CN111412869B - Detection device and method for crack size of pressure-bearing shell wall based on gas leakage rate measurement - Google Patents
Detection device and method for crack size of pressure-bearing shell wall based on gas leakage rate measurement Download PDFInfo
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- CN111412869B CN111412869B CN202010302558.0A CN202010302558A CN111412869B CN 111412869 B CN111412869 B CN 111412869B CN 202010302558 A CN202010302558 A CN 202010302558A CN 111412869 B CN111412869 B CN 111412869B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B13/00—Measuring arrangements characterised by the use of fluids
- G01B13/02—Measuring arrangements characterised by the use of fluids for measuring length, width or thickness
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B13/00—Measuring arrangements characterised by the use of fluids
- G01B13/14—Measuring arrangements characterised by the use of fluids for measuring depth
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M3/00—Investigating fluid-tightness of structures
- G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
- G01M3/26—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
- G01M3/32—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for containers, e.g. radiators
- G01M3/3281—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for containers, e.g. radiators removably mounted in a test cell
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
- G06F17/11—Complex mathematical operations for solving equations, e.g. nonlinear equations, general mathematical optimization problems
Abstract
A device and a method for detecting the crack size of a pressure-bearing shell wall based on gas leakage rate measurement belong to the field of crack detection. The method is established according to a Rizkalla gas leakage equation, and the crack size is inverted by the gas leakage rate of the tiny through crack of the wall of the pressure-bearing shell, so that whether the through crack occurs in the area to be measured can be sensitively reflected. The device comprises a leakage response assembly, a closed cover, a pressure reduction device, an air pressure detection assembly, a photographic recording assembly, a processing assembly and a display assembly. When the device is used, the opening end of the leakage response assembly is attached to an area to be detected, the sealing cover surrounds a plurality of leakage response assemblies, and the air pressure in the sealing cover is reduced; the deformation of the elastic membrane is reflected through the position change of positioning points on the leakage response assembly and the air pressure detection assembly, and the gas leakage rate of the area to be detected and the air pressure in the closed cover are calculated respectively according to the deformation of the elastic membrane; and substituting the crack length extracted from the crack image recorded by the photographic recording component into the analysis model to obtain the comprehensive scale of the crack of the region to be measured of the shell wall.
Description
Technical Field
The invention belongs to the field of crack detection, and particularly relates to a device and a method for detecting the crack size of a pressure-bearing shell wall based on gas leakage rate measurement.
Background
In engineering structural analysis, the evaluation of the cracking condition of damaged structures is of great importance, and the functional damage of the shell structure is generally characterized by the cracking of the shell wall, particularly the through crack of the damaged shell wall, which can cause the accelerated leakage of gas in the sealed shell and cause safety accidents. The experimental research shows that the gas tightness of the intact shell is good, the damaged and damaged shell wall provides a passage for gas leakage, and the leakage rate can be increased by more than 40 times at times, but the shell is still in a low-speed leakage state.
The cracking surface of the pressure-bearing shell wall is generally not straight, the front edge of the cracking surface is not strictly along the normal direction of the structure surface, the opening and the depth of the crack are difficult to directly measure, and whether the cracking line penetrates through the shell wall is difficult to judge. At present, some crack detection technologies are still mainly direct detection methods, such as feature extraction of directly acquired crack images or images acquired through CT and ultrasonic signals, and measurement of crack sizes; and destructive indirect detection methods, such as extruding clay into a gap to form on a large cracked wall, and indirectly obtaining the opening degree of the gap by measuring the width of the clay. In engineering, besides the need of defining the form of the existing cracks, great attention is paid to the process from the development of the microcracks to the penetration, especially to the time when the cracks penetrate, which plays an important role in engineering early warning, and a simple and effective monitoring means is also lacked. The gas leakage rate of the pressure-bearing shell wall can be used as a sensitive indirect index for the development and penetration of cracks.
According to the method, the cracking degree of the shell wall is inverted according to the leakage rate measurement of the tiny through cracks, whether the through cracking occurs in a target area can be sensitively reflected, and accordingly, an effective mathematical model is established to estimate the comprehensive opening degree of the cracks of the damaged shell wall. In order to measure the gas leakage rate of the crack, the invention provides a method for indirectly calculating the leakage rate through the deformation of an elastic membrane caused by leakage airflow. The invention changes the traditional pressurizing mode at the inner side of the shell wall into the local depressurizing mode at the outer side, so that the detection of the large-scale shell structure is easier to operate, and the shell is prevented from being damaged again in the pressurizing process. Therefore, aiming at the problem of local cracking, the device and the method for detecting the crack size of the wall of the pressure-bearing shell based on gas leakage rate measurement are established, and the rapid monitoring technology in the field is effectively enriched.
Disclosure of Invention
The present invention is directed to an apparatus and method for detecting a crack size of a wall of a pressure-bearing housing based on a gas leakage rate measurement that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
The technical scheme of the invention is as follows:
a detection device for detecting the crack size of a pressure-bearing shell wall based on gas leakage rate measurement comprises a leakage response assembly 1, a closed cover 2, a pressure reduction device 3, an air pressure detection assembly 4, a photographic recording assembly 5, a processing assembly 6 and a display assembly 7;
the closed cover 2 is used for providing a closed detection environment; the pressure reduction device 3 is arranged on the side surface of the closed cover 2 and is used for reducing the air pressure in the closed cover 2; the air pressure detection assembly 4 is arranged on the side surface of the closed cover 2 and is used for detecting the air pressure in the closed cover 2 and comprises a cylinder, a distance sensor 43 and an elastic membrane B41; the wall of the cylinder is hermetically connected with the closed cover 2, the elastic membrane B41 is arranged at the inner end of the cylinder, the distance sensor 43 is arranged at the outer end of the cylinder, and the elastic membrane B41 is provided with a positioning point B42; the leakage response assembly 1 is arranged in the closed cover 2, comprises a cylinder and an elastic membrane A12 and is used for reflecting the gas leakage rate of the area to be measured through the shape change of the elastic membrane A12; the elastic membrane A12 is arranged at the inner end of the cylinder, the outer end of the cylinder is provided with an opening, the wall of the cylinder is provided with a pressure relief hole 14, and the outer surface of the elastic membrane A12 is provided with a plurality of positioning points A13;
the photographic recording component 5 is arranged on the top surface of the closed cover 2, the lens is opposite to the central position of the inner end of the cylinder of the leakage response component 1 and is used for recording a crack image in a region to be detected and the position of a positioning point A13, and the positioning point A13 can be used for correcting the position of the photographic recording component 5 during installation.
The processing component 6 is respectively connected with the air pressure detection component 4, the photography recording component 5 and the display component 7, and is used for receiving, storing, processing and displaying information and calculating the crack size.
The two ends of the pressure reduction device 3 are communicated and comprise a cylinder and a piston 31, and the cylinder wall of the cylinder is hermetically connected with the closed cover 2.
The leakage response assembly 1 and the closed cover 2 are both attached and sealed with the shell wall through sealing rings made of elastic materials.
The top surface of the closed cover 2 is transparent, and the elastic membrane A12 is transparent.
A method for detecting the crack size of a pressure-bearing shell wall based on gas leakage rate measurement comprises the following steps:
step one, fitting the opening end of the leakage response component 1 to an area to be detected; if the region to be measured has a through cracking surface, the elastic membrane A12 is deformed due to the leakage airflow;
step two, attaching the opening end of the closed cover 2 to the shell wall, and enclosing a plurality of leakage response assemblies 1; the photographic recording assembly 5 is arranged right above the leakage response assembly 1, the position change of a positioning point A13 on the elastic film A12 is recorded, and a crack image in a region to be detected is recorded;
thirdly, the photographing and recording component 5 and the distance sensor 43 are connected with the processing component 6 and transmit recorded information; the air pressure in the closed cover 2 is reduced through the pressure reducing device 3;
fourthly, calculating the change of the air pressure in the closed cover 2 according to the deformation amount of the elastic membrane B41 in the air pressure detection assembly 4; if the covering area of the closed cover 2 is provided with a through cracking surface, the air pressure in the closed cover 2 rises back along with the leakage of the gas, when the air pressure rises back to a set value, the processing component 6 records the deformation of the corresponding elastic membrane A12 on the leakage response component 1, calculates the corresponding gas leakage rate, and calculates the crack opening w of the area to be measured according to the recorded two groups of data by a formula (3); if the elastic membrane a12 on the leak-responsive component 1 is not deformed significantly all the time, it is considered that the crack surface in the detection area is not penetrated;
w＝2.4801×10-4×(2-logB A)-4.1152 (3)
wherein the content of the first and second substances,
P11、P21the air pressure inside and outside the shell wall is the first time; p12、P22The air pressure inside and outside the shell wall for the second time; q1、Q2The leakage rate of the crack under two different air pressure conditions is shown;
step five, acquiring the crack length from the crack image of the region to be detected recorded by the photographic recording component 5 by using a crack image processing technology, substituting the crack length l, the crack opening w calculated by a formula (3), the inside and outside air pressure values of the region to be detected under an air pressure condition and the corresponding leakage rate into an equation (1), and directly calculating the depth t of the crack:
wherein n is 0.133w-0.243,k＝2.907×107w1.284(ii) a μ represents the aerodynamic viscosity; r represents an ideal gas constant; t represents the absolute temperature of the environment; p1、P2Indicating the pressure at both sides of the shell wall where it is cracked; q represents the gas leakage rate of the crack; l, w and t represent the length, opening and depth of the crack respectively;
further estimating the inclination angle of the fracture surface according to the relation between the depth of the fracture and the thickness of the shell wall;
and step six, outputting the calculation result of the processing component 6 on the display component 7.
The formula (3) is obtained by calculating the crack opening according to the relation of the air pressure and the leakage rate of the area to be measured and deducing the calculation formula according to a Rizkalla crack gas leakage equation;
theoretically, the opening w of the crack can be inverted by the formula (1) through the primary measured values of the gas pressure at the two sides of the shell wall and the crack leakage rate, but the calculation is an iterative process, the calculation efficiency is not high, the gas leakage of the crack can cause the rise of the gas pressure in the closed cover, and the stable pressure difference-leakage relation is difficult to measure. Therefore, the invention improves the calculation method as follows:
if the air pressures at the inner and outer sides of the shell wall are changed, the leakage rate of the crack under two different air pressure conditions is measured to be Q1、Q2Simultaneously recording the air pressure value, substituting the obtained two groups of data into equation (1), and simultaneously using the equation
Wherein, P11、P21The air pressure inside and outside the shell wall is the first time; p12、P22The second air pressure inside and outside the shell wall. Dividing the formula (2.1) and the formula (2.2), eliminating equal terms, and finishing the equation to obtain the crack opening degree
w＝2.4801×10-4×(2-logB A)-4.1152 (3)
Wherein the content of the first and second substances,
it should be noted that, in the leakage model, the crack is treated as an equal-width crack, and although there is a certain difference from the actual uneven extension of the crack, the estimated crack size can objectively describe the development of the through-fracture surface to some extent.
The invention has the beneficial effects that: whether the target area of the shell wall generates the through crack or not can be sensitively reflected, and the through crack dimension of the target area is measured.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
Fig. 1 is a schematic diagram of a detection device for detecting the crack size of a wall of a pressure-bearing shell based on gas leakage rate measurement.
FIG. 2 is a flow chart of the detection principle of the crack size of the wall of the pressure-bearing shell based on the gas leakage rate measurement.
FIG. 3 is a front view of a detecting device for detecting the crack size of the wall of a pressure-bearing shell based on gas leakage rate measurement.
FIG. 4 is a top view and a front view of a leak responsive assembly in a pressure bearing housing wall crack size detection apparatus based on gas leak rate determination in accordance with the present invention. Wherein, (a) is a plan view and (b) is a front view.
Fig. 5 is a schematic diagram of a gas pressure detection assembly in a detection device for detecting the crack size of a wall of a pressure-bearing shell based on gas leakage rate measurement. Wherein, (a) is an outer end side view, and (b) is an inner end side view.
In the figure: 1 a leak response component; 2, sealing the cover; 3 a pressure reduction device; 4, an air pressure detection component; 5 a photogrammetric recording component; 6, processing the component; 7 a display component; 11, a sealing ring A; 12 an elastic film A; 13, positioning point A; 14 a pressure relief vent; 21 a seal ring B; 31 a piston; 41 an elastic film B; 42, positioning point B; 43 distance sensor.
Detailed Description
The technical solution of the present invention will be described in detail below with reference to the accompanying drawings. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. Other embodiments, which can be derived by one of ordinary skill in the art from the embodiments given herein without any creative effort, shall fall within the protection scope of the present invention.
The exemplary embodiment of the present invention provides a device for detecting a crack size of a pressure-bearing housing wall based on gas leakage rate measurement, and as shown in fig. 2 to 5, the device for detecting a crack size of the present embodiment may include a leakage response module 1, a hermetic enclosure 2, a pressure reduction device 3, a gas pressure detection module 4, a photogrammetric module 5, a processing module 6, and a display module 7.
In this embodiment, when the leak response module 1 is used, the sealing ring a11 provided at the opening end of the leak response module 1 can contact with the region to be measured and tightly adhere to the region to be measured, and if gas leaks due to a through crack in the region to be measured, the elastic membrane a12 is deformed accordingly.
In this embodiment, the leak-responsive assembly 1 may further comprise a sealing ring a11, which may be made of rubber or other elastic material. The shape of the sealing ring a11 may be the same as the open end of the leak responsive assembly 1. The inner diameter of seal ring a11 may be no greater than the inner diameter of the open end, and the outer diameter of seal ring a11 may be no less than the outer diameter of the open end, so as to completely cover the end face of the open end.
A seal ring a11 may be secured to the end face of the open end of the leak responsive assembly 1, for example: the sealing ring A11 can be fixed on the end surface of the opening end in an adhesive mode through an adhesive; or a convex rib can be formed on the sealing ring A11, a groove can be formed on the end surface of the opening end, and the convex rib can be clamped in the groove, so that the sealing ring A11 can be fixed on the end surface of the opening end in a clamping manner; in addition, still can adopt the internal diameter to be less than the internal diameter of open end, and the external diameter is greater than the sealing washer A11 of the external diameter of open end, can set up the draw-in groove on the sealing washer A11, and this draw-in groove can be blocked into to can be fixed in the terminal surface of open end with sealing washer A11. Of course, the sealing ring a11 can be fixed on the end surface of the opening end in other ways, and will not be described in detail here.
When detecting, sealing washer A11 can with the region contact that awaits measuring, because sealing washer A11 has elasticity, be favorable to more closely with the region laminating that awaits measuring, prevent to leak the side direction gas leakage that has the clearance and lead to between response subassembly 1 and the region that awaits measuring.
In this embodiment, seal B21 in closure 2 is similar to seal a11 and will not be described in detail herein.
In the present embodiment, the shape of the sealing cover 2 may be a rectangular parallelepiped, but is not limited thereto, and may be another shape. A pressure reducing device 3 is provided on one side surface of the enclosure 2, and an air pressure detecting unit 4 may be provided on the other side surface thereof. When the leakage response component 1 is used, the end face of the opening end of the closed cover 2 can be attached to the surface of a structure to be detected, and the leakage response component 1 is covered. The material of the piston 31 can be rubber or other elastic materials with good tightness; the material of the sealing cover 2 may be a transparent material such as glass, plastic, etc., and is not particularly limited herein. In use, after the enclosure 2 is fixed, the photogrammetric package 5 is mounted on the top surface of the enclosure 2, and its position can be corrected using the positioning point a13 so that its center is aligned with the center of the leak responsive package 1. The distance sensor 43 on the air pressure detecting assembly 4 and the photogrammetry assembly 5 are then connected to respective interfaces of the processing assembly 6. After the installation of the device is completed and the device is checked to be correct, the piston 31 can be pulled to reduce the ambient air pressure.
In this embodiment, the processing component 6 may be a single chip, but is not limited thereto, and other devices with storage and calculation functions may be adopted, and the device may receive information recorded by the photographing and recording component 5 and the air pressure detecting component 4, calculate the leakage rate of the region to be measured and the air pressure in the sealed enclosure according to the received positioning point position information, identify the crack image to obtain the crack length, calculate the crack size according to the crack length, and determine the severity of the crack in the region to be measured.
In this embodiment, the air pressure inside the enclosure 2 is lowered to below the set value by pulling the piston 31, and the air pressure inside the enclosure gradually rises as air leaks into the enclosure 2 through the cracks of the area to be measured. Recorded pressure in the enclosure raised to 1 atm alpha1% leakage rate Q1Recording the pressure of said gas raised to 1 atm α2% leakage rate Q2Then the parameter A, B in equation (3) can be expressed as
Wherein, 0<α1％<α2％<1; η represents the ratio of the leak rate under the above two atmospheric pressure conditions.
Note that if the pressure condition at the time of recording the leak rate is changed, that is, alpha is changed1And alpha2The formula (4) obtained after the above simplification may also change, but still belongs to the inversion of the crack size of the region to be measured according to the gas pressures inside and outside the shell wall and the corresponding gas leakage rate, and is not listed here.
In this embodiment, the crack size detection apparatus may further include a display component 7, the display component 7 may be a liquid crystal display, and may be disposed on the top surface of the processing component 6, and the processing component 6 may control the display component 7 to display the detection result of the crack size, so that an operator may read data. Of course, the display component 7 may also be other components with display function, which are not listed here.
In this embodiment, both the processing module 6 and the display module 7 can be fixed in the mounting box by means of bolt connection, etc., the mounting box can be opened with an observation port for observing the display content of the display module 7, and the mounting box can be in the shape of a cuboid, a cylinder, etc.
For example, the mounting box may comprise a box body and a cover plate, wherein: the size and shape of the box body can be matched with the processing component 6 and the display component 7; meanwhile, the box body can be provided with an open end, and the processing component 6 and the display component 7 can be fixed in the box body; the apron can cover in this open end and with the box body joint to seal the box body, form the mounting box, can be equipped with the viewing aperture corresponding to display module 7 on the apron, so that observe display module 7.
In the present embodiment, the crack size detection device may further include a power supply unit that is provided in the mounting case and is connected to the air pressure detection unit 4, the processing unit 6, and the display unit 7 to supply electric power. The power supply unit may include a battery or the like as long as it can serve as a power source.
In this embodiment, the crack size detection device may further include a warning light, the warning light may be connected to the processing component 6, the processing component 6 may compare the recorded leakage rate with a preset upper limit value and a preset lower limit value, when the recorded leakage rate exceeds the preset upper limit value, the device may not accurately determine the cracking degree of the area to be detected, and the processing component 6 may control the warning light to be turned on. The prompting lamp can be an LED lamp and the like.
When the crack size detection device of the exemplary embodiment of the present invention is used, the open end of the leakage response component 1 may be attached to the region to be detected through the sealing ring a11, and a plurality of leakage response components 1 may work simultaneously; then the open end of the closed cover 2 is attached to the surface of the structure through a sealing ring B21, and a plurality of leakage response assemblies 1 are enclosed; installing a photogrammetric component 5 at the top end of the closed cover 2, and correcting the installation position of the photogrammetric component by using 4 positioning points A13, wherein each leakage response component 1 corresponds to one photogrammetric component; reducing the air pressure value in the closed cover 2 to be lower than 50kPa by pulling the piston 31 in the pressure reducing device 3; the distance sensor 43 in the air pressure detecting assembly 4 inputs the position information of the positioning point B42 into the processing assembly 6; the photogrammetric component 5 inputs the position information of the positioning point A13 in the leakage response component 1 and the crack image of the detection area into the processing component 4; in the process, the air pressure in the cover can be increased along with the leakage of the air until the 1 standard atmospheric pressure is recovered; the processing component 4 calculates the leakage rate and the density of the region to be measured according to the position changes of the positioning point A13 and the positioning point B42 respectivelyThe air pressure in the closed hood 2 rises to 1 standard atmospheric pressure when the air pressure rises to alpha1％、α2% time, recording leakage rate of the area to be measured as Q1、Q2(ii) a The processing component 4 obtains the crack length through the crack image of the region to be detected, the crack size of the region to be detected is inverted according to the formula (4) and the formula (1), and the detection result is output on the display component 7. Therefore, the device is simple and easy to operate, convenient to carry and low in detection cost while the detection result is reliable.
The example of the calculation result is:
detecting a cracked shell wall with a thickness of 3cm and setting alpha1＝60、α2＝70。
Recording the leakage rate of the detection area: q1＝0.7649ft3/min、Q2＝0.5435ft3And/min, wherein the ambient temperature is 30 ℃ at that time, and the crack length of the region to be detected is 10cm by obtaining the crack image.
The opening of the crack is calculated by the formula (4) to be 0.2mm, the depth of the crack is calculated by the formula (1) and is 3.5cm, and accordingly, the included angle between the crack surface and the normal direction of the surface of the structural layer is about 31 degrees.
And if the area to be measured does not have obvious gas leakage, indicating that the cracking surface of the area to be measured does not penetrate through.
Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.
Claims (5)
1. The detection method of the detection device of the crack size of the wall of the pressure-bearing shell based on the gas leakage rate measurement is characterized in that the detection device comprises a leakage response component (1), a closed cover (2), a pressure reduction device (3), an air pressure detection component (4), a photographic recording component (5), a processing component (6) and a display component (7);
the closed cover (2) is used for providing a closed detection environment; the pressure reduction device (3) is arranged on the side surface of the closed cover (2) and is used for reducing the air pressure in the closed cover (2); the air pressure detection assembly (4) is arranged on the side surface of the closed cover (2) and used for detecting air pressure in the closed cover (2), and comprises a cylinder, a distance sensor (43) and an elastic membrane B (41); the wall of the cylinder is hermetically connected with the closed cover (2), the elastic membrane B (41) is arranged at the inner end of the cylinder, the distance sensor (43) is arranged at the outer end of the cylinder, and the elastic membrane B (41) is provided with a positioning point B (42); the leakage response assembly (1) is arranged in the closed cover (2), comprises a cylinder and an elastic membrane A (12), and is used for reflecting the gas leakage rate in the area to be detected through the shape change of the elastic membrane A (12); the elastic membrane A (12) is arranged at the inner end of the cylinder, the outer end of the cylinder is provided with an opening, the wall of the cylinder is provided with a pressure relief hole (14), and the outer surface of the elastic membrane A (12) is provided with a plurality of positioning points A (13);
the photographic recording component (5) is arranged on the top surface of the closed cover (2), and the lens is opposite to the central position of the inner end of the cylinder of the leakage response component (1) and is used for recording crack images and the position of a positioning point A (13) in a region to be detected;
the processing component (6) is respectively connected with the air pressure detection component (4), the photography recording component (5) and the display component (7) and is used for receiving, storing, processing and displaying information and calculating the crack size;
the detection method adopting the detection device comprises the following steps:
step one, fitting an opening end of a leakage response assembly (1) to an area to be detected; if the region to be detected has a through cracking surface, the elastic membrane A (12) is deformed due to the leakage airflow;
step two, fitting the opening end of the closed cover (2) to the surface of the structure and enclosing the leakage response assembly (1); arranging a photographic recording component (5) right above the leakage response component (1), recording the position change of a positioning point A (13) on an elastic film A (12), and recording a crack image in a region to be detected;
thirdly, the photographing recording component (5) and the distance sensor (43) are connected with the processing component (6) and transmit recorded information; the air pressure in the closed cover is reduced through the pressure reduction device (3), and the elastic membrane B (41) is deformed due to the change of the air pressure;
fourthly, calculating the air pressure in the closed cover (2) according to the deformation of the elastic membrane B (41) in the air pressure detection assembly (4); if the covering area of the closed cover (2) is provided with a through crack surface, the air pressure in the closed cover (2) can rise back along with the leakage of the air, when the air pressure rises back to a set value, the processing component (6) records the deformation of the corresponding elastic membrane A (12) on the leakage response component (1), calculates the corresponding air leakage rate, and calculates the crack opening w of the area to be measured according to the recorded two groups of data by the formula (3); if the elastic membrane A (12) on the leakage response assembly (1) is not obviously deformed all the time, the crack surface in the detection area is considered not to penetrate through;
w＝2.4801×10-4×(2-logBA)-4.1152 (3)
wherein the content of the first and second substances,
P11、P21the air pressure inside and outside the shell wall is the first time; p12、P22The air pressure inside and outside the shell wall for the second time; q1、Q2The leakage rate of the crack under two different air pressure conditions is shown;
acquiring the crack length from the crack image of the region to be detected recorded by the photographic recording component (5) by using a crack image processing technology, substituting the crack length l, the crack opening w calculated by the formula (3), the internal and external air pressure values of the region to be detected under one air pressure condition and the corresponding leakage rate into the equation (1), and directly calculating the depth t of the crack:
wherein n is 0.133w-0.243，k＝2.907×107w1.284(ii) a μ represents the aerodynamic viscosity; r represents an ideal gas constant; t represents the absolute temperature of the environment; p1、P2Indicating the pressure at both sides of the shell wall where it is cracked; q represents gas leakage of crackRate; l, w and t represent the length, opening and depth of the crack respectively;
further estimating the inclination angle of the fracture surface according to the relation between the depth of the fracture and the thickness of the shell wall;
and step six, outputting the analysis result of the processing component (6) on a display component (7).
2. The detection method according to claim 1, wherein the depressurization device (3) is through at both ends and comprises a cylinder and a piston (31), and the cylinder wall of the cylinder is hermetically connected with the closed cover (2).
3. The detection method according to claim 1 or 2, wherein the leakage response assembly (1) and the closed cover (2) are respectively in fit sealing with the shell wall through a sealing ring, and the sealing ring is made of elastic material.
4. The detection method according to claim 1 or 2, wherein the top surface of the closed enclosure (2) is transparent and the elastic membrane a (12) is transparent.
5. The detection method according to claim 3, wherein the top surface of the enclosure (2) is transparent and the elastic membrane A (12) is transparent.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202010302558.0A CN111412869B (en) | 2020-04-17 | 2020-04-17 | Detection device and method for crack size of pressure-bearing shell wall based on gas leakage rate measurement |
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| CN202010302558.0A CN111412869B (en) | 2020-04-17 | 2020-04-17 | Detection device and method for crack size of pressure-bearing shell wall based on gas leakage rate measurement |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103925474A (en) * | 2014-04-17 | 2014-07-16 | 西北工业大学 | Leakage on-line detection method for weld joint of petroleum and natural gas pipeline |
| CN105295565A (en) * | 2015-12-08 | 2016-02-03 | 常熟市裕茗企业管理咨询有限公司 | Gas leakage measurement and detection device |
| CN107655639A (en) * | 2017-09-01 | 2018-02-02 | 西北工业大学 | Released gas rate detection means |
| CN108139242A (en) * | 2015-10-14 | 2018-06-08 | 高准公司 | Diaphragm displacement flowmeter |
| CN109186876A (en) * | 2018-09-07 | 2019-01-11 | 中国电子科技集团公司第十三研究所 | Ceramic shell air-leakage test test fixture |
| JP6800220B2 (en) * | 2015-09-30 | 2020-12-16 | アプライド メディカル リソーシーズ コーポレイション | Blow-feed stabilization system |
-
2020
- 2020-04-17 CN CN202010302558.0A patent/CN111412869B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103925474A (en) * | 2014-04-17 | 2014-07-16 | 西北工业大学 | Leakage on-line detection method for weld joint of petroleum and natural gas pipeline |
| JP6800220B2 (en) * | 2015-09-30 | 2020-12-16 | アプライド メディカル リソーシーズ コーポレイション | Blow-feed stabilization system |
| CN108139242A (en) * | 2015-10-14 | 2018-06-08 | 高准公司 | Diaphragm displacement flowmeter |
| CN105295565A (en) * | 2015-12-08 | 2016-02-03 | 常熟市裕茗企业管理咨询有限公司 | Gas leakage measurement and detection device |
| CN107655639A (en) * | 2017-09-01 | 2018-02-02 | 西北工业大学 | Released gas rate detection means |
| CN109186876A (en) * | 2018-09-07 | 2019-01-11 | 中国电子科技集团公司第十三研究所 | Ceramic shell air-leakage test test fixture |
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