Intelligent testing method for mechanical property of wood component
Through intelligent testing methods, probes and multiple sensors are used to measure the resistance and depth of wooden components, and calculate their density and stress wave propagation speed, solving the problems of long time and complex equipment of traditional detection methods, and achieving fast and convenient wood mechanical properties Inspection reduces damage to wooden components and detection costs.
Patent Information
- Application Number
- CN202411442681.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-16
- Publication Date
- 2024-12-24
AI Technical Summary
The existing wood mechanical properties detection methods have problems such as long detection time, harsh conditions, unsuitable for non-destructive and rapid detection, and the non-destructive testing equipment is large and complex and complex in operation.
An intelligent test method for mechanical properties of wooden components is adopted, including two probes, mechanical sensors, moisture content sensors, laser ranging sensors, integrated circuit boards, power supply modules and display instruments, and the resistance value is obtained by inserting the wooden components into the wooden components and Depth, combining laser ranging and moisture content sensor data, the density, stress wave propagation speed and mechanical properties of wooden components, such as elastic modulus and flexural strength.
It realizes fast and convenient mechanical performance detection of wooden components, the equipment is simple and light, and the operation is more convenient, reducing damage to wooden components, shortening testing time, and saving manpower, economic and time costs.
Smart Images
Figure CN119178872A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of wood component detection, and in particular relates to an intelligent testing method for mechanical properties of wood components. Background Art
[0002] There are a large number of excellent existing buildings in my country, such as traditional wooden ancient buildings and brick-wood mixed structures. These wooden structures are important cultural relics and precious historical and cultural heritage of my country. At the same time, many modern wooden structures have also been newly built in recent years.
[0003] During the construction phase of a wooden structure building, it is very important to accurately evaluate the mechanical properties of the materials and select components that meet the mechanical design properties in order to ensure the quality of the materials and the safety of the structure.
[0004] In the protection and restoration of existing wooden structure construction projects, it is necessary to obtain the material performance information of wooden components as accurately as possible, which is of great significance for judging their safety and health, implementing preventive protection, and conducting scientific and reasonable repairs. Traditionally, the mechanical properties of wood are mostly tested by instruments or mechanical testing machines, which takes a long time, has harsh conditions, poor stability and reproducibility, and is not suitable for non-destructive and rapid testing.
[0005] At present, non-destructive testing of wood components mainly uses non-destructive testing technologies such as stress wave method and micro-drill resistance method to measure the mechanical properties of wood materials and components, which can overcome the defects of traditional methods. However, stress wave detection method and micro-drill resistance method have disadvantages such as large and complex equipment and complicated operation. There is an urgent need for a fast and easy-to-operate detection method. Summary of the invention
[0006] The present invention aims to provide an intelligent testing method for the mechanical properties of wood components, which solves the problem that the existing wood mechanical properties testing using instruments or mechanical testing machines are not suitable for non-destructive and rapid testing, and the existing non-destructive testing equipment is large and complex, and the operation is complicated.
[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:
[0008] An intelligent testing method for mechanical properties of wood components comprises the following steps:
[0009] Step 1: Determine the position of the wood component to be tested, hold the intelligent testing device for mechanical properties of the wood component, the intelligent testing device for mechanical properties of the wood component comprises two probes, a mechanical sensor, a moisture sensor, a laser ranging sensor, an integrated circuit board, a power supply module, a display instrument and an insulating shell, the mechanical sensor, the moisture sensor, the integrated circuit board and the power supply module are respectively located inside the insulating shell, the display instrument is arranged on the outer surface of the insulating shell, the two probes are arranged in parallel, one end of the probe is arranged inside the insulating shell, the other end of the probe is provided with a conical needle tip and is located outside the insulating shell, the mechanical sensor is arranged on the end of one of the probes located inside the insulating shell, the two probes are respectively connected to the two ends of the moisture sensor, the laser ranging sensor is arranged on the insulating shell between the two probes, the laser direction of the laser ranging sensor is parallel to the length direction of the probe, the transmitting end and the receiving end of the laser ranging sensor are both flush with the outer surface of the insulating shell, the integrated circuit board is respectively connected to the mechanical sensor, the moisture sensor, the laser ranging sensor, the power supply module and the display instrument, the two probes are perpendicular to the surface of the wood component, and the probe tips are inserted into the wood component;
[0010] Step 2: Obtain the distance between the wooden component and the insulating shell when the probe penetrates the wooden component by using a laser ranging sensor, and obtain the penetration depth h of the probe into the wooden component by subtracting the distance between the wooden component and the insulating shell from the total length of the probe outside the shell;
[0011] Step 3: Obtain the resistance value F of the probe penetrating into the wooden component through the mechanical sensor;
[0012] Step 4: Calculate the density ρ of the wood component through the functional relationship between the ratio of the resistance value F of the probe penetrating into the wood component and the depth h of the probe penetrating into the wood component and the density ρ of the wood component;
[0013] Step 5: Use the moisture sensor to measure the resistance R between the two probes inserted into the wood component, and use the function formula of moisture content and resistance: W = e (4.09547-(0.1406*ln R)) , obtain the moisture content W of the wood component;
[0014] Step 6: The integrated circuit board calculates the stress wave propagation velocity v of the wood component according to the functional relationship between the stress wave propagation velocity v of the wood component and the moisture content W of the wood component;
[0015] Step 7: The product of the square of the stress wave velocity v of the wood component and the density ρ of the wood component is ρv 2 The elastic modulus E of the wood component is obtained by the functional formula of the elastic modulus E of the wood component; the product of the square of the stress wave velocity v of the wood component and the density ρ of the wood component is ρv 2 The bending strength of wood components b The function formula of the wood component bending strength σb .
[0016] Preferably, in the above-mentioned intelligent testing method for the mechanical properties of wooden components, the functional relationship between the ratio of the resistance value F of the probe penetrating into the wooden component to the depth h of the probe penetrating into the wooden component and the density ρ of the wooden component is obtained by deep learning fitting or by regression analysis fitting; the functional relationship between the ratio of the resistance value F of the probe penetrating into the wooden component to the depth h of the probe penetrating into the wooden component and the density ρ of the wooden component is ρ=0.0779F / h+0.0021.
[0017] Preferably, in the above-mentioned intelligent testing method for the mechanical properties of wood components, the functional relationship between the stress wave propagation velocity v of the wood component and the moisture content W of the wood component is obtained by deep learning fitting or by regression analysis fitting; the functional relationship between the stress wave propagation velocity v of the wood component and the moisture content W of the wood component is v=0.2915W^2-33.508W+5191.6.
[0018] Preferably, in the above-mentioned intelligent testing method for mechanical properties of wood components, when the probe tip is inserted into the interior of the wood component, the line connecting the insertion points of the two probes on the surface of the wood component is parallel to the grain direction of the wood component.
[0019] Preferably, in the above-mentioned intelligent testing method for the mechanical properties of wooden components, both ends of the moisture content sensor are respectively provided with holes for one end of the probe to pass through, and the rod section of the probe located inside the insulating shell is provided with an external thread, and one end of the two probes respectively pass through the corresponding holes on the moisture content sensor and are respectively fixed with two first nuts.
[0020] Preferably, in the above-mentioned intelligent testing method for the mechanical properties of wooden components, the integrated circuit board includes a core processor, an acquisition module, a transmission module and a storage module, the acquisition module, the transmission module and the storage module are respectively connected to the core processor, and the acquisition module is respectively connected to the mechanical sensor, the moisture content sensor and the laser ranging sensor.
[0021] Preferably, in the above-mentioned intelligent testing method for mechanical properties of wooden components, the display instrument adopts a touch display screen.
[0022] Preferably, in the above-mentioned intelligent testing method for mechanical properties of wood components, in step 7, the product ρv of the square of the stress wave velocity v of the wood component and the density ρ of the wood component is 2 Function formula of elastic modulus E of wood component: E = ρv 2 ; The product of the square of the stress wave velocity v of the wood component and the density ρ of the wood component ρv 2 The bending strength of wood components b Function formula: σ b =-0.0018ρv2 +90.172.
[0023] Preferably, in the above-mentioned intelligent testing method for mechanical properties of wooden components, the mechanical sensor, moisture content sensor, laser ranging sensor, integrated circuit board and display instrument are respectively fixed to the insulating shell by screws or screws.
[0024] It can be seen from the technical solutions disclosed above that, compared with the prior art, the beneficial effects of the present invention are as follows:
[0025] In summary, the present invention provides an intelligent testing method for the mechanical properties of a wood component, comprising two probes, a mechanical sensor, a moisture content sensor, a laser ranging sensor, an integrated circuit board, a power supply module, a display instrument and an insulating shell, wherein the mechanical sensor, the moisture content sensor, the integrated circuit board and the power supply module are respectively located inside the insulating shell, the display instrument is arranged on the outer surface of the insulating shell, the two probes are arranged in parallel, one end of the probe is arranged inside the insulating shell, the other end of the probe is provided with a conical needle tip and is located outside the insulating shell, the mechanical sensor is arranged on the end of one of the probes located inside the insulating shell, the two probes are respectively connected to the two ends of the moisture content sensor, the laser ranging sensor is arranged on the insulating shell between the two probes, and the laser direction of the laser ranging sensor is parallel to the length direction of the probe, The transmitting end and the receiving end of the laser distance sensor are both flush with the outer surface of the insulating shell, and the integrated circuit board is respectively connected to the mechanical sensor, the moisture content sensor, the laser distance sensor, the power supply module and the display instrument; when the two probes penetrate into the wood component, the moisture content W of the wood component can be measured by the moisture content sensor, and the resistance value F of the probe penetrating into the wood component can be obtained by the mechanical sensor; the depth h of the probe penetrating into the wood component can be obtained by the laser distance sensor; the integrated circuit board can calculate the stress wave propagation velocity v of the wood component according to the functional relationship between the stress wave propagation velocity v of the wood component and the moisture content W of the wood component; the density ρ of the wood component can be calculated according to the functional relationship between the ratio of the resistance value F of the probe penetrating into the wood component and the depth h of the probe penetrating into the wood component and the density ρ of the wood component; the product ρv of the square of the stress wave velocity v of the wood component and the density ρ of the wood component is obtained. 2 The functional relationship between the elastic modulus E of the wood component and the wood component can be used to obtain the elastic modulus E of the wood component; according to the product of the square of the stress wave velocity v of the wood component and the density ρ of the wood component, ρv 2 The bending strength of wood components b The functional relationship of b .
[0026] On the one hand, the present invention can measure the moisture content W of the wood component, the resistance value F of the probe penetrating into the wood component, and the depth h of the probe penetrating into the wood component by holding the wood component mechanical property intelligent testing device in hand, and calculate the density ρ of the wood component, the stress wave velocity v of the wood component, and the mechanical properties of the wood component (including the elastic modulus E of the wood component and the bending strength σ of the wood component) b ), compared with traditional micro-drill resistance meters and stress wave equipment, the equipment is simple and light, and on-site operation is more convenient and faster.
[0027] On the other hand, the present invention inserts two probes into the surface of the wood component perpendicularly by holding the intelligent testing device for mechanical properties of the wood component, so as to simultaneously measure the moisture content W of the wood component, the resistance value F of the probe penetrating into the wood component and the depth h of the probe penetrating into the wood component, and calculate the density ρ of the wood component, the stress wave velocity v of the wood component and the mechanical properties of the wood component. The traditional test needs to test the density ρ of the wood component, the stress wave velocity v of the wood component and the moisture content W of the wood component respectively, which will cause multiple damages to the wood component. The present invention only needs to insert the handheld testing device into the wood component once, and the operation is simple and convenient. In addition, the insertion depth of the probe is shallow, there is no requirement for the insertion depth, and the damage to the wood component is smaller, thereby achieving micro-damage detection.
[0028] On the other hand, the present invention uses the functional relationship between the stress wave velocity v of the wood component and the moisture content W of the wood component to calculate the stress wave velocity v of the wood component; uses the functional relationship between the density ρ of the wood component and the ratio of the resistance value F of the probe penetrating into the wood component and the depth h of the probe penetrating into the wood component to calculate the density ρ of the wood component; uses the elastic modulus E of the wood component and the bending strength σ of the wood component to calculate the density ρ of the wood component. b The functional relationship between the stress wave velocity v of the wood component and the density ρ of the wood component is used to calculate the elastic modulus E of the wood component and the bending strength σ of the wood component. b There is no need to use stress wave equipment to obtain stress wave velocity v, and there is no need to use micro-drill resistance meter to continuously drill or other methods to obtain density ρ. Therefore, there is no need to use multiple devices to operate separately, which shortens the test time and effectively saves labor costs, economic costs and time costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] Figure 1 It is a structural schematic diagram of an intelligent testing device for mechanical properties of wood components.
[0030] Figure 2 It is a schematic diagram of the use status of the intelligent testing device for the mechanical properties of wood components.
[0031] Figure 3 It is a schematic diagram of the functional relationship between the ratio of the resistance value F of the probe penetrating into the wood component and the depth h of the probe penetrating into the wood component and the density ρ of the wood component.
[0032] Figure 4 It is a schematic diagram of the functional relationship between the stress wave propagation velocity v of the wood component and the moisture content W of the wood component.
[0033] In the figure: 1-probe, 2-mechanical sensor, 3-moisture content sensor, 4-laser ranging sensor, 5-integrated circuit board, 6-power supply module, 7-display instrument, 8-insulating shell, 9-first nut, 10-second nut, 11-wooden component. DETAILED DESCRIPTION
[0034] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The technical content and features of the present invention will be described in detail below by combining the enumerated embodiments with the accompanying drawings. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. For the convenience of description, the "upper" and "lower" described below are consistent with the upper and lower directions of the accompanying drawings, but this cannot be a limitation of the technical solution of the present invention.
[0035] See also Figures 1 to 4 This embodiment discloses an intelligent testing method for mechanical properties of wood components, comprising the following steps:
[0036] Step 1: Determine the position of the wood component 11 to be tested, hold the intelligent testing device for mechanical properties of the wood component, the intelligent testing device for mechanical properties of the wood component includes two probes 1, a mechanical sensor 2, a moisture sensor 3, a laser ranging sensor 4, an integrated circuit board 5, a power supply module 6, a display instrument 7 and an insulating shell 8, the mechanical sensor 2, the moisture sensor 3, the integrated circuit board 5 and the power supply module 6 are respectively located inside the insulating shell 8, the display instrument 6 is arranged on the outer surface of the insulating shell 8, the two probes 1 are arranged in parallel, one end of the probe 1 is arranged inside the insulating shell 8, and the other end of the probe 1 is provided with a conical needle tip and is located outside the insulating shell 8 The mechanical sensor 2 is arranged on the end of one of the probes located inside the insulating shell 8, the two probes 1 are respectively connected to the two ends of the moisture sensor 3, the laser distance sensor 4 is arranged on the insulating shell 8 between the two probes 1, the laser direction of the laser distance sensor 4 is parallel to the length direction of the probe 1, the transmitting end and the receiving end of the laser distance sensor 4 are both flush with the outer surface of the insulating shell 8, the integrated circuit board 5 is respectively connected to the mechanical sensor 2, the moisture sensor 3, the laser distance sensor 4, the power supply module 6 and the display instrument 7, the two probes 1 are perpendicular to the surface of the wooden component 11, and the tips of the probes 1 are inserted into the inside of the wooden component 11;
[0037] Step 2: The distance between the wooden component 11 and the insulating shell 8, i.e., the distance between the laser distance sensor 4 and the wooden component 11, is obtained by the laser distance sensor 4. The integrated circuit board 5 obtains the depth h of the probe piercing into the wooden component by subtracting the distance between the wooden component 11 and the insulating shell 8 from the total length of the probe 1 outside the shell (i.e., the total length of the probe 1 outside the insulating shell 8).
[0038] Step 3: Obtain the resistance value F of the probe penetrating into the wooden component through the mechanical sensor 2;
[0039] Step 4: the integrated circuit board 5 calculates the density ρ of the wood component through the functional relationship between the ratio of the resistance value F of the probe penetrating into the wood component and the depth h of the probe penetrating into the wood component and the density ρ of the wood component;
[0040] Step 5: Use the moisture sensor to measure the resistance R between the two probes inserted into the wood component, and use the function formula of moisture content and resistance: W = e (4.09547-(0.1406*ln R)) , obtain the moisture content W of the wood component, the unit of W value is %;
[0041] Step 6: The integrated circuit board 5 calculates the stress wave propagation velocity v of the wood component through the functional relationship between the stress wave propagation velocity v of the wood component and the moisture content W of the wood component;
[0042] Step 7: The product of the square of the stress wave velocity v of the integrated circuit board 5 passing through the wood component and the density ρ of the wood component is ρv 2 The elastic modulus E of the wood component is obtained by the function formula of the elastic modulus E of the wood component; the integrated circuit board 5 is the product of the square of the stress wave velocity v of the wood component and the density ρ of the wood component ρv 2 The bending strength of wood components b The function formula of the wood component bending strength σ b .
[0043] Preferably, in the above-mentioned intelligent testing method for mechanical properties of wood components, when the tip of the probe 1 is inserted into the wood component 11, the line connecting the insertion points of the two probes 1 on the surface of the wood component 11 is parallel to the grain direction of the wood component 11. Since the line connecting the insertion points of the two probes 1 on the surface of the wood component 11 is parallel to the grain direction of the wood component 11, the resistance can be tested along the grain direction of the wood component 11, and the moisture content of the wood component converted by resistance testing along the grain direction of the wood component 11 is more accurate.
[0044] Preferably, in the above-mentioned intelligent testing method for the mechanical properties of wooden components, holes are respectively provided at both ends of the moisture content sensor 3 for one end of the probe 1 to pass through, and an external thread is provided on the rod section of the probe 1 located inside the insulating shell 8. One ends of the two probes 1 respectively pass through the corresponding holes on the moisture content sensor 3 and are respectively fixed with two first nuts 9. The internal thread of the first nut matches the external thread on the probe, thereby achieving a stable connection between the probe 1 and the moisture sensor, thereby improving the stability and accuracy of the moisture sensor.
[0045] Preferably, in the above-mentioned intelligent testing method for mechanical properties of wood components, the functional relationship between the ratio F / h of the resistance value F of the probe penetrating into the wood component and the depth h of the probe penetrating into the wood component and the density ρ of the wood component is obtained by deep learning or regression analysis. The present invention obtains the functional relationship between the ratio F / h of the resistance value F of the probe penetrating into the wood component and the depth h of the probe penetrating into the wood component and the density ρ of the wood component by deep learning fitting or regression analysis fitting: ρ=0.0779F / h+0.0021, so that the density ρ of the wood component can be directly calculated using the resistance value F of the probe penetrating into the wood component obtained by the mechanical sensor and the depth h of the probe penetrating into the wood component obtained by the laser ranging sensor.
[0046] Preferably, in the above-mentioned intelligent testing method for mechanical properties of wood components, the functional relationship between the stress wave propagation velocity v of the wood component and the moisture content W of the wood component is obtained by deep learning or regression analysis. The present invention obtains the functional relationship between the stress wave propagation velocity v of the wood component and the moisture content W of the wood component by deep learning fitting or regression analysis fitting: v=0.2915W^2-33.508W+5191.6, so that the stress wave propagation velocity v of the wood component can be directly calculated using the moisture content W of the wood component obtained by the moisture content sensor.
[0047] After obtaining the density ρ of the wood component and the stress wave propagation velocity v of the wood component, the elastic modulus E of the wood component and the bending strength σ of the wood component can be used to calculate the stress wave propagation velocity v of the wood component. b The functional relationship between the stress wave velocity v of the wood component and the density ρ of the wood component is used to calculate the elastic modulus E of the wood component and the bending strength σ of the wood component. b , so that only by inserting the handheld test device into the wood component once, the moisture content W of the wood component, the density ρ of the wood component, the resistance value F of the probe penetrating the wood component, the elastic modulus E of the wood component and the bending strength σ of the wood component can be quickly obtained. b There is no need to use stress wave equipment to obtain stress wave velocity v, and there is no need to use micro-drill resistance meter to continuously drill or other methods to obtain density ρ. Therefore, there is no need to use multiple devices to operate separately, which effectively improves the test efficiency and saves manpower, economic and time costs.
[0048] Preferably, in the above-mentioned intelligent testing method for mechanical properties of wood components, the integrated circuit board 5 includes a core processor, an acquisition module, a transmission module and a storage module, and the acquisition module, the transmission module and the storage module are respectively connected to the core processor, and the acquisition module is respectively connected to the mechanical sensor 2, the moisture sensor 3 and the laser ranging sensor 4. The integrated circuit board 5 can realize programming calculation, data transmission and data storage functions. Specifically, the acquisition module receives the measurement data from the mechanical sensor 2, the moisture sensor 3 and the laser ranging sensor 4 respectively; the storage module realizes the storage of data; the core processor realizes the processing of data; and the transmission module realizes the transmission of logarithms. The core processor adopts an MCU chip, the full English name is: Micro Control Unit; the Chinese name is micro control unit, also known as single chip microcomputer (Single Chip Microcomputer) or single chip microcomputer.
[0049] Preferably, in the above-mentioned intelligent testing method for mechanical properties of wood components, the display instrument 7 adopts a touch screen, which can not only output data through the touch screen, but also input data through the touch screen.
[0050] Preferably, in the above-mentioned intelligent testing method for the mechanical properties of wooden components, the two ends of the moisture sensor 3 are respectively provided with holes for one end of the probe 1 to pass through, and the rod section of the probe 1 located inside the insulating shell 8 is provided with an external thread, and one end of the two probes 1 respectively passes through the corresponding holes on the moisture sensor 3 and is fixed with the corresponding first nut 9, thereby achieving a stable connection between the probe and the moisture sensor 3.
[0051] Preferably, in the above-mentioned intelligent testing method for the mechanical properties of wooden components, a through hole is opened on the insulating shell for the probe 1 to pass through, and a second nut 10 is provided in the through hole. The internal thread of the second nut 10 matches the external thread on the probe, thereby realizing a stable connection between the probe and the insulating shell 8.
[0052] Preferably, in the above-mentioned intelligent testing method for the mechanical properties of wooden components, the mechanical sensor is connected to the probe 1 via screws or clamps, and the mechanical sensor 2, moisture content sensor 3, laser ranging sensor 4, integrated circuit board 5, and display instrument 7 are respectively fixedly connected to the insulating shell 8 via screws, etc., thereby achieving stable connection of various components in the insulating shell 8.
[0053] In summary, on the one hand, the present invention can measure the moisture content W of the wood component, the resistance value F of the probe penetrating into the wood component, and the depth h of the probe penetrating into the wood component by holding the intelligent testing device for mechanical properties of the wood component in hand, and calculate the density ρ of the wood component, the stress wave velocity v of the wood component, and the mechanical properties of the wood component (including the elastic modulus E of the wood component and the bending strength σ of the wood component) b ), compared with traditional micro-drill resistance meters and stress wave equipment, the equipment is simple and light, and on-site operation is more convenient and faster.
[0054] On the other hand, the present invention holds the intelligent testing device for mechanical properties of wood components by hand, and simultaneously inserts two probes 1 vertically into the wood components 11, and simultaneously measures the moisture content value W of the wood components, the resistance value F of the probes penetrating into the wood components, and the depth h of the probes penetrating into the wood components, and calculates the density ρ of the wood components, the stress wave velocity v of the wood components, the elastic modulus E of the wood components, and the bending strength σ of the wood components. b These mechanical properties of wood, while traditionally, multiple devices are needed to test the density ρ of the wood component, the stress wave velocity v of the wood component and the moisture content value W of the wood component respectively, which will cause multiple damages to the wood component 11. The present invention only needs to insert the wood once, and the insertion depth of the probe 1 is shallow, and there is no requirement for the penetration depth, which causes less damage to the wood component 11 and realizes micro-damage detection.
[0055] On the other hand, the present invention integrates various sensors, and obtains the resistance value F of the probe penetrating into the wood component and the depth h of the probe penetrating into the wood component by quickly inserting the probe 1 into the wood component. The functional relationship between the resistance value F of the probe penetrating into the wood component, the depth h of the probe penetrating into the wood component and the density ρ of the wood component, the functional relationship between the stress wave velocity v of the wood component and the moisture content value W of the wood component, and the relationship between the resistance value F of the probe penetrating into the wood component, the density ρ of the wood component and the stress wave velocity v of the wood component are utilized. The stress wave velocity v of the wood component is calculated by testing the moisture content value W of the wood component, and there is no need for a separate stress wave device to knock. The density ρ of the wood component is calculated by the resistance value F of the probe penetrating into the wood component and the depth h of the probe penetrating into the wood component, and there is no need for continuous drilling operation. It has the characteristics of high efficiency, speed and low price, and can save manpower, economic and time costs.
[0056] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.
Claims
1. An intelligent testing method for mechanical properties of wood components, characterized in that: The steps include: Step 1: Determine the position of the wood component to be tested, hold the intelligent testing device for mechanical properties of the wood component, the intelligent testing device for mechanical properties of the wood component comprises two probes, a mechanical sensor, a moisture sensor, a laser ranging sensor, an integrated circuit board, a power supply module, a display instrument and an insulating shell, the mechanical sensor, the moisture sensor, the integrated circuit board and the power supply module are respectively located inside the insulating shell, the display instrument is arranged on the outer surface of the insulating shell, the two probes are arranged in parallel, one end of the probe is arranged inside the insulating shell, the other end of the probe is provided with a conical needle tip and is located outside the insulating shell, the mechanical sensor is arranged on the end of one of the probes located inside the insulating shell, the two probes are respectively connected to the two ends of the moisture sensor, the laser ranging sensor is arranged on the insulating shell between the two probes, the laser direction of the laser ranging sensor is parallel to the length direction of the probe, the transmitting end and the receiving end of the laser ranging sensor are both flush with the outer surface of the insulating shell, the integrated circuit board is respectively connected to the mechanical sensor, the moisture sensor, the laser ranging sensor, the power supply module and the display instrument, the two probes are perpendicular to the surface of the wood component, and the probe tips are inserted into the wood component; Step 2: Obtain the distance between the wooden component and the insulating shell when the probe penetrates the wooden component by using a laser ranging sensor, and obtain the penetration depth h of the probe into the wooden component by subtracting the distance between the wooden component and the insulating shell from the total length of the probe outside the shell; Step 3: Obtain the resistance value F of the probe penetrating into the wooden component through the mechanical sensor; Step 4: Calculate the density ρ of the wood component through the functional relationship between the ratio of the resistance value F of the probe penetrating into the wood component and the depth h of the probe penetrating into the wood component and the density ρ of the wood component; Step 5: Use the moisture sensor to measure the resistance R between the two probes inserted into the wood component, and use the function formula of moisture content and resistance: W = e (4.09547-(0.1406*ln R)) , obtain the moisture content W of the wood component; Step 6: Calculate the stress wave propagation velocity v of the wood component through the functional relationship between the stress wave propagation velocity v of the wood component and the moisture content W of the wood component; Step 7: The product of the square of the stress wave velocity v of the wood component and the density ρ of the wood component is ρv 2 The elastic modulus E of the wood component is obtained by the function formula of the elastic modulus E of the wood component; the product of the square of the stress wave velocity v of the wood component and the density ρ of the wood component is ρv 2 The bending strength of wood components b The function formula of the wood component bending strength σ b .
2. The intelligent testing method for mechanical properties of wood components according to claim 1, characterized in that: The functional relationship between the ratio of the resistance value F of the probe penetrating into the wooden component and the depth h of the probe penetrating into the wooden component and the density ρ of the wooden component is obtained by deep learning fitting or by regression analysis fitting; the functional relationship between the ratio of the resistance value F of the probe penetrating into the wooden component and the depth h of the probe penetrating into the wooden component and the density ρ of the wooden component is ρ=0.0779F / h+0.0021.
3. The intelligent testing method for mechanical properties of wood components according to claim 2, characterized in that: The functional relationship between the stress wave propagation velocity v of the wooden component and the moisture content W of the wooden component is obtained by deep learning fitting or regression analysis fitting; the functional relationship between the stress wave propagation velocity v of the wooden component and the moisture content W of the wooden component is v=0.2915W^2-33.508W+5191.
6.
4. The intelligent testing method for mechanical properties of wood components according to claim 1, characterized in that: When the probe tip is inserted into the interior of the wood component, the line connecting the insertion points of the two probes on the surface of the wood component is parallel to the grain direction of the wood component.
5. The intelligent testing method for mechanical properties of wood components according to claim 1, characterized in that: The two ends of the moisture sensor are respectively provided with holes for one end of the probe to pass through, and the rod section of the probe located inside the insulating shell is provided with external threads. One end of the two probes respectively passes through the corresponding holes on the moisture sensor and is fixed with two first nuts respectively.
6. The intelligent testing method for mechanical properties of wood components according to claim 1, characterized in that: The integrated circuit board includes a core processor, an acquisition module, a transmission module and a storage module. The acquisition module, the transmission module and the storage module are respectively connected to the core processor, and the acquisition module is respectively connected to a mechanical sensor, a moisture content sensor and a laser ranging sensor.
7. The intelligent testing method for mechanical properties of wood components according to claim 1, characterized in that: The display instrument adopts a touch display screen.
8. The intelligent testing method for mechanical properties of wood components according to claim 1, characterized in that: The insulating shell is provided with a through hole for the probe to pass through, and a second nut is arranged in the through hole, and the internal thread of the second nut matches the external thread on the probe.
9. The intelligent testing method for mechanical properties of wood components according to claim 1, characterized in that: In step 7, the product of the square of the stress wave velocity v of the wood component and the density ρ of the wood component is ρv 2 Function formula of elastic modulus E of wood component: E = ρv 2 ; The product of the square of the stress wave velocity v of the wood component and the density ρ of the wood component ρv 2 The bending strength of wood components b Function formula: σ b =-0.0018ρv 2 +90.
172.
10. The intelligent testing method for mechanical properties of wood components according to claim 1, characterized in that: The mechanical sensor, the moisture content sensor, the laser distance sensor, the integrated circuit board and the display instrument are respectively fixed to the insulating shell by screws.