A device for measuring mechanical changes of square bamboo based on digital speckle meter

Abstract

The present invention relates to the technical field of square bamboo testing devices, and in particular to a square bamboo mechanical change measuring device based on a digital speckle meter, comprising a force-applying component, a fixing component and a digital speckle meter; the force-applying component is used for statically loading the square bamboo; the fixing component is used for installing the digital speckle meter and can adjust the vertical position of the digital speckle meter and the distance relative to the force-applying component; the digital speckle meter is used for collecting speckle pattern changes when the square bamboo is statically loaded, and transmitting to a computer for analysis to obtain the physical and mechanical property changes when the square bamboo is statically loaded. The present invention uses a digital speckle meter with higher measurement accuracy, faster data acquisition speed, better environmental adaptability, and simpler operation procedures; and by setting a self-locking component, the adjustment efficiency of the vertical position of the digital speckle meter can be improved, and the adjustment process is simple and fast.

Description

Technical Field

[0001] The invention relates to the technical field of square bamboo testing devices, and in particular to a square bamboo mechanical change measuring device based on a digital speckle meter. Background Art

[0002] When bamboo is subjected to force at different angles during the test, there are many subtle changes that cannot be observed by the naked eye, and the mechanical behavior varies greatly. In recent years, most scholars have observed the mechanical changes of bamboo under force, and observed the fluctuations of the horizontal and vertical strain gauges of bamboo specimens by attaching stress strain gauges around the specimens, and analyzed the reasons for the failure of bamboo under force. The test can only observe the changes around the strain gauges, and high-frequency changes and dynamic conditions cannot be effectively monitored. Moreover, the strain gauges are composed of sensitive grids, and slight touch damage will affect the accuracy of the numbers. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a bamboo mechanical change measurement device based on a digital speckle meter.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] A square bamboo mechanical change measuring device based on a digital speckle meter comprises a force-applying component, a fixing component and a digital speckle meter;

[0006] The force-applying component is used for statically loading the square bamboo;

[0007] The fixing component is used to install the digital speckle meter and can adjust the vertical position of the digital speckle meter and the distance relative to the force-applying component;

[0008] The digital speckle instrument is used to collect the speckle pattern changes of the square bamboo when it is statically loaded, and transmit it to the computer for analysis to obtain the physical and mechanical property changes of the square bamboo when it is statically loaded.

[0009] Furthermore, the digital speckle meter is connected to the fixing component via a self-locking component, and the self-locking component is used to fix the digital speckle meter at any vertical position.

[0010] Furthermore, the fixing assembly includes a track and a frame, the frame is in an inverted T shape, and the frame is slidably arranged on the track.

[0011] Furthermore, the self-locking assembly includes a first sliding sleeve, a second sliding sleeve, a rotating sleeve and a clamp;

[0012] The first sliding sleeve is slidably arranged on the frame, the second sliding sleeve is coaxially slidably arranged outside the first sliding sleeve, and the rotating sleeve is coaxially arranged outside the second sliding sleeve;

[0013] The second sliding sleeve is provided with a plurality of arc grooves, the rotating sleeve is provided with a sliding column matched with the arc grooves, and the inner wall of the rotating sleeve is provided with a plurality of wedge blocks along the circumferential direction;

[0014] The clamp is coaxially arranged at the bottom of the first sliding sleeve, and the clamp is provided with a plurality of sliding holes along the circumferential direction. A locking column is slidably arranged in the sliding hole, and the first end of the locking column cooperates with the inclined surface of the wedge block, and the second end of the locking column is pressed tightly against the frame;

[0015] A first resetting member for resetting the second sliding sleeve is provided between the second sliding sleeve and the first sliding sleeve, and a second resetting member for resetting the locking column is provided outside the locking column.

[0016] Furthermore, the second end of the locking column is an arc-shaped structure with the same arc as that of the frame.

[0017] Furthermore, the second end of the locking column is provided with rubber.

[0018] Furthermore, the first restoring member and the second restoring member are both springs.

[0019] Furthermore, the force-applying assembly includes a universal testing machine frame and a support arranged at the bottom of the universal testing machine frame, the universal testing machine frame is provided with a gantry, the gantry is provided with a cushion block at the first end close to the support, and the square bamboo is arranged on the support.

[0020] Furthermore, the cushion block is made of steel.

[0021] The beneficial effects of the present invention are:

[0022] 1) The digital speckle pattern meter used in the present invention has higher measurement accuracy, faster data acquisition speed, better environmental adaptability (such as being able to work in high temperature or vibration environment), and simpler operation process; at the same time, the digital speckle pattern meter is applied to the online monitoring and control of the square bamboo test process. By measuring the mechanical properties of the square bamboo in real time, problems in the test can be discovered in time, the test plan can be adjusted, and the test efficiency can be improved.

[0023] 2) The present invention can not only measure the strain and displacement of square bamboo, but also obtain other mechanical performance parameters through data analysis, such as stress, elastic modulus, Poisson's ratio, etc. Multi-parameter analysis can provide more comprehensive information on the mechanical properties of square bamboo, which is helpful for in-depth research on square bamboo.

[0024] 3) The present invention can improve the adjustment efficiency of the vertical position of the digital speckle meter by arranging a self-locking component, and the adjustment process is simple and fast. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1It is a schematic diagram of the overall structure of a square bamboo mechanical change measuring device based on a digital speckle meter in an embodiment of the present invention;

[0026] Figure 2 It is a schematic diagram of a digital speckle meter being arranged on a fixed component through a self-locking component;

[0027] Figure 3 is a cross-sectional view of a self-locking component;

[0028] Figure 4 is a top view of the self-locking component;

[0029] Figure 5 It is a three-dimensional diagram of the rotating sleeve and the second sliding sleeve;

[0030] In the figure, 1, force-applying component; 2, fixing component; 3, digital speckle meter; 4, square bamboo; 5, self-locking component; 6, track; 7, frame; 8, first sliding sleeve; 9, second sliding sleeve; 10, arc groove; 11, sliding column; 12, wedge block; 13, clamp; 14, locking column; 15, first reset member; 16, second reset member; 17, universal testing machine frame; 18, support; 19, gantry; 20, cushion block; 21, rotating sleeve. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0032] See also Figure 1-Figure 5 , the present invention provides a technical solution:

[0033] Example:

[0034] like Figure 1-Figure 5 As shown, a square bamboo mechanical change measuring device based on a digital speckle meter comprises a force applying component 1, a fixing component 2 and a digital speckle meter 3;

[0035] The force applying component 1 is used for statically loading the bamboo 4;

[0036] The fixing component 2 is used to install the digital speckle meter 3 and can adjust the vertical position of the digital speckle meter 3 and the distance relative to the force applying component 1;

[0037] The digital speckle meter 3 is used to collect speckle pattern changes of the square bamboo 4 when statically loaded, and transmit the data to a computer for analysis using image processing technology to obtain physical and mechanical property changes of the square bamboo 4 when statically loaded.

[0038] The digital speckle meter 3 is connected to the fixing component 2 via a self-locking component 5, and the self-locking component 5 is used to fix the digital speckle meter 3 at any vertical position.

[0039] The fixing assembly 2 includes a rail 6 and a frame 7 . The frame 7 is in an inverted T shape and is slidably disposed on the rail 6 .

[0040] like Figure 3-Figure 5 As shown, the self-locking assembly 5 includes a first sliding sleeve 8, a second sliding sleeve 9, a rotating sleeve 21 and a hoop 13;

[0041] The first sliding sleeve 8 is slidably disposed on the frame 7, the second sliding sleeve 9 is coaxially slidably disposed outside the first sliding sleeve 8, and the rotating sleeve 21 is coaxially disposed outside the second sliding sleeve 9;

[0042] The second sliding sleeve 9 is provided with a plurality of arc grooves 10, the rotating sleeve 21 is provided with a sliding column 11 matched with the arc grooves 10, and the inner wall of the rotating sleeve 21 is provided with a plurality of wedge blocks 12 along the circumferential direction;

[0043] The clamp 13 is coaxially arranged at the bottom of the first sliding sleeve 8, and the clamp 13 is provided with a plurality of sliding holes along the circumferential direction, and a locking column 14 is slidably arranged in the sliding hole, and the first end of the locking column 14 cooperates with the inclined surface of the wedge block 12, and the second end of the locking column 14 is pressed tightly against the frame 7;

[0044] A first resetting member 15 for resetting the second sliding sleeve 9 is disposed between the second sliding sleeve 9 and the first sliding sleeve 8 , and a second resetting member 16 for resetting the locking column 14 is disposed outside the locking column 14 .

[0045] Among them, 1. When the rotating sleeve rotates counterclockwise, the locking column 14 moves toward the frame 7 under the action of the wedge block 12, and then presses against the frame 7; when the rotating sleeve rotates clockwise, the locking column 14 moves away from the frame 7 under the action of the wedge block 12, and then releases the lock. 2. The rotating sleeve 21 is rotatably connected to the bottom of the first sliding sleeve 8 through a bearing. 3. The outer wall of the first sliding sleeve 8 is also provided with a sliding groove, and the inner wall of the second sliding sleeve 9 is provided with a slider that slides with the sliding groove. One end of the first reset member 15 is fixed to the slider, and the other end is fixed to the outer wall of the first sliding sleeve 8. The provided sliding groove and slider can prevent the second sliding sleeve 9 from rotating relative to the first sliding sleeve 8.

[0046] The second end of the locking column 14 is an arc-shaped structure with the same arc as the frame 7. This arrangement can improve the fit between the second end of the locking column 14 and the frame 7 when it is pressed against the frame 7. (Wherein, the frame 7 includes a crossbar and a vertical bar, the locking column 14 is pressed against the vertical bar, and the self-locking component 5 is also arranged on the vertical bar)

[0047] The second end of the locking column 14 is provided with rubber. The provided rubber can increase the friction force, thereby improving the self-locking effect.

[0048] The first reset member 15 and the second reset member 16 are both springs. When the second sliding sleeve 9 moves downward, the first reset member 15 is compressed; when the locking column 14 is pressed against the vertical rod, the second reset button is stretched.

[0049] The force-applying assembly 1 includes a universal testing machine frame 17 and a support 18 arranged at the bottom of the universal testing machine frame 17 . A gantry 19 is arranged on the universal testing machine frame 17 . A cushion block 20 is arranged at a first end of the gantry 19 close to the support 18 . The square bamboo 4 is arranged on the support 18 .

[0050] The cushion block 20 is made of steel.

[0051] The digital speckle meter 3 is an existing technology, which is composed of a CCD camera and a fill light. The CCD camera is used to collect image information of the square bamboo 4 when it is statically loaded, and the fill light is used to fill light to the square bamboo 4.

[0052] Working principle: grind the square bamboo 4 (hereinafter referred to as the test piece), spray a thin layer of black paint on it after it is polished smooth, and after the black paint is dry, spray white paint evenly and randomly on the square bamboo 4 for multiple times and in small amounts to form uniform speckles (this process can be blocked between the test piece and the paint spraying port with the help of an iron mesh or other porous plates to facilitate the formation of speckles).

[0053] After the speckle is formed, the specimen is placed on the support 18 , and the gantry 19 (the gantry 19 can be driven by a hydraulic cylinder) is close to the square bamboo 4 , and when the cushion block 20 contacts the square bamboo 4 , the gantry 19 loads the square bamboo 4 through the cushion block 20 .

[0054] The digital speckle meter 3 collects images of the square bamboo 4 under static loading in real time (the image is accompanied by slight changes in the speckle pattern when the square bamboo 4 is under pressure) and uploads them to the computer terminal. The image processing technology is used to analyze the slight changes in the photos, and then the strain and displacement of the square bamboo 4 under stress are calculated by the computer based on the slight changes in each pixel point.

[0055] During measurement, the digital speckle meter 3 slides on the track 6 through the frame 7, and the distance between the digital speckle meter 3 and the specimen can be adjusted; by unlocking the self-locking component 5, the digital speckle meter 3 can slide vertically along the vertical pole (of the frame 7), thereby ensuring that the digital speckle meter 3 is always flush with the square bamboo 4, and ensuring the quality of (high-resolution) image acquisition. After the vertical position adjustment of the digital speckle meter 3 is completed, the digital speckle meter 3 can be fixed by locking the self-locking component 5.

[0056] The unlocking process of the self-locking assembly 5 is as follows: the second sliding sleeve 9 is pressed downward, and the second sliding sleeve 9 drives the rotating sleeve 21 through the arc groove 10 and the sliding column 11 when the second sliding sleeve 9 moves downward ( Figure 4 During this process, the locking column 14 moves toward the lower point of the wedge block 12, and then the wedge block 12 reduces the axial force applied to the locking column 14. At this time, the locking column 14 moves away from the vertical pole under the action of the second reset member 16. When the locking column 14 completely leaves the vertical pole, the self-locking assembly 5 is unlocked.

[0057] Continue to apply force to the second sliding sleeve 9. In this process, since the self-locking component 5 has been unlocked, there is no need to overcome the friction between the locking column 14 and the vertical pole. Therefore, the self-locking component 5 can be easily driven downward by the second sliding sleeve 9 (if upward adjustment is required, the self-locking component 5 can be applied with an upward force on the self-locking component 5 while maintaining the unlocked positions of the second sliding sleeve 9 and the rotating sleeve); when the digital speckle meter 3 is aligned with the square bamboo 4, the self-locking component 5 is self-locked to complete the fixing of the position of the digital speckle meter 3 relative to the vertical pole.

[0058] The self-locking process of the self-locking component 5 is as follows: the downward force applied to the second sliding sleeve 9 is released, and at this time the second sliding sleeve 9 moves upward under the action of the first reset member 15, and when the second sliding sleeve 9 moves upward, it drives the rotating sleeve to rotate in the opposite direction through the arc groove 10 and the sliding column 11. When the rotating sleeve rotates in the opposite direction, the wedge block 12 squeezes the locking column 14 to make the locking column 14 move axially until the locking column 14 is pressed against the vertical rod; at this time, the self-locking component 5 is fixed by the friction between the locking column 14 and the vertical rod.

[0059] The present invention uses a digital speckle pattern meter with higher measurement accuracy, faster data acquisition speed, better environmental adaptability (such as being able to work in high temperature or vibration environments), and a simpler operation process; at the same time, the digital speckle pattern meter is applied to online monitoring and control during the square bamboo test process. By measuring the mechanical properties of the square bamboo in real time, problems in the test can be discovered in time, the test plan can be adjusted, and the test efficiency can be improved.

[0060] The present invention can not only measure the strain and displacement of square bamboo, but also obtain other mechanical performance parameters through data analysis, such as stress, elastic modulus, Poisson's ratio, etc. Multi-parameter analysis can provide more comprehensive mechanical performance information of square bamboo, which is helpful for in-depth research on square bamboo.

[0061] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. A square bamboo mechanical change measurement device based on a digital speckle meter, characterized in that: It includes a force-applying component, a fixing component and a digital speckle meter; The force-applying component is used for statically loading the square bamboo; The fixing component is used to install the digital speckle meter and can adjust the vertical position of the digital speckle meter and the distance relative to the force-applying component; The digital speckle instrument is used to collect the speckle pattern changes of the square bamboo when it is statically loaded, and transmit it to the computer for analysis; The digital speckle meter is connected to the fixing component via a self-locking component, and the self-locking component is used to fix the digital speckle meter at any vertical position; The fixing assembly comprises a track and a frame, the frame is in an inverted T shape, and the frame is slidably arranged on the track; The self-locking assembly comprises a first sliding sleeve, a second sliding sleeve, a rotating sleeve and a clamp; The first sliding sleeve is slidably arranged on the frame, the second sliding sleeve is coaxially slidably arranged outside the first sliding sleeve, and the rotating sleeve is coaxially arranged outside the second sliding sleeve; The second sliding sleeve is provided with a plurality of arc grooves, the rotating sleeve is provided with a sliding column matched with the arc grooves, and the inner wall of the rotating sleeve is provided with a plurality of wedge blocks along the circumferential direction; The clamp is coaxially arranged at the bottom of the first sliding sleeve, and the clamp is provided with a plurality of sliding holes along the circumferential direction. A locking column is slidably arranged in the sliding hole, and the first end of the locking column cooperates with the inclined surface of the wedge block, and the second end of the locking column is pressed tightly against the frame; A first resetting member for resetting the second sliding sleeve is provided between the second sliding sleeve and the first sliding sleeve, and a second resetting member for resetting the locking column is provided outside the locking column.

2. The square bamboo mechanical change measuring device based on digital speckle meter according to claim 1 is characterized by: The second end of the locking column is an arc-shaped structure with the same arc as that of the frame.

3. The square bamboo mechanical change measuring device based on digital speckle meter according to claim 2 is characterized in that: The second end of the locking column is provided with rubber.

4. The square bamboo mechanical change measuring device based on digital speckle meter according to claim 1 is characterized in that: The first restoring member and the second restoring member are both springs.

5. The square bamboo mechanical change measuring device based on digital speckle meter according to claim 1 is characterized in that: The force-applying assembly comprises a universal testing machine frame and a support arranged at the bottom of the universal testing machine frame. The universal testing machine frame is provided with a gantry, a cushion block is provided at the first end of the gantry close to the support, and the square bamboo is arranged on the support.

6. The square bamboo mechanical change measuring device based on digital speckle meter according to claim 5 is characterized in that: The cushion block is made of steel.

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