Infrared pulse phase nondestructive testing device and method based on electrorheological thermal resistance change

Abstract

The present invention provides an infrared pulse phase nondestructive testing device and method based on the change of electrorheological thermal resistance, comprising a heat storage body (2), an electrorheological body (3), a thermal imager (4), a computer (5), a switch (6), and a pulse generator (7); one side of the electrorheological body (3) is in close contact with the heat storage body (2); the heat storage body (2) and the electrorheological body (3) are connected to the pulse generator (7) via a cable (8); the pulse generator (7) is connected to the computer (5), the switch (6) is arranged between the pulse generator (7) and the computer (5); and the thermal imager (4) is connected to the computer (5). This technical solution is suitable for detecting defects in deep hidden places.

Description

Technical Field

[0001] The present invention relates to the field of infrared detection technology, in particular to an infrared pulse phase nondestructive detection device and method based on the change of electrorheological thermal resistance. Background Art

[0002] The infrared pulse phase method is an advanced detection technology that applies strong pulsed light to the surface of the sample to be tested. When the infrared heat wave encounters a defect during its propagation in the component, its phase will change. By comparing the phase difference between the transmitted heat wave and the received heat wave, non-destructive detection of component defects can be achieved, which has the advantages of being fast and intuitive. However, the depth of defects that can be detected by this technology is not large, and it is usually used to detect shallow surface defects. The signal-to-noise ratio of deep defects is low because the temperature rise of deep defects is weak (usually <0.5°C) due to insufficient thermal excitation, which can easily be confused with background noise, resulting in missed detection or misjudgment. In addition, the instruments and equipment required for detection are large and costly, making it difficult to achieve online detection. Summary of the Invention

[0003] In view of this, the object of the present invention is to provide an infrared pulse phase nondestructive testing device and method based on the change of electrorheological thermal resistance, which is suitable for detecting defects in deeply buried areas.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: an infrared pulse phase nondestructive testing device based on the change of electrorheological thermal resistance, comprising a thermal storage body 2, an electrorheological device 3, a thermal imager 4, a computer 5, a switch 6, and a pulse generator 7; the thermal storage body 2 is closely attached to one side of the electrorheological device 3, and the thermal storage body 2 and the electrorheological device 3 are connected to the pulse generator 7 via a cable 8; the pulse generator 7 is connected to the computer 5, and the switch 6 is arranged between the pulse generator 7 and the computer 5; the thermal imager 4 is connected to the computer 5; the thermal storage body 2 includes a thermal storage body microcolumn array 23, and the electrorheological device 3 includes an electrorheological fluid 32;

[0005] Through the synergistic effect of the heat storage body 2 and the electrorheological fluid 3, when power is applied during the detection phase, heat is directionally transferred to the deep defect area of ​​the test piece 1 through the heat storage body microcolumn array 23 and the orderly arranged electrorheological fluid 32; the infrared thermal imager 4 monitors the defects encountered by the infrared heat wave when propagating in the test piece 1, and detects deep defects of the test piece 1.

[0006] In a preferred embodiment, the thermal storage body 2 is composed of a copper electrode 21 embedded in a base, a serpentine resistance wire 22 and a thermal storage body microcolumn array 23; the copper electrode 21 embedded in the base is connected to the pulse generator 7 through the cable 8.

[0007] In a preferred embodiment, the thermal storage microcolumn array 23 specifically includes a first metal substrate and a semiconductor material coating, and the semiconductor material coating is provided on the surface of the first metal substrate.

[0008] In a preferred embodiment, the electrorheological device 3 is composed of a flexible packaging layer 31, an electrorheological fluid 32, a pre-embedded electrode 33, a protective layer micro-pillar array 34, a copper sheet 35, and a flexible thermal conductive sheet 36; the pre-embedded electrode 33 is connected to the pulse generator 7 via the cable 8;

[0009] The flexible packaging layer 31 , the electrorheological fluid 32 , the protective layer micro-pillar array 34 , the copper sheet 35 and the flexible thermal conductive sheet 36 are arranged in sequence.

[0010] In a preferred embodiment, the protective layer micro-pillar array 34 , the copper sheet 35 and the flexible heat conductive sheet 36 form a protective layer of the electrorheological device 3 .

[0011] In a preferred embodiment, the protective layer microcolumn array 34 specifically includes a second metal substrate, a semiconductor polymer layer and a flexible copper foil layer; the outer layer of the second metal substrate is sequentially provided with the semiconductor polymer layer and the flexible copper foil layer.

[0012] In a preferred embodiment, the electrorheological fluid 32 uses high-viscosity silicone oil as the liquid matrix, and by adding hydrophobic fumed silica as a thixotropic agent, the liquid matrix presents a gel state when standing still. Diamond powder, graphene and ceramic particles are selected as fillers to form the filling layer of the electrorheological fluid 32.

[0013] In a preferred embodiment, the infrared thermal imager 4 transmits the captured surface dynamic temperature field of the test piece 1 to the computer 5 via a USB cable. Based on the temperature data measured by the infrared thermal imager 4, a time-temperature matrix is ​​established, the differential temperature field is calculated, the thermal diffusion rate field is constructed, and phase information is extracted and defects are detected using the phase method.

[0014] In a preferred embodiment, the computer 5 sends a synchronization start instruction to the pulse generator 7 and the infrared thermal imager 4 through a hardware interrupt mechanism to ensure synchronization between the thermal excitation signal and the recording of the infrared thermal imager 4 .

[0015] The present invention also provides an infrared pulse phase nondestructive testing method based on electrorheological thermal resistance changes, which utilizes an infrared pulse phase nondestructive testing device based on electrorheological thermal resistance changes. A thermal storage body 2 and an electrorheological fluid 3 are first placed in close contact with one side of the surface of a test object 1. The thermal storage body 2 and the electrorheological fluid 3 are then charged and discharged at a frequency. Through the synergistic action of the thermal storage body 2 and the electrorheological fluid 3, when power is applied during the testing phase, heat is directed to the deep defect area of ​​the test object 1 through the high-conductivity thermal storage body microcolumn array 23 and the orderly arranged electrorheological fluid 32. After power is removed during non-operating periods, the microcolumn array increases thermal resistance, and the electrorheological fluid transitions to an adiabatic state, effectively preventing heat diffusion and maintaining system thermal stability. Simultaneously, an infrared thermal imager 4 is used to capture the dynamic temperature distribution of the surface of the test object 1 on the other side of the test object 1, and a computer 5 is used to collect temperature distribution information. When an infrared heat wave encounters a defect while propagating through the test object 1, its phase changes. By comparing the phase difference between the transmitted and received heat waves, phase analysis of the information data is performed on the computer 5 to diagnose the defect.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] First, the temperature control is precise and the changes are regular, which facilitates signal collection and analysis; second, the equipment used is small and easy to carry; third, it can be applied to the detection of in-service equipment. For example, when the temperature of the internal medium is very high, an electrorheological device can be attached to the inner wall of the equipment, and the heat source inside the equipment itself can be used (without the use of additional heating devices) to realize the detection of the equipment, thus creating a new and widely applicable detection method for the infrared pulse phase method.

[0018] Main Application: Suitable for buried defect detection in oil and gas pipelines, pressure vessels, and other environments. Periodic thermal stimulation and data analysis can help prevent sudden leaks. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the overall structure of an infrared pulse phase nondestructive testing device based on electrorheological thermal resistance change according to a preferred embodiment of the present invention;

[0020] Figure 2 Schematic diagram of the heat storage structure of the infrared pulse phase nondestructive testing device based on electrorheological thermal resistance change according to a preferred embodiment of the present invention;

[0021] Figure 3 Schematic diagram of the electrorheological structure of an infrared pulse phase nondestructive testing device based on electrorheological thermal resistance change according to a preferred embodiment of the present invention;

[0022] Figure 4Schematic diagram of the heat storage micro-pillar array structure of the infrared pulse phase non-destructive testing device based on electrorheological thermal resistance change according to a preferred embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the protective layer micro-pillar array structure of an infrared pulse phase non-destructive testing device based on electrorheological thermal resistance change in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application; as used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form, and it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations.

[0027] Infrared pulse phase nondestructive testing device based on the change of electrorheological thermal resistance, reference Figure 1-5 , including a heat storage body 2, an electrorheological device 3, a thermal imager 4, a computer 5, a switch 6 and a pulse generator 7; one side of the electrorheological device 3 is closely attached to the heat storage body 2, and the heat storage body 2 and the electrorheological device 3 are connected to the pulse generator 7 via a cable 8; the pulse generator 7 is connected to the computer 5, and the switch 6 is arranged between the pulse generator 7 and the computer 5; the thermal imager 4 is connected to the computer 5.

[0028] Specifically, the thermal storage body 2 is composed of a copper electrode 21 embedded in a base, a serpentine resistance wire 22 and a thermal storage body microcolumn array 23; the copper electrode 21 embedded in the base is connected to the pulse generator 7 through the cable 8.

[0029] The thermal storage microcolumn array 23 specifically includes a first metal substrate 231 and a semiconductor material coating 232. The semiconductor material coating 232 is provided on the surface of the first metal substrate 231. Specifically, the first metal substrate 231 is a copper substrate.

[0030] Specifically, the electrorheological device 3 is composed of a flexible packaging layer 31, an electrorheological fluid 32, a pre-embedded electrode 33, a protective layer micro-pillar array 34, a copper sheet 35 and a flexible thermal conductive sheet 36; the pre-embedded electrode 33 is connected to the pulse generator 7 via the cable 8;

[0031] The flexible packaging layer 31 , the electrorheological fluid 32 , the protective layer micro-pillar array 34 , the copper sheet 35 and the flexible thermal conductive sheet 36 are sequentially arranged to form the protective layer of the electrorheological fluid 3 .

[0032] The protective layer microcolumn array 34 specifically includes a second metal substrate 341 , a semiconductor polymer layer 342 and a flexible copper foil layer 343 ; the outer layer of the second metal substrate 341 is sequentially provided with the semiconductor polymer layer 342 and the flexible copper foil layer 343 .

[0033] Specifically, the electrorheological fluid 32 uses high-viscosity silicone oil as the liquid matrix, and adds hydrophobic fumed silica as a thixotropic agent to make the liquid matrix present a gel state when standing still. Diamond powder, graphene and ceramic particles are used as fillers to form the filling layer of the electrorheological fluid 32.

[0034] Specifically, the infrared thermal imager 4 transmits the captured surface dynamic temperature field of the test piece 1 to the computer 5 via a USB cable. Based on the temperature data measured by the infrared thermal imager 4, a time-temperature matrix is ​​established, the differential temperature field is calculated, the thermal diffusion rate field is constructed, and phase information is extracted and defects are detected using the phase method.

[0035] Specifically, the computer 5 sends a synchronization start instruction to the pulse generator 7 and the infrared thermal imager 4 through the hardware interrupt mechanism to ensure synchronization between the thermal excitation signal and the recording of the infrared thermal imager 4 .

[0036] The infrared pulse phase nondestructive testing method based on electrorheological thermal resistance changes employs the aforementioned infrared pulse phase nondestructive testing device based on electrorheological thermal resistance changes. A thermal storage body 2 and an electrorheological fluid 3 are first placed in close contact with one side of the surface of a test object 1. The thermal storage body 2 and the electrorheological fluid 3 are then charged and discharged at a frequency. Through the synergistic action of the thermal storage body 2 and the electrorheological fluid 3, when power is applied during the testing phase, heat is directed to the deep defect region of the test object 1 through the highly conductive thermal storage body microcolumn array 23 and the orderly arranged electrorheological fluid 32. After power is removed during non-operating periods, the microcolumn array increases thermal resistance, and the electrorheological fluid transitions to an adiabatic state, effectively preventing heat diffusion and maintaining system thermal stability. Simultaneously, an infrared thermal imager 4 is used to capture the dynamic temperature distribution of the surface of the test object 1 on the other side of the test object 1, and a computer 5 is used to collect temperature distribution information. When an infrared heat wave encounters a defect while propagating through the test object 1, its phase changes. By comparing the phase difference between the transmitted and received heat waves, phase analysis of the information data is performed on the computer 5 to diagnose the defect.

[0037] The heat transfer of the thermal storage body 2 to the test piece 1 is controlled by the coordinated "micro-column array + electric field regulation" mechanism to achieve directional guidance of transient heat flow. Its working principle is as follows: the thermal storage body micro-column array 23 has a composite structure of a first metal matrix 231 and a semiconductor material coating 232. When voltage is applied, the thermal resistance of the semiconductor material coating 232 is reduced, thereby achieving efficient directional conduction of heat to the electrorheological fluid 3; electric field regulation: the electrorheological fluid 3 produces a phase change response under the action of the electric field. When power is turned on: the fillers of the electrorheological fluid 32 are arranged in an orderly manner along the direction of the electric field to form a continuous heat conduction channel, and the thermal conductivity coefficient is improved; when power is turned off: the fillers of the electrorheological fluid 32 are randomly dispersed, and the thermal conductivity coefficient drops to the level of an insulating material. Through the synergistic effect of these two elements, when power is applied during the test phase, heat is directed to the deep defect areas of the test piece 1 through the highly conductive thermal storage micropillar array 23 and the orderly arrayed electrorheological fluid 3. When power is removed from the non-operating period, the thermal storage micropillar array 23 increases thermal resistance, and the electrorheological fluid 3 transforms into an adiabatic state, effectively preventing heat diffusion and maintaining the thermal stability of the system. To prevent the electrorheological fluid 3's encapsulation film from being punctured by thorns or protrusions, a protective layer is added to the exterior of the encapsulation layer. This protective layer, which adheres closely to the electrorheological fluid encapsulation layer and the test piece, consists of a copper sheet 35, two rows of protective layer micropillar arrays 34, and a flexible thermal conductive sheet 36. It combines thermal conductivity and external force protection, effectively preventing electrorheological fluid leakage due to external factors. During testing, a pulse generator 7 provides electrical signals to the thermal storage element 2 and the electrorheological fluid 3, respectively controlling the heat release function of the thermal storage element 2 and the electric field switching of the electrorheological fluid 3. The timing of the thermal storage element 2 switching and the electrorheological fluid 3 switching can be independently adjusted to match the heat diffusion time. For example, after the switch of the heat storage body 2 is started, the switch of the electrorheological device 3 is started after a delay of 0.1 to 0.5 seconds. The delay time is dynamically adjusted according to the thermal conductivity of the material of the test piece 1 and the defect depth to ensure that heat is fully transferred to the deep defect area. By precisely controlling the opening and closing frequency of the circuit, the efficiency of heat transfer to deep defects is effectively improved. The periodic thermal resistance switching of the electrorheological device can also significantly improve the temperature contrast in the deep defect area, thereby improving the signal-to-noise ratio.

[0038] Before testing, an electric pulse generator 7 sends an electrical signal to the thermal storage element 2 via a cable 8. The thermal storage element 2 transmits the electrical signal internally via copper electrodes 21 embedded within the substrate. Internal serpentine resistors 22 then convert the electrical energy into thermal energy, actively generating heat. The thermal storage element's micropillar array 23 is made of a highly thermally conductive metal (such as copper), with a surface nanocoating of a semiconductor material (such as doped silicon or silicon carbide) to form a metal-semiconductor composite structure. The metal portion is responsible for efficient heat conduction, while the semiconductor layer further optimizes the heat conduction path through electric field regulation. This enhances heat conduction from the thermal storage element 2 to the electrorheological element 3 by increasing the contact area with the electrorheological element 3.

[0039] During testing, cable 8 sends an electrical signal to the embedded electrodes 33 of the electrorheological device 3, causing the filler of the electrorheological fluid within its encapsulation layer to align in the direction of the electric field, forming a highly thermally conductive path. High-viscosity silicone oil is used as the liquid matrix for the electrorheological fluid 32 to enhance its resistance to flow and self-sustaining properties while maintaining its electric field responsiveness. A small amount of hydrophobic fumed silica is added as a thixotropic agent, causing the liquid matrix to gel when static. However, under pressure or an electric field, it regains its fluidity, achieving controllable switching between solid and liquid states. A specific proportion of diamond powder, graphene, and ceramic particles are used as fillers to form the electrorheological fluid's filling layer. PDMS (polydimethylsiloxane) is used as the flexible encapsulation layer 31, with electrodes 33 embedded within the filling layer.

[0040] The protective layer consists of a copper sheet 35, two rows of micro-pillar arrays 34, and a flexible thermally conductive sheet 36. The protective layer's micro-pillar array is composed of alternating copper and semiconductor polymer, forming a "metal-semiconductor-metal" sandwich structure. The metal micro-pillars increase the contact area, while the semiconductor polymer layer adjusts thermal resistance through electric field response. When power is applied, the semiconductor polymer's conductivity increases, reducing the interfacial thermal resistance, and heat is transferred directionally along the metal micro-pillars to the test piece. When power is removed, the semiconductor layer returns to a high-resistance state, blocking the heat conduction path. Combined with the phase change properties of the electrorheological fluid 3-2, the directional heat transfer capability is enhanced. The flexible thermally conductive sheet adheres closely to the test piece, preventing the encapsulation layer from being punctured and providing excellent flexibility, allowing it to conform to test pieces 1 of varying shapes.

[0041] The infrared thermal imager 4's support structure can be moved forward, backward, left, right, and rotated 360° horizontally via wheels, and features a self-locking function, facilitating optimization of the shooting position. Furthermore, the infrared thermal imager transmits the captured dynamic temperature field of the specimen surface to the console computer 5 via a USB cable for storage, reproduction, and analysis of the dynamic infrared thermal images. This includes establishing a time-temperature matrix based on the camera's measured temperature data, calculating the differential temperature field, constructing a thermal diffusion rate field, extracting phase information, and performing phase-based defect detection.

[0042] The switch 6 of the pulse generator 7 is connected to the computer 5. In order to realize synchronous control, the computer 5 has a built-in multi-threaded applet, whose functions include: synchronous triggering: sending synchronous start instructions to the pulse generator 7 and the infrared thermal imager 4 through the hardware interrupt mechanism to ensure strict synchronization between the thermal excitation signal and the infrared thermal imager recording; communication management: communicating with the pulse generator 7 and the infrared thermal imager 4, and interacting with the PLC controller in real time to transmit delay time parameters and control instructions.

[0043] The switch control of the current rheostat 3 is realized by the PLC controller. The specific process is: when the heat storage body 2 is started, the PLC built-in high-speed timer module starts countdown, and after the countdown ends, the power-on signal of the current rheostat 3 is triggered.

Claims

1. Infrared pulse phase nondestructive testing device based on electrorheological thermal resistance change, characterized in that: The invention comprises a heat storage body (2), an electrorheological device (3), a thermal imager (4), a computer (5), a switch (6) and a pulse generator (7); one side of the electrorheological device (3) is in close contact with the heat storage body (2); the heat storage body (2) and the electrorheological device (3) are connected to the pulse generator (7) via a cable (8); the pulse generator (7) is connected to the computer (5); the switch (6) is arranged between the pulse generator (7) and the computer (5); the thermal imager (4) is connected to the computer (5); the heat storage body (2) comprises a heat storage body microcolumn array (23); the electrorheological device (3) comprises an electrorheological fluid (32); Through the synergistic effect of the heat storage body (2) and the electrorheological fluid (3), when power is applied during the detection phase, heat is directed to the deep defect area of ​​the test piece (1) through the heat storage body microcolumn array (23) and the orderly arranged electrorheological fluid (32); the infrared thermal imager (4) monitors the defects encountered by the infrared heat wave when propagating in the test piece (1), thereby detecting the deep defects of the test piece (1); The electrorheological device (3) is composed of a flexible packaging layer (31), an electrorheological fluid (32), a pre-buried electrode (33), a protective layer micro-column array (34), a copper sheet (35), and a flexible thermal conductive sheet (36); the pre-buried electrode (33) is connected to the pulse generator (7) via the cable (8); The flexible packaging layer (31), the electrorheological fluid (32), the protective layer microcolumn array (34), the copper sheet (35) and the flexible heat-conducting sheet (36) are arranged in sequence.

2. The infrared pulse phase nondestructive testing device based on electrorheological thermal resistance change according to claim 1 is characterized in that: The heat storage body (2) is composed of a copper electrode (21) embedded in a substrate, a serpentine resistance wire (22), and a heat storage body microcolumn array (23); the copper electrode (21) embedded in the substrate is connected to the pulse generator (7) via the cable (8).

3. The infrared pulse phase nondestructive testing device based on electrorheological thermal resistance change according to claim 2 is characterized in that: The heat storage microcolumn array (23) specifically comprises a first metal substrate and a semiconductor material coating, wherein the semiconductor material coating is provided on the surface of the first metal substrate.

4. The infrared pulse phase nondestructive testing device based on electrorheological thermal resistance change according to claim 1 is characterized in that: The protective layer microcolumn array (34), the copper sheet (35) and the flexible heat conductive sheet (36) form a protective layer of the electrorheological device (3).

5. The infrared pulse phase nondestructive testing device based on electrorheological thermal resistance change according to claim 1 is characterized in that: The protective layer microcolumn array (34) specifically comprises a second metal matrix, a semiconductor polymer layer and a flexible copper foil layer; the outer layer of the second metal matrix is ​​provided with the semiconductor polymer layer and the flexible copper foil layer in sequence.

6. The infrared pulse phase nondestructive testing device based on electrorheological thermal resistance change according to claim 1 is characterized in that: The electrorheological fluid (32) uses high-viscosity silicone oil as a liquid matrix, and by adding hydrophobic fumed silica as a thixotropic agent, the liquid matrix presents a gel state when standing still. Diamond powder, graphene and ceramic particles are selected as fillers to form a filling layer of the electrorheological fluid (32).

7. The infrared pulse phase nondestructive testing device based on electrorheological thermal resistance change according to claim 1 is characterized in that: The infrared thermal imager (4) transmits the captured surface dynamic temperature field of the test piece (1) to the computer (5) via a USB cable. Based on the temperature data measured by the infrared thermal imager (4), a time-temperature matrix is ​​established, the differential temperature field is calculated, the thermal diffusion rate field is constructed, and the phase information is extracted and the defects are detected by the phase method.

8. The infrared pulse phase nondestructive testing device based on electrorheological thermal resistance change according to claim 1 is characterized in that: The computer (5) sends a synchronization start instruction to the pulse generator (7) and the infrared thermal imager (4) through a hardware interrupt mechanism to ensure synchronization between the thermal excitation signal and the recording of the infrared thermal imager (4).

9. Infrared pulse phase nondestructive testing method based on electrorheological thermal resistance change, characterized in that: An infrared pulse phase nondestructive testing device based on the change of electrorheological thermal resistance as described in any one of claims 1 to 8 is used; first, the heat storage body (2) and the electrorheological body (3) are placed close to the surface side of the test piece (1), and then the heat storage body (2) and the electrorheological body (3) are charged and discharged according to the frequency. When the heat storage body (2) and the electrorheological body (3) are energized during the detection phase, the heat is transferred directionally to the deep defect area of ​​the test piece (1) through the high-conductivity heat storage body microcolumn array (23) and the orderly arranged electrorheological fluid (32); during the non-working period, After power is turned off, the heat storage microcolumn array (23) increases thermal resistance, and the electrorheological state is converted into an adiabatic state, effectively preventing heat diffusion and maintaining the thermal stability of the system; at the same time, an infrared thermal imager (4) is used to shoot the dynamic temperature distribution of the surface of the test piece (1) on the other side of the test piece (1), and a computer (5) is used to collect temperature distribution information; when the infrared heat wave encounters a defect during propagation in the test piece (1), its phase will change, and by comparing the phase difference between the transmitted heat wave and the received heat wave, the phase analysis of the information data is performed on the computer (5) to achieve diagnosis of the defect.

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