A multi-proportional biaxial stretch material testing device and method capable of real-time observation

Abstract

The present invention belongs to the field of testing technology, and specifically relates to a multi-proportional bidirectional stretching material testing device and method capable of real-time observation; the device comprises an upper clamp, a lower clamp and a steel wire, wherein the upper clamp and the lower clamp are connected by the steel wire; the upper clamp comprises an upper pulling block and a stretching rod, wherein a groove is provided on the upper pulling block, and a protrusion is provided in the middle of the groove; the device of the present invention is simple, has a large stretching stroke, can better control the constant speed stretching, and its vertical structure and vertical frame are convenient for observation and monitoring, and a plurality of slide cylinders can be assembled at both ends of the stretching rod and the two ends of the frame, thereby realizing variable proportion stretching.

Description

Technical Field

[0001] The invention belongs to the field of testing technology, and in particular relates to a multi-proportional biaxial stretching material testing device and a method thereof capable of real-time observation. Background Art

[0002] Due to technical and cost limitations, research on the mechanical properties of materials is usually conducted on uniaxial tensile machines, and research on the biaxial tensile mechanical properties of materials usually requires the design of a special test device. In the current research on uniaxial to biaxial test devices, a horizontal design is usually adopted. However, since the test loading equipment is usually located directly above the test device, this method cannot be used to observe the test piece from the front. Some biaxial tensile test devices that can be used for horizontal front observation have complex processes and high costs, and require special photography and video equipment, which are less practical. In addition, existing vertical test devices almost always place two branches of a cross-shaped test piece vertically, in which the two vertical branches of the test piece coincide with the direction of gravity, and the two horizontal branches of the test piece are perpendicular to the direction of gravity. This method easily causes the two branches of the test piece to be in different initial load states, and usually the load in the vertical direction is greater than the load in the horizontal direction. Moreover, during the stretching process, the gravity exerted on the test piece connection device in the vertical direction directly acts on the test piece, which causes a large measurement error in the test results. In addition, most of the current real-time observation methods for micro- and macroscopic observations involve high-cost instruments and equipment, such as scanning electron microscopes, high-speed cameras, X-CT and other equipment, which are too expensive and not suitable for popularization. Summary of the invention

[0003] In view of the problems mentioned in the prior art, the present invention provides a multi-ratio biaxial stretch material testing device and method thereof which has a simple structure, an adjustable stretch ratio, and a vertical structure and can be observed in real time.

[0004] The present invention discloses a multi-proportional bidirectional tensile material testing device capable of real-time observation, comprising an upper clamp, a lower clamp and a steel wire, wherein the upper clamp is connected to the lower clamp by the steel wire; the upper clamp comprises an upper pull block and a tensile rod, wherein a groove is provided on the upper pull block, and a protrusion is provided in the middle of the groove, a through hole adapted to the protrusion is provided in the middle of the tensile rod, and a plurality of first threaded holes are respectively provided along the axial direction at both ends of the tensile rod with the through hole as the center, and the protrusion passes through the through hole to connect the upper pull block with the tensile rod, wherein both ends of the upper pull block are provided with a pin hole, The upper pull block and the stretching rod can be fixedly assembled by cooperating with the latch, and a connecting hole is also provided on the latch; the lower clamp includes a frame, a guide rail and a slider, pulley seats are provided at opposite ends of the bottom of the frame, and a first square groove and a second square groove are provided at two ends of the top of the frame respectively, and a first connecting plate is provided in the pulley seat and the first square groove; the guide rails are a pair and cross-arranged, and a second connecting plate is provided at both ends of the guide rails, and the first connecting plate and the second connecting plate are connected by a main shaft, and an opening is also provided at the intersection of the guide rails, and the slider is arranged on the guide rails.

[0005] Preferably, a plurality of second threaded holes are provided between the first square groove and the second square groove.

[0006] Preferably, it also includes a slide cylinder, on which a pulley is provided, and increasing the number of slide cylinders can correspond to setting different loading ratios.

[0007] Preferably, the slider is C-shaped, the bottom of the slider is connected to the guide rail with a pin, one end of the slider is provided with a rope hole for connecting to a steel wire, and the other end is provided with a fixing hole connected to the test piece.

[0008] Preferably, it also includes a support rod, which is arranged between the upper clamp and the lower clamp, and the support rod is threadedly connected to the lower clamp.

[0009] Preferably, the central axis of the pulley seat and the central axis of the second square groove are located in the same vertical plane.

[0010] Preferably, the length of the stretching rod is equivalent to the distance between the two second square grooves on the frame.

[0011] A method for a multi-ratio biaxial stretch material testing device capable of real-time observation,

[0012] Step 1: Connect the test piece to be tested to the slider, place the test piece on the guide rail, and align the center of the test piece with the center of the opening;

[0013] Step 2: Add a light source 10 cm away from the back of the specimen, and place a screen parallel to the plane of the specimen 1 m away from the other side of the specimen;

[0014] Step 3: The protrusion is driven by the loading device to stretch the specimen through the steel wire. During the stretching process, the change of the shadow of the specimen projected on the screen is observed, and the deformation of the specimen is calculated based on the distance between the light source and the specimen and the distance between the light source and the screen.

[0015] Step 4: Repeat step 3. When the specimen is stretched, observe whether there is a bright spot at the center of the specimen's shadow on the screen. This can determine the moment when the specimen is damaged and unstable during stretching.

[0016] Step 5: By adding slide tubes to both ends of the stretching rod, different numbers of slide tubes are installed in coordination with the pulleys on the slide tubes and the second threaded holes on the frame, so as to adjust different loading ratios.

[0017] Compared with the prior art, the present invention has achieved the following technical effects:

[0018] The device of the present invention is simple, has a large stretching stroke, can better control the constant speed stretching, and its vertical structure and vertical frame are convenient for observation and monitoring. A plurality of slide cylinders can be assembled at both ends of the stretching rod and the frame, thereby realizing variable ratio stretching. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of the pull-up block of the present invention;

[0021] Figure 3 It is a schematic diagram of the structure of the stretching rod of the present invention;

[0022] Figure 4 It is a schematic diagram of the latch of the present invention;

[0023] Figure 5 This is a schematic diagram of the structure of the slider of the present invention;

[0024] Figure 6 It is a schematic diagram of the structure of the slide cylinder of the present invention;

[0025] Figure 7 This is a schematic diagram of Example 2 of the present invention.

[0026] Figure markings: 1-steel wire; 2-upper pull block; 3-stretching rod; 4-support block; 5-guide rail; 6-slider; 7-opening; 8-first square groove; 9-second square groove; 10-pulley seat; 11-second threaded hole; 12-protrusion; 13-pin hole; 14-first threaded hole; 15-pin; 16-pull rope hole; 17-slide; 18-pulley; 19-fixing hole. DETAILED DESCRIPTION

[0027] Example 1

[0028] The present invention provides a multi-proportional biaxial stretch material testing device capable of real-time observation, such as Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, it includes an upper clamp, a lower clamp and a steel wire 1, and the upper clamp and the lower clamp are connected by the steel wire 1; the upper clamp includes an upper pull block 2 and a stretching rod 3, the upper pull block 2 is provided with a groove, and a protrusion 12 is provided in the middle of the groove, and a through hole adapted to the protrusion 12 is provided in the middle of the stretching rod 3, and a plurality of first threaded holes 14 are respectively provided along the axial direction of both ends of the stretching rod 3 with the through hole as the center, and the protrusion 12 passes through the through hole to connect the upper pull block 2 with the stretching rod 3, wherein both ends of the upper pull block 2 are provided with a pin hole 13, and the upper pull block 2 can be connected with the pin 15 The pull block 2 and the stretching rod 3 are fixedly assembled, and the latch 15 is also provided with a connection hole; the lower fixture includes a frame, a guide rail 5 and a slider 6, and the two ends of the bottom of the frame are oppositely provided with a pulley seat 10, and the two ends of the top of the frame are respectively provided with a first square groove 8 and a second square groove 9, and the pulley seat 10 and the first square groove 8 are both provided with a first connection plate; the guide rails are a pair and cross-arranged, and the two ends of the guide rails are provided with a second connection plate, and the first connection plate and the second connection plate are connected through a main shaft, wherein an opening 7 is also provided at the intersection of the guide rails 5, and the slider 6 is arranged on the guide rail 5. The slider 6 is C-shaped, and the bottom of the slider 6 is connected to the guide rail 5 with a pin, and one end of the slider 6 is provided with a pull rope hole 16 for connecting to the steel wire 1, and the other end is provided with a fixing hole connected to the specimen. It also includes a support rod 4, which is arranged between the upper fixture and the lower fixture, and the support rod 4 is threadedly connected to the lower fixture. The central axis of the pulley seat 10 and the central axis of the second square groove 9 are located in the same vertical plane. The length of the stretching rod 3 is equivalent to the distance between the two second square grooves 9 on the frame.

[0029] In this embodiment, the length of the stretching rod 3 is longer than that of the upper pull block 2, and the size of the upper pull rod groove matches the size of the stretching rod 3, so as to ensure that the stretching rod 3 can be placed in the groove. The positioning function of the protrusion 12 set in the middle of the groove cooperates with the through hole in the middle of the stretching rod 3 to connect the upper pull block 2 with the stretching rod 3. The pin holes 13 set at both ends of the upper pull block 2 cooperate with the connected pins 15 to fix the stretching rod 3; the pin 15 in this embodiment is provided with a baffle at one end and a through hole for the steel wire 1 to pass through at the other end, which cooperates with the steel wire 1 to connect the entire upper clamp; the support rod 4 in this embodiment is arranged between the upper clamp and the lower clamp to play the role of supporting the upper clamp, and the support rod 4 is threadedly connected to the lower clamp. The support distance can be adjusted by rotating the support rod 4. In this embodiment, there are two support rods; the lower clamp It is a frame structure, with pulley seats 10 installed at both ends of the bottom of the frame, and a first square groove 8 and a second square groove 9 are respectively provided at both ends of the top of the frame. At the same time, a fixing hole 19 is also provided at the bottom of the lower fixture, and the fixing hole 19 can be used to be threadedly connected to the test fixture and provide support for the lower fixture. In this embodiment, the first square groove 8 is closer to the middle of the frame, and a first connecting plate is provided in the first square groove 8 and the pulley seat 10. The guide rails 5 in this embodiment are a pair and the two guide rails 5 are cross-arranged to form a cross structure. A second connecting plate is provided at both ends of the guide rails 5, wherein the central axes of the first connecting plate and the second connecting plate are located in the same horizontal plane, and the first connecting plate and the second connecting plate are connected by a main shaft. In this device, one end of the steel wire is connected to the slider 6, and the other end bypasses the main shaft and is connected to the upper fixture.

[0030] The guide rail 5 is also provided with four sliders 6, which are respectively provided on the four arms of the guide rail 5; the device also includes a U-shaped buckle for a wire rope (not shown in the figure), and the wire 1 can be locked by using the first threaded hole provided with the U-shaped buckle for the wire rope. The U-shaped buckle for the wire rope is a prior art and will not be elaborated here; the slider 6 of this embodiment is C-shaped, such as Figure 6 As shown, the slider 6 is sleeved on the guide rail 5, and the hole set at the bottom can be connected to the guide rail 5 with screws. When the screws are connected, it is necessary to ensure that the slider 6 can slide along the guide rail 5; when the device is installed, one end of one of the steel wires 1 is connected to the slider 6 near the top of the frame, and the other end bypasses the main shaft in the first square groove 8 and is connected to the first threaded hole 14 on the stretching rod 3 through a locking ring. After one end of the other steel wire 1 is connected to the slider 6 near the bottom of the frame, the other end bypasses the main shaft set in the pulley seat 10 and passes through the second square groove 9 to be connected to the first threaded hole 14 on the stretching rod 3 through a locking ring.

[0031] The opening 7 in the device is used for irradiating the specimen with a light source so as to project the specimen onto the screen. The specimen and the opening 7 satisfy a certain relationship. When it is necessary to observe the crack of the specimen from a microscopic perspective, the size of the opening 7 only needs to be equal to the specimen setting; when it is necessary to observe the deformation of the specimen from a macroscopic perspective, the size of the opening 7 is (1+ε) times the length of the specimen, where ε is the elongation, which refers to the percentage of the elongation of the original gauge length to the original gauge length after the specimen is stretched and fractured, which is a well-known technology in the art and will not be elaborated on here.

[0032] When in use, step 1: connect the test piece to be tested to the slider 6, place the test piece on the guide rail 5, and align the center of the test piece with the center of the opening 7;

[0033] Step 2: Add a light source 10 cm away from the test piece and at the back of the test piece, and place a screen parallel to the plane where the test piece is located 1 m away from the other side of the test piece. The light source in this embodiment is a high-efficiency film and television lamp, but is not limited to a high-efficiency film and television lamp;

[0034] Step 3: The protrusion 12 is driven by the loading device to stretch the specimen through the steel wire 1. During the stretching process, the change of the shadow of the specimen projected on the screen is observed, and the deformation of the specimen is calculated based on the distance between the light source and the specimen and the distance between the light source and the screen.

[0035] Step 4: Repeat step 3. When the specimen is stretched, observe whether there is a bright spot at the center of the specimen's shadow on the screen. This can determine the moment when the specimen is damaged and unstable during stretching.

[0036] Step 5: By adding slide cylinders 17 to both ends of the stretching rod 3, different numbers of slide cylinders 17 are installed in coordination with the pulleys 18 on the slide cylinders 17 and the second threaded holes 11 on the frame, so as to adjust different loading ratios.

[0037] Example 2

[0038] This embodiment is basically the same as the embodiment 1. This embodiment is an improvement on the embodiment 1. A plurality of second threaded holes 11 are provided between the first square groove 8 and the second square groove 9. A slide cylinder 17 is also included. A pulley 18 is provided on the slide cylinder 17. Increasing the number of slide cylinders can correspond to setting different loading ratios.

[0039] like Figure 7The figure shows the 1:2 ratio stretching structure of the device. The pulley 18 provided in the present embodiment is installed on the slide 17. When in use, one end of two steel wires 1 located on the guide rail 5 is connected to the slider 6, and the other end passes around the main shaft located at the bottom of the frame and extends out from the second square groove 9, then passes around the pulley 18 provided on the slide 17 and passes through the second threaded hole 11 provided on the top of the frame and is fixed by a locking ring. The connection method of the other two steel wires 1 remains unchanged. When it is necessary to load different loading ratios such as 1:3, 1:4, etc., it is only necessary to add different numbers of slides 17, and the pulley 18 on the slide 17 is used to cooperate with the steel wire 1 to achieve stretching with different loading ratios.

Claims

1. A multi-proportional biaxially stretched material testing device capable of real-time observation, characterized in that: It comprises an upper clamp, a lower clamp and a steel wire (1), wherein the upper clamp and the lower clamp are connected via the steel wire (1); The upper clamp comprises an upper pull block (2) and a stretching rod (3), wherein the upper pull block (2) is provided with a groove, and a protrusion (12) is provided in the middle of the groove, and a through hole adapted to the protrusion (12) is provided in the middle of the stretching rod (3), and a plurality of first threaded holes (14) are provided axially along both ends of the stretching rod (3) with the through hole as the center, and the protrusion (12) passes through the through hole to connect the upper pull block (2) with the stretching rod (3), wherein both ends of the upper pull block (2) are provided with a latch hole (13), and the upper pull block (2) and the stretching rod (3) can be fixedly assembled by cooperating with a latch (15), and a connecting hole is also provided on the latch (15); The lower clamp comprises a frame, a guide rail (5) and a slider (6); pulley seats (10) are arranged opposite to each other at two ends of the bottom of the frame; a first square groove (8) and a second square groove (9) are respectively arranged at two ends of the top of the frame; a first connecting plate is arranged in the pulley seat (10) and the first square groove (8); the guide rails are a pair and are arranged crosswise; a second connecting plate is arranged at both ends of the guide rails; the first connecting plate and the second connecting plate are connected via a main shaft; an opening (7) is also arranged at the intersection of the guide rails (5); and the slider (6) is arranged on the guide rails (5).

2. A multi-proportional biaxially stretched material testing device capable of real-time observation according to claim 1, characterized in that: A plurality of second threaded holes (11) are also provided between the first square groove (8) and the second square groove (9).

3. A multi-proportional biaxially stretched material testing device capable of real-time observation according to claim 2, characterized in that: It also includes a slide cylinder (17), on which a pulley (18) is provided. By increasing the number of slide cylinders, different loading ratios can be set accordingly.

4. A multi-proportional biaxially stretched material testing device capable of real-time observation according to claim 3, characterized in that: The slider (6) is C-shaped, and the bottom of the slider (6) is connected to the guide rail (5) by means of a matching pin. One end of the slider (6) is provided with a rope hole (16) for connecting to the steel wire (1), and the other end is provided with a fixing hole connected to the test piece.

5. A multi-proportional biaxially stretched material testing device capable of real-time observation according to claim 4, characterized in that: It also comprises a support rod (4), wherein the support rod (4) is arranged between the upper clamp and the lower clamp, and the support rod (4) is threadedly connected to the lower clamp.

6. A multi-proportional biaxially stretched material testing device capable of real-time observation according to claim 5, characterized in that: The central axis of the pulley seat (10) and the central axis of the second square groove (9) are located in the same vertical plane.

7. A multi-proportional biaxially stretched material testing device capable of real-time observation according to claim 6, characterized in that: The length of the stretching rod (3) is equivalent to the distance between the two second square grooves (9) on the frame.

8. A method for a multi-ratio biaxially stretched material testing device capable of real-time observation according to any of claims 3 to 7, characterized in that: Step 1: Connect the test piece to be tested to the slider (6), place the test piece on the guide rail (5), and align the center of the test piece with the center of the opening (7); Step 2: Add a light source 10 cm away from the back of the specimen, and place a screen parallel to the plane of the specimen 1 m away from the other side of the specimen; Step 3: The protrusion (12) is driven by the loading device to stretch the specimen through the steel wire (1). During the stretching process, the change of the shadow of the specimen projected on the screen is observed, and the deformation of the specimen is calculated based on the distance between the light source and the specimen and the distance between the light source and the screen. Step 4: Repeat step 3. When the specimen is stretched, observe whether there is a bright spot at the center of the specimen's shadow on the screen. This can determine the moment when the specimen is damaged and unstable during stretching. Step 5: By adding slide cylinders (17) to both ends of the stretching rod (3), different numbers of slide cylinders (17) are installed in coordination with the pulleys (18) on the slide cylinders (17) and the second threaded holes (11) on the frame, thereby adjusting different loading ratios.

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