Method for laying out spmt of marine structure based on model structure analysis method

Abstract

The application discloses a marine structure SPMT layout method based on a model structure analysis method, belongs to the technical field of SPMT layout, and is used for SPMT layout. The method comprises the following steps: determining a SPMT layout area range as a general constraint condition based on physical information of a deck piece; modeling a physical model of the deck piece on the physical information of the deck piece; and judging the distribution of a main beam in the deck piece. The method further comprises the following steps: taking a SPMT layout state as a chromosome structure to initialize a population; calculating hydraulic balance; connecting the physical model of the deck piece with a physical model of each SPMT; performing finite element analysis to obtain a structural strength value; taking the hydraulic balance and the structural strength value as two variables of a fitness function; and obtaining a unique solution of the SPMT layout state. Through automatic calculation, the method obtains a solution set of the best compromise scheme of the overall structural safety and hydraulic balance, and obtains a relatively optimized SPMT layout scheme of a marine structure.

Description

Technical Field

[0001] This invention discloses a SPMT (Surface Mount Technology) deployment method for marine structures based on model structure analysis, belonging to the field of SPMT deployment technology. Background Technology

[0002] In the field of marine engineering, the land transportation of large marine structures (such as deck panels and modules) is a complex and crucial step. Self-propelled modular transporters (SPMTs), due to their powerful load-bearing capacity and flexible modularity, have become the primary equipment for completing such transportation tasks. The design of SPMT deployment schemes—that is, how to plan and arrange multiple SPMT vehicles to jointly carry a huge structure—directly relates to the safety and feasibility of the transportation process. To solve such complex engineering optimization problems, academia and industry have introduced multi-objective optimization algorithms. SPMT deployment is a typical multi-objective optimization problem, where objectives are often conflicting. For example, achieving the highest structural safety (i.e., the lowest structural stress value) and optimal hydraulic balance (i.e., the lowest hydraulic pressure difference) often cannot be simultaneously optimized.

[0003] Against this backdrop, the Non-Dominated Sorting Genetic Algorithm with Elite Retention Strategy (NSGA-II) has emerged as an advanced technique for solving such problems. NSGA-II is a powerful multi-objective optimization algorithm capable of handling multiple conflicting objective functions simultaneously. Through mechanisms such as "non-dominated sorting" and "crowding calculation," this algorithm efficiently searches for and obtains a set of numerous optimal trade-off solutions, known as the "Pareto Front." Each solution in this set represents an optimal compromise between different objectives, providing decision-makers with a diverse and high-quality choice space, rather than a single, absolutely optimal solution. However, effectively combining advanced optimization algorithms like NSGA-II with the physical models and finite element analysis methods of marine structures to automate and intelligently generate SPMT deployment schemes remains a significant technical challenge. Therefore, there is an urgent need for an SPMT deployment method that can comprehensively consider structural strength and hydraulic equilibrium, and automatically find the optimal or near-optimal solution set, to replace tedious and inaccurate manual planning, thereby improving the safety and efficiency of transporting large structures. Summary of the Invention

[0004] The purpose of this invention is to provide a SPMT (Surface Mount Technology) deployment method for marine structures based on model structural analysis, in order to solve the problem that in the prior art, it is often impossible to simultaneously achieve the highest structural safety (i.e., the lowest structural stress value) and the best hydraulic balance (i.e., the lowest hydraulic pressure difference).

[0005] The SPMT (Surface Mount Technology) deployment method for marine structures based on model-based structural analysis includes:

[0006] S1. Based on the physical information of the deck plates, determine the SPMT deployment area as a general constraint.

[0007] S2. Model the physical information of the deck plate and determine the distribution of the main beams in the deck plate.

[0008] S3. Initialize the population by using the SPMT deployment state as the chromosome structure. The SPMT state parameters include the SPMT's front coordinates, SPMT's orientation angle, the number of axles per SPMT, and the hydraulic distribution of each SPMT.

[0009] S4. Calculate hydraulic balance;

[0010] S5. Based on the distribution of the main beams in the deck section, connect the physical model of the deck section with the physical model of each SPMT vehicle.

[0011] S6. Perform finite element analysis to obtain the structural strength values;

[0012] S7. Using hydraulic balance and structural strength values ​​as two variables of the fitness function, the SPMT deployment state with a unique solution is obtained.

[0013] S8. Based on the SPMT deployment status, output the SPMT deployment scheme for marine structures using a graphical interface.

[0014] S1 includes selecting the main beam range of the deck piece as the outer edge of the layout area based on the physical information of the deck piece, excluding the range where the deck piece overhangs beyond a first set threshold, and ensuring that the span on both sides of the deck piece does not exceed a second set threshold, so that the range that satisfies the above conditions is used as a general constraint condition.

[0015] The physical modeling of the deck segments based on their physical information includes classifying the deck segments into five categories: nodes, beams, types, loads, and combined loads, and constructing geometric and mechanical models for each category.

[0016] Determining the distribution of main beams in the deck section includes identifying all beams of type I-beams with a height exceeding a third set threshold and forming them into a main beam as a whole, connecting main beam segments with the same X or Y coordinate into a single main beam.

[0017] Population initialization includes:

[0018] ;

[0019] ;

[0020] In the formula, It is the initialized population. It is the first The front coordinates of each SPMT are under general constraints. It is the first The direction and angle of each SPMT It is the first Number of axes in SPMT It is the first The average pressure of the SPMT hydraulic group, and Obtained through discrete uniform sampling.

[0021] The calculation of hydraulic balance includes dividing the SPMT shaft into 4 parts, with each part hydraulically connected to the other parts, and deducting points when the line connecting the centroid coordinates of each part falls within the set range of the overall center of gravity of the deck piece.

[0022] Hydraulic balance for:

[0023] ;

[0024] In the formula, It is the average hydraulic pressure of all SPMT axes involved in the calculation. It is the penalty score coefficient. It is the preset minimum safety radius. The overall center of gravity is to the first The straight-line distance between the centroids of the hydraulic group groups. It is the first The hydraulic group of the SPMT.

[0025] Connecting the physical model of the deck section with the physical model of each SPMT includes calculating the starting and ending coordinates of the SPMT and the possible intersections between the SPMT and all main beams based on the state parameters of the SPMT and the information of each main beam obtained from S2.

[0026] Based on the type of main beam, calculate the distance from SPMT to a specific type of main beam, add a connection between the physical model of the deck piece and the physical model of SPMT, the connection is located at the intersection of SPMT and all possible main beams, and the connection length is the distance from SPMT to a specific type of main beam;

[0027] Based on the weight borne by the hydraulic assembly, add load-bearing and load-bearing weights to the physical model of the SPMT.

[0028] Calculating the start and end coordinates of SPMT includes:

[0029] ;

[0030] ;

[0031] In the formula, and It is the first The end coordinates of each SPMT and It is the first The starting coordinates of each SPMT.

[0032] Obtaining the structural strength value involves fixing the physical model of the connected SPMT, fixing the starting and ending coordinates of the two sets of SPMTs (a total of four nodes), using the finite element analysis method to calculate the physical model of the fixed SPMT, and obtaining the UC values ​​of all nodes and beams. The largest UC value is taken as the structural strength value.

[0033] The SPMT deployment state that yields a unique solution includes ranking the hydraulic equilibrium and structural strength values ​​as two variables in the fitness function based on non-dominated relationships:

[0034] ;

[0035] ;

[0036] In the formula, These are general constraints. This is the value for hydraulic balance;

[0037] Based on the ranking results, combined with the elite retention mechanism, the optimal solutions of the retained part are crossovered and mutated to generate new offspring;

[0038] Repeat the above process until the loop exceeds 1000 generations or the result does not improve after 50 generations. Output the current frontier solution, add parameters to the two variables of the solution in the frontier solution to obtain the final unique solution, and output the SPMT deployment state contained in the unique solution.

[0039] Determine the SPMT deployment status. Based on the physical model of the deck panel, use the top and side views of the deck panel as the base map for the SPMT deployment diagram. Based on the SPMT deployment status and the connection status between the SPMT and the deck panel, draw the SPMT deployment status on the base map and add labels, charts, and notes.

[0040] Compared with the prior art, the present invention has the following advantages: the present invention obtains the solution set of the best compromise between structural safety and hydraulic balance through automated calculation, and obtains a more optimized SPMT layout scheme for marine structures. Attached Figure Description

[0041] Figure 1For Pareto front solution set.

[0042] Figure 2 The distribution of the Pareto front solution set in the three-objective case.

[0043] Figure 3 An overview diagram of the SPMT system, which represents the comprehensive optimal solution in the Pareto front solution set.

[0044] Figure 4 SPMT hydraulic equilibrium diagram for the comprehensive optimal solution in the Pareto front solution set. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention are described clearly and completely below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0046] The SPMT (Surface Mount Technology) deployment method for marine structures based on model-based structural analysis includes:

[0047] S1. Based on the physical information of the deck plates, determine the SPMT deployment area as a general constraint.

[0048] S2. Model the physical information of the deck plate and determine the distribution of the main beams in the deck plate.

[0049] S3. Initialize the population by using the SPMT deployment state as the chromosome structure. The SPMT state parameters include the SPMT's front coordinates, SPMT's orientation angle, the number of axles per SPMT, and the hydraulic distribution of each SPMT.

[0050] S4. Calculate hydraulic balance;

[0051] S5. Based on the distribution of the main beams in the deck section, connect the physical model of the deck section with the physical model of each SPMT vehicle.

[0052] S6. Perform finite element analysis to obtain the structural strength values;

[0053] S7. Using hydraulic balance and structural strength values ​​as two variables of the fitness function, the SPMT deployment state with a unique solution is obtained.

[0054] S8. Based on the SPMT deployment status, output the SPMT deployment scheme for marine structures using a graphical interface.

[0055] S1 includes selecting the main beam range of the deck piece as the outer edge of the layout area based on the physical information of the deck piece, excluding the range where the deck piece overhangs beyond a first set threshold, and ensuring that the span on both sides of the deck piece does not exceed a second set threshold, so that the range that satisfies the above conditions is used as a general constraint condition.

[0056] The physical modeling of the deck segments based on their physical information includes classifying the deck segments into five categories: nodes, beams, types, loads, and combined loads, and constructing geometric and mechanical models for each category.

[0057] Determining the distribution of main beams in the deck section includes identifying all beams of type I-beams with a height exceeding a third set threshold and forming them into a main beam as a whole, connecting main beam segments with the same X or Y coordinate into a single main beam.

[0058] Population initialization includes:

[0059] ;

[0060] ;

[0061] In the formula, It is the initialized population. It is the first The front coordinates of each SPMT are under general constraints. It is the first The direction and angle of each SPMT It is the first Number of axes in SPMT It is the first The average pressure of the SPMT hydraulic group, and Obtained through discrete uniform sampling.

[0062] The calculation of hydraulic balance includes dividing the SPMT shaft into 4 parts, with each part hydraulically connected to the other parts, and deducting points when the line connecting the centroid coordinates of each part falls within the set range of the overall center of gravity of the deck piece.

[0063] Hydraulic balance for:

[0064] ;

[0065] In the formula, It is the average hydraulic pressure of all SPMT axes involved in the calculation. It is the penalty score coefficient. It is the preset minimum safety radius. The overall center of gravity is to the first The straight-line distance between the centroids of the hydraulic group groups. It is the first The hydraulic group of the SPMT.

[0066] Connecting the physical model of the deck section with the physical model of each SPMT includes calculating the starting and ending coordinates of the SPMT and the possible intersections between the SPMT and all main beams based on the state parameters of the SPMT and the information of each main beam obtained from S2.

[0067] Based on the type of main beam, calculate the distance from SPMT to a specific type of main beam, add a connection between the physical model of the deck piece and the physical model of SPMT, the connection is located at the intersection of SPMT and all possible main beams, and the connection length is the distance from SPMT to a specific type of main beam;

[0068] Based on the weight borne by the hydraulic assembly, add load-bearing and load-bearing weights to the physical model of the SPMT.

[0069] Calculating the start and end coordinates of SPMT includes:

[0070] ;

[0071] ;

[0072] In the formula, and It is the first The end coordinates of each SPMT and It is the first The starting coordinates of each SPMT.

[0073] Obtaining the structural strength value involves fixing the physical model of the connected SPMT, fixing the starting and ending coordinates of the two sets of SPMTs (a total of four nodes), using the finite element analysis method to calculate the physical model of the fixed SPMT, and obtaining the UC values ​​of all nodes and beams. The largest UC value is taken as the structural strength value.

[0074] The SPMT deployment state that yields a unique solution includes ranking the hydraulic equilibrium and structural strength values ​​as two variables in the fitness function based on non-dominated relationships:

[0075] ;

[0076] ;

[0077] In the formula, These are general constraints. This is the value for hydraulic balance;

[0078] Based on the ranking results, combined with the elite retention mechanism, the optimal solutions of the retained part are crossovered and mutated to generate new offspring;

[0079] Repeat the above process until the loop exceeds 1000 generations or the result does not improve after 50 generations. Output the current frontier solution, add parameters to the two variables of the solution in the frontier solution to obtain the final unique solution, and output the SPMT deployment state contained in the unique solution.

[0080] Determine the SPMT deployment status. Based on the physical model of the deck panel, use the top and side views of the deck panel as the base map for the SPMT deployment diagram. Based on the SPMT deployment status and the connection status between the SPMT and the deck panel, draw the SPMT deployment status on the base map and add labels, charts, and notes.

[0081] This invention is applied to the construction of offshore platforms. It calculates the optimal SPMT (Surface Mount Technology) deployment scheme and, combined with other aspects of the project, directly generates a feasible construction plan to guide the construction of offshore platforms. The SPMT physical model in this invention refers to the actual structure of the SPMT in practical applications. Figure 1 The Pareto front solution set is shown in the figure. Each blue dot represents a non-dominated solution, and the set of all these points constitutes the Pareto front. The horizontal axis represents the strength check ratio, a key indicator for measuring structural safety. The vertical axis represents hydraulic balance, which is the standard deviation of the pressure of each hydraulic group or the difference between the maximum and minimum pressures, a key indicator for measuring the hydraulic stability of the support system. Figure 2 The Pareto front solution set is distributed under a three-objective scenario by adding a third objective: cost, with the number of axes of the SPMT used as the evaluation criterion. This figure uses a 30m x 50m deck panel containing a circular cavity in the center. Figure 3 An overview diagram of the SPMT system for the comprehensive optimal solution in the Pareto front solution set shows the relative positions of the reaction center and the deck center of gravity of the four SPMTs, each acting as a hydraulic group. Figure 4 The SPMT hydraulic equilibrium diagram for the comprehensive optimal solution in the Pareto front solution set shows that each of the four SPMTs is a hydraulic group, and the reaction force borne by each hydraulic group.

[0082] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A SPMT (Surface Mount Technology) deployment method for marine structures based on model-based structural analysis, characterized in that: include: S1. Based on the physical information of the deck plates, determine the SPMT deployment area as a general constraint. S2. Model the physical information of the deck plate and determine the distribution of the main beams in the deck plate. S3. Initialize the population by using the SPMT deployment state as the chromosome structure. The SPMT state parameters include the SPMT's front coordinates, SPMT's orientation angle, the number of axles per SPMT, and the hydraulic distribution of each SPMT. S4. Calculate hydraulic balance; S5. Based on the distribution of the main beams in the deck section, connect the physical model of the deck section with the physical model of each SPMT vehicle. S6. Perform finite element analysis to obtain the structural strength values; S7. Using hydraulic balance and structural strength values ​​as two variables of the fitness function, the SPMT deployment state with a unique solution is obtained. S8. Based on the SPMT deployment status, output the SPMT deployment scheme for marine structures using a graphical interface. The calculation of hydraulic balance includes dividing the SPMT shaft into 4 parts, with each part hydraulically connected to the other parts, and deducting points when the line connecting the centroid coordinates of each part falls within the set range of the overall center of gravity of the deck piece. Hydraulic balance for: ； In the formula, It is the average hydraulic pressure of all SPMT axes involved in the calculation. It is the penalty score coefficient. It is the preset minimum safety radius. The overall center of gravity is to the first The straight-line distance between the centroids of the hydraulic group groups. It is the first Hydraulic groups of SPMTs It is the first The average pressure of the SPMT hydraulic group.

2. The SPMT layout method for marine structures based on model structural analysis as described in claim 1, characterized in that, S1 includes selecting the main beam range of the deck piece as the outer edge of the layout area based on the physical information of the deck piece, excluding the range where the deck piece overhangs beyond a first set threshold, and ensuring that the span on both sides of the deck piece does not exceed a second set threshold, so that the range that satisfies the above conditions is used as a general constraint condition.

3. The SPMT layout method for marine structures based on model structural analysis method according to claim 2, characterized in that, The physical modeling of the deck segments based on their physical information includes classifying the deck segments into five categories: nodes, beams, types, loads, and combined loads, and constructing geometric and mechanical models for each category. Determining the distribution of main beams in the deck section includes identifying all beams of type I-beams with a height exceeding a third set threshold and forming them into a main beam as a whole, connecting main beam segments with the same X or Y coordinate into a single main beam.

4. The SPMT layout method for marine structures based on model structural analysis method according to claim 3, characterized in that, Population initialization includes: ； ； In the formula, It is the initialized population. It is the first The front coordinates of each SPMT are under general constraints. It is the first The direction and angle of each SPMT It is the first Number of axes in SPMT and Obtained through discrete uniform sampling.

5. The SPMT layout method for marine structures based on model structural analysis method according to claim 4, characterized in that, Connecting the physical model of the deck section with the physical model of each SPMT includes calculating the starting and ending coordinates of the SPMT and the possible intersections between the SPMT and all main beams based on the state parameters of the SPMT and the information of each main beam obtained from S2. Based on the type of main beam, calculate the distance from SPMT to a specific type of main beam, add a connection between the physical model of the deck piece and the physical model of SPMT, the connection is located at the intersection of SPMT and all possible main beams, and the connection length is the distance from SPMT to a specific type of main beam; Based on the weight borne by the hydraulic assembly, add load-bearing and load-bearing weights to the physical model of the SPMT.

6. The SPMT layout method for marine structures based on model structural analysis method according to claim 5, characterized in that, Calculating the start and end coordinates of SPMT includes: ； ； In the formula, and It is the first The end coordinates of each SPMT and It is the first The starting coordinates of each SPMT.

7. The SPMT layout method for marine structures based on model structural analysis as described in claim 6, characterized in that, Obtaining the structural strength value involves fixing the physical model of the connected SPMT, fixing the starting and ending coordinates of the two sets of SPMTs (a total of four nodes), using the finite element analysis method to calculate the physical model of the fixed SPMT, and obtaining the UC values ​​of all nodes and beams. The largest UC value is taken as the structural strength value.

8. The SPMT layout method for marine structures based on model structural analysis method according to claim 7, characterized in that, The SPMT deployment state that yields a unique solution includes ranking the hydraulic equilibrium and structural strength values ​​as two variables in the fitness function based on non-dominated relationships: ； ； In the formula, These are general constraints. This is the value for hydraulic balance; Based on the ranking results, combined with the elite retention mechanism, the optimal solutions of the retained part are crossovered and mutated to generate new offspring; Repeat the above process until the loop exceeds 1000 generations or the result does not improve after 50 generations. Output the current frontier solution, add parameters to the two variables of the solution in the frontier solution to obtain the final unique solution, and output the SPMT deployment state contained in the unique solution.

9. The SPMT layout method for marine structures based on model structural analysis method according to claim 8, characterized in that, Determine the SPMT deployment status. Based on the physical model of the deck panel, use the top and side views of the deck panel as the base map for the SPMT deployment diagram. Based on the SPMT deployment status and the connection status between the SPMT and the deck panel, draw the SPMT deployment status on the base map and add labels, charts, and notes.

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