Rapid design method and system for spatial trend of slender pipeline in random vibration environment

Abstract

The invention relates to pipeline space trend design, in particular to a rapid design method and system for the space trend of a long and thin pipeline in a random vibration environment. The method comprises the following steps: acquiring change parameters and constraint parameters of a to-be-designed slender pipeline; establishing constraint conditions; establishing a random vibration analysis model; judging whether the current change parameter accords with a constraint condition and a constraint rule or not, and if not, optimizing the change parameter; if so, obtaining random vibration result data through a random vibration analysis model; and 5, judging whether the random vibration result data accords with an optimization target or not, if so, completing the design, and if not, optimizing the current change parameter, and returning to the step 5 until the optimization target is met. The method solves the problem that the spatial trend of the elongated pipeline of the liquid rocket power system meeting the design requirement is difficult to accurately obtain at present in a heterogenous random vibration environment, and improves the reliability of the pipeline trend design.

Description

Technical Field

[0001] This invention relates to pipeline spatial routing design, specifically to a rapid design method for the spatial routing of slender pipelines under random vibration conditions, and a system for implementing this method. Background Technology

[0002] To ensure the normal operation of liquid rocket propulsion systems, numerous slender pipelines exist for transporting the propellant. Improper design can easily lead to excessive pipeline mass or structural failure due to localized high stress during testing or operation, resulting in mission failure. During transportation, testing, and operation, the pipeline structure of a liquid rocket propulsion system is subjected to various mechanical environments. Among these, the mechanical environment of random vibrations from different sources at both ends of the pipeline is the most prominent. The length and spatial orientation of the pipeline structure are crucial factors affecting its adaptability to these mechanical environments.

[0003] Currently, the design of pipeline structure length and spatial orientation relies more on previous models or individual research and development experience, which usually makes it difficult to quickly and accurately obtain a design solution that meets the requirements, and at the same time, there are high technical risks. Summary of the Invention

[0004] To address the technical problem that existing rapid design methods for the spatial routing of slender pipes are difficult to quickly and accurately obtain design solutions that meet requirements, and also pose high technical risks, this invention provides a rapid design method for the spatial routing of slender pipes under random vibration environments.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A rapid design method for the spatial orientation of slender pipes under random vibration conditions, characterized by the following steps: Step 1: Obtain the fixed points at both ends of the slender pipe to be designed, multiple key points in the middle, and the radii of curvature at the multiple key points. Select several key points and the radii of curvature at the key points as parameters for the spatial orientation of the slender pipe. At the same time, use the mass of the slender pipe to be designed as a constraint parameter. The key points refer to the inflection points in the slender pipe. Step 2: Based on the distance between the fixed point and its adjacent key points, as well as the radius of curvature and the included angle at the adjacent key points, establish the constraint conditions between the fixed point and its adjacent key points. Step 3: Based on the distance between two adjacent key points, as well as the radius of curvature and the included angle at the two adjacent key points, establish the constraint conditions between the two adjacent key points. Step 4: Establish a random vibration analysis model that includes the slender pipe to be designed and the external mechanical environment at both ends of the pipe; Step 5: Determine whether the current changing parameters meet the constraints established in Steps 2 and 3. Simultaneously, determine whether the current constraint parameters meet the preset constraint rules. If not, use a preset optimization algorithm to optimize the current changing parameters within the given range until they meet the requirements. If all parameters meet the requirements, obtain random vibration result data based on the optimized changing parameters using a random vibration analysis model. This data includes the maximum stress power spectrum value within the analysis frequency band on the pipeline and the maximum stress RMS value of the entire analysis frequency band. The constraint rule is: the mass of the designed slender pipeline does not exceed N times the mass of the straight pipeline between two fixed points, where N is greater than 1. Step 6: Determine whether the random vibration result data meets the optimization objective. If it does, the design is completed. If it does not, use the preset optimization algorithm to optimize the current variation parameters within the given variation range, and return to step 5 until the optimization objective is met. The optimization objective refers to minimizing the maximum stress power spectrum in the analysis frequency band of the pipeline and the maximum stress RMS value of the entire analysis frequency band.

[0006] Furthermore, in step 1, the slender pipe to be designed is a pipe containing three key points; Define the two fixed points at the ends of the slender pipe to be designed as fixed point A and fixed point B, respectively, and their spatial coordinates as (X, Y, Z, Y, Z). A Y A Z A ), (X) B Y B Z B The three key points are key point G1, key point G2, and key point G3, and their spatial coordinates are (X, G1, G2, and G3). G1 Y G1 Z G1 ), (X) G2 Y G2 Z G2 ), (X) G3 Y G3 Z G3 The radii of curvature at the three key points are R1, R2, and R3, respectively. In step 2, the constraints between the fixed point and its adjacent key points, as well as the constraints between any two adjacent key points, are as follows: ; ; ; ; In the formula: and These are the constraints between a fixed point and its adjacent key points. and These are the constraints between two adjacent key points; It is half the angle between lines A-G1 and G1-G2. It is half the angle between lines G1-G2 and G2-G3. It is half the angle between lines G2-G3 and G3-B; ; ; ; ; ; ; .

[0007] Furthermore, in step 5, the optimization algorithm is the non-dominated sorting genetic algorithm NSGA-II.

[0008] Furthermore, in step 5, the range of variation of the key points is determined based on the spatial location that the slender pipe is allowed to appear in actual use; The radius of curvature of the key point varies from 10 mm to 30 mm.

[0009] Meanwhile, this invention also provides a rapid design system for the spatial orientation of slender pipes under random vibration environments, used to implement the aforementioned rapid design method for the spatial orientation of slender pipes under random vibration environments, characterized by: It includes the Optimization component, and the Calculator component, Abaqus component, OSCommand component and Data Exchanger component connected in sequence; The output of the Optimization component is connected to the input of the Calculator component; The second output of the Calculator component and the output of the Data Exchanger component are both connected to the input of the Optimization component; The first output of the Calculator component is connected to the input of the Abaqus component via a data flow method with a first execution condition; the second output of the Calculator component is connected to the input of the Optimization component via a data flow method with a second execution condition. The first execution condition is: the constraints between the fixed point and the adjacent key point are met, as well as the constraints between two adjacent key points. The second execution condition is: the constraint conditions between the fixed point and the adjacent key point are not met, as well as the constraint conditions between two adjacent key points. The Optimization component is used to determine whether the current constraint parameters are within the preset constraint rules, to optimize the current changing parameters within a given range of variation using a preset optimization algorithm, and to determine whether the random vibration result data meets the optimization objective. The Calculator component is used to determine whether the current changing parameters meet the constraints. If they do, the changing parameters are output to the Abaqus component; otherwise, the changing parameters are output to the Optimization component. The Abaqus component is used to carry a random vibration analysis model and obtain random vibration result data based on the optimized changing parameters; The OS Command component is used to store random vibration result data; The Data Exchanger component is used to read random vibration result data and output it to the Optimization component.

[0010] The beneficial effects of this invention are: 1. It solves the problem of accurately obtaining the spatial orientation of slender pipelines in liquid rocket propulsion systems that meet design requirements under heterogeneous random vibration environments, thus improving the reliability of pipeline orientation design.

[0011] 2. This patent proposes a rapid design process that combines numerical simulation and optimization analysis, which can realize the rapid design of the spatial routing of slender pipelines in liquid rocket propulsion systems, significantly improving the design efficiency of pipeline spatial routing and having important application prospects. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the spatial orientation of a slender pipe, including three key points, in an embodiment of a rapid design method for the spatial orientation of a slender pipe under random vibration environment according to the present invention. Figure 2 This is a schematic diagram of the architecture of an embodiment of the rapid design system for the spatial orientation of slender pipelines under random vibration environment according to the present invention; Figure 3 This is a schematic diagram of a random vibration analysis model of a slender pipe and the external mechanical environment at both ends of the pipe, in an embodiment of a rapid design method for the spatial orientation of a slender pipe under random vibration environment according to the present invention. a is a schematic diagram of the unsimplified model, and b is a schematic diagram of the simplified model. Figure 4This is a schematic diagram of the slender pipe before and after simplification in an embodiment of a rapid design method for the spatial orientation of a slender pipe under random vibration environment according to the present invention. a is a schematic diagram of the slender pipe before simplification, and b is a schematic diagram of the slender pipe after simplification. Figure 5 This is a schematic diagram of the external mechanical environment at both ends of the pipe before and after simplification in an embodiment of a rapid design method for the spatial orientation of a slender pipe under random vibration environment according to the present invention. a is a schematic diagram of the external mechanical environment at both ends of the pipe before simplification, and b is a schematic diagram of the external mechanical environment at both ends of the pipe after simplification. Figure 6 This is a schematic diagram of various parameters in an embodiment of the rapid design method for the spatial orientation of slender pipelines under random vibration environment according to the present invention. Detailed Implementation

[0013] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. 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.

[0014] This invention provides a rapid design method for the spatial orientation of slender pipes under random vibration conditions. The design method includes the following steps: Step 1: Obtain the fixed points at both ends of the slender pipe to be designed, multiple key points in the middle, and the radii of curvature at multiple key points. Select several key points and the radii of curvature at key points as variation parameters of the spatial direction of the slender pipe. At the same time, use the mass of the slender pipe to be designed as a constraint parameter. Step 2: Based on the distance between the fixed point and its adjacent key points, as well as the radius of curvature and the included angle at the adjacent key points, establish the constraint conditions between the fixed point and its adjacent key points. Step 3: Based on the distance between two adjacent key points, as well as the radius of curvature and the included angle at the two adjacent key points, establish the constraint conditions between the two adjacent key points. Step 4: Establish a random vibration analysis model that includes the slender pipe to be designed and the external mechanical environment at both ends of the pipe; Step 5: Determine whether the current changing parameters all meet the constraints established in Step 2 and Step 3. At the same time, determine whether the current constraint parameters meet the preset constraint rules. If they do not all meet the constraints, use the preset optimization algorithm to optimize the current changing parameters within the given range of change until they meet the constraints. If they all meet the constraints, obtain random vibration result data based on the optimized changing parameters through the random vibration analysis model. This data includes the maximum stress power spectrum in the analysis frequency band of the pipeline and the maximum stress RMS value of the entire analysis frequency band. Step 6: Determine whether the random vibration results data meet the optimization objective. If they do, the design is complete. If they do not, return to step 5 until the optimization objective is met. The optimization objective is to minimize the maximum stress power spectrum in the analysis frequency band of the pipeline and the maximum stress RMS value of the entire analysis frequency band.

[0015] In this embodiment, the invention is further described in detail through an example of rapid spatial design of slender pipes with three key points. A similar approach can be used to rapidly design the spatial orientation of slender pipes with other key points.

[0016] like Figure 1 As shown, the spatial orientation of the pipeline at the three key points is determined by the fixed point A, fixed point B, key point G1, key point G2, key point G3, and the radius of curvature R1 at key point G1, the radius of curvature R2 at key point G2, and the radius of curvature R3 at key point G3.

[0017] In Isight, an automated optimization design system for the spatial routing of slender pipelines is constructed through the orderly connection of the Optimization, Calculator, Abaqus, OS Command, and Data Exchanger components. (See...) Figure 2 The aforementioned rapid design method can be implemented through this system.

[0018] Specifically, the output of the Optimization component is connected to the input of the Calculator component; The second output of the Calculator component and the output of the Data Exchanger component are both connected to the input of the Optimization component; The first output of the Calculator component is connected to the input of the Abaqus component via a data flow method with a first execution condition; the second output of the Calculator component is connected to the input of the Optimization component via a data flow method with a second execution condition. The Optimization component is used to optimize the current changing parameters within a given range of variation using a preset optimization algorithm, determine whether the current constraint parameters are within the preset constraint rules, and determine whether the random vibration result data meets the optimization objective. The Calculator component is used to determine whether the current changing parameters meet the constraints. If they do, the changing parameters are output to the Abaqus component; otherwise, they are output to the Optimization component. The Abaqus component is used to mount a random vibration analysis model and obtain random vibration result data based on the optimized changing parameters; The OS Command component is used to store random vibration result data; The Data Exchanger component is used to read random vibration result data and output it to the Optimization component.

[0019] A stochastic vibration analysis model in the Abaqus components, including a slender pipe and the external mechanical environment at both ends of the pipe, is established. (See...) Figure 3 The data is then saved as a CAE file, which can be used to generate the corresponding ODB file through calculations using Abaqus components. The slender pipes are simulated using beam elements, see [link to relevant documentation]. Figure 4 The external mechanical environment at both ends of the pipeline is effectively simulated using beam elements, see [link / reference]. Figure 5 .

[0020] Open the Abaqus component interface, read the created CAE file into its input module, and input the spatial coordinates (X, Y, F, G) of keypoints G1, G2, and G3. G1 Y G1 Z G1 ), (X) G2 Y G2 Z G2 ), (X) G3 Y G3 Z G3 The curvature radii R1, R2, and R3 at each key point are defined as variables, serving as parameters for the spatial orientation of the slender pipe. The output module reads the odb output file specified in the created CAE file and defines the pipe model quality as a variable, serving as a constraint parameter for optimizing the spatial orientation of the slender pipe.

[0021] The OS Command component in Isight is used to call the Python program to read the data from the generated ODB result file, including the maximum stress power spectrum value in the analysis band of the pipeline and the maximum stress RMS value of the entire analysis band, and save it in the A.txt document.

[0022] The Data Exchanger component in Isight reads the generated A.txt file and extracts the results data, including the maximum stress power spectrum value in the analysis frequency band of the pipeline and the maximum stress RMS value of the entire analysis frequency band. Ultimately, the Data Exchanger component has all the variables needed for the pipeline spatial routing optimization design.

[0023] Open the Calculator component in Isight and calculate the following equations to obtain L1, L2, L3, L4, and L5 respectively. , , , of which (X A Y A Z A ), (X) B Y B Z B The coordinates of fixed points A and B are shown below: ; ; ; ; ; ; ; In the formula: and These are the constraints between a fixed point and its adjacent key points. and These are the constraints between two adjacent key points.

[0024] In Isight, create a conditionally executed data stream between the Calculator component and the input of the Abaqus component, with the following execution conditions: ; ; ; ; In Isight, create a conditionally executed data flow between the Calculator component and the input of the Optimization component, with the following execution conditions: ; ; ; ; Open the Optimization component in Isight, and select the Non-Dominated Sorting Genetic Algorithm (NSGA-II) as the optimization algorithm under the General Settings module.

[0025] Open the Optimization component in Isight, and under the Variable Settings module, select the spatial coordinates (X, Y, F, G) of each keypoint G1, G2, and G3. G1 Y G1 Z G1 ), (X) G2Y G2 Z G2 ), (X) G3 Y G3 Z G3 The curvature radii R1, R2, and R3 at each key point are used as design variables in the optimization process, while a reasonable expected range of variation is given.

[0026] Open the Optimization component in Isight, and create the following two optimization goals under the Target Settings module: The optimization objective 1 is to "minimize the maximum value of the stress power spectrum of the pipeline structure within the analysis frequency band"; The optimization objective 2 is to "minimize the maximum stress RMS value across the entire analysis frequency band".

[0027] In addition, the following supplementary requirements and explanations apply to the above content: 1. The radius of curvature R1 at key point G1 refers to the radius of the arc segment tangent to lines A-G1 and G1-G2 respectively; the radius of curvature R2 at key point G2 refers to the radius of the arc segment tangent to lines G1-G2 and G2-G3 respectively; the radius of curvature R3 at key point G3 refers to the radius of the arc segment tangent to lines G2-G3 and G3-B respectively.

[0028] 2. The components are connected by data streams. The input terminals of the Calculator and Optimization components, and the input terminals of the Calculator and Abaqus components are connected by conditional data streams. All other components are connected by unconditional data streams.

[0029] 3. In the created CAE model, slender pipes are modeled using circular annular beam elements with an inner radius of 2mm and an outer radius of 3mm. The model and the external mechanical environment at both ends of the pipe generally need to be connected using rigid elements. At the same time, the output of the model should include the Mises stress and its RMS value. In addition, the calculation efficiency of the CAE model has an important impact on the optimization efficiency of the pipe routing. Therefore, the CAE calculation model should be simplified as much as possible while meeting the accuracy requirements.

[0030] 4. The calculated distances L1, L2, L3, and L4 are the distances between fixed point A and key point G1, key point G1 and G2, key point G2 and G3, and key point G3 and fixed point B, respectively. It is half the angle between lines A-G1 and G1-G2. It is half the angle between lines G1-G2 and G2-G3. It is half the angle between lines G2-G3 and G3-B, see Figure 6 .

[0031] 5. The inequalities in the execution conditions include model coordination inequalities between fixed points and adjacent key points, and between adjacent key points.

[0032] 6. The locations of critical pipeline points G1, G2, and G3 should be determined separately for (X). G1 Y G1 Z G1 ), (X) G2 Y G2 Z G2 ), (X) G3 Y G3 Z G3 The range of variation is set, and the range of variation of R1, R2, and R3 is generally determined according to the actual pipeline cross-sectional size and the characteristics of the production process. For this example only, the range of variation of R1, R2, and R3 is 10mm to 30mm.

[0033] 7. The length of the slender pipe is controlled by the ratio of the straight-line distance between the two fixed points A and B. In this embodiment, the length is required to be no more than 1.5 times the straight-line distance between the two fixed points A and B. Therefore, the mass of the pipe model is given to be no more than 1.5 times the mass of the straight pipe between the two fixed points A and B. This setting is determined by the designer's requirements for the length of the slender pipe.

[0034] 8. The two optimization objectives are established to improve the adaptability of the pipeline structure to the vibration environment by reducing the maximum value of the stress power spectrum and the maximum stress RMS value in the analysis frequency band.

[0035] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A rapid design method for the spatial orientation of slender pipes under random vibration conditions, characterized in that, Includes the following steps: Step 1: Obtain the fixed points at both ends of the slender pipe to be designed, multiple key points in the middle, and the radii of curvature at multiple key points. Select several key points and the radii of curvature at key points as variation parameters of the spatial direction of the slender pipe. At the same time, use the mass of the slender pipe to be designed as a constraint parameter. Step 2: Based on the distance between the fixed point and its adjacent key points, as well as the radius of curvature and the included angle at the adjacent key points, establish the constraint conditions between the fixed point and its adjacent key points. Step 3: Based on the distance between two adjacent key points, as well as the radius of curvature and the included angle at the two adjacent key points, establish the constraint conditions between the two adjacent key points. Step 4: Establish a random vibration analysis model that includes the slender pipe to be designed and the external mechanical environment at both ends of the pipe; Step 5: Determine whether the current changing parameters meet the constraints established in Steps 2 and 3. Simultaneously, determine whether the current constraint parameters meet the preset constraint rules. If not, use a preset optimization algorithm to optimize the current changing parameters within the given range until they meet the requirements. If all parameters meet the requirements, obtain random vibration result data based on the optimized changing parameters using a random vibration analysis model. This data includes the maximum stress power spectrum value within the analysis frequency band on the pipeline and the maximum stress RMS value of the entire analysis frequency band. The constraint rule is: the mass of the designed slender pipeline does not exceed N times the mass of the straight pipeline between two fixed points, where N is greater than 1. Step 6: Determine whether the random vibration result data meets the optimization objective. If it does, the design is completed. If it does not, use the preset optimization algorithm to optimize the current variation parameters within the given variation range, and return to step 5 until the optimization objective is met. The optimization objective refers to minimizing the maximum stress power spectrum in the analysis frequency band of the pipeline and the maximum stress RMS value of the entire analysis frequency band.

2. The rapid design method for the spatial orientation of slender pipelines under random vibration environment according to claim 1, characterized in that: In step 1, the slender pipe to be designed is a pipe containing three key points; Define the two fixed points at the ends of the slender pipe to be designed as fixed point A and fixed point B, respectively, and their spatial coordinates as (X, Y, Z, Y, Z). A Y A Z A ), (X) B Y B Z B The three key points are key point G1, key point G2, and key point G3, and their spatial coordinates are (X, G1, G2, and G3). G1 Y G1 Z G1 ), (X) G2 Y G2 Z G2 ), (X) G3 Y G3 Z G3 The radii of curvature at the three key points are R1, R2, and R3, respectively. In steps 2 and 3, the constraints between the fixed point and its adjacent key points, as well as the constraints between two adjacent key points, are as follows: ； ； ； ； In the formula: and These are the constraints between a fixed point and its adjacent key points. and These are the constraints between two adjacent key points; It is half the angle between lines A-G1 and G1-G2. It is half the angle between lines G1-G2 and G2-G3. It is half the angle between lines G2-G3 and G3-B; ； ； ； ； ； ； 。 3. The rapid design method for the spatial orientation of slender pipelines under random vibration environment according to claim 1 or 2, characterized in that: In step 5, the optimization algorithm is the non-dominated sorting genetic algorithm NSGA-II.

4. The rapid design method for the spatial orientation of slender pipelines under random vibration environment according to claim 3, characterized in that: In step 5, the range of variation of the key points is determined based on the spatial location that the slender pipe is allowed to appear in actual use; The radius of curvature of the key point varies from 10 mm to 30 mm.

5. A rapid design system for the spatial orientation of slender pipes under random vibration environment, used to implement the rapid design method for the spatial orientation of slender pipes under random vibration environment as described in any one of claims 1-4, characterized in that: It includes the Optimization component, and the Calculator component, Abaqus component, OS Command component and Data Exchanger component connected in sequence; The output of the Optimization component is connected to the input of the Calculator component; The second output of the Calculator component and the output of the Data Exchanger component are both connected to the input of the Optimization component; The first output of the Calculator component is connected to the input of the Abaqus component via a data flow method with a first execution condition; the second output of the Calculator component is connected to the input of the Optimization component via a data flow method with a second execution condition. The first execution condition is: the constraints between the fixed point and the adjacent key point are met, as well as the constraints between two adjacent key points. The second execution condition is: the constraint conditions between the fixed point and the adjacent key point are not met, as well as the constraint conditions between two adjacent key points. The Optimization component is used to determine whether the current constraint parameters are within the preset constraint rules, to optimize the current changing parameters within a given range of variation using a preset optimization algorithm, and to determine whether the random vibration result data meets the optimization objective. The Calculator component is used to determine whether the current changing parameters meet the constraints. If they do, the changing parameters are output to the Abaqus component; otherwise, the changing parameters are output to the Optimization component. The Abaqus component is used to carry a random vibration analysis model and obtain random vibration result data based on the optimized changing parameters; The OS Command component is used to store random vibration result data; The Data Exchanger component is used to read random vibration result data and output it to the Optimization component.

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