Ultrasonic array sensor and stress field distribution detection method and system of in-service component

Abstract

The invention relates to the technical field of in-service component stress nondestructive testing, in particular to an ultrasonic array sensor and a stress field distribution detection method and system of an in-service component. The ultrasonic array sensor comprises a transmitting transducer and a receiving transducer which are oppositely arranged, and a sonic path distance fixing plate fixedly connected with the transmitting transducer and the receiving transducer; the transmitting transducer comprises at least two ultrasonic generators and is used for transmitting at least two groups of detection ultrasonic waves to the in-service component; after each group of detection ultrasonic waves enters the in-service component, a critical refraction longitudinal wave signal propagating along the surface of the in-service component is excited; the receiving transducer comprises at least two ultrasonic receivers which are used for correspondingly receiving critical refraction longitudinal wave signals excited by the opposite ultrasonic generators respectively. According to the invention, the measurement efficiency and the measurement precision of the in-service component can be improved, and the real stress state of the in-service component can be reflected more accurately.

Description

Technical Field

[0001] The present invention relates to the technical field of nondestructive detection of stress of in-service components, and in particular to an ultrasonic array sensor, a method for detecting stress field distribution of in-service components, and a system for detecting stress field distribution of in-service components. Background Art

[0002] Corrosion and damage of in-service components, especially metal components, will lead to redistribution of internal stress. By measuring the absolute stress of in-service metal components, the safety of metal structure buildings can be evaluated. However, under the action of complex loads and microcracks, the absolute stress field of in-service metal components is usually non-uniformly distributed. Traditional ultrasonic stress detection methods mostly use single-transmit and single-receive or self-transmit and self-receive sensor arrangements, and a single detection can only achieve stress detection at one point. If regional stress detection is performed, the sensor must be moved multiple times to achieve multi-point measurement, which is inefficient, and multiple operations will increase measurement deviations.

[0003] At present, certain experience has been accumulated in the use of ultrasound to identify stress in metal components, but its main achievements are concentrated on unidirectional stress identification. In actual engineering, however, there are relatively few components in a unidirectional stress state, which limits the application of current ultrasonic stress detection technology. In engineering, steel components are mostly in a spatial stress state or a plane stress state. For steel components in a plane stress state, such as deep beams in building structures and gates in water conservancy projects, unidirectional stress identification cannot accurately obtain the true stress state of the components. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides an ultrasonic array sensor, a method and system for detecting stress field distribution of in-service components, which solve the technical problems of low measurement efficiency and low measurement accuracy of in-service components in the prior art.

[0006] (II) Technical solution

[0007] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0008] In a first aspect, an embodiment of the present invention provides an ultrasonic array sensor for detecting stress field distribution of an in-service component, the ultrasonic array sensor comprising:

[0009] A transmitting transducer and a receiving transducer arranged opposite to each other, and a sound path fixing plate fixedly connected to the two;

[0010] The transmitting transducer includes at least two ultrasonic generators for transmitting at least two groups of detection ultrasonic waves to the in-service component; after each group of the detection ultrasonic waves is incident on the in-service component, it excites a critical refracted longitudinal wave signal that propagates along the surface of the in-service component;

[0011] The receiving transducer includes at least two ultrasonic receivers for respectively correspondingly receiving critical refracted longitudinal wave signals excited by the relative ultrasonic generators;

[0012] When the ultrasonic array sensor is used to detect the stress field distribution of an in-service component, the ultrasonic array sensor is arranged on the surface of the in-service component, and obtains three groups of detection signals in three preset directions by rotating around the geometric center of the ultrasonic array sensor; obtains the first propagation sound time of at least two groups of corresponding critical refracted longitudinal wave signals according to each group of the detection signals; and obtains the second propagation sound time by using the same measurement method for a zero stress component replicated with reference to the in-service component; subtracts the first propagation sound time from the second propagation sound time to obtain a three-way array acoustic time difference at at least four intersection points of the propagation path of the critical refracted longitudinal wave signals in three preset directions on the surface of the in-service component; and calculates the stress measurement values ​​of the in-service component at the at least four intersection points according to the three-way array acoustic time difference.

[0013] Optionally, the ultrasonic generator is a piezoelectric chip, and / or the ultrasonic receiver is a piezoelectric chip.

[0014] Optionally, the ultrasonic generator is rotatably disposed on the transmitting transducer via a first rotating seat, and when the first rotating seat rotates, the ultrasonic generator is driven to change its inclination angle relative to the surface of the in-service component, so that after the detection ultrasonic wave emitted by the ultrasonic generator is incident on the in-service component, a critical refracted longitudinal wave signal propagating along the surface of the in-service component is excited; and / or,

[0015] The ultrasonic receiver is rotatably arranged on the receiving transducer via a second rotating seat. When the second rotating seat rotates, it drives the ultrasonic receiver to change its inclination angle relative to the surface of the in-service component to receive the critical refracted longitudinal wave signal.

[0016] In a second aspect, an embodiment of the present invention provides a method for detecting stress field distribution of an in-service component, comprising:

[0017] Based on the ultrasonic array sensor, the first propagation sound of at least two groups of critical refracted longitudinal wave signals excited by ultrasonic waves propagating for a preset distance in three preset directions on the surface of the in-service component is detected respectively; and the second propagation sound is obtained by using the same measurement method for a zero-stress component replicated with reference to the in-service component;

[0018] Subtract the first propagation acoustic time from the second propagation acoustic time to obtain a three-way array acoustic time difference at at least four intersection points of the propagation path of the critical refracted longitudinal wave signal on the surface of the in-service component in three preset directions;

[0019] The stress measurement values ​​of the in-service component at the at least four intersection points are obtained by solving the three-way array acoustic time difference.

[0020] Optionally, respectively detecting the first propagation sound of at least two groups of critical refracted longitudinal wave signals excited by ultrasonic waves propagating a preset distance in three preset directions on the surface of the in-service component includes:

[0021] The included angle between each preset direction and the other two preset directions is 60°, which are respectively referred to as the 0° direction, the 60° direction and the 120° direction.

[0022] Optionally, according to the three-way array acoustic time difference, the stress measurement values ​​of the in-service component at the at least four intersection points are calculated, including:

[0023] The three-way array acoustic time difference corresponding to each intersection point includes the acoustic time difference in the 0° direction, the 60° direction and the 120° direction; based on the three-way array acoustic time difference corresponding to a target intersection point, according to the preset non-uniform absolute stress field detection equation, the stress measurement value on the target intersection point is solved;

[0024] The preset non-uniform absolute stress field detection equation is:

[0025]

[0026] Wherein, σ1 is the maximum principal stress measurement value at the target intersection, σ2 is the minimum principal stress measurement value at the target intersection, θ is the angle between the maximum principal stress and the 0° direction, T1 is the acoustic time difference of the critical refracted longitudinal wave signal at the target intersection at 0° direction, T2 is the acoustic time difference of the critical refracted longitudinal wave signal at the target intersection at 60° direction, T3 is the acoustic time difference of the critical refracted longitudinal wave signal at the target intersection at 120° direction, K ∥ is the first sound time difference coefficient, K ⊥ is the time difference coefficient of the second sound;

[0027] The first sound time difference coefficient and the second sound time difference coefficient are obtained based on a pre-test process.

[0028] Optionally, the preliminary testing process includes:

[0029] Replicate zero-stress components with reference to in-service components;

[0030] Use ultrasonic array sensors to measure the initial propagation sound of zero stress components when there is no test stress loading;

[0031] Gradiently load the test stress to the zero stress component, and use an ultrasonic array sensor to measure the parallel propagation sound time of the critical refracted longitudinal wave signal in the direction parallel to the test stress loading direction under each gradient test stress, subtract the parallel propagation sound time of each gradient from the initial propagation sound time to obtain the parallel propagation sound time difference corresponding to the test stress of each gradient; perform linear fitting on the test stress and the parallel propagation sound time difference, and use the obtained fitting slope as the first sound time difference coefficient; and

[0032] A test stress is gradient loaded onto the zero-stress component, and an ultrasonic array sensor is used to measure the vertical propagation sound time of the critical refracted longitudinal wave signal perpendicular to the test stress loading direction under each gradient test stress. The vertical propagation sound time of each gradient is subtracted from the initial propagation sound time to obtain the vertical propagation sound time difference corresponding to the test stress of each gradient; a linear fit is performed on the test stress and the vertical propagation sound time difference, and the obtained fitting slope is used as the second sound time difference coefficient.

[0033] Optionally, zero stress components are replicated with reference to in-service components, including:

[0034] A replica is made with reference to the specification, material and surface roughness of the in-service component, and the residual stress of the replica is eliminated by heat treatment to obtain a zero-stress component.

[0035] In a third aspect, an embodiment of the present invention provides a stress field distribution detection system for an in-service component, comprising: a signal generator, an ultrasonic array sensor, and a host computer.

[0036] The signal generator is used to generate a pulse excitation signal;

[0037] The ultrasonic array sensor comprises a transmitting transducer and a receiving transducer arranged opposite to each other, and a sound path fixing plate fixedly connected to the two; the transmitting transducer comprises at least two ultrasonic generators, which are used to transmit at least two groups of detection ultrasonic waves to the in-service component based on the pulse excitation signal; each group of the detection ultrasonic waves excites a critical refracted longitudinal wave signal propagating along the surface of the in-service component after incident on the in-service component; the receiving transducer comprises at least two ultrasonic receivers, which are used to respectively and correspondingly receive the critical refracted longitudinal wave signals excited by the opposite ultrasonic generators;

[0038] When the ultrasonic array sensor is used to detect the stress field distribution of an in-service component, the ultrasonic array sensor is arranged on the surface of the in-service component, and three groups of detection signals in three preset directions are obtained by rotating around the geometric center of the ultrasonic array sensor;

[0039] The host computer is used to obtain the first propagation acoustic time of at least two groups of the corresponding critical refracted longitudinal wave signals according to each group of the detection signals; to make a difference between the first propagation acoustic time and the second propagation acoustic time to obtain the three-way array acoustic time difference at at least four intersection points of the propagation path of the critical refracted longitudinal wave signals in three preset directions on the surface of the in-service component; and to solve and obtain the stress measurement values ​​of the in-service component at the at least four intersection points according to the three-way array acoustic time difference;

[0040] The second propagation sound is data obtained in advance by using the same measurement method on a zero-stress component replicated with reference to an in-service component and stored locally in the host computer.

[0041] Optionally, the detection system further comprises an oscilloscope.

[0042] The oscilloscope is communicatively connected with the receiving transducer of the ultrasonic array sensor and is used for displaying the critical refracted longitudinal wave signal received by the receiving transducer.

[0043] (III) Beneficial effects

[0044] The ultrasonic array sensor proposed in the present invention includes a transmitting transducer and a receiving transducer arranged opposite to each other, and a sound path fixing plate fixedly connected to the two; the transmitting transducer includes at least two ultrasonic generators for transmitting at least two groups of detection ultrasonic waves to the in-service component; after the at least two groups of detection ultrasonic waves are incident on the in-service component, at least two groups of critical refracted longitudinal wave signals propagating along the surface of the in-service component are generated; the receiving transducer includes at least two ultrasonic receivers for respectively correspondingly receiving the at least two groups of critical refracted longitudinal wave signals.

[0045] Based on the above arrangement, when the ultrasonic array sensor is used to detect the stress field distribution of an in-service component, the ultrasonic array sensor is arranged on the surface of the in-service component, and obtains detection signals in three preset directions by rotating around its geometric center; obtains the corresponding first propagation sound time of at least two groups of the critical refracted longitudinal wave signals according to the detection signals in the three preset directions; and obtains the second propagation sound time by using the same measurement method for a zero stress component replicated with reference to the in-service component; subtracts the first propagation sound time from the second propagation sound time to obtain a three-way array acoustic time difference of at least two groups of critical refracted longitudinal wave signals in three preset directions at at least four intersection points of the propagation path on the surface of the in-service component; and calculates the stress measurement value of the in-service component at the at least four intersection points according to the three-way array acoustic time difference.

[0046] Therefore, the ultrasonic array sensor provided by the present invention can measure the stress values ​​of at least four points of the in-service component at one time, which can effectively improve the measurement efficiency; moreover, for in-service components in a plane stress state, compared with the existing unidirectional stress identification method, the measurement results obtained by the present invention can more accurately reflect the actual stress state of the in-service components. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a schematic structural diagram of an ultrasonic array sensor provided in an embodiment;

[0048] Figure 2 is a schematic structural diagram of a transmitting transducer provided in an embodiment;

[0049] Figure 3 It is a schematic structural diagram of the first rotating seat and the ultrasonic generator provided in the embodiment;

[0050] Figure 4 A schematic flow chart of a stress field distribution detection method for an in-service component provided in an embodiment;

[0051] Figure 5 A schematic diagram of the direction in which the ultrasonic array sensor is arranged on the in-service component in the embodiment;

[0052] Figure 6 A schematic diagram of the propagation path of the critical refracted longitudinal wave signal on the surface of the in-service component in the embodiment;

[0053] Figure 7 (a) is a schematic diagram of an arrangement direction of an ultrasonic array sensor on a zero stress component in an embodiment;

[0054] Figure 7 (b) is a schematic diagram of another arrangement direction of the ultrasonic array sensor on the zero stress component in the embodiment;

[0055] Figure 8 Schematic diagram of the stress process of gradient loading test on zero stress components in the embodiment;

[0056] Fig. 9 This is a schematic diagram of the linear fitting results of the test stress and the parallel propagation time difference in the embodiment;

[0057] Fig.10 This is a schematic diagram of the linear fitting results of the test stress and the vertical propagation time difference in the embodiment;

[0058] Fig.11 A schematic diagram of the architecture of a stress field distribution detection system for an in-service component provided in an embodiment;

[0059] Fig.12 It is a schematic diagram of the critical refracted longitudinal wave signal in the embodiment forming 19 target intersection points in the detection area of ​​the steel member to be tested;

[0060] Fig.13 for Fig.12 Schematic diagram of the numbering of the 19 target intersection points.

[0061] [Description of Reference Numerals]

[0062] 10. Transmitting transducer; 20. Receiving transducer; 30. Sound path fixing plate; 40. In-service components; 50. Signal generator; 60. Host computer; 70. Oscilloscope;

[0063] 101. First rotating seat; 102. Housing; 103. Signal input terminal; 104. Magnet; 105. Ultrasonic generator. DETAILED DESCRIPTION

[0064] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0065] For steel components in a spatial stress state, engineers usually ignore the stress in the direction with smaller stress value and treat it as a plane stress component for calculation. However, most common components are plate-shaped, and the stress in the thickness direction is much smaller than that in the other two directions. It can usually be simplified to a plane stress state within the plane of the component. By performing plane stress detection on it, the internal stress state of the component can also be obtained.

[0066] The ultrasonic array sensor, stress field distribution detection method and system of in-service components provided by the present invention, when detecting the stress field distribution of in-service components, the ultrasonic array sensor is arranged on the surface of the in-service component, and obtains detection signals in three preset directions by rotating around its geometric center; obtains the corresponding first propagation sound time of at least two groups of the critical refracted longitudinal wave signals according to the detection signals in the three preset directions; and obtains the second propagation sound time using the same measurement method for the zero stress component replicated with reference to the in-service component; subtracts the first propagation sound time from the second propagation sound time to obtain the three-way array sound time difference at at least four intersections of the propagation path on the surface of the in-service component of at least two groups of critical refracted longitudinal wave signals in three preset directions; according to the three-way array sound time difference, the stress measurement value of the in-service component at the at least four intersections is solved to obtain the non-uniform absolute stress field of the steel component to be tested. Its detection process is simple and fast, with high feasibility, and the detection results are highly accurate, stable and reliable.

[0067] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0068] Embodiment 1

[0069] like Figure 1As shown, an embodiment of the present invention provides an ultrasonic array sensor for detecting stress field distribution of in-service components. The ultrasonic array sensor includes: a transmitting transducer 10 and a receiving transducer 20 that are arranged opposite to each other, and a sound path fixing plate 30 fixedly connected to the two.

[0070] The transmitting transducer 10 includes at least two ultrasonic generators for transmitting at least two groups of detection ultrasonic waves to the in-service component 40 ; after each group of the detection ultrasonic waves is incident on the in-service component 40 , it excites a critical refracted longitudinal wave signal that propagates along the surface of the in-service component 40 .

[0071] The receiving transducer 20 includes at least two ultrasonic receivers for respectively receiving critical refracted longitudinal wave signals excited by opposite ultrasonic generators.

[0072] Preferably, the ultrasonic generator is a piezoelectric chip, and / or the ultrasonic receiver is a piezoelectric chip.

[0073] Based on the above arrangement, when the ultrasonic array sensor is used to detect the stress field distribution of an in-service component, the ultrasonic array sensor is arranged on the surface of the in-service component, and obtains three groups of detection signals in three preset directions by rotating around the geometric center of the ultrasonic array sensor; obtains the first propagation sound time of at least two groups of corresponding critical refracted longitudinal wave signals according to each group of the detection signals; and obtains the second propagation sound time by using the same measurement method for a zero stress component replicated with reference to the in-service component; subtracts the first propagation sound time from the second propagation sound time to obtain a three-way array acoustic time difference at at least four intersection points of the propagation path of the critical refracted longitudinal wave signals in three preset directions on the surface of the in-service component; and calculates the stress measurement value of the in-service component at the at least four intersection points according to the three-way array acoustic time difference.

[0074] Therefore, the ultrasonic array sensor provided by the present invention can measure the stress values ​​of at least four points of the in-service component at one time, which can effectively improve the measurement efficiency; moreover, for in-service components in a plane stress state, compared with the existing unidirectional stress identification method, the measurement results obtained by the present invention can more accurately reflect the actual stress state of the in-service components.

[0075] In a specific implementation of this embodiment, in order to adapt to in-service components of different materials and surfaces of different shapes, as well as the degree of coupling between the ultrasonic generator and the in-service component, it is sometimes necessary to adjust the inclination angle of the ultrasonic generator relative to the surface of the in-service component so that the detection ultrasonic wave emitted by it can emit the ultrasonic wave to the in-service component at a critical incident angle, so that after incident on the in-service component, a critical refracted longitudinal wave signal propagating along the surface of the in-service component is stimulated. Preferably, the ultrasonic generator provided in this embodiment is rotatably disposed on the transmitting transducer through a first rotating seat, and the ultrasonic receiver is rotatably disposed on the receiving transducer through a second rotating seat.

[0076] Specifically, Figure 2 and 3 As shown, the transmitting transducer 10 provided in this embodiment includes a housing 102 and a first rotating seat 101 rotatably arranged on the housing 102. The first rotating seat 101 is provided with a plurality of ultrasonic generators 105 spaced along its axial direction. The ultrasonic generators 105 can be specifically piezoelectric chips. When the first rotating seat 101 rotates, the ultrasonic generators 105 are driven to change their inclination angles relative to the surface of the in-service component 40, so that the detection ultrasonic waves emitted by the ultrasonic generators are incident on the in-service component 40, and the critical refracted longitudinal wave signals propagating along the surface of the in-service component 40 are excited.

[0077] In addition, the top of the housing 102 is fixedly connected to the sound path fixing plate 30, and a magnet 104 can be fixedly arranged at the bottom of the housing 102, so that when detecting an in-service component made of metal, the ultrasonic array sensor can be directly adsorbed on the in-service component. A signal input terminal 103 is provided on the side of the housing, and the signal input terminal 103 is electrically connected to the piezoelectric chip to receive the pulse excitation signal generated by the signal generator. Each ultrasonic generator 105 can uniquely correspond to a signal input terminal 103, so that the working state of the corresponding ultrasonic generator 103 can be controlled by the signal generator. Figure 2 and Figure 3 Five groups of ultrasonic generators are shown in the figure. In actual applications, the number of ultrasonic generators 105 and the distance between two adjacent ultrasonic generators 105 can be adjusted according to the size of the in-service components to be detected and the fineness of the stress field distribution to be detected.

[0078] Accordingly, the receiving transducer provided in this embodiment includes a housing and a second rotating seat rotatably arranged on the housing, wherein the second rotating seat is provided with a plurality of ultrasonic receivers spaced apart along its axial direction, wherein the ultrasonic receivers may be piezoelectric wafers. When the second rotating seat rotates, the ultrasonic receivers are driven to change their inclination angles relative to the surface of the in-service component to receive the critical refracted longitudinal wave signal.

[0079] It should be noted that an ultrasonic generator and an ultrasonic receiver arranged opposite to it form a group of detection channels. Since an ultrasonic array sensor includes multiple groups of detection channels, in order to avoid interference between multiple detection channels, the multiple groups of detection channels can be used to perform detection in sequence, that is, when one group of detection channels is working, other detection channels are closed to prevent signal interference between each other.

[0080] Embodiment 2

[0081] This embodiment provides a method for detecting the stress field distribution of an in-service component. The detection method can be implemented based on the ultrasonic array sensor provided in the first embodiment. Figure 4 As shown, it specifically includes steps S1 to S3:

[0082] S1. Based on the ultrasonic array sensor, the first propagation sound of at least two groups of critical refracted longitudinal wave signals excited by ultrasonic waves propagating for a preset distance in three preset directions on the surface of the in-service component is detected respectively; and the second propagation sound is obtained by using the same measurement method for a zero-stress component replicated with reference to the in-service component.

[0083] In this embodiment, the measurement order of in-service components and zero-stress components is not limited. In actual application, if the measurement efficiency is to be further improved, the production of zero-stress components and the measurement of the second propagation sound can be completed in the laboratory in advance, so as to ensure that steps S2 and S3 can be immediately executed after the first propagation sound of the in-service components is measured at the engineering site to solve the corresponding stress field distribution data.

[0084] The method for manufacturing the zero stress component is: making a replica with reference to the specification, material and surface roughness of the in-service component, and eliminating the residual stress of the replica by heat treatment to obtain the zero stress component.

[0085] Specifically, the angle between each of the above preset directions and the other two preset directions is 60°, which are respectively referred to as the 0° direction, the 60° direction and the 120° direction. This embodiment does not limit the measurement order of the three preset directions. For the convenience of operation, Figure 5 As shown, an ultrasonic array sensor can be used to first measure the first propagation sound time in the 0° direction; then the ultrasonic array sensor is rotated 60° counterclockwise around its geometric center to measure the first propagation sound time in the 60° direction; then the ultrasonic array sensor is rotated 60° counterclockwise around its geometric center to measure the first propagation sound time in the 120° direction, thereby obtaining the first propagation sound time in three preset directions.

[0086] S2. Subtract the first propagation acoustic time from the second propagation acoustic time to obtain a three-way array acoustic time difference of at least four intersection points of the propagation path of the critical refracted longitudinal wave signal in three preset directions on the surface of the in-service component.

[0087] Specifically, take the above-mentioned ultrasonic array sensor including five groups of detection channels as an example. Figure 6 As shown, there are five propagation paths of critical refracted longitudinal wave signals in each preset direction, and there are 19 target intersections in total for the 15 propagation paths. For any one of the 19 target intersections, there must be a propagation path passing through the target intersection in the 0° direction, the 60° direction, and the 120° direction.

[0088] by Figure 6 Taking point P in the figure as an example, the five groups of detection channels of the ultrasonic array sensor are called channel one, channel two, channel three, channel four and channel five from top to bottom according to the order in the 0° direction. The propagation paths passing through the target intersection point P are the propagation path of channel one in the 0° direction, the propagation path of channel one in the 60° direction and the propagation path of channel three in the 120° direction.

[0089] Based on the three propagation paths passing through the target intersection, the first propagation sound time on the propagation path is subtracted from the corresponding second propagation sound time, and the sound time difference of the target intersection in the 0° direction, 60° direction and 120° direction can be obtained, which is called the three-way array sound time difference corresponding to the target intersection.

[0090] S3. According to the three-way array acoustic time difference, the stress measurement values ​​of the in-service components at the above 19 intersection points are calculated one by one, so as to obtain the stress field distribution of the in-service components.

[0091] Specifically, for each target intersection, the stress measurement value at the target intersection can be solved based on the three-way array acoustic time difference corresponding to the target intersection and the preset non-uniform absolute stress field detection equation. The stress measurement value of the target intersection includes the maximum principal stress measurement value, the minor principal stress measurement value, and the angle between the maximum principal stress and the 0° direction.

[0092] The preset non-uniform absolute stress field detection equation is:

[0093]

[0094] Wherein, σ1 is the maximum principal stress measurement value at the target intersection, σ2 is the minimum principal stress measurement value at the target intersection, θ is the angle between the maximum principal stress and the 0° direction, T1 is the acoustic time difference of the critical refracted longitudinal wave signal at the target intersection at 0° direction, T2 is the acoustic time difference of the critical refracted longitudinal wave signal at the target intersection at 60° direction, T3 is the acoustic time difference of the critical refracted longitudinal wave signal at the target intersection at 120° direction, K ∥ is the first sound time difference coefficient, K ⊥ is the time difference coefficient of the second sound.

[0095] The first sound time difference coefficient and the second sound time difference coefficient are obtained based on a pre-test process.

[0096] Embodiment 3

[0097] This embodiment specifically describes the preliminary testing process in the second embodiment.

[0098] The pre-test process provided in this embodiment includes steps 001 to 003:

[0099] 001. Copy zero stress components by referring to the components in service.

[0100] Specifically, the method comprises: making a replica according to the specification, material and surface roughness of the in-service component, and eliminating the residual stress of the replica by heat treatment to obtain a zero-stress component.

[0101] 002. Use ultrasonic array sensors to measure the initial propagation sound of zero stress components when there is no test stress loading.

[0102] 003. Gradiently load the test stress to the zero stress component, and use the ultrasonic array sensor to measure the parallel propagation sound time of the critical refracted longitudinal wave signal in the direction parallel to the test stress loading direction under each gradient test stress, and subtract the parallel propagation sound time of each gradient from the initial propagation sound time to obtain the parallel propagation sound time difference corresponding to the test stress of each gradient; perform linear fitting on the test stress and the parallel propagation sound time difference, and use the obtained fitting slope as the first sound time difference coefficient K ∥ The measurement direction of the ultrasonic array sensor parallel to the test stress loading direction is as follows: Figure 7 (a) shown.

[0103] Gradual test stress is applied to the zero stress component, and the vertical propagation acoustic time of the critical refracted longitudinal wave signal perpendicular to the test stress loading direction is measured using an ultrasonic array sensor under each gradient test stress. The vertical propagation acoustic time of each gradient is subtracted from the initial propagation acoustic time to obtain the vertical propagation acoustic time difference corresponding to the test stress of each gradient; a linear fit is performed between the test stress and the vertical propagation acoustic time difference, and the obtained fitting slope is used as the second acoustic time difference coefficient K ⊥ The measurement direction of the ultrasonic array sensor when perpendicular to the test stress loading direction is as follows: Figure 7 (b) as shown.

[0104] In step 103, the order of measuring the first acoustic time difference coefficient and the second acoustic time difference coefficient is not limited. In order to save materials and steps, after a gradient test stress is applied to the zero stress component, the parallel propagation acoustic time and the vertical propagation acoustic time under the gradient test stress are measured, and then the next gradient test stress is applied, and the parallel propagation acoustic time and the vertical propagation acoustic time under the next gradient test stress are measured, until the measurement under all gradient test stresses is completed, so that all parallel propagation acoustic time and vertical propagation acoustic time data can be obtained through a single stress gradient loading process.

[0105] For example, the specific operations corresponding to the above steps 002 and 003 are:

[0106] A universal testing machine is used to perform gradient loading on the zero stress component. The size of the zero stress component is 300×200×25mm and the material is Q345b. The universal testing machine performs gradient axial compression loading on the zero stress component. Specifically, the initial propagation sound time is measured for the zero stress component under 0MPa, i.e., no stress loading (the initial propagation sound time corresponding to the same propagation distance in each direction under zero stress conditions is the same). Then, as Figure 8 As shown, the zero-stress component is stress loaded with test stresses of 20MPa, 40MPa, 60MPa,..., 180MPa, and 200MPa in sequence, with 20MPa as a loading step, and the parallel propagation sound time of the critical refracted longitudinal wave in the direction parallel to the stress and the vertical propagation sound time in the direction perpendicular to the stress under different stress gradients are collected.

[0107] Subtract the parallel propagation acoustic time of each gradient from the initial propagation acoustic time to obtain the parallel propagation acoustic time difference corresponding to the test stress of each gradient; perform linear fitting on the test stress and the parallel propagation acoustic time difference, and use the obtained fitting slope as the first acoustic time difference coefficient. This embodiment sets the test stress of each gradient and the corresponding parallel propagation acoustic time difference to end when the deviation of the linear fitting result is less than 5%. The linear fitting result of the test stress and the parallel propagation acoustic time difference is as follows: Fig. 9 As shown. Since the ultrasonic array sensor has 5 detection channels, 5 fitting slopes will be obtained. The average value of the linear fitting results of the 5 channels will be taken as the first sound time difference coefficient K ∥ The first sound time difference coefficients of the five detection channels are shown in Table 1.

[0108] Similarly, the vertical propagation acoustic time of each gradient is subtracted from the initial propagation acoustic time to obtain the vertical propagation acoustic time difference corresponding to the test stress of each gradient; the test stress and the vertical propagation acoustic time difference are linearly fitted, and the obtained fitting slope is used as the second acoustic time difference coefficient. This embodiment sets the test stress of each gradient and the corresponding parallel propagation acoustic time difference to end when the deviation of the linear fitting result is less than 5%. The linear fitting result of the test stress and the vertical propagation acoustic time difference is as follows: Fig.10 Similarly, since the ultrasonic array sensor has 5 detection channels, 5 fitting slopes will be obtained, and the average value of the linear fitting results of the 5 channels will be taken as the second sound time difference coefficient K ⊥ The second sound time difference coefficients of the five detection channels are shown in Table 1.

[0109] Table 1 Calibration results of stress acoustic time difference coefficient (ns / MPa)

[0110]

[0111] Based on the above-mentioned preliminary testing process, accurate reference parameters can be provided for the non-uniform absolute stress field detection equation used in Example 2, which can be applied to the non-uniform absolute stress field detection of steel components in steel structure buildings under construction and already built. It is simple, fast and easy to implement, thereby further improving the measurement efficiency and measurement accuracy of stress field distribution detection.

[0112] Embodiment 4

[0113] Based on the ultrasonic array sensor and detection method provided in embodiments 1 to 3, Fig.11 As shown, this embodiment provides a stress field distribution detection system for an in-service component, including: a signal generator 50 , an ultrasonic array sensor, a host computer 60 and an oscilloscope 70 .

[0114] The signal generator 50 is used to generate a pulse excitation signal.

[0115] The ultrasonic array sensor includes a transmitting transducer 10 and a receiving transducer 20 arranged opposite to each other, and a sound path fixing plate 30 fixedly connected to the two; the transmitting transducer 10 includes at least two groups of ultrasonic generators, which are used to transmit at least two groups of detection ultrasonic waves to the in-service component 40 based on the pulse excitation signal; after each group of the detection ultrasonic waves is incident on the in-service component 40, it excites a critical refracted longitudinal wave signal propagating along the surface of the in-service component 40; the receiving transducer 20 includes at least two groups of ultrasonic receivers, which are used to respectively receive the critical refracted longitudinal wave signals excited by the relative ultrasonic generators 10.

[0116] When the ultrasonic array sensor is used to detect the stress field distribution of the in-service component 40, the ultrasonic array sensor is disposed on the surface of the in-service component 40, and three groups of detection signals in three preset directions are obtained by rotating around the geometric center of the ultrasonic array sensor.

[0117] The host computer 60 is used to obtain the first propagation acoustic time of at least two groups of the critical refracted longitudinal wave signals corresponding to each group of the detection signals; to make a difference between the first propagation acoustic time and the second propagation acoustic time to obtain the three-way array acoustic time difference at at least four intersections of the propagation path of the critical refracted longitudinal wave signals in three preset directions on the surface of the in-service component; and to calculate the stress measurement values ​​of the in-service component at the at least four intersections according to the three-way array acoustic time difference. The second propagation acoustic time is data obtained in advance using the same measurement method for the zero stress component copied with reference to the in-service component and stored locally in the host computer.

[0118] The oscilloscope 70 is in communication connection with the receiving transducer 20 of the ultrasonic array sensor, and is used for displaying the critical refracted longitudinal wave signal received by the receiving transducer 20 .

[0119] The stress field distribution detection system for in-service components provided herein generates and collects critical refracted longitudinal wave signals in three directions in the in-service components to be tested through ultrasonic array sensors, collects and analyzes them through digital oscilloscopes and host computers, and then calculates the in-service non-uniform absolute stress field through pre-defined non-uniform absolute stress field detection equations. The system has a simple structure, fast detection speed, high efficiency, little time and scene restrictions, high feasibility, high detection accuracy, and stable detection result deviation.

[0120] This embodiment is also experimentally verified based on the above detection system, which specifically includes the following steps:

[0121] A1. Take an arbitrary steel component with the size of 350×250×25mm and the material of Q345b. Use a universal testing machine to perform three-point bending loading on the steel component to form a non-uniform absolute stress field inside the steel component.

[0122] A2. Select a suitable position on the steel structure as the area to be tested, grind and polish the surface of the area to be tested, apply coupling agent to the test area to fix the ultrasonic array sensor, and after all the equipment connections of the detection system are ready, adjust the appropriate parameters of the above detection system to a normal working state, save the second propagation sound time corresponding to the steel structure in the host computer, and set the corresponding non-uniform absolute stress field detection equation according to the first sound time difference coefficient and the second sound time difference coefficient corresponding to the steel structure.

[0123] A3. Arrange the ultrasonic array sensors in sequence at the 0°, 60°, and 120° directions of the detection area of ​​the steel component to be tested, and collect three groups of detection signals in the three preset directions in the detection area of ​​the steel component to be tested; the upper computer obtains the first propagation sound time of at least two groups of corresponding critical refracted longitudinal wave signals according to each group of the detection signals, and subtracts the first propagation sound time from the pre-saved second propagation sound time to obtain the three-way array sound time difference of the critical refracted longitudinal wave signals in the three preset directions at each target intersection of the propagation path on the surface of the in-service component.

[0124] In this embodiment, an ultrasonic array sensor with five detection channels is still used for detection, and the critical refracted longitudinal wave signal propagating along the directions of 0°, 60°, and 120° forms 19 target intersection points in the detection area of ​​the steel member to be detected, such as Fig.12 As shown; Fig.12 The number of each target intersection point in is as follows Fig.13 19 strain gauges are arranged at the other side of the component at the position opposite to the target intersection to simultaneously measure the stress value to verify the accuracy of this method. The comparison of the detection results of the ultrasonic method and the strain gauge method provided in this embodiment is shown in Table 2.

[0125]

[0126] According to Table 2, the relative deviation distribution range between the stress value detected by this method and the stress value detected by the strain gauge can be calculated as shown in Table 3:

[0127]

[0128] It can be seen from this that the relative deviation of the detection system provided in this embodiment does not exceed 10%, and the detection accuracy is relatively high.

[0129] The ultrasonic array sensor group designed in this implementation realizes the rapid and high-precision detection of the non-uniform absolute stress field of steel components. It can be used for the detection of non-uniform absolute stress field of steel components in steel structures under construction and completed, and improves the detection accuracy and efficiency of non-uniform absolute stress field of steel components. The test process is simple, and the test instrument is easy to install, low-cost and easy to implement.

[0130] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0131] The present invention is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present invention. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions.

[0132] It should be noted that in the claims, any reference numerals placed between brackets shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention may be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In the claims enumerating several means, several of these means may be embodied by the same hardware. The use of the words first, second, third, etc., is for convenience of expression only and does not indicate any order. These words may be understood as part of the component name.

[0133] In addition, it should be noted that, in the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0134] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments after knowing the basic creative concept. Therefore, the claims should be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0135] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention should also include these modifications and variations.

Claims

1. An ultrasonic array sensor used to detect the stress field distribution of an in-service component, characterized in that: The ultrasonic array sensor comprises: A transmitting transducer and a receiving transducer arranged opposite to each other, and a sound path fixing plate fixedly connected to the two; The transmitting transducer includes at least two ultrasonic generators for transmitting at least two groups of detection ultrasonic waves to the in-service component; after each group of detection ultrasonic waves is incident on the in-service component, it excites a critical refracted longitudinal wave signal that propagates along the surface of the in-service component; The receiving transducer includes at least two ultrasonic receivers for respectively correspondingly receiving critical refracted longitudinal wave signals excited by the relative ultrasonic generators; When the ultrasonic array sensor is used to detect the stress field distribution of an in-service component, the ultrasonic array sensor is arranged on the surface of the in-service component, and obtains three groups of detection signals in three preset directions by rotating around the geometric center of the ultrasonic array sensor; obtains the first propagation sound time of at least two groups of corresponding critical refracted longitudinal wave signals according to each group of the detection signals; and obtains the second propagation sound time by using the same measurement method for a zero stress component replicated with reference to the in-service component; subtracts the first propagation sound time from the second propagation sound time to obtain a three-way array acoustic time difference at at least four intersection points of the propagation path of the critical refracted longitudinal wave signals in three preset directions on the surface of the in-service component; and calculates the stress measurement values ​​of the in-service component at the at least four intersection points according to the three-way array acoustic time difference.

2. The ultrasonic array sensor according to claim 1, characterized in that: The ultrasonic generator is a piezoelectric chip, and / or the ultrasonic receiver is a piezoelectric chip.

3. The ultrasonic array sensor according to claim 1, characterized in that: The ultrasonic generator is rotatably arranged on the transmitting transducer via a first rotating seat, and when the first rotating seat rotates, the ultrasonic generator is driven to change its inclination angle relative to the surface of the in-service component, so that after the detection ultrasonic wave emitted by the ultrasonic generator is incident on the in-service component, a critical refracted longitudinal wave signal propagating along the surface of the in-service component is excited; and / or, The ultrasonic receiver is rotatably arranged on the receiving transducer via a second rotating seat. When the second rotating seat rotates, it drives the ultrasonic receiver to change its inclination angle relative to the surface of the in-service component to receive the critical refracted longitudinal wave signal.

4. A method for detecting stress field distribution of an in-service component, characterized in that: include: Based on the ultrasonic array sensor, the first propagation sound of at least two groups of critical refracted longitudinal wave signals excited by ultrasonic waves propagating in three preset directions on the surface of the in-service component for a preset distance is detected respectively; and, when the second propagated sound is obtained using the same measurement method on a zero-stress member replicated with the reference in-service member; Subtract the first propagation acoustic time from the second propagation acoustic time to obtain a three-way array acoustic time difference at at least four intersection points of the propagation path of the critical refracted longitudinal wave signal on the surface of the in-service component in three preset directions; The stress measurement values ​​of the in-service component at the at least four intersection points are obtained by solving the three-way array acoustic time difference.

5. The detection method according to claim 4, characterized in that: When first propagation sound of critical refracted longitudinal wave signals excited by at least two groups of ultrasonic waves propagating in three preset directions on the surface of the in-service component for a preset distance is detected respectively, it includes: The included angle between each preset direction and the other two preset directions is 60°, which are respectively referred to as the 0° direction, the 60° direction and the 120° direction.

6. The detection method according to claim 5, characterized in that: The stress measurement values ​​of the in-service component at the at least four intersection points are obtained by solving the three-way array acoustic time difference, including: The three-way array acoustic time difference corresponding to each intersection point includes the acoustic time difference in the 0° direction, the 60° direction and the 120° direction; based on the three-way array acoustic time difference corresponding to a target intersection point, according to the preset non-uniform absolute stress field detection equation, the stress measurement value on the target intersection point is solved; The preset non-uniform absolute stress field detection equation is: Wherein, σ1 is the maximum principal stress measurement value at the target intersection, σ2 is the minimum principal stress measurement value at the target intersection, θ is the angle between the maximum principal stress and the 0° direction, T1 is the acoustic time difference of the critical refracted longitudinal wave signal at the target intersection at 0° direction, T2 is the acoustic time difference of the critical refracted longitudinal wave signal at the target intersection at 60° direction, T3 is the acoustic time difference of the critical refracted longitudinal wave signal at the target intersection at 120° direction, K ∥ is the first sound time difference coefficient, K ⊥ is the time difference coefficient of the second sound; The first sound time difference coefficient and the second sound time difference coefficient are obtained based on a pre-test process.

7. The detection method according to claim 6, characterized in that: The preliminary testing process includes: Replicate zero-stress components with reference to in-service components; Use ultrasonic array sensors to measure the initial propagation sound of zero stress components when there is no test stress loading; Gradiently load the test stress to the zero stress component, and use an ultrasonic array sensor to measure the parallel propagation sound time of the critical refracted longitudinal wave signal in the direction parallel to the test stress loading direction under each gradient test stress, subtract the parallel propagation sound time of each gradient from the initial propagation sound time to obtain the parallel propagation sound time difference corresponding to the test stress of each gradient; perform linear fitting on the test stress and the parallel propagation sound time difference, and use the obtained fitting slope as the first sound time difference coefficient; and A test stress is gradient loaded onto the zero-stress component, and an ultrasonic array sensor is used to measure the vertical propagation sound time of the critical refracted longitudinal wave signal perpendicular to the test stress loading direction under each gradient test stress. The vertical propagation sound time of each gradient is subtracted from the initial propagation sound time to obtain the vertical propagation sound time difference corresponding to the test stress of each gradient; a linear fit is performed on the test stress and the vertical propagation sound time difference, and the obtained fitting slope is used as the second sound time difference coefficient.

8. The detection method according to claim 7, characterized in that: Replicate zero-stress components based on in-service components, including: A replica is made with reference to the specification, material and surface roughness of the in-service component, and the residual stress of the replica is eliminated by heat treatment to obtain a zero-stress component.

9. A stress field distribution detection system for in-service components, characterized in that: include: Signal generator, ultrasonic array sensor and host computer, The signal generator is used to generate a pulse excitation signal; The ultrasonic array sensor comprises a transmitting transducer and a receiving transducer arranged opposite to each other, and a sound path fixing plate fixedly connected to the two; the transmitting transducer comprises at least two ultrasonic generators, which are used to transmit at least two groups of detection ultrasonic waves to the in-service component based on the pulse excitation signal; each group of the detection ultrasonic waves excites a critical refracted longitudinal wave signal propagating along the surface of the in-service component after incident on the in-service component; the receiving transducer comprises at least two ultrasonic receivers, which are used to respectively and correspondingly receive the critical refracted longitudinal wave signals excited by the opposite ultrasonic generators; When the ultrasonic array sensor is used to detect the stress field distribution of an in-service component, the ultrasonic array sensor is arranged on the surface of the in-service component, and three groups of detection signals in three preset directions are obtained by rotating around the geometric center of the ultrasonic array sensor; The host computer is used to obtain the first propagation sound of at least two groups of the critical refracted longitudinal wave signals corresponding to each group of the detection signals; Subtract the first propagation acoustic time from the second propagation acoustic time to obtain a three-way array acoustic time difference at at least four intersection points of the propagation path of the critical refracted longitudinal wave signal on the surface of the in-service component in three preset directions; According to the three-way array acoustic time difference, the stress measurement values ​​of the in-service component at the at least four intersection points are obtained by solving; The second propagation sound is data obtained in advance by using the same measurement method on a zero-stress component replicated with reference to an in-service component and stored locally in the host computer.

10. The detection system according to claim 9, characterized in that: The detection system also includes an oscilloscope, The oscilloscope is communicatively connected with the receiving transducer of the ultrasonic array sensor and is used for displaying the critical refracted longitudinal wave signal received by the receiving transducer.

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