阅读说明：本技术 一种基于dic的液压管路接头侧向力测试方法 (Hydraulic pipeline joint lateral force testing method based on DIC ) 是由 侯磊 陈毅 昌泽元 梁廷伟 徐浚之 靳宇宏 于 2021-01-11 设计创作，主要内容包括：本发明涉及一种基于DIC的液压管路接头侧向力测试方法,包括如下步骤：步骤一、采用DIC双目识别测振系统测量液压管路接头位移；步骤二、根据测试所得的位移数据,采用Abaqus有限元仿真软件,计算液压管路接头侧向力。本发明采用DIC双目识别测振系统,直接检测管路指定位置的位移,可检测的范围广,且能获取较长时间段内管路的振动情况。而后通过数据分析,得到液压管路的振动位移和相对位移,并结合有限元仿真,计算指定的管路位置的侧向力。(The invention relates to a hydraulic pipeline joint lateral force testing method based on DIC, which comprises the following steps: measuring displacement of a hydraulic pipeline joint by adopting a DIC binocular identification vibration measurement system; and step two, calculating the lateral force of the hydraulic pipeline joint by adopting Abaqus finite element simulation software according to the displacement data obtained by testing. The invention adopts the DIC binocular recognition vibration measurement system to directly detect the displacement of the specified position of the pipeline, has wide detectable range and can acquire the vibration condition of the pipeline in a longer time period. And then, obtaining the vibration displacement and the relative displacement of the hydraulic pipeline through data analysis, and calculating the lateral force of the specified pipeline position by combining finite element simulation.)

1. A hydraulic pipeline joint lateral force testing method based on DIC is characterized by comprising the following steps:

measuring displacement of a hydraulic pipeline joint by adopting a DIC binocular identification vibration measurement system;

and step two, calculating the lateral force of the hydraulic pipeline joint by adopting Abaqus finite element simulation software according to the displacement data obtained by testing.

2. The hydraulic pipeline joint lateral force testing method based on the DIC as described in claim 1, wherein in the first step, the DIC binocular recognition vibration measurement system measures the displacement of the hydraulic pipeline joint in the following specific manner:

calculating the size of speckles according to the geometric characteristics of the pipeline, and manufacturing the speckles;

installing imaging equipment and then calibrating;

and starting the DIC system to shoot software to record data.

And (5) performing data analysis by using software in the DIC system to obtain vibration information of the experimental object.

3. The hydraulic pipeline joint lateral force testing method based on DIC as claimed in claim 2, wherein in the first step, when the imaging device is installed, a tripod head, a camera, a lens, a connecting line, a light source and camera position and parameters are installed in sequence, so that the camera can image clearly.

4. The DIC-based hydraulic pipeline joint lateral force testing method of claim 2, wherein in the first step, a calibration plate is selected for calibration, and after calibration is completed, the camera position is not changed.

5. The hydraulic pipeline joint lateral force testing method based on DIC as claimed in claim 2, wherein in the first step, Vic-3D software in DIC system is opened to perform data analysis, and information of displacement, frequency spectrum and strain of experimental object is obtained.

6. The DIC-based hydraulic pipeline joint lateral force testing method of claim 1, wherein the second step is implemented as follows:

establishing a simulation model according to the size and the shape of the hydraulic pipeline joint;

setting analysis time and step length according to different measuring objects;

assembling the model, considering the displacement of a reference point as zero according to the principle of relative displacement, applying lateral uniform force to the section to be solved by adopting solid support constraint, wherein the product of the uniform force and the area of the section is the magnitude of the applied lateral force;

carrying out mesh division on the model, and setting unit attributes, mesh shapes and seed numbers;

submitting and analyzing the model to obtain a displacement cloud picture, a support reaction cloud picture, stress, a strain cloud picture and the like, and obtaining required data such as lateral force of a hydraulic pipeline joint and the like;

and comparing the displacement of the section to be solved obtained in the displacement cloud picture with the actually measured displacement, and multiplying the applied lateral force by a proportionality coefficient according to a linear correlation principle to obtain the actual lateral force of the hydraulic pipeline joint.

Technical Field

The invention belongs to the field of hydraulic pipelines, and particularly relates to a hydraulic pipeline joint lateral force testing method based on DIC.

Background

In recent years, as hydraulic systems are increased in pressure and high power, the vibration problem of hydraulic pipelines is gradually prominent, and the pipeline joint lateral force caused by vibration is often an important cause of pipeline joint failure. At present, the calculation of the lateral force of the pipeline joint is mainly realized through theoretical analysis and finite element simulation, models of the pipeline joint need to be simplified, and the calculation result often cannot be well matched with the actual engineering problem.

Modern hydraulic pressure pipeline is because power is high, and pressure is big, and in the course of the work, the pipeline often can take place comparatively violent vibration, produces great yawing force, causes the pipeline joint to destroy, causes oil leak and oil leakage scheduling problem. At present, analysis aiming at hydraulic pipeline vibration is mostly based on theoretical analysis and finite element analysis, the two methods can analyze the vibration condition of the pipeline and show the vibration mechanism of the pipeline, but because the model of the method is often required to be simplified and always has deviation with actual engineering application, the method is sometimes not well suitable for engineering practical problems. Some scholars also test the vibration strain of the hydraulic pipeline by adopting an experimental method, and further obtain the stress of the pipeline through the constitutive relation, and most of the experimental methods are tests by using strain gauges.

When the vibration analysis of the hydraulic pipeline is performed by using theoretical analysis or finite element simulation, the model of the hydraulic pipeline usually needs to provide some basic assumptions and is simplified to a certain extent, and sometimes the model cannot represent the actual engineering condition. The existing stress experiment testing method for the hydraulic pipeline mainly uses a strain gauge to carry out testing, and the method has the defects that the strain gauge has errors, dangerous points need to be judged in advance, strain of partial points of the pipeline can be obtained only by using the strain gauge, the error is relatively large in use, and the measurable range is small.

Disclosure of Invention

The invention aims to solve the technical problems and further provides a hydraulic pipeline joint lateral force testing method based on DIC, which comprises the following steps:

measuring displacement of a hydraulic pipeline joint by adopting a DIC binocular identification vibration measurement system;

and step two, calculating the lateral force of the hydraulic pipeline joint by adopting Abaqus finite element simulation software according to the displacement data obtained by testing.

In the first step, the concrete mode of measuring the displacement of the hydraulic pipeline joint by the DIC binocular recognition vibration measurement system is as follows:

calculating the size of speckles according to the geometric characteristics of the pipeline, and manufacturing the speckles;

installing imaging equipment and then calibrating;

and starting the DIC system to shoot software to record data.

And (5) performing data analysis by using software in the DIC system to obtain vibration information of the experimental object.

In the first step, when the imaging device is installed, the tripod head, the camera, the lens and the connecting circuit are installed in sequence, and the light source is installed, and the position and the parameters of the camera are adjusted so that the camera can clearly image.

In the first step, a calibration plate is selected for calibration, and the position of the camera is not changed after calibration is completed.

In the first step, Vic-3D software in a DIC system is opened, data analysis is carried out, and information of displacement, frequency spectrum and strain of an experimental object is obtained.

The specific implementation steps in the second step are as follows:

establishing a simulation model according to the size and the shape of the hydraulic pipeline joint;

setting analysis time and step length according to different measuring objects;

assembling the model, considering the displacement of a reference point as zero according to the principle of relative displacement, applying lateral uniform force to the section to be solved by adopting solid support constraint, wherein the product of the uniform force and the area of the section is the magnitude of the applied lateral force;

carrying out mesh division on the model, and setting unit attributes, mesh shapes and seed numbers;

submitting and analyzing the model to obtain a displacement cloud picture, a support reaction cloud picture, stress, a strain cloud picture and the like, and obtaining required data such as lateral force of a hydraulic pipeline joint and the like;

and comparing the displacement of the section to be solved obtained in the displacement cloud picture with the actually measured displacement, and multiplying the applied lateral force by a proportionality coefficient according to a linear correlation principle to obtain the actual lateral force of the hydraulic pipeline joint.

Advantageous effects

The invention adopts the DIC binocular recognition vibration measurement system to directly detect the displacement of the specified position of the pipeline, has wide detectable range and can acquire the vibration condition of the pipeline in a longer time period. And then, obtaining the vibration displacement and the relative displacement of the hydraulic pipeline through data analysis, and calculating the lateral force of the specified pipeline position by combining finite element simulation.

Drawings

FIG. 1 is a schematic diagram of a hydraulic pump pipeline joint of a high-pressure fracturing truck engine in an embodiment of the invention;

FIG. 2 is a diagram illustrating displacement of a hydraulic pump line connector during engine start in an embodiment of the present invention;

FIG. 3 is a displacement diagram of the hydraulic pump line connector when the engine is operating steadily according to the embodiment of the present invention;

FIG. 4 is a diagram illustrating relative displacement of the hydraulic pump line connector when the engine is started according to an embodiment of the present invention;

FIG. 5 is a diagram illustrating the relative displacement of the hydraulic pump line connector during steady operation of the engine according to an embodiment of the present invention;

fig. 6 is a schematic diagram of the range of lateral forces of a hydraulic pump pipeline joint in the embodiment of the invention.

Detailed Description

The invention discloses a hydraulic pipeline joint lateral force testing method based on DIC, which comprises the following steps:

measuring displacement of a hydraulic pipeline joint by adopting a DIC binocular identification vibration measurement system;

calculating the size of speckles according to the geometric characteristics of the pipeline, and manufacturing the speckles;

installing imaging equipment and then calibrating;

and starting the DIC system to shoot software to record data.

And (5) performing data analysis by using software in the DIC system to obtain vibration information of the experimental object.

When the imaging device is installed, a tripod head, a camera, a lens and a connecting circuit are installed in sequence, and a light source is installed, and the position and parameters of the camera are adjusted so that the camera can image clearly.

And selecting a calibration plate for calibration, and after the calibration is finished, not changing the position of the camera.

And opening Vic-3D software in the DIC system, and performing data analysis to obtain information of displacement, frequency spectrum and strain of the experimental object.

And step two, calculating the lateral force of the hydraulic pipeline joint by adopting Abaqus finite element simulation software according to the displacement data obtained by testing.

Establishing a simulation model according to the size and the shape of the hydraulic pipeline joint;

setting analysis time and step length according to different measuring objects;

assembling the model, considering the displacement of a reference point as zero according to the principle of relative displacement, applying lateral uniform force to the section to be solved by adopting solid support constraint, wherein the product of the uniform force and the area of the section is the magnitude of the applied lateral force;

carrying out mesh division on the model, and setting unit attributes, mesh shapes and seed numbers;

submitting and analyzing the model to obtain a displacement cloud picture, a support reaction cloud picture, stress, a strain cloud picture and the like, and obtaining required data such as lateral force of a hydraulic pipeline joint and the like;

and comparing the displacement of the section to be solved obtained in the displacement cloud chart with the actually measured displacement, and multiplying the applied lateral force by a proportionality coefficient according to a linear correlation principle to obtain the actual lateral force of the hydraulic pipeline joint.

The present embodiment will be described below with reference to fig. 1 to 6.

In the present embodiment, a hydraulic pump pipeline of a fracturing truck is taken as an example, and a hydraulic pump pipeline joint is shown in fig. 1.

In order to conveniently describe the vibration of the pipeline joint, a coordinate system of the pipeline is established, wherein the coordinate system is that the X direction is positive, the horizontal direction is rightward, the direction is opposite to the advancing direction of a vehicle body, the Y direction is positive, the vertical direction is upward, and the Z direction and the former two form a right-hand system.

The DIC binocular vibration measurement system is adopted for testing, VIC-3D software matched with the system is used for data analysis, vibration displacement time history curves of the pipeline joint are respectively drawn when the engine is started and when the engine stably runs, and 1s time history is respectively intercepted, as shown in fig. 2 and 3.

As can be seen from fig. 2, when the engine is started, the hydraulic pump pipeline joint generates relatively severe vibration, and the duration of the large vibration is relatively long, which is about 0.5 s. It P is₁Maximum vibration displacement of 0.86mm, P, in the x-direction of the point₀The maximum vibration displacement in the x-direction of the point is 0.73mm and P is the maximum vibration displacement in the whole starting process₀Vibration displacement of point is always than P₁The small point indicates that the vibration at the joint of the hydraulic pump pipeline is stronger during the starting process, and the closer to the pump end, the smaller the vibration amplitude.

As can be seen from fig. 3, when the engine is in steady operation, the vibration amplitude of the hydraulic pump pipeline joint is smaller than that of the engine in starting. It P is₁Maximum vibration displacement of 0.23mm, P, in the x-direction of the point₀The maximum vibration displacement in the x direction of the point is 0.14mm, and when the engine runs stably, P is₁The vibration displacement in the x direction of the point is always in a ratio P₀The dots are large.

According to the calculation results of the displacement, the x direction P at the joint of the hydraulic pump pipeline is calculated when the engine is started and stably runs respectively₁Point relative to P₀The relative displacement of the dots is shown in fig. 4 and 5.

As can be seen from FIG. 4, during engine start-up, the hydraulic pump line junction is at the x-direction P₁Point relative to P₀The relative displacement of the point changes along with the displacement change of the pipeline joint, and within the time length of about 0.4s, the relative displacement amplitude is large, the positive maximum relative displacement is 0.268mm, and the negative maximum relative displacement is 0.083 mm. As can be seen from FIG. 5, when the engine is running stably, the hydraulic pump pipeline joint is in the x direction P₁Point relative to P₀The relative displacement amplitude of the point is small, at the moment, the maximum relative displacement amplitude is 0.131mm, and the minimum relative displacement amplitude is 0.065 mm.

And calculating the relative displacement of the pipeline joint of the hydraulic pump of the high-pressure fracturing truck according to the measured vibration displacement of the pipeline joint, and further calculating the lateral force of the pipeline joint under the working conditions according to the calculation result and relevant knowledge of material mechanics. Wherein, the material of hydraulic pressure pipeline joint is 45 steel. According to the material parameters and the geometric parameters of the pipeline joint, the relative displacement of each point at the pipeline joint under the current working condition is obtained through finite element simulation calculation, then the lateral force at the pipeline joint can be further obtained through simulation, and the range of the lateral force at the pipeline joint is shown in figure 6.

As shown in fig. 6, during engine start-up, the maximum positive side force at its hydraulic pump line connection is 17836N and the maximum negative side force is 5524N; when the engine runs stably, the maximum positive lateral force at the hydraulic pump pipeline joint is 8719N, and the minimum positive lateral force is 4326N.

In conclusion, during the no-load process, in the starting process of the engine, the pipeline joint of the hydraulic pump can generate severe vibration, and generate large vibration displacement and relative displacement, so that the lateral force is large; when the engine runs stably, the vibration displacement and the relative displacement of the hydraulic pump pipeline joint are small, and the lateral force is also small.

The above-mentioned embodiments are only preferred embodiments of the present invention, and are not intended to limit the embodiments of the present invention, and those skilled in the art can easily make various changes and modifications according to the main concept and spirit of the present invention, so the protection scope of the present invention shall be subject to the protection scope of the claims.