A vibration reduction and impact resistance integrated structure optimization method suitable for ship foundation

Abstract

The present invention discloses a method for optimizing an integrated vibration-damping and impact-resistant structure suitable for ship foundations. The method comprises: parameterizing the tensile profile of a three-dimensional, negative Poisson's ratio honeycomb foundation structure to obtain various foundation design parameters; selecting two of these parameters as design variables and establishing a foundation model based on a parametric modeling method; simulating the foundation model using a steady-state excitation simulation method to obtain an acceleration level drop, and simulating the foundation model using a transient impact simulation method to obtain an impact amplification factor, respectively evaluating the foundation's vibration-damping and impact-resistant performance; fitting a mathematical model of the two design variables' effects on vibration-damping and impact-resistant performance using a response surface methodology; encoding the two design variables into an individual gene string, selecting an optimization target, and optimizing using a genetic algorithm. The present invention allows for comprehensive consideration of the foundation's vibration-damping and impact-resistant performance, and combines a genetic algorithm with finite element calculations to ensure the accuracy and reliability of the optimization results.

Description

Technical Field

[0001] The present invention belongs to the technical field of structural optimization of ship foundations, and in particular relates to a vibration reduction and impact resistance integrated structural optimization method applicable to ship foundations. Background Art

[0002] During operation, ships are often subjected to various internal and external excitation loads, which can cause various vibration problems. With the increasing demands for speed on modern ships, and the increasing rotational speeds and power of shipboard equipment such as main engines, ship vibration issues are receiving increasing attention. Furthermore, because ships undertake a variety of combat missions, they are inevitably exposed to the threat of explosion shock during combat. The shock caused by explosions can cause damage to shipboard equipment, especially damage to the power and electrical systems, which can directly render the ship incapable of combat. The base structure, as the primary carrier of vibration sources for various mechanical equipment on board, is the primary channel for transmitting equipment vibration to the ship's structure. Depending on the type of equipment carried, the base structure will also vary. One effective way to reduce the level of radiated noise from ships is to rationally design the structure to enhance the base's ability to isolate the equipment from complex excitations while ensuring normal operation of the equipment.

[0003] Analysis of existing ship foundation vibration isolation structural designs reveals that they primarily meet two performance requirements: first, they must be able to isolate or absorb external energy; second, they must possess a certain degree of rigidity and strength to provide support, emphasizing the combination of structural load-bearing capacity and specialized functionality. In recent years, with the deepening of relevant research and the rapid advancement of manufacturing processes, the performance requirements for ship foundations have also increased. Whether these foundations can achieve superior vibration isolation while also balancing impact resistance to reduce equipment damage has become a key research focus. Consequently, the design and parameter optimization of ship foundation structures that integrate vibration reduction and impact resistance have become a pressing need.

[0004] Current research is exploring the use of various new metamaterials in the design of pedestals. Porous structures and negative Poisson's ratio structures have been shown to offer excellent vibration isolation performance, achieving both load-bearing and vibration reduction capabilities through rational structural and parameter design. However, current structural designs for new pedestals often focus on a single objective and lack parameter optimization. Summary of the Invention

[0005] In order to meet the demand of taking into account the impact resistance performance on the basis of better vibration isolation performance, the base structure design of various new metamaterials has received widespread attention. However, the current related designs are still mainly carried out for a single goal and lack parameter optimization. The present invention provides a vibration reduction and impact resistance integrated structure optimization method suitable for ship foundations. Based on the parametric modeling idea, the finite element model establishment and parameter setting steps of the negative Poisson's ratio honeycomb base structure are scripted. The multi-objective optimization model is simplified by combining the response surface method and the genetic algorithm main program is written using MATLAB software. The ABAQUS finite element software is jointly mobilized to calculate and solve evaluation parameters such as the base acceleration level drop under steady-state excitation and the base impact amplification coefficient under the impact of the three-fold impact spectrum. The structural design parameters are optimized generation by generation to achieve the optimization of the design parameters of the ship foundation structure with integrated vibration reduction and impact resistance.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] According to a first aspect of the present invention, a method for optimizing a vibration-damping and shock-resistant integrated structure applicable to a ship foundation is provided, the method comprising:

[0008] The tensile section of the plate-frame three-dimensional negative Poisson's ratio honeycomb base structure is parameterized to obtain the design parameters of the base.

[0009] Two design parameters are selected from various design parameters of the foundation as design variables, the remaining design parameters are used as constants, and a foundation model is established based on a parametric modeling method;

[0010] The base model is simulated using a steady-state excitation simulation method to obtain the acceleration level difference, and the base model is simulated using a transient impact simulation method to obtain the impact amplification factor. The acceleration level difference is used to evaluate the vibration reduction performance of the base, and the impact amplification factor is used to evaluate the impact resistance performance of the base.

[0011] The response surface methodology was used to fit the mathematical model of the two design variables in terms of vibration reduction performance and impact resistance, and the response surface model of acceleration level difference and impact amplification factor was obtained.

[0012] Encode the two design variables into an individual gene string;

[0013] Select vibration reduction performance or impact resistance as the primary optimization target, and the other as the secondary optimization target; the primary optimization target is obtained by model simulation and used as the individual fitness; the secondary optimization target is obtained by response surface model, and the secondary optimization target threshold is set as a constraint condition;

[0014] Two design variables are optimized using genetic algorithm.

[0015] In the above scheme, the base model is established, including:

[0016] The stretched section is stretched to obtain a stretched entity, the stretched entity is rotated 90° and combined to obtain a unit cell structure model, and the unit cell structure model is arranged and combined in the X, Y, and Z directions to obtain a base model.

[0017] In the above scheme, the design parameters of the base include: main side length L1, oblique side length L2, extended support length L3, cell angle α and honeycomb thickness T H .

[0018] In the above scheme, the base model is simulated using the steady-state excitation simulation method to obtain the acceleration level difference, including:

[0019] The steady-state excitation simulation method uses the modal superposition method to perform harmonic response analysis, extracts the acceleration data at each evaluation point in the base model, and obtains the vibration level through calculation and processing;

[0020] The calculation method of acceleration level difference is as follows:

[0021] For the calculation of the total vibration level at N different frequencies for a certain evaluation point j in the harmonic response analysis, the sum of the vibration levels at each frequency is taken:

[0022]

[0023] Where, is the total vibration level of the evaluation point j, is the vibration level of evaluation point j at the i-th frequency;

[0024] Assuming there are K evaluation points, the acceleration level L all is the average value of the total vibration level of each evaluation point:

[0025]

[0026] Finally, the acceleration level drop is expressed as:

[0027]

[0028] Where, L r is the acceleration level difference, is the acceleration level of the panel on the base, is the acceleration level of the lower panel of the base.

[0029] In the above scheme, the transient impact simulation method is used to simulate the base model to obtain the impact amplification factor, including:

[0030] The transient impact simulation method uses a three-fold impact spectrum to simulate and convert the impact spectrum into a positive and negative double triangle wave acceleration time history curve for loading, and extracts the output load curve and amplitude of the base model;

[0031] The impact amplification factor is calculated using the ratio of the input impact load amplitude at the base root to the output load amplitude of the base panel:

[0032]

[0033] Where η is the impact amplification coefficient, a m is the maximum amplitude of the output response, a i is the maximum amplitude of the input load.

[0034] In the above scheme, the response surface methodology adopts the central composite design method;

[0035] The central composite design method was used to conduct experimental design and corresponding working condition calculations for the two design variables. The accuracy of the fitting model was tested by variance analysis, and a mathematical model was obtained to understand the influence of each design variable on the single performance of the foundation.

[0036] In the above scheme, the two design variables are encoded into an individual gene string, including:

[0037] Encode each of the two design variables into a string, concatenate the two strings into a long string as the individual gene string; map the decimal value range of each string to the value range of the design variable;

[0038] The selection strategy of the genetic algorithm adopts proportional selection and forcibly inserts the best individuals of the previous generation when generating a new population;

[0039] If the secondary optimization objective of the newly generated individual does not meet the secondary optimization objective threshold, the fitness value of the newly generated individual is 0.

[0040] In the above scheme, the method is specifically as follows:

[0041] Based on the parametric modeling method of ABAQUS finite element software, including the script generation method of recording operations and reading JNL files to generate scripts, the model establishment code of the parametric modeling script is written. According to the steady-state excitation simulation method and transient impact simulation method, the load input, result output, meshing and related settings are completed and the relevant code is written to form the final parametric modeling script;

[0042] Write a post-processing script to calculate the acceleration level drop and impact amplification factor;

[0043] The main program of the genetic algorithm is written in MATLAB software, and data interaction between MATLAB software and ABAQUS software is realized. After the main program of the genetic algorithm generates the initialized population, the txt file in the specified path is modified according to the individual parameters, and the parametric modeling script reads the txt file to realize the numerical modification. The ABAQUS software is opened and the working directory is set. The parametric modeling script is run and the inp file is output. After completion, the calculation file and related calculation parameters are submitted to ABAQUS through a system call. After the calculation is completed, the post-processing script is automatically called. The post-processing script extracts relevant data, calculates the fitness value and outputs it in a txt file in the specified path. The MATLAB software reads the txt file data to realize the return of the fitness value.

[0044] The main genetic algorithm program optimizes two design variables through iteration.

[0045] According to a second aspect of the present invention, there is provided an electronic device comprising: a processor and a memory, the memory storing programs or instructions that can be run on the processor, and the program or instructions, when executed by the processor, implementing the steps of any one of the above-mentioned methods for optimizing a vibration-damping and impact-resistant integrated structure applicable to a ship base.

[0046] According to a third aspect of the present invention, a readable storage medium is provided, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the vibration-damping and impact-resistant integrated structure optimization method suitable for a ship foundation are implemented as described in any one of the above.

[0047] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0048] The present invention is based on MATLAB and ABAQUS software, takes the integrated structural optimization of marine foundation vibration reduction and impact resistance as the goal, compiles steady-state excitation and transient impact scripts based on a parametric modeling method, rationally selects foundation design parameters, and adopts a response surface method to fit a mathematical model of the influence of the selected design variables on the foundation vibration reduction performance and impact resistance performance. A genetic algorithm main program is compiled to realize data interaction between MATLAB software and ABAQUS software, completes relevant settings, and performs multi-objective optimization of foundation structural parameters by means of a constrained response surface fitting model. This can achieve comprehensive consideration of the foundation vibration reduction performance and impact resistance performance, and combines the genetic algorithm with finite element calculation to ensure the accuracy and reliability of the optimization results.

[0049] In addition, the use of parametric modeling scripts, post-processing scripts and the establishment of software interactive functions can improve efficiency and achieve automation, providing a reference for related research on parameter design and optimization of marine foundation structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a flow chart of a vibration reduction and impact resistance integrated structure optimization method applicable to a ship foundation in an embodiment of the present invention;

[0051] Figure 2 A flowchart of the genetic algorithm and software interaction in an embodiment of the present invention;

[0052] Figure 3 Schematic diagram of parameterization of the stretched cross section of the honeycomb base in an embodiment of the present invention;

[0053] Figure 4 This is a model diagram of a three-dimensional negative Poisson's ratio honeycomb base in an embodiment of the present invention;

[0054] Figure 5 This is a finite element model diagram for steady-state excitation simulation calculation in an embodiment of the present invention;

[0055] Figure 6 Schematic diagram of acceleration level difference calculation and evaluation points in an embodiment of the present invention;

[0056] Figure 7 This is a transient impact positive and negative double triangle wave curve diagram in an embodiment of the present invention;

[0057] Figure 8 This is a genetic algorithm fitness optimization curve diagram in an embodiment of the present invention;

[0058] Figure 9 This is the static load displacement cloud diagram of the optimized model in the embodiment of the present invention. DETAILED DESCRIPTION

[0059] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0060] At present, the structural design of new bases is often carried out for a single objective and lacks parameter optimization. To address this problem, the present invention is based on parametric modeling and genetic optimization algorithm, combined with the response surface method to simplify the mathematical model, and combines MATLAB software and ABAQUS software to realize an integrated optimization method for the vibration reduction and impact resistance of the base structure. It can complete single-objective optimization and multi-objective optimization of the vibration reduction performance and impact resistance of various marine bases such as negative Poisson's ratio honeycomb bases, providing a reference for the parameter design of the corresponding base structure.

[0061] Example 1

[0062] The present embodiment is applicable to the optimization method of the integrated structure of vibration reduction and shock resistance for ship foundation, such as Figure 1 and Figure 2 As shown, the following steps are included:

[0063] (1) Based on the parametric modeling method, steady-state excitation simulation calculation method and transient impact simulation calculation method of ABAQUS finite element software, a parametric modeling script is written for the design model.

[0064] (2) Select reasonable evaluation criteria for relevant performance, including acceleration level drop and impact amplification factor, and write a calculation post-processing script corresponding to the parameterized modeling script.

[0065] (3) Finally, the optimized design variables are selected, and the response surface method is used to carry out experimental design and corresponding working condition calculation for each design variable. The accuracy of the fitting model is tested by variance analysis to obtain the mathematical fitting model of the influence of each design variable on the single performance of the base.

[0066] (4) In order to achieve multi-objective optimization of the base performance, a MATLAB genetic algorithm master program was written and an interaction method with ABAQUS finite element software was established.

[0067] (5) Set genetic algorithm related parameters such as genetic generation, population size, and structural design related parameters such as structural parameter value range and weight constraints in the MATLAB main control program.

[0068] (6) The genetic algorithm optimization is carried out through the master control program formed by steps (4) and (5), and the ABAQUS software is called to calculate the corresponding individual fitness values, and the base structure design parameters are optimized generation by generation to obtain the final optimization results.

[0069] (7) Based on the final optimization parameters of step (6), multiple parametric modeling scripts are generated to calculate and test the static load-bearing performance, vibration reduction performance and impact resistance of the optimized base. If the corresponding requirements are met, the calculation is terminated, otherwise step (6) is repeated.

[0070] Preferably, in step (1), the preliminary stretching sketch of the base design structure is parameterized, and based on the parametric modeling method of ABAQUS finite element software, including the recording operation generation script method and the JNL file reading script generation method, the model establishment related code of the parametric modeling script is written; according to the steady-state excitation simulation method and the transient impact simulation method, the load input, result output, meshing and other related settings are completed and the related code is written to form the final parametric modeling script. Figure 3 As shown, the design parameters of the base include: main side length L1, oblique side length L2, extended support length L3, cell angle α and honeycomb thickness T H .

[0071] Preferably, the steady-state excitation simulation method uses the modal superposition method to perform harmonic response analysis and extracts the acceleration data at each evaluation point of the base as the output result; the transient impact simulation method uses a three-fold impact spectrum simulation, such as Figure 7 As shown, the impact spectrum is converted into an acceleration time history curve of positive and negative double triangle waves for loading, and finally the base output load curve and its amplitude are extracted as the output results.

[0072] Preferably, in step (2), the acceleration level difference is used to evaluate the vibration reduction performance of the base, and the impact amplification coefficient is used to evaluate the impact resistance of the base, and the corresponding post-processing script is written to complete the data processing calculation.

[0073] The calculation method of acceleration level difference is as follows:

[0074] For the calculation of the total vibration level at N different frequencies for a certain evaluation point j in the harmonic response analysis, the sum of the vibration levels at each frequency is taken:

[0075]

[0076] Where, is the total vibration level of the evaluation point j, is the vibration level at the i-th frequency of the evaluation point j (i.e., the vibration acceleration level, which can be obtained by substituting the acceleration data into the formula and summing them up);

[0077] Assuming there are K evaluation points, the acceleration vibration level of the structure is the average value of the vibration levels of each evaluation point:

[0078]

[0079] The acceleration level difference can be expressed as:

[0080]

[0081] The calculation method of the impact amplification factor is as follows:

[0082] The calculation is based on the ratio of the input impact load amplitude at the base root to the output load amplitude of the base panel:

[0083]

[0084] Where a m is the maximum amplitude of the output response, a i is the maximum amplitude of the input load.

[0085] Preferably, in step (3), the base optimization structural parameter target is selected, and the central composite design method (central composite design) is used for experimental design according to the number of parameters. After completing all the design working condition calculations, it is necessary to perform variance analysis on the fitting results. In the analysis results: R 2 is the correlation coefficient, R 2 The higher the value, the higher the fitting accuracy of the model; the significance of the influence of each factor on the response index is obtained by the F test, and the smaller the P value, the more significant the influence of the independent variable on the response value; the model P value is less than 0.05, which indicates that the final fitted mathematical model is significant and the selected influencing factors are reasonable and effective.

[0086] Preferably, in step (4), the functions of the main program of the genetic algorithm include: initializing the population, calculating the fitness of the population, selection, crossover, mutation, and recombination, wherein the selection strategy adopts a proportional selection method, and the probability of an individual being selected to enter the next generation is determined according to its fitness; to ensure that the calculation results are optimized from generation to generation, the best individual of the previous generation is forcibly inserted when the new population is generated by recombination; and interaction with ABAQUS finite element software is realized in the code for calculating the fitness of the population, and the main interactive functions include modifying the parametric modeling script through a txt file, submitting the calculation file to the system, and reading the calculation results through a txt file.

[0087] Preferably, in step (5), the genetic algorithm related parameters and the structural design related parameters are set according to actual needs, and the constraints of the optimization algorithm can be finally defined by combining engineering processing restrictions and lightweight design concepts.

[0088] Preferably, in step (6), the individual fitness value is calculated and output to a txt file in a specified path by ABAQUS finite element software. According to the difference in the calculation working condition type, the individual fitness value is the evaluation index value of the corresponding working condition, including the acceleration level drop and the impact amplification factor. In order to achieve multi-objective optimization of the vibration reduction and impact resistance of the base, the extreme value or fixed range of another optimization target response surface fitting model is set in the genetic algorithm main program. When the optimization parameter is substituted into the calculation result and the corresponding requirement is not met, the ABAQUS calculation link is skipped and the individual fitness value is directly returned to 0, completing the comprehensive consideration of multiple performances.

[0089] Preferably, in step (7), the static load-bearing performance of the base is calculated by static loading using a vertical force of 500 kg, and the ratio of the maximum displacement of the base to the original scale is used as the basis for evaluation.

[0090] Example 2

[0091] This embodiment takes the optimization of the vibration reduction and impact resistance performance of a certain plate-type three-dimensional negative Poisson's ratio honeycomb base as an example to illustrate the method, which includes the following steps:

[0092] (1) According to the plate-frame three-dimensional negative Poisson's ratio honeycomb base structure, its tensile section is parameterized and the corresponding script is written. The tensile entity is rotated 90° and combined to obtain a unit cell structure model. The unit cell model is arranged and combined in the X, Y, and Z directions to obtain a honeycomb core layer structure model, as shown in Figure 4 As shown in the figure, all displacements are represented by the combination of parameters, and the complete modeling process can be completed automatically.

[0093] (2) Figure 5 As shown in the figure, according to the steady-state excitation and transient impact simulation calculation method, by reading the JNL file and modifying the relevant setting code, the shell unit thickness, grid size, etc. are also expressed in parameter form, and combined with the modeling code to form the final parameterized modeling script file.

[0094] (3) According to the acceleration level difference calculation formula, write code to extract and calculate the acceleration curve data and acceleration level difference of the point set consisting of 9 evaluation points, such as Figure 6 As shown; according to the shock amplification coefficient calculation formula, write code to extract and calculate the reference point shock amplification coefficient; supplement the code to output the calculation results in a fixed format to a txt file in the specified path, forming two sets of post-processing script files corresponding to their respective working conditions.

[0095] (4) The relevant parameters that can be optimized in this example include the main side length L1, the oblique side length L2, the extended support length L3, the cell angle α and the honeycomb thickness T H Any two-way combination can be used to carry out subsequent optimization steps. In this example, the cell angle and honeycomb thickness are selected as the design variables of the negative Poisson's ratio honeycomb base, and the acceleration level drop and impact amplification factor of the honeycomb base are taken as optimization targets. The parameter value range is selected and the CCD experimental design method in the response surface method is used to obtain the required pre-condition calculation table, as shown in Table 1.

[0096] Table 1 CCD test design table

[0097]

[0098] (5) Calculate the corresponding working condition results according to the design table, select a reasonable model for fitting, and use variance analysis to test the model accuracy, as shown in Tables 2 and 3.

[0099] Table 2 Acceleration level drop fitting variance analysis table

[0100]

[0101] Table 3 Analysis of variance table of shock amplification coefficient fitting

[0102]

[0103]

[0104] The response surface model of acceleration level difference and impact amplification factor is finally obtained as follows:

[0105]

[0106] (6) The main program of the genetic algorithm is written using MATLAB software. The cell angle and honeycomb thickness are encoded as individual gene strings. In this example, the length of the individual string is 20, and the length of each string of the two optimization variables is 10. The decimal value range returned by the decoding function is 0 to 1024 (2 10 ), and its value range can be adjusted by zooming and translating; the selection strategy adopts proportional selection, and the best individuals of the previous generation are forcibly inserted when generating a new population.

[0107] (7) Build software interactive functions: After the genetic algorithm main program generates the initialized population, the txt file in the specified path is modified according to the individual parameters, and the parametric modeling script reads the txt file to realize the numerical modification. Open the ABAQUS software and set the working directory, run the parametric modeling script and output the inp file. After completion, the calculation file and related calculation parameters are submitted to ABAQUS through system call, and the post-processing script is automatically called after the calculation is completed. The script will extract relevant data, calculate the fitness value and output it in the txt file in the specified path. The MATLAB software reads the txt file data to realize the return of the fitness value.

[0108] (8) After selecting the main optimization target, the input of the other optimization target uses the response surface fitting model as the mathematical model constraint condition. In this example, the acceleration level drop is the main optimization target, and the optimization of the impact resistance performance of the base is written into the constraint condition in the form of limiting the calculation result of the fitting model of the impact amplification coefficient to no more than 0.8. The final optimization mathematical model and constraint conditions are as follows:

[0109]

[0110] For the main optimization target, the parameterized modeling script and the post-processing script are used to accurately calculate it through model simulation; for the other optimization target, it is directly calculated using the fitting model in step (5).

[0111] (9) Set the initial population size to 4, the length of individual gene characters to 20, the crossover probability to 0.6, the mutation probability to 0.001, the genetic generation to 100 generations, and the optimization algorithm to end only when the set genetic generation is reached. When the impact amplification coefficient fitting value exceeds the threshold of 0.8, set its return fitness to 0, and perform multi-objective optimization calculations on the negative Poisson's ratio honeycomb base. Figure 8 This is the fitness optimization curve.

[0112] (10) The parameters of the final optimized negative Poisson's ratio honeycomb structure are: cell angle 61.351°, honeycomb thickness 0.953 mm, and its vibration reduction performance, impact resistance, and static load-bearing performance are tested. Figure 9 As shown in the figure, the acceleration level difference is 5.820dB, the impact amplification factor is 0.814, and the maximum displacement under the static force of 500kg is 1.699mm.

[0113] In the present invention, a tensile cross-section of a marine foundation structure is parameterized based on a parametric modeling method, and a parametric modeling script is written in combination with a steady-state excitation and transient impact finite element calculation method. The foundation design parameters are reasonably selected, and a CCD experimental design method in the response surface method is adopted in combination with simulation calculation to fit a mathematical model of the influence of each parameter on the vibration reduction performance and impact resistance of the foundation. The data interaction between MATLAB software and ABAQUS software is realized by writing a genetic algorithm main program, and the multi-objective generation-by-generation optimization of the foundation structure parameters is completed by combining a constrained response surface fitting model, a proportional selection method and a method of forcibly inserting the optimal individual.

[0114] The present invention also provides an electronic device comprising: a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the programs or instructions are executed by the processor, the steps of any one of the above-mentioned methods for optimizing the vibration-damping and impact-resistant integrated structure applicable to a ship base are implemented.

[0115] The present invention also provides a readable storage medium having a program or instruction stored thereon, which, when executed by a processor, implements the steps of any one of the above-mentioned methods for optimizing a vibration-damping and impact-resistant integrated structure applicable to a ship base.

[0116] In summary, the present invention is based on MATLAB and ABAQUS software, takes the integrated structural optimization of marine foundation vibration reduction and impact resistance as the direction, compiles steady-state excitation and transient impact scripts based on the parametric modeling method, reasonably selects the foundation design parameters and adopts the response surface method to fit the mathematical model of their influence on the foundation vibration reduction performance and impact resistance, compiles the genetic algorithm main program to realize the data interaction between MATLAB software and ABAQUS software, completes the relevant settings and performs multi-objective optimization of the foundation structure parameters by means of constrained response surface fitting model, and finally performs various performance tests on the foundation after parameter optimization.

[0117] Compared with the existing technology, the present invention provides a vibration-damping and impact-resistant integrated structural optimization method suitable for ship foundations. Combined with result processing, it can effectively realize the vibration-damping and impact-resistant integrated structural optimization of ship foundations. By fitting a mathematical model using a response surface, it can realize comprehensive consideration of the foundation's vibration-damping performance and impact resistance under a single working condition calculation. Combining genetic algorithms with finite element calculations ensures the accuracy and reliability of the optimization results. The use of parametric modeling scripts, post-processing scripts, and the construction of software interactive functions can improve efficiency and achieve automation. It provides a reference for research related to parameter design and optimization of ship foundation structures.

[0118] It should be noted that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0119] It should be pointed out that, according to the needs of implementation, the various steps / components described in this application can be split into more steps / components, or two or more steps / components or partial operations of steps / components can be combined into new steps / components to achieve the purpose of the present invention.

[0120] It will be easily understood by those skilled in the art that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A vibration reduction and impact resistance integrated structure optimization method suitable for ship foundation, characterized in that: The method includes: The tensile section of the plate-frame three-dimensional negative Poisson's ratio honeycomb base structure is parameterized to obtain the design parameters of the base. Two design parameters are selected from various design parameters of the foundation as design variables, the remaining design parameters are used as constants, and a foundation model is established based on a parametric modeling method; The base model is simulated using a steady-state excitation simulation method to obtain the acceleration level difference, and the base model is simulated using a transient impact simulation method to obtain the impact amplification factor. The acceleration level difference is used to evaluate the vibration reduction performance of the base, and the impact amplification factor is used to evaluate the impact resistance performance of the base. The response surface methodology was used to fit the mathematical model of the two design variables in terms of vibration reduction performance and impact resistance, and the response surface model of acceleration level difference and impact amplification factor was obtained. Encode the two design variables into an individual gene string; Select vibration reduction performance or impact resistance as the primary optimization target, and the other as the secondary optimization target; the primary optimization target is obtained by model simulation and used as the individual fitness; the secondary optimization target is obtained by response surface model, and the secondary optimization target threshold is set as a constraint condition; Genetic algorithm is used to optimize two design variables.

2. The vibration reduction and shock resistance integrated structure optimization method for ship foundation according to claim 1 is characterized in that: Build the base model, including: The stretched section is stretched to obtain a stretched entity, the stretched entity is rotated 90° and combined to obtain a unit cell structure model, and the unit cell structure model is arranged and combined in the X, Y, and Z directions to obtain a base model.

3. The vibration reduction and shock resistance integrated structure optimization method for ship foundation according to claim 1 is characterized in that: The design parameters of the base include: main side length L1, oblique side length L2, extended bracket length L3, cell angle α and honeycomb thickness T H .

4. The vibration reduction and shock resistance integrated structure optimization method for ship foundation according to claim 1, characterized in that: The base model is simulated using the steady-state excitation simulation method to obtain the acceleration level difference, including: The steady-state excitation simulation method uses the modal superposition method to perform harmonic response analysis, extracts the acceleration data at each evaluation point in the base model, and obtains the vibration level through calculation and processing; The calculation method of acceleration level difference is as follows: For the calculation of the total vibration level at N different frequencies for a certain evaluation point j in the harmonic response analysis, the sum of the vibration levels at each frequency is taken: Where, is the total vibration level of the evaluation point j, is the vibration level of evaluation point j at the i-th frequency; Assuming there are K evaluation points, the acceleration level L all is the average value of the total vibration level of each evaluation point: Finally, the acceleration level drop is expressed as: Where, L r is the acceleration level difference, is the acceleration level of the panel on the base, is the acceleration level of the lower panel of the base.

5. The vibration reduction and shock resistance integrated structure optimization method for ship foundation according to claim 1, characterized in that: The transient impact simulation method is used to simulate the base model to obtain the impact amplification factor, including: The transient impact simulation method uses a three-fold impact spectrum to simulate and convert the impact spectrum into a positive and negative double triangle wave acceleration time history curve for loading, and extracts the output load curve and amplitude of the base model; The impact amplification factor is calculated using the ratio of the input impact load amplitude at the base root to the output load amplitude of the base panel: Where η is the impact amplification coefficient, a m is the maximum amplitude of the output response, a i is the maximum amplitude of the input load.

6. The vibration reduction and shock resistance integrated structure optimization method for ship foundation according to claim 1 is characterized in that: The response surface methodology used the central composite design method; The central composite design method was used to conduct experimental design and corresponding working condition calculations for the two design variables. The accuracy of the fitting model was tested by variance analysis, and a mathematical model was obtained to understand the influence of each design variable on the single performance of the foundation.

7. The vibration reduction and shock resistance integrated structure optimization method for ship foundation according to claim 1, characterized in that: Encode the two design variables into an individual gene string consisting of: Encode each of the two design variables into a string, concatenate the two strings into a long string as the individual gene string; map the decimal value range of each string to the value range of the design variable; The selection strategy of the genetic algorithm adopts proportional selection and forcibly inserts the best individuals of the previous generation when generating a new population; If the secondary optimization objective of the newly generated individual does not meet the secondary optimization objective threshold, the fitness value of the newly generated individual is 0.

8. The vibration reduction and shock resistance integrated structure optimization method for ship foundation according to claim 1, characterized in that: The method is specifically: Based on the parametric modeling method of ABAQUS finite element software, including the method of generating scripts by recording operations and reading JNL files to generate scripts, write the model establishment related code of the parametric modeling script; According to the steady-state excitation simulation method and transient impact simulation method, complete the load input, result output, mesh division related settings and write the relevant code to form the final parameterized modeling script; Write a post-processing script to calculate the acceleration level drop and impact amplification factor; The main program of the genetic algorithm is written in MATLAB software, and data interaction between MATLAB software and ABAQUS software is realized. After the main program of the genetic algorithm generates the initialized population, the txt file in the specified path is modified according to the individual parameters, and the parametric modeling script reads the txt file to realize the numerical modification. The ABAQUS software is opened and the working directory is set. The parametric modeling script is run and the inp file is output. After completion, the calculation file and related calculation parameters are submitted to ABAQUS through a system call. After the calculation is completed, the post-processing script is automatically called. The post-processing script extracts relevant data, calculates the fitness value and outputs it in a txt file in the specified path. The MATLAB software reads the txt file data to realize the return of the fitness value. The main genetic algorithm program optimizes two design variables through iteration.

9. An electronic device, characterized in that: include: A processor and a memory, the memory storing programs or instructions that can be run on the processor, which, when executed by the processor, implement the steps of the vibration-damping and shock-resistant integrated structure optimization method for a ship foundation as described in any one of claims 1 to 8.

10. A readable storage medium, characterized in that: Programs or instructions are stored thereon, and when the programs or instructions are executed by the processor, the steps of the vibration-damping and impact-resistant integrated structure optimization method applicable to the ship foundation as described in any one of claims 1 to 8 are implemented.

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