CN212321230U - Test specimen for testing shear performance of foam core material - Google Patents
Test specimen for testing shear performance of foam core material Download PDFInfo
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- CN212321230U CN212321230U CN202021931407.3U CN202021931407U CN212321230U CN 212321230 U CN212321230 U CN 212321230U CN 202021931407 U CN202021931407 U CN 202021931407U CN 212321230 U CN212321230 U CN 212321230U
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Abstract
The utility model discloses a sample for testing the shearing performance of a foam core material, which comprises a foam core material body, and an upper skin layer and a lower skin layer which are bonded and cured on the upper surface and the lower surface of the foam core material body; the upper surface and the lower surface of the sample are respectively provided with an upper notch and a lower notch along the thickness direction of the sample, and the upper notch and the lower notch are positioned at two sides of the center of the sample and have the same length from the center of the sample; the upper and lower incisions extend through the entire sample in the width direction of the sample. The utility model discloses difficult emergence unstability phenomenon in the test process, the test gained data representativeness is strong. The utility model is suitable for a use when shearing the capability test to the foam core.
Description
Technical Field
The utility model belongs to the technical field of the panel shear behavior test, a shear behavior test to the foam core is related to, specifically speaking is a sample for testing foam core shear behavior.
Background
The sandwich plate structure of the foam core material has the characteristics of light weight, high rigidity, corrosion resistance, electromagnetic shielding and the like, and is widely applied to the field of aerospace at present. The resin-based fiber surface layer in the foam core material sandwich plate structure mainly bears the positive stress caused by bending deformation; the middle is a core material, and light materials such as foam are selected, so that enough section moment of inertia and bending rigidity are provided for the structural member, and the structural member bears shear stress. The shear performance, the compressive rigidity and the strength of the foam core sandwich plate structure are important standards for measuring the quality of the foam core sandwich plate structure at present.
The existing compression shear test method for the foam core material sandwich plate is difficult to obtain effective test data, most of failures do not occur to the shear failure of the foam core material sandwich plate, but the foam core material is directly separated from a clamp because the interface between the foam core material and a surface layer is easy to peel, so that the test data is invalid, repeated test tests are needed to obtain the effective data meeting the requirements, and the relative test efficiency is very low.
On the other hand, there is no generally applicable test standard in the industry to perform an effective tensile shear test on the foam core material, and most of the tests are to improve the structure of a clamp used for a compression shear test of the sandwich panel of the foam core material so as to reduce the occurrence of the situation that the foam core material is separated from the clamp in the test process. During the shearing performance test, carry out the installation of specific anchor clamps to foam core sandwich panel, not only additionally increased anchor clamps, made operation process more loaded down with trivial details, and the joining of specific anchor clamps often can restrict the size of foam core sandwich panel, is difficult to test the foam core of various differences, can not fundamentally solve the problem, and application scope is less.
Disclosure of Invention
For solving exist among the prior art more than not enough, the utility model aims at providing a sample for testing foam core material shear property to avoid the emergence of unstability phenomenon in the testing process, thereby reach the purpose that improves efficiency of software testing.
In order to achieve the above object, the utility model adopts the following technical scheme: a sample for testing the shearing performance of a foam core material comprises a foam core material body, an upper skin layer and a lower skin layer, wherein the upper skin layer and the lower skin layer are bonded and cured on the upper surface and the lower surface of the foam core material body; the upper surface and the lower surface of the sample are respectively provided with an upper notch and a lower notch along the thickness direction of the sample, and the upper notch and the lower notch are positioned at two sides of the center of the sample and have the same length from the center of the sample; the upper and lower incisions extend through the entire sample in the width direction of the sample.
As the utility model discloses a injecing, going up incision and undercut's degree of depth and being half of the whole thickness of sample, the width of going up incision and undercut is 1 ~ 2 mm.
As another limitation of the present invention, the width W of the foam core body120-25 mm, length L1120 to 250mm, and a thickness H12-13 mm.
As a further limitation of the present invention, the thickness H of the upper skin layer and the lower skin layer2The thickness of the foam core material is 0.5-3 mm, and the width and the length of the foam core material are the same as those of the foam core material body.
As other limitations of the utility model, the upper skin layer and the lower skin layer are made of any one of the materials of pre-impregnated fiber, glass fiber reinforced plastic or carbon fiber composite.
Since the technical scheme is adopted, compared with the prior art, the utility model, the beneficial effect who gains is:
(1) the utility model discloses an incision and undercut are gone up in the upper and lower surface offside processing of sample, form the shear deformation district, and then realize the shear performance test to foam core material sandwich panel. The utility model discloses the sample that forms utilizes universal sample machine standard matching panel sample tensile fixture can carry out shearing performance test, needn't increase extra anchor clamps, and the operation is simpler, and whole test procedure can reduce sample and the off-going condition of anchor clamps and appear, has guaranteed test data's validity, has improved efficiency of software testing.
(2) The utility model discloses to foam core, go up the skin layer, down the skin layer and go up incision, down the size restriction that the incision goes on, make the sample representativeness that forms stronger, the shearing performance of reaction play foam core sandwich panel that test gained data can be better. The standard is generally applicable to foam core material sandwich plates with different models and structures, and provides a reliable reference basis for manufacturing foam core material sandwich plate samples in the industry. The utility model discloses under the effectual prerequisite of assurance test data, the accuracy of data has further been improved.
(3) The utility model discloses the test method who adopts can effectively solve because of the easy throw-off problem that causes test data invalid of interface between foam core and the surface course, has reduced the test number of times relatively, has simplified the test procedure, has improved efficiency of software testing.
To sum up, the utility model is simple in operation, the difficult unstability phenomenon that takes place in the test process, the test gained data representativeness is strong, can respond well out the shear behavior of foam core sandwich panel. The utility model is suitable for a use when carrying out shear property test to foam core material sandwich panel.
Drawings
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.
Fig. 1 is a schematic structural diagram of embodiment 1 of the present invention;
fig. 2 is a longitudinal sectional view showing a structural relationship of embodiment 1 of the present invention.
In the figure: 1. a foam core body; 2. an upper skin layer; 3. a lower skin layer; 4. an upper notch; 5. a lower incision; 6. and (4) clamping.
Detailed Description
The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It is to be understood that the preferred embodiments described herein are for purposes of illustration and understanding only and are not intended to limit the invention.
Example 1 a sample for testing shear properties of a foam core
The upper incision 4 and the lower incision 5 are machined on the upper side and the lower side of the sample formed in the embodiment, a shearing deformation area is formed between the upper incision 4 and the lower incision 5, and the occurrence of instability can be reduced when a shearing performance test is carried out, so that the validity of test data is ensured.
As shown in fig. 1 to 2, the present embodiment includes a foam core material body 1, and upper and lower skin layers 2 and 3 adhesively cured on upper and lower surfaces of the foam core material body 1, and a composite structure of the upper skin layer 2, the foam core material body 1, and the lower skin layer 3 forms a test piece for testing shear performance of the foam core material. The upper surface and the lower surface of the sample are respectively provided with an upper notch 4 and a lower notch 5 which are 1-2 mm wide along the thickness direction of the sample, the upper notch 4 and the lower notch 5 are located on two sides of the center of the sample, and the upper notch 4 and the lower notch 5 penetrate through the whole sample along the width direction of the sample. In order to ensure that the whole sample is uniformly stressed when being subjected to shear failure in the shear performance test process, in this embodiment, the distances between the upper notch 4 and the lower notch 5 and the center of the sample are the same, specifically as shown in fig. 2, and the depths of the upper notch 4 and the lower notch 5 are half of the whole thickness of the sample.
The width W of the foam core body 1 is such that the data obtained from the test better reflects the shear performance of the foam core in order to make the sample more representative1Limited within the range of 20-25 mm and the length L1Limited within the range of 120-250 mm, and a thickness H1Limiting the size of the particles to be within the range of 2-13 mm; and the thickness H of the upper skin layer 2 and the lower skin layer 32The width and the length of the foam core material are both limited within the range of 0.5-3 mm and are both the same as those of the foam core material body 1.
When a sample is manufactured, the upper skin layer 2 and the lower skin layer 3 can be made of prepreg fiber materials or other composite materials (glass fiber reinforced plastics, carbon fiber composite materials and the like formed by a wet process); the upper skin layer 2 and the lower skin layer 3 can be cured and molded together with the foam core material body 1, or the upper skin layer 2 and the lower skin layer 3 can be molded separately and bonded with the foam core material body 1 through an adhesive.
The sample provided in this example has a foam core material body 1 with a width W1Is 25mm, length L1Is 250mm and has a thickness H1Is 13 mm; width W of upper skin layer 2 and lower skin layer 32Are all 25mm, length L2Are all 250mm, and have a thickness H2Are all 3 mm; the width of the upper incision 4 and the lower incision 5 is 2 mm. In the embodiment, the upper skin layer 2 and the lower skin layer 3 are both made of prepreg fiber materials, and are bonded and cured with the foam core material body 1 into a whole through an adhesive.
Examples 2-6A test specimen for testing the shear properties of a foam core
The sample structures formed in examples 2-6 were identical to the sample structure formed in example 1, except for the dimensional parameters involved, as detailed in table one.
Example 7 method of making a sample for testing the shear properties of a foam core
This example is a sample prepared according to example 1 for testing the shear properties of a foam core, comprising the following steps performed in sequence:
s1, after the upper surface layer 2 and the lower surface layer 3 are respectively bonded and solidified on the upper surface and the lower surface of the foam core material body 1, a rectangular blank with the width W of 20-25 mm, the length L of 120-250 mm and the thickness H of 2.5-16 mm is processed. The foam core material body 1, the upper skin layer 2 and the lower skin layer 3 can be molded and cured together; the skin layer 2 and the lower skin layer 3 can be formed separately and then bonded and cured with the foam core material body 1 through an adhesive.
In the embodiment, the foam core material body 1, the upper skin layer 2 and the lower skin layer 3 are molded and cured together; the width W of the rectangular blank formed by processing is 25mm, the length L is 250mm, and the thickness H is 16 mm.
S2, separating the upper surface of the rectangular blank from the center L of the rectangular blank3One side of the rectangular blank is processed to form a width W along the thickness direction of the rectangular blank31-2 mm, depth T1An upper cut 4 of H/2, the upper cut 4 is along a rectangleThe width direction of the blank runs through the whole rectangular blank. In this embodiment, the upper slit 4 has a width of 2 mm.
S3, separating the lower surface of the rectangular blank from the center L of the rectangular blank3The other side of the rectangular blank is processed to form a width W along the thickness direction of the rectangular blank41-2 mm, depth T2And the lower cut 5 is H/2, and the lower cut 5 penetrates through the whole rectangular blank along the width direction of the rectangular blank to finally form a sample for testing the shearing performance of the foam core material. In this embodiment, the width of the lower slit 5 is 2 mm.
S4, the test specimen for testing the shear properties of the foam core formed a length L between two opposite upper cuts 4 and lower cuts 53The shear deformation zone of (a).
Example 8A test method for testing shear properties of foam core
This example utilizes the test specimens described in example 1 for testing shear performance of a foam core for shear performance testing of a foam core comprising the following steps performed in order:
firstly, a sample is prepared, and the preparation method of the sample is the same as the preparation method of the sample for testing the shearing performance of the foam core material in the embodiment 7; after the sample is manufactured, clamping the universal plate stretching clamps 6 of the universal testing machine at two ends of the sample, and performing a stretching shear test; after the tensile shear failure, recording the maximum load Fb, and calculating the maximum load by the formula
The shear stress τ of the foam core was determined.
Wherein, Fb: maximum load when the sample is damaged by tensile shearing; (Unit/N)
W: the width of the sample; (unit/m)
L3: the length of the shear deformation zone of the sample. (unit/m)
It should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and the present invention is not limited thereto, and although the present invention has been described in detail with reference to the above-mentioned embodiments, it will be apparent to those skilled in the art that modifications can be made to the technical solutions described in the above-mentioned embodiments, or some technical features can be replaced with equivalents. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (5)
1. A sample for testing shear performance of a foam core, characterized by: the foam core material comprises a foam core material body, and an upper skin layer and a lower skin layer which are bonded and solidified on the upper surface and the lower surface of the foam core material body; the upper surface and the lower surface of the sample are respectively provided with an upper notch and a lower notch along the thickness direction of the sample, and the upper notch and the lower notch are positioned at two sides of the center of the sample and have the same length from the center of the sample; the upper and lower incisions extend through the entire sample in the width direction of the sample.
2. The test specimen for testing shear performance of a foam core material according to claim 1, characterized in that: the depth of the upper notch and the depth of the lower notch are both half of the whole thickness of the sample, and the width of the upper notch and the width of the lower notch are both 1-2 mm.
3. A test specimen for testing the shear properties of a foam core according to claim 1 or 2, characterized in that: width W of foam core body120-25 mm, length L1120 to 250mm, and a thickness H12-13 mm.
4. A test specimen for testing the shear properties of a foam core material according to claim 3, characterized in that: thickness H of upper and lower skin layers2The thickness of the foam core material is 0.5-3 mm, and the width and the length of the foam core material are the same as those of the foam core material body.
5. The test specimen for testing shear performance of a foam core material according to any one of claims 1 to 2 and 4, characterized in that: the upper skin layer and the lower skin layer are made of any one of prepreg fiber, glass fiber reinforced plastic or carbon fiber composite materials.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202021931407.3U CN212321230U (en) | 2020-09-07 | 2020-09-07 | Test specimen for testing shear performance of foam core material |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202021931407.3U CN212321230U (en) | 2020-09-07 | 2020-09-07 | Test specimen for testing shear performance of foam core material |
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| CN212321230U true CN212321230U (en) | 2021-01-08 |
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Address after: 071000 northwest of Henan Zhuang village, high tech Zone, Baoding City, Hebei Province Patentee after: Baoding Kaiborui Technology Co.,Ltd. Address before: 071000 northwest of Henan Zhuang village, high tech Zone, Baoding City, Hebei Province Patentee before: BAODING KAIBORUI MACHINERY MANUFACTURING Co.,Ltd. |