Loading tool assembly of a nail hole extrusion test device and nail hole extrusion test device

Abstract

The application discloses a loading tool assembly of a nail hole extrusion test device and the nail hole extrusion test device. The loading tool assembly of the nail hole extrusion test device comprises a loading pin and a loading block. The loading block comprises a mounting groove arranged at a first end and a hollow hole arranged at a middle part and penetrating through in a thickness direction. The mounting groove extends from the first end to the hollow hole. A top end edge of the hollow hole comprises a limiting groove. The loading pin is clamped in the limiting groove. During the test, a test piece passes through the mounting groove and extends into the hollow hole, so that a nail hole of the test piece is exposed in the hollow hole, and the loading pin is inserted into the nail hole. The loading tool assembly is provided with the hollow hole at the middle part of the loading block, so that the nail hole of the test piece is exposed, and the surrounding area of the nail hole is also exposed, thereby facilitating the measurement of the strain distribution data of the surrounding area of the nail hole, and providing more comprehensive test data support for subsequent engineering research.

Description

TECHNICAL FIELD

[0001] The present application relates to a loading tool assembly of a pin-hole extrusion test device and a pin-hole extrusion test device. BACKGROUND

[0002] In engineering design, pin-hole extrusion performance is an important performance index for reference in designing pin-hole connection structure of a composite material part, which is generally measured by a single pin double shear pin-hole extrusion test. Pin-hole extrusion deformation data and strain distribution data of the surrounding area of the pin-hole in the pin-hole extrusion test are important test data for studying the pin-hole extrusion performance and damage failure mechanism of the measured composite material, and are also important support data for supporting the design of the pin-hole connection structure of the part.

[0003] The existing pin-hole extrusion test measuring device generally uses a contact type extensometer to measure the extrusion deformation of the hole edge. The measuring arm of the extensometer is fixed on an auxiliary positioning tool, and the auxiliary positioning tool is fixed on the test piece and the loading tool by mechanical installation or adhesive. In the existing test scheme, there are many tool assemblies, the installation operation of the auxiliary positioning tool and the contact type extensometer is inconvenient, and the installation state significantly affects the measurement results of the extrusion deformation of the hole edge. During the loading process, the extensometer is prone to installation displacement, slipping and other phenomena, which leads to large measurement error of the extrusion deformation of the hole edge or directly causes data distortion. In addition, in the existing test scheme, the hole edge area of the test piece is usually covered by the loading plate, and the strain distribution data of the surrounding area of the hole cannot be measured, and only the extrusion deformation data of the hole edge can be measured.

[0004] It should be noted that the statements in this background section are provided only to assist in understanding the present application and are not necessarily prior art. SUMMARY

[0005] The present application provides a loading tool assembly of a pin-hole extrusion test device and a pin-hole extrusion test device and a pin-hole extrusion test device to obtain the strain distribution of the surrounding area of the pin-hole.

[0006] The present application provides a loading tool assembly of a pin-hole extrusion test device and a pin-hole extrusion test device and a pin-hole extrusion test device to obtain the strain distribution of the surrounding area of the pin-hole.

[0007] A loading pin; and

[0008] A loading block, comprising a mounting groove provided at a first end and a hollow hole provided at a middle part and penetrating in a thickness direction, the mounting groove extending from the first end to the hollow hole, the top end edge of the hollow hole comprising a limiting groove, the loading pin being clamped in the limiting groove, during the test, the test piece passing through the mounting groove and extending into the hollow hole so that the pin-hole of the test piece is exposed in the hollow hole, and the loading pin being inserted into the pin-hole.

[0009] In some embodiments, the top end edge of the hollow hole further comprises two inclined segments respectively located on both sides of the limiting groove, and the bottom end of the inclined segment is connected with the limiting groove.

[0010] In some embodiments, the included angle between the two inclined segments is obtuse.

[0011] In some embodiments, a through hole is arranged on the side wall of the loading block forming the mounting groove, and the loading tool assembly further comprises a positioning rod, the positioning rod passes through the through hole into the mounting groove and is configured to be connected with the surface of the test piece.

[0012] In some embodiments, the inner diameter of the through hole is greater than the outer diameter of the positioning rod so that there is no contact between the positioning rod and the inner wall of the through hole during the test.

[0013] In some embodiments, two through holes are arranged on the side wall and are spaced apart in the height direction, and the positioning rod selectively passes through one of the two through holes.

[0014] In some embodiments, the loading block further comprises a clamping segment arranged at the second end, and the clamping segment is used to be clamped by the chuck.

[0015] In some embodiments, the loading tool assembly is used for testing the test piece of the composite material.

[0016] The second aspect of the present application provides a pinhole extrusion test device, comprising a first chuck, a second chuck and the loading tool assembly, the first chuck is used for clamping the test piece, and the second chuck is used for clamping the loading block.

[0017] In some embodiments, the pinhole extrusion test device further comprises a DIC full-field strain measurement system, and the speckle for DIC test is arranged on the surrounding area of the pinhole of the test piece, and the DIC full-field strain measurement system obtains the strain distribution of the surrounding area of the pinhole according to the position of the speckle for DIC test during the test.

[0018] Based on the aspects provided by the present application, the loading tool assembly is arranged with a hollow hole in the middle of the loading block, so that the pinhole of the test piece is exposed, and the surrounding area of the pinhole is also exposed, thereby facilitating the measurement of the strain distribution data of the surrounding area of the pinhole, and providing more comprehensive test data support for subsequent engineering research.

[0019] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments thereof, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0020] The drawings described herein are used to provide further understanding of the present application, and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0021] Figure 1 The structure schematic diagram of the nail hole extrusion test device of the embodiment of the present application.

[0022] Figure 2 The structure schematic diagram of the nail hole extrusion test device of the embodiment of the present application. Figure 1 The structure schematic diagram of the nail hole extrusion test device of the embodiment of the present application.

[0023] Figure 3 The structure schematic diagram of the nail hole extrusion test device of the embodiment of the present application. Figure 1 The structure schematic diagram of the nail hole extrusion test device of the embodiment of the present application.

[0024] Figure 4 The structure schematic diagram of the nail hole extrusion test device of the embodiment of the present application. Figure 3 The structure schematic diagram of the nail hole extrusion test device of the embodiment of the present application.

[0025] Figure 5 The structure schematic diagram of the nail hole extrusion test device of the embodiment of the present application. Figure 1 The structure schematic diagram of the nail hole extrusion test device of the embodiment of the present application.

[0026] Figure 6 The structure schematic diagram of the nail hole extrusion test device of the embodiment of the present application. Figure 1 The structure schematic diagram of the nail hole extrusion test device of the embodiment of the present application.

[0027] Figure 7 The structure schematic diagram of the nail hole extrusion test device of the embodiment of the present application. Figure 1 The structure schematic diagram of the nail hole extrusion test device of the embodiment of the present application. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way limiting on the application or its application or uses. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0029] Unless otherwise specifically noted, the relative arrangement of parts, numerical expressions, and values stated in these embodiments do not limit the scope of the present application. Meanwhile, it should be understood that the sizes of the various parts shown in the drawings are not drawn in accordance with the actual proportional relationship for the convenience of description. The techniques, methods and devices known to those skilled in the art can not be discussed in detail, but in appropriate cases, the techniques, methods and devices should be considered as part of the authorized description. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0030] For purposes of the description hereinafter, spatially relative terms, such as "above", "below", "up", "down", "between", "within", "left", "right", "front", "back", "upper", "lower", "horizontal", "vertical", "above", "below", "up", "down", "top", "bottom", "side", "end", etc., can be used for ease of description to describe one element's or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if a device in the figures is inverted, elements described as "above" or "up" other elements or features would then be oriented "below" or "below" the other elements or features. Thus, the exemplary term "above" can encompass both an orientation of above and below. The device can be otherwise oriented (e.g., rotated 90 degrees, inverted, etc.) and the spatially relative descriptors used herein interpreted accordingly. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if a device in the figures is inverted, elements described as "above" or "up" other elements or features would then be oriented "below" or "below" the other elements or features. Thus, the exemplary term "above" can encompass both an orientation of above and below. The device can be otherwise oriented (e.g., rotated 90 degrees, inverted, etc.) and the spatially relative descriptors used herein interpreted accordingly.

[0031] Reference Figures 1 to 7 In some embodiments, the loading tool assembly of the nail hole extrusion test device includes a loading pin 3 and a loading block 2. The loading block 2 includes a mounting groove 22 disposed at a first end and a hollow hole 23 disposed at a middle portion and extending through in a thickness direction. The mounting groove 22 extends from the first end to the hollow hole 23. The top end edge of the hollow hole 23 includes a limiting groove 24. The loading pin 3 is clamped in the limiting groove 24. During the test, the test piece passes through the mounting groove 22 and extends into the hollow hole 23, so that the nail hole of the test piece is exposed in the hollow hole 23, and the loading pin 3 is inserted into the nail hole.

[0032] The loading tool assembly exposes the nail hole 23 of the test piece and the surrounding area of the nail hole 23 by providing the hollow hole 23 at the middle portion of the loading block 2, so as to facilitate the measurement of the strain distribution data of the surrounding area of the nail hole 23, and provide more comprehensive test data support for subsequent engineering research.

[0033] In some embodiments, in order to expose more of the surrounding area of the nail hole, with reference to Figure 6 The top end edge of the hollow hole 23 further includes two inclined sections 27 respectively located on both sides of the limiting groove 24. The bottom end of the inclined section 27 is connected with the limiting groove 24. That is, the inclined section 27 is inclined upward, so that more than half of the circumferential direction of the nail hole 12 is exposed, so that a larger area of the surrounding area of the nail hole 12 can be collected.

[0034] In some embodiments, the included angle between the two inclined sections 27 is an obtuse angle.

[0035] In some embodiments, with reference to Figure 6 The side wall of the loading block 2 forming the mounting groove 22 is provided with a through hole 25. With reference to Figure 3In the enlarged view in FIG. 1, the loading tool assembly further comprises a positioning rod 4 which passes through the through hole 25 into the mounting groove 22 and is configured to be connected with the surface of the test piece 1. When the positioning rod 4 is connected with the surface of the test piece 1, the position of the positioning rod 4 can change along with the position of the test piece 1 during the test. Specifically, referring to Figure 4 A positioning feature point can be provided on the outer end surface of the positioning rod 4 for recognition by the DIC full-field strain measurement system.

[0036] Further, a positioning feature point is also provided on the end surface of the loading pin 3 for recognition by the DIC full-field strain measurement system. The DIC full-field strain measurement system recognizes the positioning feature point on the outer end surface of the positioning rod 4 and the positioning feature point on the end surface of the loading pin 3, and obtains the relative position change of the two positioning feature points during the loading process through image calculation to obtain the data of the hole edge extrusion deformation.

[0037] In some embodiments, the inner diameter of the through hole 25 is greater than the outer diameter of the positioning rod 4 so that there is no contact between the positioning rod 4 and the inner wall of the through hole 25 during the test. There is sufficient gap between the positioning rod 4 and the through hole 25 so that the positioning rod 4 can follow the movement of the test piece 1 during the loading process.

[0038] In some embodiments, referring to Figure 6 Two through holes 25 are provided on the side wall at intervals in the height direction, and the positioning rod 4 can selectively pass through one of the two through holes 25.

[0039] In some embodiments, referring to Figure 6 The loading block 2 further comprises a clamping section 21 provided at the second end, which is used to be clamped by the chuck.

[0040] In some embodiments, the loading tool assembly is used for testing the test piece of the composite material.

[0041] In some embodiments, the present application further provides a pinhole extrusion test device. The pinhole extrusion test device comprises a first chuck, a second chuck and the above-mentioned loading tool assembly, the first chuck is used to clamp the test piece 1, and the second chuck is used to clamp the loading block 2.

[0042] In some embodiments, the pinhole extrusion test device further comprises a DIC full-field strain measurement system (DIC, Digital Image Correlation). The surrounding area 13 of the pinhole 12 of the test piece 1 is provided with a DIC test speckle. The DIC full-field strain measurement system obtains the strain distribution of the surrounding area 13 of the pinhole 12 according to the position of the DIC test speckle during the test. Specifically, the DIC full-field strain measurement system analyzes the degree of deformation of the test piece sample by comparing and analyzing the images before and after deformation, and then calculates the test piece surface displacement field and strain field distribution.

[0043] The structure and working process of the pinhole extrusion test device according to a specific embodiment of the present application are described in detail below. Figures 1 to 7 The structure and working process of the pinhole extrusion test device according to a specific embodiment of the present application are described in detail below.

[0044] As shown in Figure 1 In this embodiment, the pinhole extrusion test device includes a loading tool assembly, a first chuck and a second chuck. The loading tool assembly includes a loading block 2 and a loading pin 3. The first chuck and the second chuck are not shown in the figure.

[0045] As shown in Figure 6 The loading block 2 includes a clamping section 21, a mounting groove 22, a hollow hole 23, a limiting groove 24 and a through hole 25. The clamping section 21 is clamped on the second chuck. The mounting groove 22 extends from the upper end face of the loading block 2 to the top edge of the hollow hole 23 and communicates with the hollow hole 23. The mounting groove 22 is used for the test piece 1 to pass through. The hollow hole 23 is arranged in the middle of the loading block 2 and is arranged through in the thickness direction. As shown in Figure 3 When the pinhole extrusion test of the test piece 1 is needed, the test piece 1 is inserted from the top end of the mounting groove 22 and the lower end of the test piece 1 is exposed to the hollow hole 23, so that the surrounding area 13 of the pinhole 12 of the test piece 1 is exposed, and the DIC full-field strain measurement system can measure the strain distribution data of the surrounding area 13 of the pinhole 12 of the test piece 1. As shown in Figure 3 The top edge of the hollow hole 23 has a limiting groove 24, which is used for limiting the loading pin 3 and making the loading pin 3 abut on the limiting groove 24, thereby playing a role of transmitting load.

[0046] In this embodiment, the cross section of the loading pin 3 is circular, and the limiting groove 24 is an arc structure matched with the shape of the loading pin 3.

[0047] As shown in Figure 7 The upper end of the test piece 1 has a clamping area for clamping on the first chuck.

[0048] In the preparation process before the test, in order to protect the above-mentioned clamping area, the reinforcing sheet 11 is symmetrically arranged on both sides of the upper end of the test piece 1. Then the test speckle which meets the requirements of DIC test is sprayed on the surrounding area 13 of the nail hole 12 of the test piece 1. Then the clamping of the test piece 1 and the loading block 2 is carried out, first the test piece 1 is clamped by the first chuck and the length direction of the test piece 1 is ensured to coincide with the loading direction, then the clamping section 21 of the loading block 2 is clamped by the second chuck and the center line of the loading block 2 is ensured to coincide with the center line of the test piece 1, and the coaxiality of the first chuck and the second chuck relative to the test piece 1 is ensured. Then adjust the relative position of the first chuck and the second chuck, so that the lower end of the test piece 1 passes through the mounting groove 22 and the nail hole 12 is exposed in the hollow hole 23. Then the loading pin 3 is inserted through the nail hole 12 of the test piece 1, by adjusting the relative position of the first chuck and the second chuck to change the relative position between the test piece 1, the loading pin 3 and the loading block 2, so that the loading pin 3 is just clamped and abuts in the limiting groove 24 of the loading block 2, then according to the need of hole edge extrusion deformation measurement, select a through hole 25 on the loading block 2, insert the positioning rod 4 through the through hole 25 and stick one end of the positioning rod 4 on the surface of the test piece 1 by using adhesive, so that the sticking position of the positioning rod 4 relative to the test piece 1 is relatively fixed, and the specific state is shown in Figure 3 Fig. 2. At this time, the installation of the test piece 1 and the loading tool assembly on the chuck of the test device is completed.

[0049] It should be noted that there is enough gap between the positioning rod 4 and the through hole 25, so that the positioning rod 4 can change with the test piece 1 during the loading process and does not contact with the through hole 25, in addition, the end surface of the loading pin 3 and the positioning rod 4 are in the same horizontal plane in the installed state, which is convenient for the camera focusing and shooting of the DIC full-field strain measurement system, and small size positioning marks are designed and processed on the end surfaces of the loading pin 3 and the positioning rod 4, which can be well recognized by the DIC full-field strain measurement system. During the test, the first chuck and the second chuck apply relative tensile load to the test piece 1 and the loading block 2 respectively, and the extrusion load between the loading pin 3 and the nail hole 12 of the test piece 1 is generated, and the load value is recorded by the system of the test device. The DIC full-field strain measurement system is started synchronously during the loading process, so as to synchronously record the speckle features in the surrounding area 13 of the nail hole 12 of the test piece 1 and the positioning mark features on the end surfaces of the loading pin 3 and the positioning rod 4, then the relative position change between the loading pin 3 and the positioning rod 4 along the loading direction is calculated based on the image data by the DIC data storage and processing system, which is the nail hole extrusion deformation data, and the nail hole extrusion strain distribution data of the surrounding area 13 of the nail hole 12 is obtained.

[0050] To sum up, the loading tool assembly of the embodiment exposes the surrounding area of the nail hole by designing the loading block with a specific structure, so as to measure the strain distribution data of the surrounding area of the hole. Compared with the existing test scheme, the tool assembly of the embodiment has the advantages of simple structure, simple installation operation, real and stable measurement results, etc., significantly improves the test effect and test efficiency, and adds the measured hole edge area strain distribution data to provide more comprehensive test data support for subsequent scientific and engineering research.

[0051] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalent ones; without departing from the spirit of the technical solutions of the present application, they should be covered in the technical solution range of the present application.

Claims

1. A loading tooling assembly for a nail hole extrusion test apparatus, characterized by, The loading pin (3) and the loading block (2) are included. The loading block (2) includes a mounting groove (22) arranged at a first end and a hollow hole (23) arranged at a middle part and penetrating in a thickness direction, the mounting groove (22) extending from the first end to the hollow hole (23), a top end edge of the hollow hole (23) including a limiting groove (24), the loading pin (3) being clamped in the limiting groove (24), during a test, a test piece passing through the mounting groove (22) and extending into the hollow hole (23) so that a pin hole of the test piece and a surrounding area of the pin hole are exposed in the hollow hole (23), the loading pin (3) being inserted into the pin hole, the surrounding area of the pin hole being provided with speckles for DIC test to obtain a strain distribution of the surrounding area of the pin hole. The top end edge of the hollow hole (23) further includes two inclined sections respectively located at two sides of the limiting groove (24), bottom ends of the two inclined sections being connected with the limiting groove (24), and an included angle between the two inclined sections being an obtuse angle. The loading block (2) is provided with a through hole (25) on a side wall forming the mounting groove, and the loading tool assembly further includes a positioning rod (4), the positioning rod (4) passing through the through hole (25) to reach the mounting groove and being configured to be connected with a surface of the test piece.

2. The pin puncture test apparatus loading tooling assembly of claim 1, wherein, An inner diameter of the through hole (25) is greater than an outer diameter of the positioning rod (4) so that the positioning rod (4) is not in contact with an inner wall of the through hole (25) during a test process.

3. The loading fixture assembly for a nail hole extrusion test apparatus according to claim 2, wherein The side wall is provided with two through holes (25) arranged at intervals in a height direction, and the positioning rod (4) selectively passes through one of the two through holes (25).

4. The pin puncture test apparatus loading tooling assembly of claim 2, wherein, The loading block (2) further includes a clamping section (21) arranged at a second end, the clamping section (21) being used for being clamped by a chuck.

5. The loading tool assembly for a nail hole extrusion test apparatus according to claim 1 or 2, characterized by, The loading tool assembly is used for testing a test piece of a composite material.

6. The pin puncture test apparatus loading fixture assembly of claim 1, wherein, The pin hole extrusion test device further includes a DIC full-field strain measurement system, a surrounding area of a pin hole of the test piece being provided with speckles for DIC test, and the DIC full-field strain measurement system obtaining a strain distribution of the surrounding area of the pin hole according to a position of the speckles for DIC test during a test process.

7. A pin crush test device characterized by, ​ 8. The pin puncture extrusion test apparatus of claim 7, wherein, ​

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