Natural environment test rack and sample coating damage quantitative evaluation monitoring method

Abstract

The invention discloses a natural environment test rack and a sample coating damage quantitative evaluation method. A probe detection system is arranged on a main body frame of the test rack, the probe detection system comprises a displacement mechanism installed on the main body frame, a through hole is formed in a supporting rod, a connecting plate is arranged above the supporting rod, the connecting plate and the supporting rod move synchronously, and a plurality of metal probes which are arranged in an array and can move up and down are arranged in the through hole; the supporting rod and the metal probe are jointly used as a power supply positive electrode, the connecting plate is used as a power supply negative electrode, and when the metal probe moves up and down, circuits of the power supply positive electrode and the power supply negative electrode are conducted and a detection result signal is fed back through the control module; the method comprises the steps that in the natural environment test process, the displacement mechanism is regularly controlled to operate, the connecting plate and the supporting rod synchronously move according to the preset speed, and a detection result signal fed back by the control module is obtained in real time. According to the invention, coating bulge and spalling defects of the large plate-shaped sample can be observed timely and accurately.

Description

Technical Field

[0001] The invention belongs to the technical field of natural environment testing of large plate-shaped specimens, and particularly relates to a natural environment testing stand and a method for quantitatively evaluating and monitoring damage of specimen coatings. Background Art

[0002] Currently, when conducting environmental testing on panel products, standard specimens are typically cut according to industry standards. These specimens typically do not exceed 0.4 m by 0.4 m in size. These specimens are then mounted on an environmental testing frame, and the test is conducted according to the specified test parameters. However, for many large panel products (1.5 m by 1.5 m or greater), all environmental stresses experienced during actual use are reflected through the entire panel. Localized changes in morphology and performance do not accurately represent changes in the overall panel. For example, in equipment panels used in long-term desert observation stations, the thermal stresses induced by solar radiation in various parts of such panels interact with each other, ultimately manifesting through macroscopic and microscopic phenomena across the entire product. Therefore, it is necessary to develop a suitable environmental testing frame for large panel specimens to facilitate more accurate environmental testing.

[0003] When evaluating product performance through environmental testing, coating degradation (particularly the quantification of coating damage) is a key evaluation metric. Currently, there are two main approaches for monitoring coating degradation: one involves regularly capturing the coating's surface morphology with a high-definition camera and analyzing each change individually; the other involves technicians regularly visually observing and recording the coating's surface morphology. However, both approaches are suitable for existing small standard specimens and are not suitable for large plate-shaped specimens. Observing coating bulges on large plate-shaped specimens requires multiple high-definition cameras and complex image processing systems, which are extremely expensive (often costing hundreds of thousands of yuan) and difficult to visually observe. Furthermore, when coating bulges are no more than 3mm in height, the bulged area still appears highly integrated or consistent with other areas when viewed from the front (facing the coating), making it difficult to detect in a timely manner. Summary of the Invention

[0004] At least in response to the problems mentioned in the background technology, the present invention aims to provide a natural environment test stand and a method for quantitative evaluation and monitoring of sample coating damage.

[0005] The present invention adopts the following technical solutions.

[0006] A natural environment test frame includes a main frame, on which a probe detection system is arranged. The probe detection system includes a displacement mechanism installed on the main frame, a support rod is arranged on the displacement mechanism, the axis of the support rod is parallel to the surface of a large plate-shaped specimen, a through hole is provided on the support rod, a connecting plate is provided above the support rod, the connecting plate moves synchronously with the support rod, and a plurality of metal probes arranged in an array and capable of moving up and down are arranged in the through hole; the support rod and the metal probes are used together as the positive electrode of the power supply, and the connecting plate is used as the negative electrode of the power supply. When the metal probes move up and down, the circuits of the positive electrode of the power supply and the negative electrode of the power supply are connected, and a detection result signal is fed back through a control module.

[0007] Furthermore, the metal probe is a copper needle with a diameter not exceeding 1 mm, the top of the copper needle is a needle tip structure, and the bottom of the copper needle is fixedly connected to a tetrafluoroethylene microsphere (polytetrafluoroethylene sphere). Such a structure can more smoothly perform coating damage detection.

[0008] Furthermore, the connecting plate is composed of a frame and a plurality of graphite blocks mounted on the frame, and each graphite block serves as an independent negative power terminal.

[0009] Furthermore, the through-hole is filled with graphite powder to a thickness of no more than 5mm, through which the metal probe passes. A fluffy carbon fiber layer is placed on the graphite block, and the upwardly-moving tip of the metal probe can be inserted into the carbon fiber layer, establishing electrical continuity between the metal probe and the carbon fiber layer. This structure facilitates more stable and smooth monitoring of coating surface morphology.

[0010] Preferably, the main frame is used to install large plate-shaped specimens with a size of not less than 1.5m*1.5m.

[0011] Furthermore, the depth of the through hole is not less than 1 / 3 of the length of the metal probe.

[0012] Furthermore, the distance between the top surface of the support rod and the bottom surface of the connecting plate is no more than 10 mm, and when the metal probe is in the initial state, the limiter on the metal probe just rests against the top surface of the support rod, which is conducive to more accurate coating damage detection.

[0013] A method for quantitatively assessing and monitoring coating damage of a specimen using the aforementioned natural environment test stand comprises the following steps: Step 1: Install the large plate-shaped specimen on the main frame; Step 2: Conduct natural environment tests on large plate specimens according to the set test specifications; Step 3: During the natural environment test, the displacement mechanism is regularly controlled to move synchronously with the connecting plate and the support rod at a preset speed, and the control module feedback detection result signal is obtained in real time; Step 4: When the detection result signal fed back by the control module corresponds to a circuit being turned on, the corresponding detection location and detection time are recorded. This detection location has coating bulges, and the corresponding coating bulge information is output.

[0014] Furthermore, it also includes step 5: after a bulge appears at the detection site A, when the metal probe moves to the detection site A again in the subsequent detection process, if the circuit corresponding to the detection result signal fed back by the control module is not conductive, the corresponding detection time is recorded. At this time, there is coating peeling at the detection site A, and the corresponding coating peeling information is output.

[0015] Preferably, the large plate-shaped specimen is an equipment panel used in a desert observation station.

[0016] Beneficial effects: The present invention provides a natural environment test stand specifically for large plate-shaped specimens. Without the need for high-definition cameras and complex image processing systems, it can be used to timely and accurately observe coating bulging and peeling defects of large plate-shaped specimens. In the process of quantitative evaluation of coating damage (coating bulging and peeling) monitoring, it has the advantages of low implementation cost, good stability, and easy and smooth monitoring. It is particularly suitable for timely detection of coating bulges with a height of not less than 4 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a three-dimensional schematic diagram of the natural environment test stand in Example 1; Figure 2 for Figure 1 Schematic diagram of part A in the middle; Figure 3 Schematic diagram of the initial state of the probe detection system of the natural environment test stand in Example 1; Figure 4 This is a schematic diagram of the probe detection system detecting coating bulges in Example 1; Figure 5 This is a schematic diagram of the probe detection system in Example 1 detecting coating peeling. DETAILED DESCRIPTION

[0018] The following is a clear and complete description of the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention. Example 1

[0019] Combine Figures 1 to 5As shown, a natural environment test frame includes a main frame 12, which is used to install a large plate specimen 2 with a size of not less than 1.5m*1.5m. A probe detection system 13 is arranged on the main frame 12, and the probe detection system 13 includes a displacement mechanism 14 installed on the main frame 12. The displacement mechanism 14 includes a screw mechanism and a guide rail installed on the edge of the main frame 12, the screw 19 and the guide rail 20 of the screw mechanism are parallel, and the screw 19 and the guide rail 20 are respectively located on two parallel frame beams of the main frame 12; a support rod 1 is arranged on the displacement mechanism 14, one end of the support rod 1 is connected to the movable seat 21 of the screw mechanism through a first connecting member, and the other end of the support rod 1 is matched with the guide rail 20 through a second connecting member, and the first connecting member, the support rod 1 and the second connecting member together constitute a gate-shaped support frame, and when the screw mechanism is running, the movable seat 21 of the screw mechanism and the gate-shaped support frame move synchronously. Among them, the axis of the support rod 1 is parallel to the surface of the large plate-shaped specimen 2, and a through hole 3 is provided on the support rod 1. The depth of the through hole 3 is 1 / 3 to 1 / 2 of the length of the metal probe 5. A connecting plate 4 is provided above the support rod 1, and the connecting plate 4 moves synchronously with the support rod 1. A plurality of metal probes 5 arranged in an array and capable of moving up and down are provided in the through hole 3; the support rod 1 and the metal probe 5 are used together as the positive pole of the power supply, and the connecting plate 4 and its built-in carbon fiber layer 10 are used as the negative pole of the power supply, and when the metal probe 5 moves up and down, the circuit of the positive pole of the power supply and the negative pole of the power supply is connected and the detection result signal is fed back through the control module.

[0020] In this embodiment, the metal probe 5 is a copper needle with a diameter (diameter of the main body) of 1 mm. The top of the copper needle is a needle tip structure, and the bottom of the copper needle is fixedly connected to the tetrafluoroethylene microsphere 11. The diameter of the tetrafluoroethylene microsphere 11 is 5 mm.

[0021] In this embodiment, the connecting plate 4 is composed of a skeleton 7 and several graphite blocks 8 installed on the skeleton 7. A carbon fiber layer 10 in a fluffy state is provided on the graphite block 8. Specifically, a stepped hole is started on the graphite block 8, and the carbon fiber layer 10 in a fluffy state is stuffed into the stepped hole. Then, a cover plate is provided on the top of the carbon fiber layer 10, and each graphite block 8 serves as an independent negative power supply terminal 15; the through hole 3 is filled with graphite powder 9, and the filling thickness of the graphite powder 9 is 5 mm. The metal probe 5 passes through the graphite powder 9; after moving upward, the top of the metal probe 5 can be inserted into the carbon fiber layer 10, and the circuit conduction between the metal probe 5 and the carbon fiber layer 10 is realized.

[0022] In this embodiment, the distance between the top surface of the support rod 1 and the bottom surface of the connecting plate 4 (i.e., the gap 6) is not greater than 10 mm, and when the metal probe 5 is in the initial state, the limiter 18 on the metal probe 5 is just against the top surface of the support rod 1. At this time, the distance between the top end of the metal probe 5 and the carbon fiber layer 10 is 2~3.5 mm.

[0023] In this embodiment, a method for quantitatively evaluating and monitoring coating damage of a specimen using the natural environment test frame of this embodiment is used to provide technical support for the coating performance evaluation of a certain equipment panel product at a desert observation station. The steps include: Step 1: Install the large plate-shaped specimen 2 on the main frame 12; Step 2: Perform a natural environment test on the large plate specimen 2 according to the set test specifications; Step 3: During the natural environment test, the displacement mechanism 14 is regularly controlled to move synchronously with the connecting plate 4 and the support rod 1 at a preset speed, and the control module feedback detection result signal is obtained in real time; wherein, the translation speed of the connecting plate 4 and the support rod 1 is 2 mm / s; Step 4: When the detection result signal fed back by the control module corresponds to the circuit being turned on, the corresponding detection location and detection time are recorded. This detection location indicates that there is coating bulging, and the corresponding coating bulging information is output; Step 5. After a bulge appears at the detection site A, when the metal probe 5 moves to the detection site A again in the subsequent detection process, if the circuit corresponding to the detection result signal fed back by the control module is not conductive, the corresponding detection time is recorded. At this time, there is coating peeling at the detection site A, and the corresponding coating peeling information is output.

[0024] During use: When there is no bulge on the surface of the large plate sample 2, the metal probe 5 on the connecting plate 4 is always in the initial state, such as Figure 3 As shown, at this time, the top of the metal probe 5 is not in contact with the carbon fiber layer 10, and the negative electrode of the power supply and the positive electrode of the power supply are not energized; when a bulge appears on the surface of the large plate-shaped specimen 2, the metal probe 5 on the connecting plate 4 contacts the bulge 17 (that is, the tetrafluoroethylene microspheres 11 are located on the bulge 17), as shown in FIG. Figure 4 As shown, at this time, the metal probe 5 is pushed upward, and the top end of the metal probe 5 is inserted into the carbon fiber layer 10 through the stepped hole on the graphite block 8, thereby realizing the connection between the negative electrode of the power supply and the positive electrode of the power supply, and the detection result signal is fed back through the control module. Once the detection result signal of "the negative electrode of the power supply and the positive electrode of the power supply are connected" is detected, it indicates that there is a bulge 17 at the corresponding position, for example Figure 4 The power negative electrode unit 15 and the power positive electrode unit 16 are connected to each other; when the bulge on the surface of the large plate sample 2 is broken and peeled off, as shown in FIG. Figure 5 As shown, when the tetrafluoroethylene microspheres 11 on the metal probe 5 are located in the peeling area 18 (that is, when the tetrafluoroethylene microspheres 11 are again located in the bulge area 17 detected previously), the metal probe 5 on the connecting plate 4 will be in the initial state again. At this time, the top of the metal probe 5 is not in contact with the carbon fiber layer 10, and the negative pole of the power supply and the positive pole of the power supply are not energized.

[0025] In this embodiment, since the metal probe 5 passes through the graphite powder 9, the electrical connection between the metal probe 5 and the support rod 1 can be guaranteed. Since the carbon fiber layer 10 is embedded in the graphite block 8, the circuit between the metal probe 5 and the negative electrode of the power supply can be smoothly connected. Since the force that the coating bulge area can withstand is very small and it is very easy to be compacted, a specific probe is required to perform stable and reliable detection. If the needle tip is used directly, the bulge will be easily pierced. If the needle body used is thicker, the bulge will be easily flattened, and the metal probe 5 will be easily stuck, resulting in detection failure. The present invention cleverly utilizes the aforementioned specific metal probe 5 with tetrafluoroethylene microspheres 11, and cooperates with graphite powder 9 and carbon fiber layer 10 as a medium for conducting the circuit, so as to ensure that when the tetrafluoroethylene microspheres 11 at the lower end of the metal probe 5 touch the bulge, the metal probe 5 can be smoothly and stably driven to be inserted into the carbon fiber layer 10, thereby achieving effective monitoring.

[0026] Comparative Implementation Example 1: Referring to Example 1, the difference from Example 1 is that the graphite powder 9 and the carbon fiber layer 10 are omitted, and a conductive sheet is provided on the top of the metal probe 5. Other structures are the same.

[0027] Comparative Implementation Example 2: Referring to Example 1, the difference between it and Example 1 is that: the graphite powder 9 and the carbon fiber layer 10 are omitted, the diameter of the metal probe 5 is 8 mm, and the other structures are the same.

[0028] The test frames in Example 1 and the comparative implementation scheme were used to detect three bulges with a height of 5 mm on the coating. The results showed that: using the scheme in Example 1, the detection result signal can be fed back through the control module (that is, the bulge defect can be effectively detected); using comparative implementation schemes 1 and 2, the control modules both fed back the detection result signal, that is, the bulge defect could not be effectively detected.

[0029] The present invention provides a natural environment test stand specifically for large plate-shaped specimens. Without the need for high-definition cameras and complex image processing systems, it can be used to promptly and accurately observe coating bulging and peeling defects on large plate-shaped specimens. Furthermore, in the process of quantitatively assessing coating damage (coating bulging and peeling), the stand has the advantages of low implementation cost, good stability, and ease of monitoring. It is particularly suitable for promptly detecting coating bulges with a height of no less than 4 mm.

Claims

1. A natural environment test frame, comprising a main frame (12), characterized in that: A probe detection system (13) is provided on the main frame (12), and the probe detection system (13) includes a displacement mechanism (14) installed on the main frame (12), a support rod (1) is provided on the displacement mechanism (14), the axis of the support rod (1) is parallel to the surface of the large plate-shaped specimen (2), a through hole (3) is provided on the support rod (1), a connecting plate (4) is provided above the support rod (1), the connecting plate (4) and the support rod (1) move synchronously, and a plurality of metal probes (5) arranged in an array and capable of moving up and down are provided in the through hole (3); the support rod (1) and the metal probes (5) are used together as the positive electrode of the power supply, and the connecting plate (4) is used as the negative electrode of the power supply, and when the metal probes (5) move up and down, the circuit of the positive electrode of the power supply and the negative electrode of the power supply is connected and the detection result signal is fed back through the control module.

2. The natural environment test stand according to claim 1, characterized in that: The metal probe (5) is a copper needle with a diameter not exceeding 1 mm, the top of the copper needle is a needle tip structure, and the bottom of the copper needle is fixedly connected to the tetrafluoroethylene microsphere (11).

3. The natural environment test stand according to claim 2, characterized in that: The connecting plate (4) is composed of a frame (7) and a plurality of graphite blocks (8) mounted on the frame (7), and each graphite block (8) serves as an independent negative power terminal (15).

4. The natural environment test stand according to claim 3, characterized in that: The through hole (3) is filled with graphite powder (9), the filling thickness of the graphite powder (9) is not greater than 5 mm, and the metal probe (5) passes through the graphite powder (9); a carbon fiber layer (10) in a fluffy state is provided on the graphite block (8), and the top of the metal probe (5) after moving upward can be inserted into the carbon fiber layer (10), thereby realizing circuit conduction between the metal probe (5) and the carbon fiber layer (10).

5. The natural environment test stand according to claim 4, characterized in that: The main frame (12) is used to install a large plate-shaped specimen (2) with a size of not less than 1.5m*1.5m.

6. The natural environment test stand according to claim 5, characterized in that: The depth of the through hole (3) is not less than 1 / 3 of the length of the metal probe (5).

7. The natural environment test stand according to claim 5, characterized in that: The distance between the top surface of the support rod (1) and the bottom surface of the connecting plate (4) is no more than 10 mm, and when the metal probe (5) is in the initial state, the limiting member (18) on the metal probe (5) just rests against the top surface of the support rod (1).

8. A method for quantitatively evaluating coating damage of a sample using the natural environment test stand according to any one of claims 1 to 7, characterized in that: The steps include: Step 1, installing the large plate-shaped specimen (2) on the main frame (12); Step 2, conducting a natural environment test on the large plate specimen (2) according to the set test specifications; Step 3, during the natural environment test, regularly controlling the displacement mechanism (14) to move synchronously with the connecting plate (4) and the support rod (1) at a preset speed, and obtaining a control module feedback detection result signal in real time; Step 4: When the detection result signal fed back by the control module corresponds to a circuit being turned on, the corresponding detection location and detection time are recorded. This detection location has coating bulges, and the corresponding coating bulge information is output.

9. The method for quantitatively evaluating sample coating damage according to claim 8, characterized in that: The method further includes step 5: after a bulge appears at the detection site A, when the metal probe (5) is moved to the detection site A again in the subsequent detection process, if the circuit corresponding to the detection result signal fed back by the control module is not turned on, the corresponding detection time is recorded, and at this time, the detection site A has coating peeling, and the corresponding coating peeling information is output.

10. The method for quantitatively evaluating coating damage of a sample according to claim 9, characterized in that: The large plate-shaped specimen (2) is an equipment panel used in a desert observation station.

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