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CN-122016445-A - Preparation method of composite material biaxial mechanical sample

CN122016445ACN 122016445 ACN122016445 ACN 122016445ACN-122016445-A

Abstract

The invention discloses a preparation method of a biaxial mechanical test sample of a composite material, which belongs to the field of complex load testing of composite materials and comprises the following steps of S1 grouping prepreg square sheets, S2 setting a layering sequence, arranging the prepreg square sheets layer by layer, rotating the prepreg square sheets to a preset angle, S3 pre-cutting the prepreg square sheets to obtain a reinforced area prepreg A group, a reinforced area prepreg B group and a test sample prepreg C group respectively, S4 cutting a thinning area D corresponding to a test area to be cut by the reinforced area prepreg A group, cutting a thinning area E corresponding to the test area to be cut by the reinforced area prepreg B group, S5 coaxially arranging a plurality of positioning holes, S6 arranging the prepreg square sheets in a laminated mode, placing the prepreg square sheets into a forming die to obtain a cured base material, S8 taking out the cured base material, and cutting the cured base material to obtain the biaxial mechanical test sample of the composite material. By adopting the method, the failure of the adaptation of machining cutting fiber and gluing is avoided through the prefabricated thinning area, and the accurate and true test of the mechanical property of the sample is ensured.

Inventors

  • CHEN YULI
  • WANG HUANGYIN

Assignees

  • 北京航空航天大学

Dates

Publication Date
20260512
Application Date
20260305

Claims (7)

  1. 1. A preparation method of a biaxial mechanical sample of a composite material is characterized by comprising the following steps: S1, determining the total number of layers of the prepreg for preparing the biaxial mechanical test sample of the composite material, and dividing the prepreg square into a prepreg square A group, a prepreg square B group and a prepreg square C group; s2, setting a unified layering sequence, arranging the prepreg square sheets in each group layer by layer according to the layering sequence, and rotating each layer of prepreg square sheets to a preset angle corresponding to the layering sequence, so that the three groups of prepreg square sheets all adopt the same layering rule to finish fiber orientation positioning; S3, respectively cutting the three groups of prepreg square sheets in the S2 to obtain a reinforced area prepreg A group, a reinforced area prepreg B group and a sample prepreg C group which are matched with the size of the die; S4, a plurality of test areas to be cut are formed on the sample prepreg C, a thinning area D comprising a plurality of cutting area alignment holes I is cut out by the reinforced area prepreg A corresponding to the plurality of test areas to be cut, and a thinning area E comprising a plurality of cutting area alignment holes II is cut out by the reinforced area prepreg B corresponding to the plurality of test areas to be cut out on the prepreg square sheet; S5, coaxially arranging a plurality of positioning holes at four corners of the reinforced area prepreg A group, the reinforced area prepreg B group and the sample prepreg C group; s6, stacking and arranging the square sheet groups from top to bottom according to the sequence of the group A, the group C and the group B, and placing positioning pins at the corresponding positioning holes to realize stacked fixation to obtain square sheet groups; s7, placing the square sheet group in the S6 into a forming die for curing and forming treatment to obtain a cured base material; s8, taking out the solidified base material, and cutting the thinning area of the solidified base material by taking the positions of the cutting area alignment hole I, the cutting area alignment hole II and the positioning holes on the solidified base material as references, so as to obtain the biaxial mechanical sample of the composite material.
  2. 2. The method for preparing a biaxial mechanical specimen of a composite material according to claim 1, wherein in S1, the thickness of a single-layer prepreg square sheet is measured in advance And thickness of To measure the average value of a plurality of single-layer prepreg square sheets, and presetting the thickness of a biaxial mechanical sample of the composite material to be The number of prepreg square sheets The calculated formula is as follows: 。
  3. 3. the method for preparing a biaxial mechanical specimen of a composite material according to claim 2, wherein in S1, the thickness of the prepreg sheet C set is The thickness of the prepreg square A group is The thickness of the prepreg square B group is And (2) and And the number of the prepreg square sheets in the prepreg square sheet C group is The number of the prepreg square sheets in the prepreg square sheet A group is The number of prepreg square sheets in the prepreg square sheet B group is 。
  4. 4. The method for preparing a biaxial mechanical specimen of a composite material according to claim 3, wherein the number of prepreg sheets in the prepreg group A and the number of prepreg sheets in the prepreg group B are the same.
  5. 5. The method for preparing a biaxial mechanical test sample of a composite material according to claim 4, wherein in S4, the first cutting area alignment holes of the prepreg A group in the reinforcing area and the second cutting area alignment holes of the prepreg B group in the reinforcing area are distributed corresponding to the array of thinning areas and are respectively and coaxially arranged.
  6. 6. The method for preparing a biaxial mechanical sample of a composite material according to claim 5, wherein in S5, the number of the positioning holes is 4, and the aperture of each positioning hole is smaller than the apertures of the first positioning hole and the second positioning hole in the cutting area.
  7. 7. The method of claim 6, wherein S6, the diameter of the locating pin is in clearance fit with the aperture of the locating hole, the length of the locating pin is the same as the total thickness of the composite biaxial mechanical sample, and the thinning area of the sample prepreg C group is correspondingly positioned between the thinning area D and the thinning area E after the locating pin is fixed.

Description

Preparation method of composite material biaxial mechanical sample Technical Field The invention relates to the technical field of complex load testing of composite materials, in particular to a preparation method of a biaxial mechanical sample of a composite material. Background The fiber reinforced composite material is widely used as a bearing member of special vehicles in the fields of aviation, aerospace, navigation and the like, the mechanical property research under the complex stress state is particularly important, the single-axis mechanical property test technology and standard of the material are developed and mature at present, the double-axis mechanical property test has the current national standard, but the corresponding sample preparation method has the problem of poor universality. Specifically, in the traditional preparation mode of the current fiber reinforced composite material biaxial sample, machining operation is required to be performed after the base material is cured and molded, irreversible damage is caused to fibers in the sample, so that the mechanical properties of the prepared sample and the mechanical properties of the real structure of the material are obviously different, the mechanical properties of the material in practical application cannot be accurately reflected, and in the current sample preparation method adopted by the biaxial test standard, the connection and matching of related structures are realized by means of an adhesive, and the adhesive is required to be respectively matched with a sample body and a reinforcing sheet, so that the preparation and matching requirements of various fiber reinforced composite materials are difficult to meet, the application range of the method is limited, and effective support cannot be provided for biaxial mechanical property tests of different types of fiber reinforced composite materials. Disclosure of Invention The invention aims to provide a preparation method of a biaxial mechanical sample of a composite material, which solves the technical problems. In order to achieve the above purpose, the invention provides a preparation method of a biaxial mechanical sample of a composite material, which comprises the following steps: S1, determining the total number of layers of the prepreg required for preparing a biaxial mechanical composite material sample, and dividing the prepreg square into a prepreg square A group, a prepreg square B group and a prepreg square C group; S2, setting uniform layering sequences for the prepreg square sheet A group, the prepreg square sheet B group and the prepreg square sheet C group, arranging the prepreg square sheets in each group layer by layer according to the layering sequences, and rotating each layer of prepreg square sheet to a preset angle corresponding to the layering sequences, so that the three groups all adopt the same layering rule to finish fiber orientation positioning; S3, pre-cutting the prepreg square sheet A, the prepreg square sheet B and the prepreg square sheet C which are subjected to the rotary arrangement in the S2 to obtain three groups of reinforced area prepreg A, reinforced area prepreg B and sample prepreg C with the same side length dimension and matched with the die dimension; S4, a plurality of test areas to be cut are formed on the prepreg C corresponding to the sample finished product, a thinning area D comprising a plurality of cutting area alignment holes I is cut on the prepreg square sheet of the prepreg A corresponding to the plurality of test areas to be cut, and a thinning area E comprising a plurality of cutting area alignment holes II is cut on the prepreg square sheet of the prepreg B corresponding to the plurality of test areas to be cut; S5, coaxially arranging a plurality of positioning holes at four corners of the prepreg square sheet of the prepreg A group in the reinforced area, the prepreg square sheet of the prepreg B group in the reinforced area and the prepreg square sheet of the prepreg C group in the sample; s6, stacking the reinforced area prepreg A group, the reinforced area prepreg B group and the sample prepreg C group which are provided with the positioning holes in the S5 according to the sequence of the A group, the C group and the B group from top to bottom, and placing positioning pins at the positions corresponding to the positioning holes to realize stacked fixation to obtain square sheet groups; S7, placing the square sheet groups which are arranged in a laminated manner in the S6 into a forming die for curing and forming so as to obtain a cured base material; s8, taking out the solidified base material, and cutting the thinning area of the solidified base material by taking the positions of the cutting area alignment hole I, the cutting area alignment hole II and the positioning holes on the solidified base material as references, so as to obtain the biaxial mechanical sample of the composite material. Preferably, in S1, the t