Device and method for detecting crack resistance of aluminum alloy welded pipe

Abstract

The invention relates to the technical field of aluminum alloy welded pipe mechanical property testing, in particular to an aluminum alloy welded pipe anti-cracking performance detection device and a detection method thereof. The aluminum alloy welded pipe anti-cracking performance detection device comprises a workbench, a fixed clamping seat, a sliding guide rail, a sliding clamping seat and a loading mechanism; a hydraulic cylinder is used for adjusting the height of the annular mounting frame, so that the center of the annular mounting frame is matched with the axial direction of the aluminum alloy welded pipe sample, a plurality of electric push rods are synchronously started, and radial loads which are uniformly and progressively increased are applied to the sample; the industrial camera is used for shooting a video image of a weld joint area in real time, the crack resistance of the sample is detected, by adopting the structure and synchronously applying force through the multiple electric push rods arranged in a surrounding mode, uniform radial compression of the welded pipe is achieved, stress distribution is more reasonable, the weakest link of the weld joint can be truly exposed, and the detection result is more comprehensive and reliable.

Description

Technical Field

[0001] This invention relates to the field of mechanical property testing technology for aluminum alloy welded pipes, and in particular to a device and method for testing the crack resistance of aluminum alloy welded pipes. Background Technology

[0002] Aluminum alloy welded pipes are widely used in aerospace, new energy vehicles, and high-pressure gas transportation due to their advantages such as lightweight, high strength, and corrosion resistance. The crack resistance of the welded joint area is a key indicator for evaluating the quality of welded pipes and ensuring structural safety; therefore, developing efficient crack resistance testing devices is crucial.

[0003] Currently, most existing devices for testing the crack resistance of aluminum alloy welded pipes are based on the traditional circumferential cutting or flattening test principles. Their basic structure typically includes a rigid frame, a pair of clamping dies (usually V-shaped or flat) for holding or supporting the welded pipe sample, and a hydraulically or servo-motor driven loading mechanism. The principle is to apply a radial load to the clamping dies through the loading mechanism, causing radial deformation of the welded pipe sample until cracking occurs at its weld joint. The crack resistance is then qualitatively or semi-quantitatively assessed by recording the maximum load or observing the crack morphology.

[0004] However, existing crack resistance testing devices rely on unidirectional or bidirectional loading methods, which can lead to uneven stress distribution and fail to expose the weakest link in the welded pipe, thus reducing the reliability of the test. Summary of the Invention

[0005] The purpose of this invention is to provide a device and method for testing the crack resistance of aluminum alloy welded pipes, aiming to solve the technical problem that existing crack resistance testing devices, which rely solely on unidirectional or bidirectional loading, can lead to uneven stress distribution, fail to expose the weakest link in the welded pipe, and reduce the reliability of the test.

[0006] To achieve the above objectives, the present invention provides a device for testing the crack resistance of aluminum alloy welded pipes, comprising a worktable, a fixed clamping seat, a sliding guide rail, a sliding clamping seat, and a loading mechanism. The fixed clamping seat is fixedly disposed at one end of the upper surface of the worktable, and the sliding guide rail is installed at the other end of the upper surface of the worktable. The sliding clamping seat is slidably disposed on the sliding guide rail, and a locking bolt is disposed on the sliding clamping seat. A plurality of locking holes are disposed on the sliding guide rail. The loading mechanism includes a frame, a drive assembly, a sliding seat, a hydraulic cylinder, a ring mounting bracket, multiple electric push rods, multiple force application blocks, a connecting arm, and an industrial camera. The frame is mounted on the top of the workbench. The sliding seat is slidably disposed at the bottom of the top of the frame. The drive assembly is disposed inside the top of the frame. The output end of the drive assembly is connected to the sliding seat. The hydraulic cylinder is disposed at the bottom of the sliding seat. The ring mounting bracket is mounted on the output end of the hydraulic cylinder. Multiple electric push rods are evenly disposed around the ring mounting bracket. Each electric push rod has a force application block at its output end. The multiple force application blocks are evenly distributed around the aluminum alloy welded pipe to be inspected. One end of the connecting arm is connected to the bottom of the ring mounting bracket. The industrial camera is disposed at the other end of the connecting arm. The shooting end of the industrial camera corresponds to the weld seam of the aluminum alloy welded pipe to be inspected.

[0007] The sliding seat includes a seat body, two connecting plates, and two sliding plates. Slide grooves are provided on both sides of the top of the frame. The connecting plates are fixedly provided on both sides of the seat body. The sliding plate is provided on the end of each connecting plate away from the seat body. The sliding plate is slidably connected to the corresponding slide groove.

[0008] The drive assembly includes a servo motor, a threaded rod, and a ball screw nut assembly. The servo motor is mounted on one side of the top of the frame, the threaded rod is mounted inside the top of the frame, the output end of the servo motor is connected to the threaded rod, the ball screw nut assembly is mounted on the threaded rod, and the ball screw nut assembly is connected to the sliding seat.

[0009] The threaded rod has a rotating head at both ends, and the top of the frame has rotating bearings on both sides. The rotating head is embedded in the corresponding rotating bearing, and the output end of the servo motor is connected to the corresponding rotating head.

[0010] The annular mounting bracket includes a connecting block and a regular hexagonal frame. The connecting block is fixedly installed at the top of the regular hexagonal frame and is perpendicular to the regular hexagonal frame. The end of the connecting block away from the regular hexagonal frame is connected to the output end of the hydraulic cylinder. Each side of the regular hexagonal frame is provided with an electric push rod.

[0011] The connecting arm has a fixing block at one end near the annular mounting frame, and a mounting base at the other end away from the annular mounting frame. The mounting base has an inclined surface on the side facing the center of the annular mounting frame, and the industrial camera is mounted on the inclined surface.

[0012] The aluminum alloy welded pipe crack resistance testing device also includes a protective plate. The protective plate is provided at the bottom of the top of the frame. A through groove is provided on the sliding seat. The protective plate passes through the through groove and is located outside the threaded rod.

[0013] The protective plate has mounting blocks on both sides at both ends. One end of the mounting block is connected to the side of the protective plate, and the other end of the mounting block is connected to the side of the top of the frame.

[0014] This invention also provides a method for testing the crack resistance of aluminum alloy welded pipes, applied to the aluminum alloy welded pipe crack resistance testing device described above, comprising the following steps: Sample clamping: After passing the aluminum alloy welded pipe sample through the annular mounting bracket, place one end of it at the fixed clamping seat and fix it by the fixed clamping seat. Slide the sliding clamping seat so that the sliding clamping seat corresponds to the other end of the aluminum alloy welded pipe. Fix the other end of the aluminum alloy welded pipe sample by the sliding clamping seat and fix the sliding clamping seat by the locking bolt. Loading alignment: The sliding seat is controlled to slide using the drive assembly, so that the annular mounting bracket moves to the middle of the aluminum alloy welded pipe sample. The height of the annular mounting bracket is adjusted using the hydraulic cylinder so that the center of the annular mounting bracket matches the axial direction of the aluminum alloy welded pipe sample. Multiphase synchronous loading: Multiple electric push rods are started synchronously, so that the force application blocks at their output ends move synchronously toward the center of the sample until they contact the outer wall of the sample and are pre-pressed. Then, the electric push rods are controlled to continue to output synchronously, applying a uniformly increasing radial load to the sample. Data acquisition: When multiple electric actuators simultaneously apply a uniformly increasing radial load to the sample, the output load and displacement data of each electric actuator are recorded, and video images of the weld area are captured in real time by the industrial camera; Crack critical point determination: When a crack is detected in the weld area in the video image captured in real time by the industrial camera, the load value and displacement value of the electric push rod at this time are recorded. Output results: When cracks appear in the weld area of ​​the specimen, the recorded load and displacement values ​​of the electric push rod are output as quantitative indicators of the specimen's crack resistance.

[0015] This invention discloses a device and method for testing the crack resistance of aluminum alloy welded pipes, comprising a worktable, a fixed clamping seat, a sliding guide rail, a sliding clamping seat, and a loading mechanism. The loading mechanism includes a frame, a drive assembly, a sliding seat, a hydraulic cylinder, an annular mounting frame, multiple electric push rods, multiple force application blocks, a connecting arm, and an industrial camera. The drive assembly controls the sliding seat to slide, causing the annular mounting frame to move to the center of the aluminum alloy welded pipe sample. The hydraulic cylinder adjusts the height of the annular mounting frame so that its center matches the axial direction of the aluminum alloy welded pipe sample. Simultaneously, multiple electric push rods are activated, causing the force application blocks at their output ends to move synchronously towards the center of the sample until they contact the outer wall of the sample and apply pre-pressure. The electric actuators are then controlled to continue synchronously outputting a uniformly increasing radial load onto the sample. When multiple electric actuators simultaneously apply a uniformly increasing radial load to the sample, the output load and displacement data of each electric actuator are recorded. A video image of the weld area is captured in real-time by an industrial camera. When a crack is detected in the weld area in the video image captured in real-time by the industrial camera, the load and displacement values ​​of the electric actuators at this time are recorded, thus completing the test of the sample's crack resistance. Using the above structure, the simultaneous application of force by multiple electric actuators arranged in a ring achieves uniform radial compression of the welded pipe, resulting in a more reasonable stress distribution, accurately exposing the weakest point of the weld, and providing more comprehensive and reliable test results. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of the aluminum alloy welded pipe crack resistance testing device according to the first embodiment of the present invention.

[0018] Figure 2 This invention provides Figure 1 A magnified view of the local structure at point A.

[0019] Figure 3 This invention provides Figure 1 A magnified view of the local structure at point B.

[0020] Figure 4 This is a schematic diagram of the frame structure in the first embodiment of the present invention.

[0021] Figure 5 This is a schematic diagram of the frame structure in the second embodiment of the present invention.

[0022] Figure 6 This invention provides Figure 5 A magnified view of the local structure at point C.

[0023] Figure 7 This is a flowchart of the steps in the method for testing the crack resistance of aluminum alloy welded pipes provided by the present invention.

[0024] 101-Workbench, 102-Fixed clamping seat, 103-Sliding guide rail, 104-Sliding clamping seat, 105-Frame, 106-Hydraulic cylinder, 107-Electric push rod, 108-Force application block, 109-Connecting arm, 110-Industrial camera, 111-Base, 112-Connecting plate, 113-Sliding plate, 114-Servo motor, 115-Threaded rod, 116-Ball screw nut pair, 117-Connecting block, 118-Regular hexagonal frame, 119-Locking bolt, 120-Locking hole, 121-Slide groove, 122-Rotating head, 123-Rotating bearing, 124-Fixed block, 125-Mounting seat, 126-Inclined surface, 201-Protective plate, 202-Through groove, 203-Mounting block. Detailed Implementation

[0025] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0026] First embodiment: Please see Figures 1 to 4 ,in Figure 1 This is a schematic diagram of the aluminum alloy welded pipe crack resistance testing device according to the first embodiment. Figure 2 yes Figure 1 A magnified view of the local structure at point A. Figure 3 yes Figure 1 A magnified view of the local structure at point B. Figure 4 This is a schematic diagram of the frame structure in the first embodiment.

[0027] This invention provides a device for testing the crack resistance of aluminum alloy welded pipes, comprising a worktable 101, a fixed clamping seat 102, a sliding guide rail 103, a sliding clamping seat 104, and a loading mechanism. The loading mechanism includes a frame 105, a drive assembly, a sliding seat, a hydraulic cylinder 106, a ring mounting frame, multiple electric push rods 107, multiple force application blocks 108, a connecting arm 109, and an industrial camera 110. The sliding seat includes a base 111, two connecting plates 112, and two sliding plates 113. The drive assembly includes a servo motor 114, a threaded rod 115, and a ball screw and nut assembly 116. The ring mounting frame includes a connecting block 117 and a regular hexagonal frame 118. This solution addresses the problem in existing crack resistance testing devices where unidirectional or bidirectional loading leads to uneven stress distribution, failing to expose the weakest point of the welded pipe and reducing testing reliability. Therefore, this solution can be applied to the structure of a crack resistance testing device for aluminum alloy welded pipes.

[0028] In this specific embodiment, a fixed clamping seat 102 is fixedly installed at one end of the upper surface of the workbench 101, and a sliding guide rail 103 is installed at the other end of the upper surface of the workbench 101. A sliding clamping seat 104 is slidably installed on the sliding guide rail 103, and a locking bolt 119 is provided on the sliding clamping seat 104. A plurality of locking holes 120 are provided on the sliding guide rail 103. By setting up the sliding guide rail 103 and the sliding clamping seat 104, it is possible to clamp aluminum alloy welded pipes of different lengths to be tested, which is more applicable. Furthermore, by setting up the locking bolt 119 and the locking holes 120, the sliding clamping seat 104 can be fixed.

[0029] The frame 105 is mounted on the top of the workbench 101. A sliding seat is slidably disposed at the bottom of the top of the frame 105. A drive assembly is disposed inside the top of the frame 105, and the output end of the drive assembly is connected to the sliding seat. A hydraulic cylinder 106 is disposed at the bottom of the sliding seat, and an annular mounting frame is mounted on the output end of the hydraulic cylinder 106. A plurality of electric push rods 107 are evenly disposed around the annular mounting frame, and a force-applying block 108 is disposed at the output end of each electric push rod 107. The plurality of force-applying blocks 108 are evenly distributed around the aluminum alloy welded pipe to be tested. One end of the connecting arm 109 is connected to the bottom of the annular mounting frame, and the other end of the connecting arm 109 is disposed with an industrial camera 110. The shooting end of the industrial camera 110 corresponds to the weld seam of the aluminum alloy welded pipe to be tested. The drive assembly controls the sliding seat to slide, so that the annular mounting frame moves to the middle of the aluminum alloy welded pipe sample. The hydraulic cylinder 106 adjusts the... The height of the annular mounting bracket is such that its center matches the axial direction of the aluminum alloy welded pipe sample. Multiple electric push rods 107 are simultaneously activated, causing the force-applying blocks 108 at their output ends to move synchronously towards the center of the sample until they contact and pre-compress the outer wall of the sample. Subsequently, the electric push rods 107 continue to output synchronously, applying a uniformly increasing radial load to the sample. When multiple electric push rods 107 simultaneously apply a uniformly increasing radial load to the sample, the output load and displacement data of each electric push rod 107 are recorded. A video image of the weld area is captured in real-time by the industrial camera 110. When a crack is detected in the weld area in the video image captured in real-time by the industrial camera 110, the load and displacement values ​​of the electric push rods 107 at this time are recorded, completing the test of the sample's crack resistance. Using the above structure, the synchronous application of force by multiple electric push rods 107 arranged in a ring achieves uniform radial compression of the welded pipe, resulting in a more reasonable stress distribution, accurately exposing the weakest point of the weld, and providing more comprehensive and reliable test results.

[0030] Secondly, both sides of the top of the frame 105 are provided with sliding grooves 121, and both sides of the base 111 are fixedly provided with connecting plates 112. Each connecting plate 112 is provided with a sliding plate 113 at the end away from the base 111. The sliding plate 113 is slidably connected to the corresponding sliding groove 121. Through the arrangement of the sliding plate 113 and the sliding groove 121, the sliding seat can slide at the top of the frame 105.

[0031] Meanwhile, the servo motor 114 is mounted on one side of the top of the frame 105, and the threaded rod 115 is mounted inside the top of the frame 105. The output end of the servo motor 114 is connected to the threaded rod 115. A ball screw nut assembly 116 is provided on the threaded rod 115, and the ball screw nut assembly 116 is connected to the sliding seat. When the servo motor 114 is started, it drives the threaded rod 115 to rotate. Since the ball screw nut assembly 116 is connected to the sliding seat, it drives the… The sliding seat rotates at the top of the frame 105, and both ends of the threaded rod 115 are provided with rotating heads 122. Rotating bearings 123 are provided on both sides of the top of the frame 105. The rotating heads 122 are embedded in the interior of the corresponding rotating bearings 123. The output end of the servo motor 114 is connected to the corresponding rotating head 122. Through the arrangement of the rotating heads 122 and the rotating bearings 123, the threaded rod 115 rotates more smoothly inside the top of the frame 105.

[0032] In addition, a connecting block 117 is fixedly provided at the top of the regular hexagonal frame 118. The connecting block 117 is perpendicular to the regular hexagonal frame 118. The end of the connecting block 117 away from the regular hexagonal frame 118 is connected to the output end of the hydraulic cylinder 106. Each side of the regular hexagonal frame 118 is provided with an electric push rod 107. Through the arrangement of the regular hexagonal frame 118 and the six electric push rods 107, the radial load applied to the aluminum alloy welded pipe is more uniform.

[0033] Furthermore, a fixing block 124 is provided at one end of the connecting arm 109 near the annular mounting frame, and a mounting base 125 is provided at the other end of the connecting arm 109 away from the annular mounting frame. An inclined surface 126 is provided on the side of the mounting base 125 facing the center of the annular mounting frame. The industrial camera 110 is mounted on the inclined surface 126. The installation of the connecting arm 109 is completed by the setting of the fixing block 124. The setting of the inclined surface 126 enables the shooting end of the industrial camera 110 to better collect image information of the weld area at the stress point of the sample.

[0034] When using the aluminum alloy welded pipe crack resistance testing device of this embodiment, the sliding guide rail 103 and the sliding clamping seat 104 can be used to clamp aluminum alloy welded pipes of different lengths, making it more versatile. The locking bolt 119 and the locking hole 120 can be used to fix the sliding clamping seat 104. The driving assembly controls the sliding seat to move the annular mounting bracket to the center of the aluminum alloy welded pipe sample. The hydraulic cylinder 106 adjusts the height of the annular mounting bracket so that its center matches the axial direction of the aluminum alloy welded pipe sample. Simultaneously, multiple electric push rods 107 are activated, causing the force application blocks 108 at their output ends to move synchronously towards the center of the sample until they contact the outer wall of the sample. After pre-compression, the electric push rods 107 are controlled to continue synchronously outputting a uniformly increasing radial load on the sample. When multiple electric push rods 107 synchronously apply a uniformly increasing radial load to the sample, the output load and displacement data of each electric push rod 107 are recorded. The industrial camera 110 captures video images of the weld area in real time. When a crack is detected in the weld area in the video image captured in real time by the industrial camera 110, the load value and displacement value of the electric push rod 107 at this time are recorded to complete the test of the crack resistance of the sample. By adopting the above structure, the uniform radial compression of the welded pipe is achieved by synchronously applying force through multiple electric push rods 107 arranged in a ring. The stress distribution is more reasonable, and the weakest link of the weld can be truly exposed, resulting in more comprehensive and reliable test results.

[0035] Second embodiment: Based on the first embodiment, please refer to Figure 5 and Figure 6 , Figure 5 This is a schematic diagram of the frame structure in the second embodiment. Figure 6 for Figure 5 A magnified view of the local structure at point C.

[0036] The present invention provides a device for testing the crack resistance of aluminum alloy welded pipes, which also includes a protective plate 201.

[0037] In this specific embodiment, a protective plate 201 is provided at the bottom of the top of the frame 105, and a through groove 202 is provided on the sliding seat. The protective plate 201 passes through the through groove 202 and is located outside the threaded rod 115. By providing the protective plate 201, the threaded rod 115 is shielded, preventing excessive debris from the external environment from adhering to the threaded rod 115 and affecting the operation of the drive assembly.

[0038] The protective plate 201 has mounting blocks 203 on both sides. One end of the mounting block 203 is connected to the side of the protective plate 201, and the other end of the mounting block 203 is connected to the side of the top of the frame 105. The installation of the protective plate 201 is completed by setting the mounting blocks 203.

[0039] Secondly, the protective plate 201 and the through groove 202 are fitted with a clearance, which makes the sliding seat slide more smoothly when it slides on the protective plate 201.

[0040] When using the aluminum alloy welded pipe crack resistance testing device of this embodiment, the installation of the protective plate 201 is completed by setting the mounting block 203. The protective plate 201 shields the threaded rod 115, preventing excessive debris from the external environment from adhering to the threaded rod 115 and affecting the operation of the drive assembly.

[0041] Please see Figure 7 The present invention also provides a method for testing the crack resistance of aluminum alloy welded pipes, applied to the aluminum alloy welded pipe crack resistance testing device described above, comprising the following steps: S1. Sample clamping: After passing the aluminum alloy welded pipe sample through the annular mounting frame, place one end of it at the fixed clamping seat 102 and fix it by the fixed clamping seat 102. Slide the sliding clamping seat 104 so that the sliding clamping seat 104 corresponds to the other end of the aluminum alloy welded pipe. Fix the other end of the aluminum alloy welded pipe sample by the sliding clamping seat 104 and fix the sliding clamping seat 104 by the locking bolt 119. S2. Loading and alignment: The sliding seat is controlled to slide using the drive assembly, so that the annular mounting bracket moves to the middle of the aluminum alloy welded pipe sample. The height of the annular mounting bracket is adjusted using the hydraulic cylinder 106 so that the center of the annular mounting bracket matches the axial direction of the aluminum alloy welded pipe sample. S3. Multiphase synchronous loading: Simultaneously start multiple electric push rods 107, so that the force application blocks 108 at their output ends move synchronously toward the center of the sample until they contact the outer wall of the sample and are pre-pressed. Then, control the electric push rods 107 to continue to output synchronously and apply a uniformly increasing radial load to the sample. S4. Data acquisition: When multiple electric push rods 107 simultaneously apply a uniformly increasing radial load to the sample, record the output load and displacement data of each electric push rod 107, and capture video images of the weld area in real time through the industrial camera 110. S5. Crack Critical Point Determination: When a crack is detected in the weld area in the video image captured in real time by the industrial camera 110, the load value and displacement value of the electric push rod 107 at this time are recorded. S6. Result Output: When cracks appear in the weld area of ​​the specimen, the load value and displacement value of the electric push rod 107 recorded are output as quantitative indicators of the crack resistance performance of the specimen.

[0042] In this embodiment, the aluminum alloy welded pipe sample is first passed through the annular mounting bracket, and one end is placed at the fixed clamp 102 for fixation. The sliding clamp 104 is then slid until it aligns with the other end of the aluminum alloy welded pipe, thus fixing the other end of the sample. The locking bolt 119 further secures the sliding clamp 104. The drive assembly then controls the sliding of the sliding clamp, moving the annular mounting bracket to the center of the aluminum alloy welded pipe sample. The hydraulic cylinder 106 adjusts the height of the annular mounting bracket. The center of the annular mounting bracket is aligned with the axial direction of the aluminum alloy welded pipe sample. Then, multiple electric push rods 107 are simultaneously activated, causing the force application blocks 108 at their output ends to move synchronously toward the center of the sample until they contact and pre-press against the outer wall of the sample. Subsequently, the electric push rods 107 are controlled to continue to output synchronously, applying a uniformly increasing radial load to the sample. The industrial camera 110 captures video images of the weld area in real time, and simultaneously records the output load and displacement data of each electric push rod 107. Finally, when cracks appear in the weld area of ​​the sample, the recorded load and displacement values ​​of the electric push rods 107 are output as quantitative indicators of the crack resistance of the sample.

[0043] The above description discloses only one preferred embodiment of the present invention, and should not be construed as limiting the scope of the present invention. Those skilled in the art will understand that all or part of the processes of the above embodiments can be implemented, and equivalent changes made in accordance with the claims of the present invention are still within the scope of the invention.

Claims

1. A device for testing the crack resistance of aluminum alloy welded pipes, comprising a worktable, a fixed clamping seat, a sliding guide rail, and a sliding clamping seat, wherein the fixed clamping seat is fixedly disposed at one end of the upper surface of the worktable, the sliding guide rail is mounted at the other end of the upper surface of the worktable, the sliding clamping seat is slidably disposed on the sliding guide rail, the sliding clamping seat is provided with a locking bolt, and the sliding guide rail is provided with a plurality of locking holes, characterized in that, It also includes the loading mechanism; The loading mechanism includes a frame, a drive assembly, a sliding seat, a hydraulic cylinder, a ring mounting bracket, multiple electric push rods, multiple force application blocks, a connecting arm, and an industrial camera. The frame is mounted on the top of the workbench. The sliding seat is slidably disposed at the bottom of the top of the frame. The drive assembly is disposed inside the top of the frame. The output end of the drive assembly is connected to the sliding seat. The hydraulic cylinder is disposed at the bottom of the sliding seat. The ring mounting bracket is mounted on the output end of the hydraulic cylinder. Multiple electric push rods are evenly disposed around the ring mounting bracket. Each electric push rod has a force application block at its output end. The multiple force application blocks are evenly distributed around the aluminum alloy welded pipe to be inspected. One end of the connecting arm is connected to the bottom of the ring mounting bracket. The industrial camera is disposed at the other end of the connecting arm. The shooting end of the industrial camera corresponds to the weld seam of the aluminum alloy welded pipe to be inspected. The annular mounting frame includes a connecting block and a regular hexagonal frame. The connecting block is fixedly mounted on the top of the regular hexagonal frame and is perpendicular to the regular hexagonal frame. The end of the connecting block away from the regular hexagonal frame is connected to the output end of the hydraulic cylinder. Each side of the regular hexagonal frame is provided with an electric push rod. A fixing block is provided at the end of the connecting arm near the annular mounting frame, and a mounting base is provided at the end of the connecting arm away from the annular mounting frame. The side of the mounting base facing the center of the annular mounting frame has an inclined surface, and the industrial camera is mounted on the inclined surface.

2. The aluminum alloy welded pipe crack resistance testing device as described in claim 1, characterized in that, The sliding seat includes a seat body, two connecting plates, and two sliding plates. Slide grooves are provided on both sides of the top of the frame. The connecting plates are fixedly provided on both sides of the seat body. The sliding plate is provided on the end of each connecting plate away from the seat body. The sliding plate is slidably connected to the corresponding slide groove.

3. The aluminum alloy welded pipe crack resistance testing device as described in claim 2, characterized in that, The drive assembly includes a servo motor, a threaded rod, and a ball screw nut assembly. The servo motor is mounted on one side of the top of the frame, the threaded rod is mounted inside the top of the frame, the output end of the servo motor is connected to the threaded rod, the ball screw nut assembly is provided on the threaded rod, and the ball screw nut assembly is connected to the sliding seat.

4. The aluminum alloy welded pipe crack resistance testing device as described in claim 3, characterized in that, Both ends of the threaded rod are provided with rotating heads, and both sides of the top of the frame are provided with rotating bearings. The rotating heads are embedded in the interior of the corresponding rotating bearings, and the output end of the servo motor is connected to the corresponding rotating head.

5. The aluminum alloy welded pipe crack resistance testing device as described in claim 3, characterized in that, The aluminum alloy welded pipe crack resistance testing device also includes a protective plate. The protective plate is provided at the bottom of the top of the frame. A through groove is provided on the sliding seat. The protective plate passes through the through groove and is located outside the threaded rod.

6. The aluminum alloy welded pipe crack resistance testing device as described in claim 5, characterized in that, Mounting blocks are provided on both sides of the protective plate. One end of the mounting block is connected to the side of the protective plate, and the other end of the mounting block is connected to the side of the top of the frame.

7. A method for testing the crack resistance of aluminum alloy welded pipes, applied to the aluminum alloy welded pipe crack resistance testing device as described in claim 1, characterized in that, Includes the following steps: Sample clamping: After passing the aluminum alloy welded pipe sample through the annular mounting bracket, place one end of it at the fixed clamping seat and fix it by the fixed clamping seat. Slide the sliding clamping seat so that the sliding clamping seat corresponds to the other end of the aluminum alloy welded pipe. Fix the other end of the aluminum alloy welded pipe sample by the sliding clamping seat and fix the sliding clamping seat by the locking bolt. Loading alignment: The sliding seat is controlled to slide using the drive assembly, so that the annular mounting bracket moves to the middle of the aluminum alloy welded pipe sample. The height of the annular mounting bracket is adjusted using the hydraulic cylinder so that the center of the annular mounting bracket matches the axial direction of the aluminum alloy welded pipe sample. Multiphase synchronous loading: Multiple electric push rods are started synchronously, so that the force application blocks at their output ends move synchronously toward the center of the sample until they contact the outer wall of the sample and are pre-pressed. Then, the electric push rods are controlled to continue to output synchronously, applying a uniformly increasing radial load to the sample. Data acquisition: When multiple electric actuators simultaneously apply a uniformly increasing radial load to the sample, the output load and displacement data of each electric actuator are recorded, and video images of the weld area are captured in real time by the industrial camera; Crack critical point determination: When a crack is detected in the weld area in the video image captured in real time by the industrial camera, the load value and displacement value of the electric push rod at this time are recorded. Output results: When cracks appear in the weld area of ​​the specimen, the recorded load and displacement values ​​of the electric push rod are output as quantitative indicators of the specimen's crack resistance.

Images