Annular fuel assembly T-shaped grillwork welding seam stretching detection device and use method
By designing a combined clamping device with inner and outer strip clamps, the problem of the inability to clamp T-shaped grids in the prior art was solved, and reliable tensile testing of annular fuel assemblies was achieved.
Patent Information
- Application Number
- CN202410573550.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-10
- Publication Date
- 2025-11-11
AI Technical Summary
Existing tensile clamps cannot effectively hold the T-shaped grid of annular fuel assembly with a thickness of only 0.425 mm, making it impossible to perform tensile testing on the weld.
A detection device including an inner strip clamp and an outer strip clamp is designed. The inner strip clamp consists of two wedges, and the outer strip clamp consists of a base, a pressure plate, a pressure block, and a pressure bolt. The T-shaped grid is clamped and fixed by the cooperation of the wedges and the pressure plate to ensure uniform force.
It achieves effective clamping and fixation of T-shaped grids, enabling static load tensile tests at room temperature, ensuring that the sample does not slip during the test, and providing reliable tensile strength determination.
Smart Images
Figure CN120927431A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of nuclear fuel manufacturing, and more particularly to a device for tensile testing of weld seams in T-shaped grid structures of annular fuel assemblies and its usage method. Background Technology
[0002] Static tensile testing is one of the most widely used methods for testing the mechanical properties of metals in industry. The test is generally conducted within the room temperature range (10–35)℃. Standard smooth cylindrical specimens are commonly used. The test's key feature is that, under defined test conditions (temperature, stress state, loading rate, and environment), it measures many important mechanical properties of the material, such as elasticity, strength, plasticity, and strain hardening, and reveals the three common failure modes of materials under static load: excessive elastic deformation, plastic deformation, and fracture. Currently, tensile testing methods mainly target the tensile testing of welds in pipes, plates, and right-angle tubes, realizing the force and displacement changes of the weld under uniform and continuous tensile force. Existing tensile fixtures cannot clamp T-shaped grids with a thickness of only 0.425 mm, and samples cannot be directly clamped onto the fixtures of electronic universal testing machines. Existing fixtures have gaps when clamping external strips, preventing the sample from being firmly secured. Therefore, current testing methods and technologies are only relevant for weld tensile testing; other applications are unrelated.
[0003] The tensile testing of T-shaped grid weld joints in annular fuel assemblies is a method for inspecting weld quality using tensile testing. The maximum tensile strength of the sample is determined by stretching it on a testing machine, typically until the weld fractures and the sample separates. The clamping mechanism is used to hold the sample in the testing machine fixtures, maximizing the friction between the fixtures and the sample to effectively prevent slippage during the test. It is essential to ensure that the gauge length during transition is evenly stressed. The dimensions and requirements of these two parts determine the design effectiveness of the weld tensile testing device.
[0004] Because the tensile test specimen of the T-shaped grid weld of the annular fuel assembly is a T-shaped sample formed by welding the inner and outer strips together at the vertical position of the upper and lower end faces, such as Figure 1 As shown. The thickness is only 0.425mm, so it cannot be directly used for tensile strength testing. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide a tensile testing device and method for the weld of a T-shaped grid for annular fuel assembly, which facilitates the clamping and fixing of the T-shaped grid, thereby enabling a static load tensile test of the T-shaped grid for annular fuel assembly at room temperature.
[0006] This invention provides a tensile testing device for a T-shaped grid of annular fuel assembly, comprising: an inner strip clamp and an outer strip clamp.
[0007] The inner strip clamp is composed of two wedge-shaped bodies. One end of each wedge-shaped body is a rectangular embedded groove for clamping between the upper guide rail of the testing machine and the tooling. The two wedge-shaped bodies are arranged opposite each other, with a clamping block slit between them for clamping and fixing the tooling and the inner strip.
[0008] The outer strip clamp includes a base, a clamping plate, a clamping block, and clamping bolts;
[0009] The clamping plate is fixed to the base;
[0010] The base is cylindrical with a through hole in the middle for fixing the outer strip clamp to the testing machine;
[0011] The pressure block presses the outer strip onto the pressure plate and secures it with pressure bolts.
[0012] In a specific embodiment of the present invention, the inner strip clamp and the outer strip clamp are made of H13 steel with a tensile strength of not less than 30,000 N.
[0013] In one specific embodiment of the present invention, the wedge-shaped body of the inner strip clamp has a length of 60-70mm, a width of 40mm-50mm, and a thickness of 30mm-35mm.
[0014] In a specific embodiment of the present invention, the length of the embedded groove is 40mm-45mm and the width is 10mm-12mm.
[0015] In one specific embodiment of the present invention, the corresponding surfaces of the two wedges are knurled.
[0016] In one specific embodiment of the present invention, the minimum contact size between the two wedges is 0.5mm-1mm.
[0017] In one specific embodiment of the present invention, the pressing plate is a circular plate with a diameter of Φ100mm-110mm and a height of 45mm-50mm.
[0018] In one specific embodiment of the present invention, the length of the pressing block is 45mm-50mm, the width is 30mm-35mm, and the height is 10mm-12mm.
[0019] In a specific embodiment of the present invention, the base is a Φ20 cylinder with a Φ10 through hole in the middle.
[0020] The present invention also provides a method for using a tensile testing device for a T-shaped grid of annular fuel assembly, comprising the following steps:
[0021] Step 1: Install the inner strip clamp at the upper end of the testing machine. When installing the sample, hold the end of the inner strip without the assembly groove and let the end with the assembly groove enter the slit of the clamping block. Install the outer strip clamp at the lower end, with the two clamps installed at 90°.
[0022] Step 2: When installing the sample, first use the outer strip clamp to hold the outer strip of the sample, with a distance of 0.5 to 1 mm between the pressure block and the inner strip. Then move the crossbeam and use the inner strip clamp to hold the inner strip of the sample.
[0023] Step 3: Zero the force value of the testing machine. After starting the tensile test, apply tensile load to both ends of the sample at a tensile rate of 2-3 mm / min until the sample breaks.
[0024] Compared with the prior art, the tensile testing device and method for the weld seam of the T-shaped grid of the annular fuel assembly of the present invention have the following advantages:
[0025] 1) Suitable for clamping and fixing T-shaped grid samples with a thickness of only 0.425mm;
[0026] 2) The clamping surface of the outer strip clamp uses a pressure plate to fix the sample, and the sample can be tightened and its position adjusted with screws;
[0027] 3) By designing and fabricating a tensile testing device for a T-shaped grid of annular fuel assembly, a tensile testing method for welded samples of T-shaped grids is established. Attached Figure Description
[0028] Figure 1 A schematic diagram of a tensile specimen for a T-shaped lattice weld joint;
[0029] Figure 2 A schematic diagram of a tensile test specimen for a T-shaped lattice weld joint.
[0030] Figure 3 This diagram shows the inner strip clamp.
[0031] Figure 4 This diagram shows the outer strip clamp.
[0032] Figure 5 This diagram illustrates the tensioning of a T-shaped lattice frame.
[0033] In the picture,
[0034] 1. Inner strip; 2. First outer strip; 3. Second outer strip; 4. E-weld; 5. Inner strip clamp; 6. Outer strip clamp; 7. Clamping block slit; 8. Embedded groove; 9. Base; 10. Pressure plate; 11. Pressure block; 12. Pressure bolt; 13. T-shaped grid weld point tensile test specimen. Detailed Implementation
[0035] To further understand the present invention, embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the present invention.
[0036] like Figure 1 As shown, the T-shaped lattice weld joint tensile specimen is a T-shaped sample formed by welding the tenon at the end of the inner strip to the joint of the two outer strips. It is made of Zr-4 alloy, with an overall length of 30-45 mm and a thickness of 0.425 mm. One end is inner strip 1, which is 30-40 mm long and 25-30 mm wide. The other end is composed of the first outer strip 2 and the second outer strip 3, which are 40-45 mm long and 25-30 mm wide.
[0037] There is an E-weld 4 between the first outer strip 2 and the second outer strip 3.
[0038] During tensile testing, if Figure 2 As shown.
[0039] An embodiment of the present invention discloses a tensile testing device for a T-shaped grid of an annular fuel assembly, such as... Figure 3 and Figure 4 As shown, it includes: an inner strip clamp 5 and an outer strip clamp 6.
[0040] The inner strip clamp 5 is made of H13 steel and consists of two wedge-shaped bodies.
[0041] The wedge-shaped body of the inner strip clamp 5 has a length of 60-70mm, a width of 40mm-50mm, and a thickness of 30mm-35mm.
[0042] One end of the wedge is a rectangular embedded groove 8, with a length of 40mm-45mm and a width of 10mm-12mm, used for clamping between the moving upper guide rail of the testing machine and the tooling.
[0043] Two wedge-shaped bodies are positioned opposite each other, with a narrow clamping slit 7 between them for clamping and fixing the tooling and the inner strip. The minimum contact size is 0.5mm-1mm, and the corresponding surfaces are knurled to increase the friction after clamping the sample, ensuring effective clamping. The inner strip clamp 5 is subjected to quenching and tempering treatment to ensure a tensile strength of not less than 30,000N.
[0044] The outer strip clamp 6 is made of H13 steel and includes a base 9, a clamping plate 10, a clamping block 11 and a clamping bolt 12.
[0045] The clamping plate 10 is fixed to the base 9;
[0046] The clamping plate is a circular plate with a diameter of Φ100mm-110mm and a height of 45mm-50mm;
[0047] The base 9 is a cylinder with a through hole in the middle for fixing the outer strip clamp to the testing machine;
[0048] The base is a Φ20 cylinder with a Φ10 through hole in the middle;
[0049] The pressure block 11 presses the outer strip onto the pressure plate 10 and is fixed with the pressure bolt 12.
[0050] The pressing block has a length of 45mm-50mm, a width of 30mm-35mm, and a height of 10mm-12mm.
[0051] The outer strip clamp 6 is subjected to quenching and tempering treatment to ensure that the tensile strength is not less than 30,000 N.
[0052] Embodiments of the present invention also disclose a method for using a tensile testing device for a T-shaped grid of annular fuel assembly, comprising the following steps:
[0053] Step 1: Install the inner strip clamp at the upper end of the testing machine. When installing the sample, hold the end of the inner strip without the assembly groove and let the end with the assembly groove enter the slit of the clamping block. Install the outer strip clamp at the lower end, with the two clamps installed at 90°.
[0054] Step 2: When installing the sample, first use the outer strip clamp to hold the outer strip of the sample, with a distance of 0.5 to 1 mm between the pressure block and the inner strip. Then move the crossbeam and use the inner strip clamp to hold the inner strip of the sample.
[0055] Step 3: Then, zero the force value of the testing machine and start the tensile test. Apply tensile load to both ends of the sample at a tensile rate of 2-3 mm / min until the sample breaks.
[0056] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.
[0057] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A tensile testing device for a T-shaped grid of an annular fuel assembly, characterized in that, include: Inner strip clamp and outer strip clamp, The inner strip clamp is composed of two wedge-shaped bodies. One end of each wedge-shaped body is a rectangular embedded groove for clamping between the upper guide rail of the testing machine and the tooling. The two wedge-shaped bodies are arranged opposite each other, with a clamping block slit between them for clamping and fixing the tooling and the inner strip. The outer strip clamp includes a base, a clamping plate, a clamping block, and clamping bolts; The clamping plate is fixed on the base; The base is cylindrical with a through hole in the middle for fixing the outer strip clamp to the testing machine; The pressure block presses the outer strip onto the pressure plate and secures it with pressure bolts.
2. The annular fuel assembly T-shaped grid tensile testing device according to claim 1, characterized in that, The inner and outer strip clamps are made of H13 steel with a tensile strength of not less than 30,000 N.
3. The annular fuel assembly T-shaped grid tensile testing device according to claim 2, characterized in that, The wedge-shaped body of the inner strip clamp has a length of 60-70mm, a width of 40mm-50mm, and a thickness of 30mm-35mm.
4. The annular fuel assembly T-shaped grid tensile testing device according to claim 1, characterized in that, The embedded groove has a length of 40mm-45mm and a width of 10mm-12mm.
5. The annular fuel assembly T-shaped grid tensile testing device according to claim 1, characterized in that, The corresponding surfaces of the two wedges are knurled.
6. The annular fuel assembly T-shaped grid tensile testing device according to claim 1, characterized in that, The minimum contact size between the two wedges is 0.5mm-1mm.
7. The annular fuel assembly T-shaped grid tensile testing device according to claim 1, characterized in that, The clamping plate is a circular plate with a diameter of Φ100mm-110mm and a height of 45mm-50mm.
8. The annular fuel assembly T-shaped grid tensile testing device according to claim 1, characterized in that, The pressing block has a length of 45mm-50mm, a width of 30mm-35mm, and a height of 10mm-12mm.
9. The annular fuel assembly T-shaped grid tensile testing device according to claim 1, characterized in that, The base is a Φ20 cylinder with a Φ10 through hole in the middle.
10. A method of using a tensile testing device for a T-shaped grid of an annular fuel assembly, characterized in that, Includes the following steps: Step 1: Install the inner strip clamp at the upper end of the testing machine. When installing the sample, hold the end of the inner strip without the assembly groove and let the end with the assembly groove enter the slit of the clamping block. Install the outer strip clamp at the lower end, with the two clamps installed at 90°. Step 2: When installing the sample, first use the outer strip clamp to hold the outer strip of the sample, with a distance of 0.5 to 1 mm between the pressure block and the inner strip. Then move the crossbeam and use the inner strip clamp to hold the inner strip of the sample. Step 3: Zero the force value of the testing machine. After starting the tensile test, apply tensile load to both ends of the sample at a tensile rate of 2-3 mm / min until the sample breaks.