Butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property test

Abstract

The invention discloses a butane flame in-situ heating system suitable for a non-isothermal high-temperature mechanical property test, relates to the technical field of aircraft thermal protection material testing, and solves the problem that in the prior art, high-temperature mechanical property testing of a material under a low-heat-flux thermal environment and a non-isothermal condition is lacked. The device comprises a butane flame heating system, an open type flow guide heat insulation device and a smoke filtering and discharging system. The butane flame is used for carrying out close-distance convection heating on the surface of one side of the sample material, the open type heat insulation flow guide device can effectively guide the flame and high-temperature air, interference to an optical measurement mechanical system is avoided, the smoke filtering and discharging system can adsorb and filter harmful gas generated by thermal decomposition of the material in the heating process, and environmental pollution is avoided. A material testing machine is used for carrying out mechanical loading on a sample, a non-heated side temperature field, key point temperature and material strain change of the sample are measured, speckle images of the sample are shot, and material strain response and failure damage behaviors are analyzed.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft thermal protection material testing, in particular to a butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing. Background Art

[0002] Currently, the high-speed and lightweight design goals of aerospace vehicles place increasingly stringent demands on the load-bearing capacity of structural materials in high-temperature environments. The practical application scenarios of high-temperature resistant structural materials often exhibit transient non-isothermal characteristics, characterized by large temperature fluctuations and significant temperature gradients along the thickness of the structure. Traditional isothermal heating equipment, such as temperature-controlled environmental chambers, has a low heating rate and can only measure the high-temperature mechanical properties of the material in a uniform thermal environment. The obtained results are only conservative estimates of the material's service performance and cannot explore the material's service limit. Therefore, experimental research on the thermal response and high-temperature mechanical properties of novel high-temperature resistant materials under non-isothermal heating conditions is of great significance for the development of high-temperature resistant, load-bearing integrated structures and for expanding their applicable operating conditions. Common heating methods for testing the thermal properties of high-temperature resistant materials include quartz lamp (heating wire) heating, resistance heating, laser irradiation heating, and oxyacetylene flame ablation heating. However, these equipment primarily focus on testing the material's thermal insulation properties while neglecting the evaluation of its mechanical properties. This has become a key factor restricting the application of advanced high-temperature resistant materials in practical high-temperature resistant, load-bearing integrated structures. Each of the above-mentioned heating methods has obvious defects, such as: 1. The quartz lamp radiation heating device and the oxyacetylene ablation test platform are both large in size, and are difficult to be applied to various mechanical testing machines to achieve in-situ heating of the material while it is under load. 2. Resistance heating requires that the sample being tested must be a conductor, which greatly limits the types of materials. 3. Although the laser radiation heating device is small in size and has good flexibility, it can also be integrated with a mechanical testing machine, but its heating method is significantly different from the situation in which the material is subjected to high-temperature airflow friction convection heating in the actual service environment, and it is difficult to establish a correspondence between the test results and the actual failure mode. In addition, the above-mentioned heating methods are mostly suitable for thermal-mechanical coupling performance testing of large-volume components. It is difficult to conduct relatively accurate quantitative testing of the high-temperature mechanical properties of the material at the specimen size level, and the testing process is relatively complicated and the testing cost is high.

[0003] At present, the Chinese patent with publication number CN114755265A discloses “A thermal insulation performance testing device and testing method for the selection of thermal protection materials”, which aims to characterize the thermal insulation performance of thermal protection materials by using butane flame heating. However, this method limits the size of the sample and cannot meet the testing requirements of samples of different sizes. In addition, this method can only characterize the thermal insulation performance of the material and cannot be used in conjunction with other mechanical testing equipment to test the high-temperature mechanical properties of the material. The Chinese patent with publication number CN106053247A discloses “A high-temperature mechanical performance testing system and method for materials based on laser irradiation heating”, which is a material mechanical performance testing system and method under in-situ laser heating conditions. It does not eliminate the impact of harmful gases produced by material decomposition on the environment, and the heat flux density of laser heating is significantly higher than that of butane flame, which is not suitable for high-temperature mechanical performance testing of materials in thermal environments with lower heat flux density. Chinese patent publication number CN104034601A discloses "A method for accurately determining high-temperature mechanical performance parameters of heat-resistant materials using digital image correlation technology." It is mainly suitable for testing the mechanical properties of materials in an isothermal thermal environment within the temperature range of 1000°C-2000°C. It cannot test the high-temperature mechanical properties of materials under non-isothermal conditions, and due to the load limit of its test device, it cannot load larger-sized specimens. Summary of the Invention

[0004] In order to solve the above-mentioned problem that the existing technology lacks high-temperature mechanical property testing of materials in thermal environments with lower heat flux density and non-isothermal conditions, the present invention hereby proposes a butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing. The present invention achieves effective simulation of the actual service environment of high-temperature resistant load-bearing integrated materials through single-sided butane flame heating. It can also simulate the situation where building structural materials are subjected to internal or external fires, and effectively cooperates with mechanical testing equipment to evaluate the mechanical properties of related materials under the above-mentioned complex thermomechanical coupling conditions. In addition, the system adopts an open thermal insulation and flow-guiding device, which can use a non-contact method to observe the temperature and deformation process of the sample in situ during the thermomechanical coupling loading process.

[0005] The present invention proposes a butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property tests, which specifically includes a butane flame heating system, an open flow guide and heat insulation device, and a test platform; the sample passes through the open flow guide and heat insulation device, and both ends are connected to the chuck of the material testing machine, the butane flame heating system heats the sample, and the test platform observes the test process; the butane flame heating system includes a fixed stand, a butane flame spray gun, and a butane gas tank, the fixed stand is provided with a butane gas tank, and the butane flame spray gun is provided on the butane gas tank; the open flow guide and heat insulation device includes two flame guide structures, an upper guard plate, and a lower guard plate. Guard plate, thermal insulation and smoke barrier sleeve and alumina thermal insulation sleeve, the thermal insulation and smoke barrier sleeve includes a lower thermal insulation and smoke barrier sleeve and an upper thermal insulation and smoke barrier sleeve; the lower thermal insulation and smoke barrier sleeve is placed on the lower hydraulic cylinder of the material testing machine, and a lower guard plate is provided on the upper end; two flame guide structures are provided on the lower guard plate; an upper guard plate is provided on the upper end of the flame guide structure, and an upper thermal insulation and smoke barrier sleeve is provided on the upper guard plate; alumina thermal insulation sleeves are provided in the lower thermal insulation and smoke barrier sleeves and the upper thermal insulation and smoke barrier sleeves; the specimen passes through the center of the upper guard plate, the lower guard plate, the thermal insulation and smoke barrier sleeve and the alumina thermal insulation sleeve; the two flame guide structures are symmetrically arranged on both sides of the specimen and in contact with the edge of the specimen.

[0006] Furthermore, the flame guide structure includes a flame guide plate and two guide plate adjustment plates. The flame guide plate is arranged between the two guide plate adjustment plates, and the flame guide plate is clamped by a number of clamping bolts arranged on the guide plate adjustment plates; the leading edge of the flame guide plate contacts the edge of the sample; the upper guard plate and the lower guard plate are provided with slide grooves, and the guide plate adjustment plate is slidably arranged in the slide grooves.

[0007] Furthermore, the leading edge of the flame deflector is provided with a slope, and the slope of the slope is 15°.

[0008] Furthermore, the rear sweep angle of the flame deflector is 15°.

[0009] Furthermore, silicate thermal insulation cotton is arranged in the alumina thermal insulation sleeve.

[0010] Furthermore, the butane flame heating system also includes a cooling device, which includes a water cooling pipe, a drainage hose, a water pump and a water tank. A water pump is provided inside the water tank, and the water outlet of the water pump is connected to one end of the water cooling pipe. The water cooling pipe is wrapped around the butane flame spray gun, and the other end of the water cooling pipe is connected to the drainage hose.

[0011] Furthermore, the fixed stand includes a fixed bracket, a vertical slide, a crossbeam and a spray gun adjustment sleeve. The upper end of the fixed bracket is provided with a vertical slide, and the crossbeam is connected to the slider of the vertical slide; the end of the crossbeam is provided with a spray gun adjustment sleeve, and the spray gun adjustment sleeve is provided with several clamping bolts to clamp the butane gas tank.

[0012] Furthermore, a vertical position scale is provided on the fixed bracket; a position pointer is provided on the crossbeam, and a cross laser is provided at the end.

[0013] Furthermore, it also includes a smoke filtration and emission system, which includes an exhaust elbow, an exhaust hose, an air filter box, an axial flow exhaust fan and a porous baffle; the air inlet end of the exhaust elbow is connected to the through hole on the lower guard plate, and the air outlet end of the exhaust elbow, the exhaust hose and the air filter box are connected in sequence; the inside of the air filter box is provided with bagged activated carbon, a porous baffle and an axial flow exhaust fan in sequence from the air inlet end to the air outlet end.

[0014] Furthermore, the test platform includes an array incandescent light source, a CCD camera, a 2D / 3D digital image analysis device and an infrared thermal imager; the CCD camera and the 2D / 3D digital image analysis device are connected, and the back side of the sample that is not heated by the flame is photographed by the array incandescent light source and the CCD camera; and the infrared thermal imager is used to perform real-time full-field temperature measurement on the back side of the sample that is not heated by the flame.

[0015] The beneficial effects of the butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing described in the present invention are: (1) The present invention discloses a butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing. The butane flame heating system has a simple structure, fewer movable components, is easy to move and assemble, and can be adapted to different types of material testing machines to realize the testing and analysis of non-isothermal high-temperature mechanical properties of materials under different mechanical loading conditions. The axis of the butane flame spray gun is kept horizontal by adjusting the spray gun sleeve, and the butane flame spray gun is accurately positioned at the center of the heated area of ​​the sample by using a vertical position scale, a position pointer and a cross laser. A water cooling device is provided to avoid local overheating of the butane flame spray gun, thereby improving the safety and reliability of the system and enabling long-term and multiple reuse.

[0016] (2) The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing described in the present invention has no effect on the optical path of the non-contact measurement system by setting an open thermal insulation guide device, which can ensure the measurement accuracy of key experimental data such as the full-field strain and temperature of the tested sample; at the same time, the flame guide plate can effectively limit the horizontal heating range of the sample surface to avoid the flame and high-temperature air bypassing the sample edge to heat the sample edge and back, effectively ensuring that the heating condition is single-sided heating. At the same time, the upper and lower guard plates limit the longitudinal heating range of the sample surface, avoiding the high-temperature airflow heating other areas of the sample, thereby improving the experimental accuracy and consistency of the test conditions.

[0017] (3) The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing described in the present invention can effectively reduce the pollution of waste gas and smoke generated during the test to the environment through the smoke filtration and exhaust system, and can effectively ensure good filtration effect by timely replacing the activated carbon inside the air filter box, and is easy to operate.

[0018] (4) The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing described in the present invention has a low device cost and fully meets the testing requirements of new high-temperature resistant materials in the selection and optimization stages. It can be used as an effective means for preliminary characterization of material thermal insulation and high-temperature mechanical properties in a laboratory environment, and has great use value and good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0020] In the attached figure: Figure 1 This is a structural schematic diagram of a butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to the present invention; Figure 2 This is a structural schematic diagram of a butane flame heating system of a butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to the present invention; Figure 3 The invention discloses a butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing. Figure 2 Front view at A in the middle; Figure 4 This is a schematic structural diagram of an open flow-guiding and heat-insulating device for a butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to the present invention; Figure 5 This is a schematic diagram of flame flow field control of an open thermal insulation guide device of a butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to the present invention; Figure 6 This is a schematic diagram of the change in the sweep angle of the flame guide plate of an open-type heat-insulating guide device of a butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to the present invention; Figure 7 This is a schematic structural diagram of a smoke filtration and exhaust system of a butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to the present invention; Figure 8This is a schematic diagram of a test platform for performing in-situ heating, mechanical loading, and in-situ observation of the material under test using a butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing in combination with 2D / 3D digital image analysis equipment; Figure 9 This is a schematic diagram of a test platform for a butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to the present invention, which is combined with an infrared thermal imager to perform in-situ heating, mechanical loading, and in-situ observation of the material under test; Among them: 1-fixed bracket; 2-vertical slide; 3-crossbeam; 4-butane flame spray gun; 5-butane gas tank; 6-spray gun adjustment sleeve; 7-cross laser; 8-water cooling pipe; 9-drain hose; 10-water pump; 11-water tank; 12-flame deflector; 13-deflector adjustment plate; 14-upper guard plate; 15-lower guard plate; 16-locating pin; 17-insulation and smoke barrier sleeve; 18-alumina insulation sleeve; 19-exhaust elbow; 20-exhaust hose; 21-air filter box; 22-axial flow exhaust fan; 23-vertical position scale; 24-position pointer; 25-porous baffle; 26-sample; 27-material testing machine; 28-array incandescent light source; 29-CCD camera; 30-2D / 3D digital image analysis equipment; 31-infrared thermal imager. DETAILED DESCRIPTION

[0021] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0024] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0025] Specific implementation method 1: See Figures 1-9 This embodiment is described in detail. The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical properties testing described in this embodiment specifically includes a butane flame heating system, an open flow-guiding heat-insulating device, a smoke filtration and exhaust system, and a test platform. Sample 26 passes through the open flow-guiding heat-insulating device, and both ends of sample 26 are connected to the clamps of a material testing machine 27. Material testing machine 27 is equipped with modules required for material tensile and compression performance testing. The butane flame heating system performs close-range convection heating on sample 26, which is pre-clamped on material testing machine 27. The horizontal distance between the nozzle and the heated surface of sample 26 is adjusted so that the center of the outer flame is located at the center of the heated area of ​​sample 26. The open flow-guiding heat-insulating device limits the heated area on the surface of sample 26 to a specified range. The smoke filtration and exhaust system filters the smoke and harmful gases generated during the heating process and discharges them into the atmosphere. The test platform observes the test process.

[0026] The butane flame heating system includes a fixed stand, a butane flame spray gun 4, a butane gas tank 5, and a cooling device. The fixed stand includes a fixed bracket 1, a vertical slide 2, a crossbeam 3, and a spray gun adjustment sleeve 6. The vertical slide 2 is provided at the upper end of the fixed bracket 1, and the crossbeam 3 is connected to the slider of the vertical slide 2. The end of the crossbeam 3 is provided with a spray gun adjustment sleeve 6, which is provided with several clamping bolts to clamp the butane gas tank 5. The butane flame spray gun 4 is provided on the butane gas tank 5. The position, pitch angle, and roll angle of the butane gas tank 5 and the butane flame spray gun 4 can be fine-tuned by the clamping bolts to ensure that the axis of the butane flame spray gun 4 remains horizontal with the ground. The fixed bracket 1 is provided with a vertical position scale 23, the crossbeam 3 is provided with a position pointer 24, and the end of the crossbeam 3 is provided with a cross laser 7, which is located directly below the butane flame spray gun 4. The cooling device includes a water cooling pipe 8, a drainage hose 9, a water pump 10 and a water tank 11. The water pump 10 is arranged inside the water tank 11. The water outlet of the water pump 10 is connected to one end of the water cooling pipe 8. The water cooling pipe 8 is wrapped around the front end of the butane flame spray gun 4, and the other end of the water cooling pipe 8 is connected to the drainage hose 9; the water cooling pipe 8 continuously cools and dissipates heat for the butane flame spray gun 4 through circulating cooling water to ensure the safety of the butane flame spray gun 4 for long-term use.

[0027] Before the test, the butane flame spray gun 4 connected to the butane gas tank 5 is placed in the spray gun adjusting sleeve 6, and the screws on the side wall of the spray gun adjusting sleeve 6 are adjusted to fine-tune the position of the butane flame spray gun 4. At the same time, the crossbeam 3 is adjusted horizontally until the axis of the spray gun barrel is parallel to the ground and the distance between the spray gun nozzle and the heated surface of the sample meets the test requirements. The distance L between the center of the cross laser 7 and the axis of the spray gun barrel is measured and recorded. The power of the cross laser 7 is turned on, and the position of the fixed bracket 1 and the vertical slide 2 is adjusted until the center point of the red laser cross line completely coincides with the center point of the heated area of ​​the sample. Note the scale shown on the vertical position ruler 23 indicated by the position pointer 24 at this time, and then adjust the vertical slide 2 downward to move the crossbeam downward by a distance L. At this time, the axis of the butane flame spray gun 4 barrel completely coincides with the center point of the heated area of ​​the sample 26. Completely immerse the small water pump 10 in the water tank 11, and place the outlet end of the drain hose 9 into the water tank 11, turn on the water pump power, and wait until the water flow at the drain hose outlet is stable and uniform. This can ensure the maximum cooling water flow to achieve the best cooling effect of the spray gun barrel.

[0028] The open flow-guiding heat-insulating device includes two flame flow-guiding structures, an upper guard plate 14, a lower guard plate 15, a heat-insulating smoke-blocking sleeve 17 and an alumina heat-insulating sleeve 18. The upper guard plate 14 and the lower guard plate 15 are both circular metal sheets with a square hole in the center to facilitate the passage of specimens 26 of different sizes, and rectangular slide grooves are provided on both sides thereof; the heat-insulating smoke-blocking sleeve 17 includes a lower heat-insulating smoke-blocking sleeve and an upper heat-insulating smoke-blocking sleeve; a flat plate is provided at the lower end of the lower heat-insulating smoke-blocking sleeve, and a plurality of leveling screws are provided on the flat plate. The lower heat-insulating smoke-blocking sleeve is placed on the lower hydraulic cylinder of the material testing machine 27 through the flat plate and the leveling screws, and the upper end of the lower heat-insulating smoke-blocking sleeve is made horizontal by the leveling screws; a lower guard plate 15 is provided at the upper end of the lower heat-insulating smoke-blocking sleeve; a lower guard plate 15 is provided on the lower guard plate 15 There are two flame guide structures, the lower end of which is set in a rectangular chute; the upper end of the flame guide structure is set in the rectangular chute of the upper guard plate 14, the upper guard plate 14 is provided with a positioning hole, and the lower guard plate 15 is provided with a positioning pin fixing groove, the lower end of the positioning pin 16 passes through the positioning hole and is inserted into the positioning pin fixing groove to position the upper guard plate 14 and the lower guard plate 15; the upper guard plate 14 is provided with an upper heat-insulating smoke-blocking sleeve; the lower heat-insulating smoke-blocking sleeve and the upper heat-insulating smoke-blocking sleeve are both provided with an alumina heat-insulating sleeve 18; the sample 26 passes through the center of the upper guard plate 14, the lower guard plate 15, the heat-insulating smoke-blocking sleeve 17 and the alumina heat-insulating sleeve 18; the two flame guide structures are symmetrically arranged on both sides of the sample 26 and in contact with the edge of the sample 26. The alumina heat-insulating sleeve 18 is provided with silicate heat-insulating cotton, which is used to wrap the surface of the non-heated area of ​​the sample, thereby isolating the sample 26 from heat exchange with the environment.

[0029] The flame deflector structure includes a flame deflector plate 12 and two deflector adjustment plates 13. The flame deflector plate 12 is positioned between the two deflector adjustment plates 13. The flame deflector plate 12 is clamped by a number of clamping bolts provided on the deflector adjustment plates 13 to adjust the position and angle of the flame deflector plate 12. The leading edge of the flame deflector plate 12 contacts the edge of the specimen 26. Four rectangular slots are provided on the opposing surfaces of the upper guard plate 14 and the lower guard plate 15. The four deflector adjustment plates 13 of the two flame deflector structures are slidably disposed in the rectangular slots, and the deflector adjustment plates 13 can slide linearly within the slots. Because the four deflector adjustment plates 13 are fixed in height, the spacing between the upper guard plate 14 and the lower guard plate 15 remains unchanged during the test, effectively limiting the longitudinal heat exposure range of the specimen 26 surface and improving the experimental accuracy and consistency of the test conditions.

[0030] The leading edge of the flame deflector 12 is provided with a slope with a slope of 15°, which can rectify the high-temperature air. In the horizontal direction, the vertical plane where the leading edge of the flame deflector 12 contacts the sample 26 and is parallel to the heated surface of the sample 26 is set as the starting angle 0°. The tail of the flame deflector 12 is adjusted arbitrarily within the range of 15° to 30° toward the back of the sample 26, forming a 15° sweep angle range. Figure 5 As shown. Due to the wall effect, the high-temperature air flows laminarly along the surface of flame deflector 12, guiding the flame and high-temperature air. This prevents the flame and high-temperature air from forming turbulent flow near the heated surface of specimen 26, which could lead to uneven local heat flux density distribution. It also prevents heat accumulation in the high-temperature air, which could cause thermal deformation of the insulating deflector device and affect experimental accuracy. Furthermore, because the leading edge of flame deflector 12 contacts the edge of specimen 26, it effectively prevents the flame and high-temperature air from bypassing the edge of specimen 26 to heat the edge and back of specimen 26, effectively ensuring single-sided heating.

[0031] The smoke filtering and exhaust system includes an exhaust elbow 19, an exhaust hose 20, an air filter box 21, an axial-flow exhaust fan 22 and a porous baffle 25; the two air inlet ends of the exhaust elbow 19 are inserted into the two through holes on the lower guard plate 15, the two through holes are symmetrically arranged, and are located between the two rectangular slides on the lower guard plate 15, and the air outlet end of the exhaust elbow 19, the exhaust hose 20 and the air filter box 21 are connected in sequence; the interior of the air filter box 21 is provided with bagged activated carbon, a porous baffle 25 and an axial-flow exhaust fan 22 in sequence from the air inlet end to the air outlet end, and the bagged activated carbon filters the smoke exhaust gas generated by the heated combustion of the sample; the porous baffle 25 is used to separate the bagged activated carbon and the axial-flow exhaust fan 22 to prevent the activated carbon from being inhaled into the axial-flow exhaust fan 22 and causing damage to the exhaust fan, and the exhaust end of the axial-flow exhaust fan 22 is directly connected to the outside atmosphere.

[0032] The test platform includes an array incandescent light source 28, a CCD camera 29, a 2D / 3D digital image analysis device 30, an infrared thermal imager 31, an infrared pyrometer, and a non-contact video extensometer. The CCD camera 29 and the 2D / 3D digital image analysis device 30 are connected and mounted on the unheated back side of the specimen 26. The position of the CCD camera 29 is adjusted so that the center of the camera lens and the center of the back side of the specimen 26 are in the same plane. The imaging parameters of the CCD camera 29 and the height and brightness of the array incandescent light source 28 are adjusted so that the image quality of the high-temperature-resistant speckle pattern pre-sprayed on the back side of the specimen 26 meets the analysis requirements in the software of the 2D / 3D digital image analysis device 30. While the sample is being heated and mechanically loaded in situ, the sample 26 is synchronously loaded according to the loading program preset on the material testing machine 27, and the temperature of the key points of the sample is measured and recorded in real time on the back of the heated area of ​​the sample 26 using an infrared pyrometer, the material strain change is measured using a non-contact video extensometer, and the full-field strain measurement is performed using a 2D / 3D digital image analysis device 30. The speckle image of the sample 26 is captured by the 2D / 3D digital image analysis device 30 to analyze the material strain response and failure damage behavior; the 2D / 3D digital image analysis device 30 can capture the damage evolution process and the final failure mode on the back of the sample 26 during the thermal-mechanical coupling loading process by intermittently capturing high-resolution images. Since sample 26 is affected by the flame on the heated surface, the surface strain cannot be measured. However, the temperature rise of the high-temperature resistant and load-bearing structural material in the actual service environment is caused by the frictional convection heat transfer of the high-temperature air on one side, while the other side of the structural material is located inside the aircraft and the temperature is relatively low. The lightweight design requires a small thickness of the thermal protection material to meet the plane stress assumption. Therefore, measuring the surface strain change on the back of sample 26 that is not heated by the flame can effectively evaluate the overall deformation degree of sample 26.

[0033] While the sample 26 is being heated and mechanically loaded in situ, the back of the sample 26 is measured in real time using an infrared thermal imager 31. This provides a distribution and evolution of the temperature at different locations on the back of the sample 26 as the heating time progresses. Furthermore, a temperature curve for local key points can be extracted. Key points can be selected as the center of the flame-heated surface, the center of the back of the heated area, or a point at the edge of the back. The center of the flame-heated surface represents the location where the material suffers the most severe thermal damage. The temperature at the center of the back can be used to quantitatively assess the thermal insulation performance of the material. The temperature difference between the edge and center can be used to indirectly measure the uniformity of the flame heat flux distribution and to calculate the thermal conductivity within the material surface. The measured temperature and position data are transmitted in real time to the corresponding analysis software for thermal response analysis of the material.

[0034] To summarize the above implementation cases, the butane flame in-situ heating system for non-isothermal high-temperature mechanical properties testing described in the present invention has a simple structure, fewer movable components, is easy to move and assemble, and can also be adapted to different types of material testing machines to realize the testing and analysis of non-isothermal high-temperature mechanical properties of materials under different mechanical loading conditions; the axis of the butane flame spray gun 4 is ensured to be horizontal by the spray gun adjustment sleeve 6, and the butane flame spray gun 4 is accurately positioned to the center of the heated area of ​​the sample 26 by using the vertical position scale 23, the position pointer 24 and the cross laser 7; by providing a water cooling device, local overheating of the butane flame spray gun 4 is avoided, the safety and reliability of the system are improved, and the system can be reused for a long time and multiple times.

[0035] The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property tests described in the present invention has no influence on the optical path of the non-contact measurement system by setting an open thermal insulation guide device, thereby ensuring the measurement accuracy of key experimental data such as the full-field strain and temperature of the tested sample 26; at the same time, the flame guide plate 12 is used to effectively limit the horizontal heating range of the surface of the sample 26, thereby avoiding the flame and high-temperature air bypassing the edge of the sample 26 to heat the edge and back of the sample 26, effectively ensuring that the heating condition is single-sided heating. At the same time, the upper guard plate 14 and the lower guard plate 15 limit the longitudinal heating range of the surface of the sample 26, thereby avoiding the high-temperature airflow heating other areas of the sample 26, thereby improving the experimental accuracy and the consistency of the test conditions.

[0036] The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property tests described in the present invention can effectively reduce the pollution of the exhaust gas and smoke generated during the test to the environment through the smoke filtering and exhaust system, and can effectively ensure good filtering effect by timely replacing the activated carbon inside the air filter box, and is easy to operate.

[0037] The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical properties testing described in the present invention has low device cost and fully meets the testing requirements of new high-temperature resistant materials in the selection and optimization stages. It can be used as an effective means for preliminary characterization of material insulation and high-temperature mechanical properties in laboratory environments, and has great use value and good application prospects.

[0038] The specific embodiments described above further illustrate the objectives, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is merely a specific embodiment of the present invention and is not intended to limit the invention. Reasonable combinations of the features described in the above embodiments are also possible. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing, characterized by: The invention comprises a butane flame heating system, an open flow guide heat insulation device and a test platform; the sample (26) passes through the open flow guide heat insulation device and is connected to the clamps of the material testing machine (27) at both ends; the butane flame heating system heats the sample (26) and the test platform observes the test process; The butane flame heating system comprises a fixed stand, a butane flame spray gun (4) and a butane gas tank (5), wherein the butane gas tank (5) is provided on the fixed stand, and the butane flame spray gun (4) is provided on the butane gas tank (5); The open flow-guiding heat-insulating device comprises two flame flow-guiding structures, an upper guard plate (14), a lower guard plate (15), a heat-insulating smoke-blocking sleeve (17) and an alumina heat-insulating sleeve (18), wherein the heat-insulating smoke-blocking sleeve (17) comprises a lower heat-insulating smoke-blocking sleeve and an upper heat-insulating smoke-blocking sleeve; the lower heat-insulating smoke-blocking sleeve is placed on the lower hydraulic cylinder of the material testing machine (27), and a lower guard plate (15) is provided on the upper end; two flame flow-guiding structures are provided on the lower guard plate (15); the flame flow-guiding An upper guard plate (14) is provided at the upper end of the flow structure, and an upper heat-insulating smoke-blocking sleeve is provided on the upper guard plate (14); an alumina heat-insulating sleeve (18) is provided in both the lower heat-insulating smoke-blocking sleeve and the upper heat-insulating smoke-blocking sleeve; the sample (26) passes through the center of the upper guard plate (14), the lower guard plate (15), the heat-insulating smoke-blocking sleeve (17) and the alumina heat-insulating sleeve (18); and two flame guide structures are symmetrically provided on both sides of the sample (26) and in contact with the edge of the sample (26).

2. The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to claim 1 is characterized in that: The flame guide structure comprises a flame guide plate (12) and two guide plate adjustment plates (13); the flame guide plate (12) is arranged between the two guide plate adjustment plates (13); the flame guide plate (12) is clamped by a plurality of clamping bolts arranged on the guide plate adjustment plates (13); the leading edge of the flame guide plate (12) contacts the edge of the sample (26); and the upper guard plate (14) and the lower guard plate (15) are provided with slide grooves, and the guide plate adjustment plates (13) are slidably arranged in the slide grooves.

3. The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to claim 2, characterized in that: The front edge of the flame deflector (12) is provided with a slope, and the slope of the slope is 15°.

4. The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to claim 2, characterized in that: The flame deflector (12) has a rearward sweep angle of 15°.

5. The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to claim 4, characterized in that: Silicate thermal insulation cotton is provided in the alumina thermal insulation sleeve (18).

6. The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to any one of claims 1 to 5, characterized in that: The butane flame heating system further includes a cooling device, which includes a water cooling pipe (8), a drainage hose (9), a water pump (10) and a water tank (11). The water tank (11) is provided with a water pump (10). The water outlet of the water pump (10) is connected to one end of the water cooling pipe (8). The water cooling pipe (8) is wound around the butane flame spray gun (4). The other end of the water cooling pipe (8) is connected to the drainage hose (9).

7. The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to claim 6, characterized in that: The fixed stand comprises a fixed bracket (1), a vertical slide (2), a crossbeam (3) and a spray gun adjusting sleeve (6); the vertical slide (2) is provided at the upper end of the fixed bracket (1); the crossbeam (3) is connected to the slider of the vertical slide (2); the spray gun adjusting sleeve (6) is provided at the end of the crossbeam (3); a plurality of clamping bolts are provided on the spray gun adjusting sleeve (6) and clamp the butane gas tank (5).

8. The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to claim 7, characterized in that: A vertical position scale (23) is provided on the fixed bracket (1); a position pointer (24) is provided on the crossbeam (3), and a cross laser (7) is provided at the end.

9. The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to claim 6, characterized in that: The smoke filter exhaust system further comprises an exhaust elbow (19), an exhaust hose (20), an air filter box (21), an axial flow exhaust fan (22) and a porous baffle (25); the air inlet end of the exhaust elbow (19) is connected to the through hole on the lower guard plate (15), and the air outlet end of the exhaust elbow (19), the exhaust hose (20) and the air filter box (21) are connected in sequence; and inside the air filter box (21), bagged activated carbon, a porous baffle (25) and an axial flow exhaust fan (22) are sequentially arranged from the air inlet end to the air outlet end.

10. The butane flame in-situ heating system suitable for non-isothermal high-temperature mechanical property testing according to claim 1, characterized in that: The test platform includes an array incandescent light source (28), a CCD camera (29), a 2D / 3D digital image analysis device (30) and an infrared thermal imager (31); the CCD camera (29) and the 2D / 3D digital image analysis device (30) are connected to photograph the back side of the sample (26) that is not heated by the flame through the array incandescent light source (28) and the CCD camera (29); and the infrared thermal imager (31) performs real-time full-field temperature measurement on the back side of the sample (26) that is not heated by the flame.

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