Spatial special-shaped pipeline test system and test method

Abstract

The present invention provides a spatial special-shaped pipeline test system and test method, including an integral base, a sealing flange, a fixed clamp, a thrust clamp, a fixed bracket and a thrust bracket; the bottom surface of the integral base is adapted to the size of the vibration table slide, and the sealing flange, the fixed clamp, the fixed bracket and the thrust bracket are all installed on the top surface of the integral base; the sealing flange is sealed and connected to the pipe mouth of the pipeline, and at least two sealing flanges are provided on the top surface of the integral base; the fixed clamp is installed on the fixed bracket, and the fixed clamp is engaged with the pipeline; the thrust clamp is installed on the thrust bracket, and the thrust clamp is engaged with the pipeline. The pipeline meets the external dimensions and test requirements, and the tooling itself meets the strength verification requirements. The entire test system is easy to install, the spatial layout is reasonable, and the energy transfer can be maximized by monitoring the center of mass of the pipeline. A fixed-frequency test method combining high and low frequencies is adopted to ensure the smooth completion of the fixed-frequency test.

Description

Technical Field

[0001] The present invention relates to the field of pipeline vibration testing, and in particular to a spatial special-shaped pipeline testing system and a testing method. Background Art

[0002] Pipeline strength testing is an important part of pipeline system development. For example, a dual-cryogenic launch vehicle uses liquid oxygen and liquid methane as propellants, and the second stage adopts a self-generated pressurization scheme. The pipeline system that affects the success or failure, such as the delivery pipe, return pipe and boost pipe, is subjected to loads such as pressure, temperature deformation, and vibration. However, the shape of these pipelines is usually spatially irregular. When conducting vibration tests, a gantry needs to be built to meet the boundary constraints, making the construction of the entire test system relatively cumbersome.

[0003] The existing Chinese patent application with publication number CN104879348A discloses a hydraulic pipeline vibration test simulation experimental platform, which includes a vibration excitation unit, a hydraulic power unit, a sensor detection system, a control unit and a signal acquisition and processing unit; the vibration excitation unit includes a workbench and an industrial computer, two vibration tables are placed on the workbench, and the pipeline to be tested is fixed on the vibration table. Accelerometers, strain gauges and fiber grating sensors are installed in the pipeline to be tested; the hydraulic power unit is provided with a proportional flow valve, a proportional relief valve and a digital switch valve; the sensor detection system includes a temperature sensor and a pressure sensor, both of which are arranged on the vibration table; the signal acquisition and processing unit is connected to the sensor detection system and the sensors in the hydraulic power unit.

[0004] The inventor believes that there is an urgent need for a pipeline testing system that can not only meet the pipeline's external dimensions and test requirements (the entire pipeline system can meet low-temperature and pressure test requirements), but also ensure that the device itself meets the strength verification requirements, while making the entire system more convenient to install and the spatial layout more reasonable. Summary of the Invention

[0005] In view of the defects in the prior art, the purpose of the present invention is to provide a spatial special-shaped pipeline testing system and testing method.

[0006] According to the present invention, a spatial special-shaped pipeline test system includes an integral base, a sealing flange, a fixing clamp, a thrust clamp, a fixing bracket and a thrust bracket; the bottom surface of the integral base is adapted to the size of the vibration table slide, and the sealing flange, fixing clamp, fixing bracket and thrust bracket are all installed on the top surface of the integral base; the sealing flange is sealed with the pipe mouth of the pipeline, and at least two sealing flanges are provided on the top surface of the integral base; the fixing clamp is installed on the fixing bracket, and the fixing clamp is clamped and matched with the pipeline; the thrust clamp is installed on the thrust bracket, and the thrust clamp is clamped and matched with the pipeline.

[0007] Preferably, the length and width of the integral base, the size and angle of the sealing flange, the size and angle of the fixing clamp, the size and angle of the thrust clamp, and the height of the fixing bracket and the thrust bracket are all compatible with the pipeline.

[0008] Preferably, the center of mass of the overall structure of the integral base does not exceed the boundary of the bottom surface of the integral base.

[0009] Preferably, a connecting surface between the sealing flange and the integral base is provided with an arc-shaped U-shaped hole.

[0010] Preferably, a side of the integral base facing away from the top surface is provided with vertically and horizontally intersecting fence-like reinforcement ribs.

[0011] Preferably, the pipeline meets the requirements of low temperature and pressure testing.

[0012] Preferably, the centroid of the pipeline is used as the monitoring point, and the acceleration transmissibility of the entire system is tested under random vibration excitation of the pipeline at the same magnitude and at different centroid heights of the pipeline at the same frequency; m+1 groups of data (a0, b0), (a1, b1), (a2, b2), ..., (a m , b m ), where a i (i=0,1,…,m) represents the centroid height of the pipeline, b i (i=0, 1, ..., m) represents the magnitude of the acceleration transfer rate; a polynomial order fitting is performed on these m+1 groups of data to obtain the fitting polynomial f(x) and draw a curve graph, and the point with the largest acceleration transfer rate is determined from the curve graph to determine the optimal height of the pipeline center of mass.

[0013] Preferably, the fitting polynomial is f(x)=α5x 5 +…+α1x+α0, let X=[x 5 ,...,x,1], A=[α5,...,α1,α0] T , then f(x) can be written as f(x) = X·Α; according to the principle of least squares method, find A = [α5,…,α1,α0] T , so that the residual function The value of is the smallest, where It means to sum the square of the difference between the fifth-order polynomial fitting value and the acceleration transmissibility at the corresponding center of mass height, which is converted into the problem of finding the extreme value of r(α0, ​​α1, …, α5);

[0014] According to the necessary conditions for finding the extreme value of multivariate function, the residual function of α j Partial derivatives of :

[0015]

[0016] Right now

[0017]

[0018] Equation (2) is a linear equation system about α0, α1, ..., α5, which can be expressed as a matrix:

[0019]

[0020] The coefficient matrix of equation (3) is a symmetric positive definite matrix, so there is a unique solution. i (i=0, 1, ..., 6) thus obtaining the fitting polynomial f(x)=α6x 6 +α5x 5 +…+α1x+α0.

[0021] According to a test method for a spatial special-shaped pipeline test system provided by the present invention, the test method includes the following steps: S1, installing the test system: fixing the pipeline on the entire test system tooling; S2, dividing the test frequency bands into multiple test bands according to the requirements of the segmented fixed-frequency test, and comparing the actual test results with the test requirements; S3, combining the multiple frequency bands according to high and low frequencies, and comparing the actual test results with the test requirements; S4, if the test result of step S3 is not ideal, readjusting according to the principle of combining high and low frequencies, and comparing the actual test results with the test requirements until the problem of insufficient energy transfer of the vibration table is solved.

[0022] Preferably, regarding S1: after determining the optimal height of the center of mass of the pipeline, first install the integral base on the vibration table, then install the sealing flange, fixed bracket and thrust bracket on the integral base, then install the fixed clamp on the fixed bracket, install the thrust clamp on the thrust bracket, and finally fix the pipeline on the entire tooling.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention fixes and installs the pipeline through a tooling consisting of an integral base, a sealing flange, a fixed bracket, a thrust bracket, a fixed clamp and a thrust clamp. The pipeline meets the external dimensions and test requirements, and the tooling itself meets the strength verification requirements. The entire test system is easy to install, the space layout is reasonable, and by monitoring the center of mass of the pipeline, energy transfer can be maximized.

[0025] 2. The present invention adopts an integrally processed sealing flange to ensure that the pipeline can pass the test safely and smoothly under pressure.

[0026] 3. The present invention provides an arc-shaped U-shaped hole on the connection surface E1 between the sealing flange and the integral base, thereby increasing the rotational freedom of the connection between the tooling and the pipeline, and combines it with the on-site punching method to quickly and conveniently fix the pipeline sealing surface and the other connection surface E2 of the sealing flange.

[0027] 4. The present invention adjusts the height of the fixing bracket, the angle of the fixing clamp connection surface F1, the height of the thrust bracket, and the angle of the thrust clamp connection surface G1 according to the installation status of the pipeline, which can meet the installation requirements of different pipelines and improve the applicability of the test system.

[0028] 5. The present invention solves the problem that the total mass of the spatial special-shaped pipeline test system is close to the thrust of the vibration table or approaches the limit of the vibration table's thrust capacity by adopting a fixed-frequency test method that combines high and low frequencies, thereby reducing the difficulty of performing the fixed-frequency test and ensuring the smooth completion of the fixed-frequency test. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0030] Figure 1 This is a schematic diagram of the overall structure of the spatial special-shaped pipeline test system mainly embodied in the present invention;

[0031] Figure 2 This is a schematic diagram showing the overall structure of the integral base of the present invention;

[0032] Figure 3 This is a schematic diagram of the overall structure of the sealing flange mainly embodied in the present invention;

[0033] Figure 4 This is a schematic diagram mainly showing the overall structure of the fixing clamp of the present invention;

[0034] Figure 5 This is a schematic diagram of the overall structure of the fixing bracket mainly embodied in the present invention;

[0035] Figure 6 This is a schematic diagram mainly showing the overall structure of the thrust clamp of the present invention;

[0036] Figure 7 This is a schematic diagram mainly showing the overall structure of the thrust bracket of the present invention.

[0037] As shown in the figure:

[0038] Overall base 1 Fixed bracket 4

[0039] Sealing flange 2 Thrust clamp 5

[0040] Fixing clamp 3 Thrust bracket 6 DETAILED DESCRIPTION

[0041] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0042] Example 1

[0043] like Figure 1 As shown, a spatial special-shaped pipeline testing system provided by the present invention includes an integral base 1, a sealing flange 2, a fixing clamp 3, a thrust clamp 5, a fixing bracket 4, and a thrust bracket 6. The bottom surface of the integral base 1 is adapted to the size of the vibration table slide, and the sealing flange 2, fixing clamp 3, fixing bracket 4, and thrust bracket 6 are all mounted on the top surface of the integral base 1.

[0044] The sealing flange 2 is sealedly connected to the pipe opening of the pipeline, and at least two sealing flanges 2 are provided on the top surface of the integral base 1 .

[0045] The fixing clamp 3 is mounted on the fixing bracket 4, and the fixing clamp 3 is engaged with the pipeline. The thrust clamp 5 is mounted on the thrust bracket 6, and the thrust clamp 5 is engaged with the pipeline.

[0046] Specifically, the length and width of the integral base 1, the dimensions and angles of the sealing flange 2, the dimensions and angles of the fixing clamp 3, the dimensions and angles of the thrust clamp 5, and the heights of the fixing bracket 4 and thrust bracket 6 are all adapted to the pipeline. The length and width of the integral base 1 are selected based on the actual operating conditions of the pipeline, minimizing its weight while ensuring sufficient strength.

[0047] Furthermore, a side of the integral base 1 facing away from the top surface is provided with vertical and horizontal cross-fence type reinforcement ribs, which can ensure the load-bearing strength and bending and torsional resistance of the tooling.

[0048] When the length of the top surface of the integral base 1 exceeds the maximum length of the slide of the vibration table, considering that the connection between the vibration table bull head and the slide limits the installation of the integral base 1A end, it is necessary to use the length of the integral base 1B end to make up the total length, so that the integral base 1 forms an asymmetrical structure on the left and right. And the design of the integral base 1 needs to ensure that the center of mass of the overall structure of the integral base 1 does not exceed the boundary of the bottom surface of the integral base 1. Specifically, the shape of the bottom surface of the integral base 1 of the present application is approximately rectangular, and it has four plane boundaries, namely C1 surface, C2 surface, C3 surface and C4 surface, that is, the center of mass of the overall structure cannot exceed any of the above-mentioned plane boundaries.

[0049] The pipeline meets the requirements of low temperature and pressure testing. According to the temperature and pressure requirements of the entire pipeline system, measures such as pressurization and low temperature filling are implemented.

[0050] The sealing flange 2 is processed in an integral manner to ensure that the pipeline can pass the test safely and smoothly under pressure. The special-shaped pipeline of this application has two pipe openings, and two sealing flanges 2 are installed on the top surface of the integral base 1. When installed, the two sealing flanges 2 are connected to the two pipe openings of the special-shaped pipeline respectively.

[0051] Furthermore, a circular U-shaped hole is provided on the connection surface E1 between the sealing flange 2 and the integral base 1, thereby increasing the rotational freedom of the connection between the tooling and the pipeline, and combined with the on-site punching method, the pipeline sealing surface and the other connection surface E2 of the sealing flange 2 can be quickly and conveniently fixed.

[0052] The connections between the fixed bracket 4 and the integral base 1, the thrust bracket 6 and the integral base 1, the fixed clamp 3 and the fixed bracket 4, and the thrust clamp 5 and the thrust bracket 6 of this application are all detachable, employing screws, studs, and other commonly used detachable connection methods. Therefore, when installing the pipeline on the fixture, the height of the fixed bracket 4, the angle of the fixed clamp 3's connection surface F1, the height of the thrust bracket 6, and the angle of the thrust clamp 5's connection surface G1 can be adjusted according to the pipeline's installation state. The two sealing flanges 2, the fixed clamp 3, and the thrust clamp 5 cooperate to securely mount the pipeline on the integral base 1.

[0053] When the pipeline is installed on the tooling, the center of mass height of the entire pipeline can be changed by selecting integral bases 1, sealing flanges 2, fixing brackets 4, and thrust brackets 6 of different sizes. Taking the center of mass of the pipeline as the monitoring point, the acceleration transfer rate of the entire system can be tested under random vibration excitation of the same magnitude and at different center of mass heights of the pipeline at the same frequency.

[0054] Get m+1 groups of data (a0, b0), (a1, b1), (a2, b2), ..., (a m , b m ), where a i (i=0,1,…,m) represents the centroid height of the pipeline, b i (i = 0, 1, ..., m) represents the magnitude of the acceleration transmissibility;

[0055] Perform polynomial fitting on the m+1 sets of data to obtain a fitting polynomial f(x) and draw a curve graph. From the curve graph, determine the point with the maximum acceleration transfer rate and the optimal height of the pipeline center of mass.

[0056] This application uses seven sets of data as examples to illustrate:

[0057] Get seven sets of data (a0, b0), (a1, b1), (a2, b2), ..., (a6, b6), where a i (i=0, 1, ..., 6) represents the centroid height of the pipeline, b i (i = 0, 1, ..., 6) represents the magnitude of the acceleration transfer rate. The polynomial fitting is performed on these seven sets of data, and the fitting polynomial is f(x) = α5x 5 +…+α1x+α0. Let X=[x 5 ,...,x,1], A=[α5,...,α1,α0] T , then f(x) can be written as f(x)=X·Α.

[0058] According to the principle of least squares method, we now find A = [α5,…,α1,α0] T , so that the residual function The value of is the smallest, where It means to sum the square of the difference between the fifth-order polynomial fitting value and the acceleration transmissibility at the corresponding mass center height, which is transformed into the problem of finding the extreme value of r(α0, ​​α1, ..., α5). According to the necessary conditions for finding the extreme value of the multivariate function, the residual function is obtained for α j Partial derivatives of :

[0059]

[0060] Right now

[0061]

[0062] Equation (2) is a linear equation system about α0, α1, ..., α5, which can be expressed as a matrix:

[0063]

[0064] The coefficient matrix of equation (3) is a symmetric positive definite matrix, so there is a unique solution. Solve for α i (i=0, 1, ..., 6) thus obtaining the fitting polynomial f(x)=α6x 6 +α5x 5 +…+α1x+α0. A curve graph is drawn based on the obtained fitting polynomial f(x). From the graph, the point with the maximum acceleration transfer rate can be found, thereby determining the optimal height of the pipeline's center of mass, completing system optimization and ensuring maximum energy transfer.

[0065] Example 2

[0066] Based on Example 1, a test method for a spatial special-shaped pipeline test system provided by the present invention adopts the above-mentioned spatial special-shaped pipeline test system, and the test method includes the following steps:

[0067] S1. Install the test system: Secure the piping to the entire test system fixture. After determining the optimal height for the piping's center of mass, first install the integral base 1 on the vibration table. Next, install the sealing flange 2, fixed bracket 4, and thrust bracket 6 onto the integral base 1. Then, install the fixing clamp 3 onto the fixed bracket 4 and the thrust clamp 5 onto the thrust bracket 6. Finally, secure the piping to the entire fixture.

[0068] S2. According to the requirements of the segmented fixed-frequency test, divide the test frequency bands into multiple test bands for testing, and compare the actual test results with the test requirements. This application takes eleven frequency bands as an example, and first divides them into the first three frequency bands, the middle four frequency bands, and the last four frequency bands for testing, and compares the actual test results with the test requirements.

[0069] S3. Combine multiple frequency bands according to high and low frequencies and compare the actual test results with the test requirements. For example, divide the eleven frequency bands into bands 1, 2, and 11; bands 3, 4, 9, and 10; and bands 5, 6, 7, and 8, and compare the actual test results with the test requirements.

[0070] S4. If the test result of step S3 is not ideal, readjust according to the principle of combining high and low frequencies, and compare the actual test results with the test requirements until the problem of insufficient energy transfer of the vibration table is solved.

[0071] The above-mentioned fixed-frequency test method combining high and low frequencies solves the problem that the total mass of the spatial special-shaped pipeline test system is close to the thrust of the vibration table or is close to the limit of the vibration table's thrust capacity, thereby reducing the difficulty of the fixed-frequency test and ensuring the smooth completion of the fixed-frequency test.

[0072] How it works

[0073] By selecting integral bases 1, sealing flanges 2, fixed brackets 4, and thrust brackets 6 of different sizes to change the center of mass height of the entire pipeline, and taking the center of mass of the pipeline as the monitoring point, the acceleration transfer rate of the entire system is tested under random vibration excitation of the pipeline at the same magnitude and at different center of mass heights of the pipeline at the same frequency. The fitting polynomial f(x) is obtained and a curve graph is drawn. The point with the maximum acceleration transfer rate is determined from the curve graph, and the optimal height of the center of mass of the pipeline is determined to ensure maximum energy transfer. A fixed-frequency test method combining high and low frequencies is adopted to solve the problem that the total mass of the spatial special-shaped pipeline test system is close to the thrust of the vibration table or is close to the limit of the vibration table's pushing capacity.

[0074] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0075] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A test method for a spatial special-shaped pipeline test system, characterized in that: A spatial special-shaped pipeline test system is used, wherein the spatial special-shaped pipeline test system comprises an integral base (1), a sealing flange (2), a fixing clamp (3), a thrust clamp (5), a fixing bracket (4) and a thrust bracket (6); The bottom surface of the integral base (1) is adapted to the size of the vibration table slide, and the sealing flange (2), the fixing clamp (3), the fixing bracket (4) and the thrust bracket (6) are all mounted on the top surface of the integral base (1); The sealing flange (2) is sealedly connected to the pipe opening of the pipeline, and at least two sealing flanges (2) are provided on the top surface of the integral base (1); The fixing clamp (3) is mounted on the fixing bracket (4), and the fixing clamp (3) is engaged with the pipeline; The thrust clamp (5) is mounted on the thrust bracket (6), and the thrust clamp (5) is engaged with the pipeline; The test method includes the following steps: S1. Install the test system: Fix the pipeline to the entire test system tooling; S2. According to the requirements of the segmented fixed-frequency test, divide the test frequency bands into multiple test bands for testing and compare the actual test results with the test requirements; S3. Combine multiple frequency bands according to high and low frequencies and compare the actual test results with the test requirements; S4. If the test result of step S3 is not ideal, readjust according to the principle of combining high and low frequencies, and compare the actual test results with the test requirements until the problem of insufficient energy transfer of the vibration table is solved.

2. The test method of the spatial special-shaped pipeline test system according to claim 1, characterized in that: The spatial special-shaped pipeline test system uses the center of mass of the pipeline as the monitoring point to test the acceleration transmissibility of the entire system under random vibration excitation of the pipeline at the same magnitude and at different center of mass heights of the pipeline at the same frequency. Get m+1 groups of data (a0, b0), (a1, b1), (a2, b2), ..., (a m , b m ), where a i (i=0,1,…,m) represents the centroid height of the pipeline, b i (i = 0, 1, ..., m) represents the magnitude of the acceleration transmissibility; Perform polynomial fitting on the m+1 sets of data to obtain a fitting polynomial f(x) and draw a curve graph. From the curve graph, determine the point with the maximum acceleration transfer rate and determine the optimal height of the center of mass of the pipeline. Regarding S1: After determining the optimal height of the center of mass of the pipeline, first install the integral base (1) on the vibration table, then install the sealing flange (2), the fixed bracket (4) and the thrust bracket (6) on the integral base (1), then install the fixed clamp (3) on the fixed bracket (4), install the thrust clamp (5) on the thrust bracket (6), and finally fix the pipeline to the entire tooling.

Images