-th iteration step. This enables adaptive balancing and mitigation of chaotic phenomena such as numerical oscillations caused by the energy absorption sensitivity of units during the iteration process.

[0029] In step 500, the developed energy absorption maximization efficient dynamic asymptotic strategy is adopted. In the early stage of topology optimization, optimization is carried out based on the stable volume deletion amount that is efficiently approximated. In the later stage of optimization, it is dynamically adjusted to carry out optimization by asymptotic evolution rate that slows down as the structure volume decreases.

[0030] Because there are a large number of inefficient elements in the initial structural space during the early optimization stage, and the element balancing energy absorption sensitivity... The distribution is uncertain and uneven. Therefore, a set number of approximation iterations is used. and asymptotic volume fraction conditions In the early stages of bidirectional topology optimization, the volume removal amount for each iteration step is determined. To achieve a stable and efficient approximation of the target, the following formula is used: (8) In the formula, It is the volume deletion amount in each iteration step. It is an asymptotic volume fraction condition. It represents the number of approximation iterations in the early stages.

[0031] At this point (i.e., the iteration step number) (At times) the equilibration energy absorption sensitivity of the units in the structure needs to be considered. Sort the data and delete it according to the calculated volume. Remove inefficient units with lower equilibration energy absorption sensitivity.

[0032] Due to the stable and rapid approximation in the early stages, most of the remaining elements in the later stages of topology optimization are highly efficient elements. Therefore, for these remaining highly efficient elements, as the structure volume decreases, it is necessary to gradually reduce their evolution rate (removal amount) in each iteration to avoid removing too much effective material at once, thereby ensuring the accuracy of the solution. Therefore, when the number of iterations... Then, the asymptotic evolution rate expression constructed using equation (9) is adopted: (9) In the formula, Let be the asymptotic evolution rate of the k-th iteration; The set initial evolution rate for the later stages; It is the structural volume fraction of the (k-1)th iteration; It is the set asymptotic volume fraction condition.

[0033] In step 600, the optimization result of the current iteration step is returned to step 200 until convergence, and finally the impact-resistant topology optimization design of the collision-resistant structure that satisfies the structural volume constraint condition is obtained. In step 700, based on the obtained impact-resistant topology optimization design of the anti-collision structure, a regularization interpretation of the layout is carried out. The main plate and shell support components of the structural cross-section are set along the centerline of the main distribution area of ​​the topological material, thereby obtaining a new type of ship anti-collision structure that meets the requirements of structural impact resistance and lightweighting, and is easy to produce in practice.

[0034] The method is further illustrated below with reference to the accompanying drawings and specific embodiments. In ship structures, the side structures are relatively highly susceptible to impact, and the impact resistance performance of the anti-collision side is closely related to the overall crashworthiness and safety of the structure. Therefore, this specific embodiment will optimize the impact resistance of a typical ship anti-collision side structure to improve its energy absorption capacity during a collision. The implementation process is as follows: 1. Using a typical "X"-shaped ship's anti-collision hull as a reference structure, such as... Figure 1 As shown, each module of the side structure is 2400mm long, 1080mm wide, and 3650mm high, with a boundary shell thickness of 10mm and an internal "X"-shaped support shell thickness of 5mm.

[0035] 2. Geometrically fill the area containing the entire "X"-shaped side structure to provide a larger optimization geometric space for topology optimization. Within the established optimization geometric space, a geometric mesh is generated using three-dimensional hexahedral elements. The impact conditions and boundary conditions for the bulbous bow of a 5000-ton engineering auxiliary vessel impacting the side structure are established, resulting in the following... Figure 2 The initial finite element model is shown.

[0036] 3. The minimum acceptable volume fraction of the initial finite element model design is set to 0.25 as its constraint condition. The objective function is to maximize the energy absorption of the side structure during the collision. The progressive impact-resistant topology optimization design for structural stability is carried out.

[0037] 4. Based on the current finite element model, the material of the structure is defined as ideal elastic-plastic steel in each optimization iteration by calling the finite element software, and its elastic modulus is added as 2.1*105MPa, yield stress as 235MPa, tangent modulus as 1000MPa, and element ultimate plastic strain as 0.3; and automatic single-sided contact is added in real time to the side structure to complete the transient collision simulation of the structural optimization iteration process. 5. Based on transient collision simulation, output the structural collision impact force-displacement curves for each element with and without it, such as... Figure 3 As shown. Then, by constructing the unit energy absorption sensitivity integral relative difference algorithm (as shown in Equation (1)), the energy absorption sensitivity numerical information of each unit in the finite element model of the anti-collision side during the impact process is calculated.

[0038] 6. Using the proposed adaptive stabilization algorithm for unit sensitivity, the equilibrium absorbed energy sensitivity of the unit in the k-th iteration step is calculated. This approach adaptively balances and reduces numerical oscillations in the energy absorption sensitivity of units during iteration, and suppresses the occurrence of checkerboard patterns. Furthermore, a developed, energy-maximizing, efficient dynamic evolution strategy is employed to dynamically use stable volume deletion amounts in the early and later stages of topology iteration. and asymptotic evolution rate Perform optimization. Return to step 4 and repeat the above iterative optimization process until the result converges. The obtained optimized topology structure is as follows: Figure 4 As shown.

[0039] 7. Based on Figure 4 The obtained progressive impact-resistant topology optimization design for the anti-collision side stability is used to conduct regularization interpretation of the layout. The main steel plate support components of the side profile are set along the centerline of the main distribution area of ​​the topological material, such as... Figure 5 As shown. This ultimately results in a new type of ship collision protection hull that meets the requirements of structural impact resistance and lightweighting, and is easy to produce in practice, such as... Figure 6 As shown.

[0040] In this embodiment, the proposed stable progressive shock-resistant topology optimization method achieves lightweight and high-performance design of the ship's anti-collision side structure. Figure 6 The new ship collision protection hull shown in the image exhibits a material distribution pattern similar to the referenced "X"-shaped collision protection hull structure (see...). Figure 1 This demonstrates a significant difference from the proposed impact-resistant topology optimization method, which greatly reduces reliance on designer experience and initial reference structures. By automatically searching for the optimal energy-absorbing structural layout through an evolutionary algorithm, it improves the effectiveness and efficiency of the collision optimization process.

[0041] Furthermore, the following table summarizes the various impact resistance properties of the new ship anti-collision hull obtained through impact-resistant topology optimization compared with the traditional "X"-shaped anti-collision hull in terms of structural volume and collision resistance:

[0042] Therefore, the optimized novel ship collision protection hull obtained by this invention has a significantly reduced structural volume and weight of 19.43% compared to the traditional "X"-shaped collision protection hull, demonstrating better lightweighting. Simultaneously, the maximum energy absorption and energy absorption rate per unit mass of material during a collision are also greatly improved, with the maximum energy absorption increasing by 21.41% and the energy absorption rate per unit mass of material increasing by 50.70%, significantly enhancing the structure's impact resistance. This proves that the ship collision protection hull impact-resistant topology optimization method can effectively achieve structural lightweighting and improve its impact resistance, thereby ensuring the safety and reliability of the structure during a ship collision.

[0043] At the same time, Figure 6 The final design results show that the structure is relatively regular and simple in form and layout, avoiding the occurrence of checkerboard and irregular topological layouts, thus ensuring structural performance while meeting the requirements of actual engineering construction and mass production.

[0044] Compared to traditional ship collision protection side structure optimization, this invention provides a stable, progressive impact-resistant topology optimization method for ship collision protection structures. During the design phase of the ship collision protection structure, a topology optimization approach based on structural impact resistance is employed to automatically search for the optimal energy-absorbing layout, reducing reliance on designer experience and initial reference structures, and improving optimization effectiveness and efficiency. Finite element software is used to add material elastic-plastic and ultimate plastic strain parameters in real time, and automatic single-sided contact is implemented, thereby achieving transient collision simulation during the structural iteration process. Relying on a constructed element energy absorption sensitivity integral relative difference algorithm, the energy absorption sensitivity values ​​of each element during the impact process are effectively solved. Subsequently, the proposed element sensitivity adaptive stabilization algorithm adaptively balances and reduces numerical oscillations caused by drastic changes in element energy absorption sensitivity during iteration, and suppresses the occurrence of checkerboard patterns. Furthermore, by employing a developed, energy-maximizing, efficient, dynamic, and asymptotic strategy, the topology iteration can be dynamically optimized in its early and later stages using stable volume deletion amounts and asymptotic evolution rates. This avoids issues such as slow or non-convergent convergence and inaccurate structural solutions caused by uncertainties and uneven distributions of energy absorption sensitivity among elements. Ultimately, this optimization method can achieve impact-resistant topology optimization for ship collision protection structures, effectively improving their impact resistance during collisions, increasing material utilization while achieving lightweighting. It is suitable for practical design operations and has promotional and application value.

[0045] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A progressive topology optimization method for stabilizing ship collision avoidance structures, characterized in that, Includes the following steps: Step 100: Establish a finite element model and an optimization design domain, using the lowest acceptable volume fraction as a constraint condition and maximizing the energy absorption of the structure during the collision as the objective function. Step 200: Add material elastic-plastic and ultimate plastic strain parameters in each optimization iteration, and add automatic single-sided contact in real time to complete transient collision simulation; Step 300: Construct the unit energy absorption sensitivity integral relative difference algorithm, read the impact force and collision displacement information of the transient collision simulation structure when each unit is present or absent, and calculate the energy absorption sensitivity value of each unit during the impact process. Step 400: The unit sensitivity adaptive stabilization algorithm is used to calculate the unit filtering sensitivity using the unit region sensitivity filtering technology to avoid the checkerboard phenomenon and adaptively balance and improve the drastic changes and numerical oscillations of the unit energy absorption sensitivity during the iteration process. Step 500: Employ an energy-maximizing, efficient, dynamic, and gradual strategy to dynamically adjust the volume deletion amount and the gradual evolution rate. Step 600: Return the optimized structure of the current iteration step to step 200 until convergence, and obtain the impact-resistant topology optimization design of the collision-resistant structure that satisfies the structural volume constraint conditions. Step 700: Conduct layout regularization interpretation work and set the main support components of the side profile on the center line of the main distribution area of ​​the topological material.

2. The method for progressively stabilizing and impact-resistant topology optimization of a ship's anti-collision structure according to claim 1, characterized in that, In step 100, the entire area of ​​the ship's anti-collision structure is geometrically filled, a geometric mesh is generated using three-dimensional hexahedral elements, loads and boundary conditions are applied, and an initial finite element model is established.

3. The method for progressively stabilizing and impact-resistant topology optimization of a ship's anti-collision structure according to claim 2, characterized in that, In step 200, the material is defined as ideal elastic-plastic steel, and parameters such as elastic modulus, yield stress, tangent modulus, and element ultimate plastic strain are added.

4. The method for progressively stabilizing and impact-resistant topology optimization of a ship's anti-collision structure according to claim 3, characterized in that, In step 300, the energy absorption sensitivity information of the computing unit is calculated using the following formula: (1) in, Let be the energy absorption sensitivity value of the i-th unit; Let F be the function of the impact force F on the original structure during the current optimization iteration as a function of the collision deformation displacement s, and d be its maximum collision deformation distance. It is the impact force F on the structure after the removal of the i-th unit in the current optimization iteration. i Displacement s with collision deformation i A function of change, d i It is its maximum collision deformation distance.

5. The method for progressively stabilizing and impact-resistant topology optimization of a ship's anti-collision structure according to claim 4, characterized in that, In step 400, the element energy absorption sensitivity is converted into the nodal energy absorption sensitivity using the following formula: (2) in, The energy absorption sensitivity of the nth element containing the j-th node can be found in the element energy absorption sensitivity. The value is obtained from m, where m is the total number of units involved in the j-th node. The filter weighting value for nodal energy absorption sensitivity is calculated using the following formula: (3) in, It is the filtering weight value of the j-th node relative to the i-th unit. It is the weighted filtering radius. It is the distance between the j-th node and the center of the i-th cell.

6. The method for progressively stabilizing and impact-resistant topology optimization of a ship's anti-collision structure according to claim 5, characterized in that, In step 400, when the energy absorption sensitivity of each node is obtained... With filter weights Then, the energy absorption and filtering sensitivity of the unit is further solved. As shown in the following formula, this avoids the occurrence of the checkerboard pattern: (4) in, It is the energy absorption sensitivity of each node. It is a filter weighted value. It refers to the energy absorption and filtration sensitivity of the unit.

7. The method for progressively stabilizing and impact-resistant topology optimization of a ship's anti-collision structure according to claim 6, characterized in that, Constructing the energy absorption sensitivity of the unit in the k-th iteration step The criterion for the change is as follows: (5) Identify the energy absorption sensitivity of the unit in the k-th iteration step based on the calculated value of the energy absorption sensitivity change criterion. Whether the value exhibits chaotic phenomena such as repeated numerical oscillations, as detailed below: (6)。 8. The method for progressively stabilizing and impact-resistant topology optimization of a ship's anti-collision structure according to claim 7, characterized in that, In step 400, the energy absorption sensitivity of the unit in the k-th iteration step is... Values ​​are balanced and improved: (7) Thus, the equilibrium energy absorption sensitivity of the unit is finally obtained in the k-th iteration step. .

9. The method for progressively stabilizing and impact-resistant topology optimization of a ship's anti-collision structure according to claim 8, characterized in that, In step 500, the amount of stable volume removed in each previous iteration is determined using the following formula: (8) in, It is the volume deletion amount in each iteration step. It is an asymptotic volume fraction condition. It represents the number of approximation iterations in the early stages.

10. A method for stable progressive impact-resistant topology optimization of ship collision avoidance structure according to claim 9, characterized in that, In step 500, when the iteration number... The asymptotic evolution rate expression is constructed using the following formula: (9) in, Let be the asymptotic evolution rate of the k-th iteration; The set initial evolution rate for the later stages; It is the structural volume fraction of the (k-1)th iteration; It is the set asymptotic volume fraction condition.

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