Adjustable clamp and device for bending resistance test of bamboo splints for bamboo weaving
By designing adjustable clamps and devices, the problems of testing the bending resistance and mechanical load-bearing capacity of bamboo strips at multiple joints were solved, enabling accurate measurement and multi-axis testing of bamboo strip bending strength data, and ensuring the reliability and adaptability of test results.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CENTRAL SOUTH UNIVERSITY OF FORESTRY AND TECHNOLOGY
- Filing Date
- 2026-02-04
- Publication Date
- 2026-05-29
AI Technical Summary
Existing technologies cannot effectively test the bending resistance and elasticity of particularly narrow and thin bamboo strips, especially the mechanical load-bearing capacity of multiple joints after bamboo strip weaving, making it impossible to accurately assess the strength of bamboo weaving as a load-bearing component.
An adjustable clamp and device for testing the bending mechanical strength of bamboo strips used in bamboo weaving was designed. The device includes a base plate and a sliding clamp assembly. The clamp assembly consists of a clamp body, a sliding part, and a bamboo strip clamping part. The clamp can be moved and fixed by a guide rail groove to ensure that both ends of the bamboo strip are clamped and fixed. Pressure is evenly transmitted through multiple fasteners to adapt to the testing requirements of different spans.
It enables accurate and repeatable measurement of the bending strength of bamboo strips, avoids clamp misalignment or torsion, ensures that the load is transmitted along the axis of the bamboo strip, results in more accurate test results, adapts to various test protocols, and supports multi-axis test setups.
Smart Images
Figure CN122108747A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of mechanical testing fixture technology, specifically relating to an adjustable fixture and device for testing the bending mechanical strength of bamboo strips used in bamboo weaving. Background Technology
[0002] With the support of technology and culture, bamboo weaving continues to innovate and progress, and is ubiquitous in people's lives both domestically and internationally. Bamboo strips are the key raw material for bamboo weaving. Generally speaking, bamboo strips refer to narrow, thin, and long bamboo pieces, which are the basic units used in the bamboo weaving process; bamboo laminated timber and bamboo plywood also use bamboo strips as raw materials. Due to the long fibers and good elasticity of bamboo, there are many specifications and models of bamboo strips used for bamboo weaving, ranging from over 5mm thick to less than 1mm thin, and their widths also vary widely. Bending mechanical properties are one of the key indicators for the application of bamboo strips as materials and structural units. The bending test of bamboo strips mainly measures its shear strength along the grain, tensile strength, etc. The basic principle is: using specific clamps and loading devices, a force perpendicular to the growth direction of the bamboo is applied to the bamboo strip specimen, causing shear and tensile failure at a specific cross-section, thereby calculating its bending strength. Currently, there is no device for testing the bending resistance and elasticity of particularly narrow and thin bamboo strips. In particular, it is impossible to test the mechanical load-bearing capacity of bamboo strips at one, two, or four joints after weaving, and consequently, it is impossible to predict and assess the strength of bamboo weaving as a load-bearing component.
[0003] Therefore, it is very necessary to invent a testing device that can test the bending resistance of bamboo strips and the mechanical load-bearing capacity of the junctions of multiple bamboo strips. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to overcome the deficiencies and defects mentioned in the background art above, and to provide an adjustable clamp and device for the bending mechanical test of bamboo strips for bamboo weaving that can ensure accurate and repeatable data on the bending strength of bamboo strips.
[0005] To solve the above problems, an adjustable clamp and device for testing the bending mechanical strength of bamboo strips used in bamboo weaving are provided. The technical solution is as follows:
[0006] An adjustable clamp for testing the bending mechanical strength of bamboo strips used in bamboo weaving includes: The base plate is provided with at least one guide rail groove; At least one set of clamping components, each set of clamping components includes a pair of clamps, the pair of clamps being movably mounted on the same guide rail groove, the clamps including a clamp body, a sliding part disposed at the bottom of the clamp body, and a clamping groove and a bamboo strip clamping part disposed at the top of the clamp body, the sliding part matching the guide rail groove, and during the bending mechanical test, the two ends of the bamboo strip are respectively placed in the clamping groove of the pair of clamps, and the bamboo strip is clamped and fixed by the corresponding bamboo strip clamping part.
[0007] In one embodiment, the clamping part includes a pressure plate disposed in the clamping groove and at least three fasteners passing through the pressure plate.
[0008] In one embodiment, the pressure plate has positioning holes at both ends and at least one positioning hole in the middle, and each positioning hole is provided with a fastener, which is a fastening bolt.
[0009] In one embodiment, the clamping part includes a first pressure plate disposed in a clamping groove, a second pressure plate disposed on top of the first pressure plate, and at least three fasteners passing through the second pressure plate, the fasteners passing through the second pressure plate and abutting against the first pressure plate.
[0010] In one embodiment, the first pressure plate is H-shaped and is detachably clamped in the clamping groove. The second pressure plate has positioning holes at both ends and at least one positioning hole in the middle. Each positioning hole is provided with a fastener, which is a fastening bolt.
[0011] In one embodiment, there are five fastening holes, which are evenly distributed on the second pressure plate.
[0012] In one embodiment, there are two guide rail grooves, which are arranged perpendicularly to each other, and there are two corresponding clamping assemblies. The clamps are fixed in the guide rail grooves by fastening bolts.
[0013] In one embodiment, the guide rail groove is equipped with a scale and a positioning block.
[0014] In one embodiment, the test also includes an anti-slip cushioning element, which is a strip of cloth or leather, covering the tested bamboo strip at the groove.
[0015] Based on the same inventive concept, a bamboo strip bending resistance mechanical testing device is also provided, including an adjustable clamp for testing the bending resistance mechanical properties of bamboo strips as described in any of the above claims, and a matching pressure head, which acts on the bamboo strip being tested.
[0016] Beneficial Effects: The adjustable fixture and device for the bending mechanical strength test of bamboo strips used in bamboo weaving described above, by setting at least one pair of fixtures on the guide rail groove of the base plate, and by allowing the fixtures to slide on the guide rail groove, can easily adapt to various bamboo strip specimens from short to long. Through guide rail adjustment, any required span can be precisely set and reproduced, and one set of fixtures can meet the requirements of multiple testing protocols. During the bending mechanical strength test, both ends of the bamboo strip are respectively placed in the clamping grooves of a pair of fixtures, and the bamboo strip is clamped and fixed by the corresponding bamboo strip clamping parts. Furthermore, the pair of fixtures are installed on the same guide rail groove, ensuring that the line connecting the two clamping centers is completely parallel to the guide rail (i.e., the loading direction), thereby effectively avoiding misalignment or torsion caused by independent fixture installation, ensuring that the applied load is accurately transmitted along the axial direction of the bamboo strip, reducing the bending moment caused by eccentric loading, making the test results closer to the "pure shear" state, and the data more accurate and reliable. When changing specimens or test parameters, there is no need to replace the entire fixture or use complex tools for mechanical adjustment. Simply loosen the bamboo strip clamping part of the fixture, slide it along the guide rail to the predetermined position, and then lock it.
[0017] When it is necessary to test the bending resistance of bamboo strips at 1, 2, or 4 joints after weaving, two guide rail grooves are set up to achieve multi-axis testing setup. Attached Figure Description
[0018] 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 some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 A schematic diagram of the overall structure of an adjustable clamp for a bending mechanical test of bamboo strips for bamboo weaving, as one embodiment. Figure 2 A top view of the adjustable clamp used for a bending resistance mechanical test of bamboo strips for bamboo weaving, according to one embodiment; Figure 3 This is an exploded view of a clamp assembly according to one embodiment. Figure 4 A schematic diagram of the overall performance of the bending mechanical test of bamboo strips for bamboo weaving, specifically for the uniaxial test of bamboo strips. Figure 5 A top view of a uniaxial test of bamboo strips for bamboo weaving, as one embodiment of the test. Figure 6 A schematic diagram of the uniaxial test results (displacement-load) of bamboo strips in one embodiment; Figure 7 A schematic diagram of the uniaxial test results (strain-stress) of bamboo strips according to one embodiment; Figure 8 A schematic diagram of the bending mechanical test of bamboo strips for bamboo weaving, as one embodiment, during the test of the weaving structure of a single node of the bamboo strip; Figure 9 A schematic diagram of the test results (displacement-load) of a bamboo strip one-node woven structure according to one embodiment; Figure 10 A schematic diagram of the test results (strain-stress) of a bamboo strip one-node weaving structure according to one embodiment; Figure 11 A schematic diagram of the bending mechanical test of bamboo strips for bamboo weaving, as one embodiment, during the test of the two-node weaving structure of bamboo strips; Figure 12 A schematic diagram of the test results (displacement-load) of a two-node bamboo strip weaving structure according to one embodiment; Figure 13 A schematic diagram of the test results (strain-stress) of a two-node bamboo strip weaving structure according to one embodiment; Figure 14 A schematic diagram of the bending mechanical test of bamboo strips for bamboo weaving, as one embodiment, during the test of the four-node weaving structure of bamboo strips; Figure 15 A schematic diagram of the test results (displacement-load) of a four-node bamboo weaving structure according to one embodiment; Figure 16 This is a schematic diagram (strain-stress) of the test results of a four-node bamboo weaving structure according to one embodiment.
[0020] In the attached drawings, the reference numerals are as follows: 10: base plate; 12: guide rail groove; 20: clamp; 22: clamp body; 24: sliding part; 26: bamboo strip clamping part; 262: first pressure plate; 264: second pressure plate; 266: fastener. Detailed Implementation
[0021] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.
[0022] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.
[0023] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.
[0024] Please see Figure 1-16An adjustable clamp for testing the bending strength of bamboo strips for bamboo weaving, according to one embodiment, includes a base plate 10 and at least one set of clamp assemblies slidably disposed on the base plate 10. Specifically, the base plate 10 has at least one guide rail groove 12. Each clamp assembly includes a pair of clamps 20, which are movably disposed on the same guide rail groove 12. Each clamp 20 includes a clamp body 22, a sliding part 24 disposed at the bottom of the clamp body 22, and a clamping groove and a bamboo strip clamping part 26 disposed at the top of the clamp body 22. The sliding part 24 matches the guide rail groove 12. During the bending strength test, both ends of the bamboo strip are respectively placed in the clamping grooves of the pair of clamps 20 and clamped and fixed by the corresponding bamboo strip clamping parts 26.
[0025] In one embodiment, the bamboo strip clamping part 26 includes a pressure plate disposed within a clamping groove and at least three fasteners 266 passing through the pressure plate. Since the bamboo strips are thin sheets, if only both ends are clamped, the middle portion may warp or separate from the bottom surface of the clamping groove due to uneven force. Three or more fastening points ensure that pressure is evenly transmitted along the length of the bamboo strip, allowing it to flatly conform to the bottom surface of the clamping groove, forming a stable clamping effect. Preferably, the pressure plate has positioning holes at both ends and at least one positioning hole in the middle, with each positioning hole equipped with a fastener 266, which is a fastening bolt.
[0026] In one embodiment, preferably, the clamping part includes a first pressure plate 262 disposed within a clamping groove, a second pressure plate 264 disposed on top of the first pressure plate 262, and at least three fasteners 266 passing through the second pressure plate 264, the fasteners 266 abutting against the first pressure plate 262 through the second pressure plate 264. Traditional two-point clamping easily generates extremely high local compressive stress directly below the bolt, causing the bamboo strip to be crushed at the clamping end before the test begins. In the above solution, multi-point distributed pressure significantly reduces local pressure, preventing it from concentrating at the bamboo strip clamping point, thus allowing the test results to more accurately reflect the material's bending strength.
[0027] In one embodiment, more preferably, the first pressure plate 262 is H-shaped and detachably clamped in the clamping groove. The second pressure plate 264 has positioning holes at both ends and at least one positioning hole in the middle. Each positioning hole is fitted with a fastener 266, which is a fastening bolt. The first pressure plate 262 is H-shaped, and its horizontal portion is in full contact with the bamboo strips, providing a uniform support and pressing surface. This converts the "point pressure" of the fastener 266 into "surface pressure" on the bamboo strips, protecting the surface of the bamboo strips. The vertical edges of the H-shaped first pressure plate 262 are embedded in the sidewalls of the clamping groove, preventing the pressure plate from rotating or moving laterally during tightening and ensuring clamping alignment. The first pressure plate 262 is detachable, allowing for the replacement of H-shaped pressure plates of different heights according to the different thicknesses of the bamboo strips, always ensuring effective contact and the optimal force application angle.
[0028] In one embodiment, more preferably, there are five fastening holes, evenly distributed on the second pressure plate 264. The five evenly distributed fastening bolts improve the pressure uniformity to a higher level, which is especially suitable for wider or longer bamboo strip specimens, resulting in a more perfect clamping effect.
[0029] In one embodiment, there are two guide rail grooves 12, which are arranged perpendicularly to each other, and there are two corresponding clamping assemblies. The perpendicularly intersecting guide rail grooves 12 form a planar coordinate system, and the clamps 20 can be arbitrarily positioned in the two-dimensional plane, enabling multi-axis testing arrangements when testing the bending resistance of one node, two nodes, and four nodes after bamboo strip weaving. (See reference...) Figure 4-16 The results show that the device of the present invention can accurately obtain the bending resistance of different nodes of bamboo strips.
[0030] In one embodiment, the guide rail groove 12 is equipped with a scale and a positioning block. The scale allows for precise setting and recording of the spacing (bending span) of the clamps 20. The positioning block quickly and accurately fixes the clamps 20 to the preset position. This avoids the tedious step of measuring with calipers for each test, significantly improving operation speed and batch test consistency.
[0031] Specifically, in one embodiment, the base plate 10 clamp assembly is made of stainless steel or other metal. In another embodiment, during testing, an anti-slip buffer, made of cloth or leather, is also included, covering the bamboo strip being tested at the clamping groove. The bamboo strip's smooth surface makes it prone to slipping when directly clamped to the metal. The anti-slip buffer, such as cloth or leather, greatly increases the coefficient of friction, ensuring a secure clamping. Furthermore, these materials can buffer the concentrated pressure of the bolts, further preventing the bamboo strip surface from being damaged by the metal clamp 20 or causing stress concentration, ensuring that failure occurs in the intermediate load-bearing section.
[0032] Based on the same inventive concept, a bamboo strip bending resistance mechanical testing device is also provided, including an adjustable clamp for testing the bending resistance mechanical properties of bamboo strips as described in any of the above claims, and a matching pressure head, which acts on the bamboo strip being tested.
[0033] The method of using the above-mentioned bamboo strip bending resistance mechanical testing device is as follows: S10. Determine the bending span, determine the distance between the inner clamping lines of the two clamps 20, i.e. the effective bending length, set the position of the clamps 20, refer to the scale on the guide rail slide 12, move the pair of clamps 20 to the pre-approval distance position and lock them with the positioning block. S20. Take two strips of cloth or leather of appropriate size and wrap them flat around the two ends of the bamboo strip specimen that will be clamped. Place the wrapped bamboo strip specimen straight into the clamping groove of the pair of clamps 20 that have been positioned, ensuring that the axis of the bamboo strip is parallel to the direction of the guide rail groove 12 (loading direction) and that the predetermined bearing surface (usually the area between the two clamps 20 that is not clamped) is centered.
[0034] S30. Tightening and Fixing: Cover the bamboo strips (cloth strips or leather) with the first pressure plate 262, ensuring that the first pressure plate 262 is in place. Cover it with the second pressure plate 264. Tighten the five fastening bolts in sequence and evenly, so that the pressure is evenly transmitted to the first pressure plate 262 through the second pressure plate 264, and then converted into surface pressure acting on the bamboo strips.
[0035] S30. Place the indenter at the test point on the bamboo strip, start the universal testing machine, and begin loading at the preset rate. Observe the test process. Use a high-speed camera to record the moment of failure. When the bamboo strip shows obvious breakage in the load area and the load reading drops sharply, stop the test immediately. Record the maximum failure load and calculate the bending strength.
[0036] The above are merely preferred embodiments of the present invention. It should be noted that the present invention is not limited to the above embodiments. For those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should also be considered within the scope of protection of the present invention.
Claims
1. An adjustable clamp for testing the bending mechanics of bamboo strips used in bamboo weaving, characterized in that, include: The base plate is provided with at least one guide rail groove; At least one set of clamping components, each set of clamping components includes a pair of clamps, the pair of clamps being movably mounted on the same guide rail groove, the clamps including a clamp body, a sliding part disposed at the bottom of the clamp body, and a clamping groove and a bamboo strip clamping part disposed at the top of the clamp body, the sliding part matching the guide rail groove, and during the bending mechanical test, the two ends of the bamboo strip are respectively placed in the clamping groove of the pair of clamps, and the bamboo strip is clamped and fixed by the corresponding bamboo strip clamping part.
2. The adjustable clamp for testing the bending strength of bamboo strips used in bamboo weaving according to claim 1, characterized in that, The clamping part includes a pressure plate disposed in the clamping groove and at least three fasteners passing through the pressure plate.
3. The adjustable clamp for testing the bending mechanical strength of bamboo strips used in bamboo weaving according to claim 2, characterized in that, The pressure plate has positioning holes at both ends and at least one positioning hole in the middle. Each positioning hole is equipped with a fastener, which is a fastening bolt.
4. The adjustable clamp for testing the bending mechanical strength of bamboo strips used in bamboo weaving according to claim 1, characterized in that, The clamping part includes a first pressure plate disposed in the clamping groove, a second pressure plate disposed on top of the first pressure plate, and at least three fasteners passing through the second pressure plate, the fasteners passing through the second pressure plate and abutting against the first pressure plate.
5. The adjustable clamp for testing the bending mechanical strength of bamboo strips used in bamboo weaving according to claim 4, characterized in that, The first pressure plate is H-shaped and can be detachably clamped in the clamping groove. The second pressure plate has positioning holes at both ends and at least one positioning hole in the middle. Each positioning hole is equipped with a fastener, which is a fastening bolt.
6. The adjustable clamp for testing the bending mechanical strength of bamboo strips used in bamboo weaving according to claim 5, characterized in that, There are 5 fastening holes, which are evenly distributed on the second pressure plate.
7. The adjustable clamp for testing the bending mechanical strength of bamboo strips used in bamboo weaving according to claim 1, characterized in that, There are two guide rail grooves, which are arranged perpendicularly to each other. There are two corresponding clamping assemblies, and the clamps are fixed in the guide rail grooves by fastening bolts.
8. The adjustable clamp for testing the bending mechanical strength of bamboo strips used in bamboo weaving according to claim 1, characterized in that, The guide rail groove is equipped with a scale and a positioning block.
9. The bamboo strip bending resistance mechanical testing device according to claim 1, characterized in that, The test also includes an anti-slip cushioning element, which is made of cloth or leather, covering the groove of the tested bamboo strip.
10. A testing device for the bending resistance of bamboo strips used in bamboo weaving, characterized in that, An adjustable clamp for testing the bending mechanical strength of bamboo strips for bamboo weaving, as described in any one of claims 1-9, is characterized in that it further includes a pressure head used in conjunction with the clamp, the pressure head acting on the bamboo strip being tested.