This standard specifies the equipment, specimens, test conditions, test procedures, test result calculation and test report for the compression performance test of fiber reinforced plastic thin sheets. This standard is applicable to the determination of the compressive strength, compressive elastic modulus, compressive secant modulus, compressive Poisson's ratio, compressive maximum strain and compressive stress-strain curve of glass fiber, carbon fiber, aramid and mixed fiber reinforced plastic thin sheets. Method A is applicable to fiber reinforced plastic thin sheets of 0.5~4mm as an arbitration test method. Method B is applicable to fiber reinforced plastic thin sheets of 1~4mm. GB/T 5258-1995 Test method for compression performance of fiber reinforced plastic thin sheets GB/T5258-1995 Standard download decompression password: www.bzxz.net

83.120
National Standard of the People's Republic of China
GB:T 5258-1995
Test method for compressive properties offiber reinforced plastic thin laminates1995-12-20Promulgated
National Technical Supervision Committee
Implementation on August 1, 1996
National Standard of the People's Republic of China
Fiber reinforced plastic thin laminates
Test method for compressive properties offiber reinforced plastic thin laminates1995-12-20Promulgated
National Technical Supervision Committee
Implementation on August 1, 1996 1 Main content and scope of application
GB/T5258--1995
This standard specifies the equipment, test selection, test conditions, test steps, test duration and test report for the compressive performance test of fiber reinforced plastic thin sheets.
This standard is used to determine the compression plasticity, compression elastic modulus, compression cutting modulus, compression ratio, compression strain and compressive stress-strain curve of glass fiber, carbon fiber, aramid and mixed fiber reinforced plastic thin sheets. Method A is suitable for fiber reinforced plastic thin sheets with a diameter of 0.5-4 mm as a secondary test method. Method B is used for fiber reinforced plastic thin sheets with a diameter of 1-4 mm. 2 Reference standards
GB1446 General test methods for fiber reinforced plastics 3 Terminology
3.1 Compressive strength Compressive strength The stress of the specimen when it is compressed or damaged. The unit is MP. 3.2 Compressive elastic modulus trio-elasticity in compressive stress-strain curve The slope of the straight line within the proportional limit. The unit is M. 3.3 Compressive elastic modulus of secani in compressive stress-strain curve The slope of the line connecting the origin on the compressive stress-strain curve and the corresponding point of the strain exceeding the proportional limit, the unit is MP. 3.4 Maximum compressive strain maximum cumpressivstrain The maximum compressive strain of the specimen during compression or ring cutting, that is, the strain corresponding to the normal strain. Principle
Axial flexibility is applied to the specimen by compression that can avoid specimen failure and prevent damage to the center and ends of the specimen, so that the specimen is compressed in the working section.
5 Equipment
5.1 Test equipment
The test equipment shall comply with the provisions of GB1446 Section 5. 5.2 Test Equipment 5.2.7 Schematic diagram of the test fixture for compression test method A is shown in Figure 1. 5.2.2 Schematic diagram of the test fixture for compression test method B is shown in Figure 2. 1995-12-20 Standard 1996-08-01 GH/T5258—1995 5.2.3 Any test fixture that can sustain the test without losing stability and without causing damage to the cortex can be used. 5.3 Any strain gauge that can measure the shape of the pair or the specimen within the working section and whose measurement error does not exceed 1% can be used. 5.4 The accuracy of the test fixture of the selected size shall comply with the provisions of Chapter 1 of GB141. Figure 1 Schematic diagram of test fixture and specimen assembly for compression test method A 1-support 12-center 3 specimen: 4 clamp + 5-roller F-nationality! 7-base plate-test color change mouth
6 specimen
6.1 Specimen shape and size
GB/T5258--1995
Figure 2 Schematic diagram of test fixture and specimen assembly for compression test method B 1-compression test head; 2-elastic sound 3-style 6.1.1 The shape and size of the specimen for compression test method A are shown in Figure 3. Specimen thickness The actual thickness of the product, 6.1.2 The shape and size of the specimen for compression test method B are shown in Figure 4. Generally, type I specimens are selected. When crack damage occurs, type II specimens can be selected. The specimen thickness is the actual thickness of the product. 6.1.3 The thickness of the specimen is 2 mm. 6.2 Preparation of specimens 6.2.1 Test details According to the provisions of GR 1446, Section 1, 6.2.2 The two end faces of the specimen shall be aligned with each other, with a verticality not greater than 0.1% of the initial specimen height, and perpendicular to the specimen axis, with a verticality not greater than 1% of the initial specimen height. 6.2.3 If the reinforcement sheet can be made of aluminum, or other appropriate materials close to the deformation of the test material, the thickness can be adjusted according to the thickness and elasticity of the specimen itself. The thickness should not be greater than 0.05 mm. The bonding surface of the specimen should be polished and cleaned, and no damage to the fiber is allowed. Then use a heavy-duty adhesive or a material curing temperature of 40°C to bond the joint. The head and width of the reinforcement sheet should be consistent with the specimen to ensure that the reinforcement sheet does not fall off during the test. 6.2.5 The reinforcing sheet can also be firstly bonded with the fiber reinforced plastic layer and then processed into the test specimen. 6.3 Number of test specimens
The number of test specimens shall be determined in accordance with Chapter 2 of GB1446.
7 Test properties
GB/T5258-.1995
Figure 3: Shape and size of test specimen for compression test method A
Figure 4: Shape and size of test specimen for compression test method B 7.1 Test environment and conditions shall be in accordance with Chapter 3 of GB1446. 7.2 Test specimen conditions shall be in accordance with Chapter 3 of GB1446. 7.3 Loading speed is 1~2mm/min
8 Test steps
8.1 Test according to GB1446 Section 2, 82 7.2 Test state adjustment,
GB/T5258—1995
.3 Number the samples of the grid, and measure the width and length of the test working section, and take the average. According to GB1446 Section 4,
.4 Test method A, lift the sample into the shrink test fixture, as shown in Figure 1, align the end circle of the fixture with the end face of the sample, and align it with the axis of the sample, and use four screws to evenly tighten the four screws so that the sample can move between the clamping plates. 8.5 Test method B. Install the specimen in the compression test fixture as shown in Figure 3. When it is necessary to install side supports to prevent the specimen from falling, the side pressure must be uniform and not more than 1% of the breaking stress. In order to reduce the vibration, polytetrafluoroethylene film or other suitable lubricating materials can be added between the support and the specimen. 6. Place the compression test fixture with the prepared specimen between the test machine platform, adjust the center, and adjust the zero point of the test machine. 8.7 Loading speed is in accordance with 7.3.
BB. When measuring the compressive strength, the loading should be uniform and continuous until the specimen is damaged. Record the breaking load (or maximum load). When measuring the compression elasticity, install the strain gauge in the working part of the specimen (including the small port for strain measurement). Apply shear force (5% of the failure load), adjust the measuring instrument, and then add a predetermined preload (20% of the failure load); check the instrument reading. If it is asymmetric, adjust the tool or spherical support after unloading, and then load again. After the instrument readings on both sides of the specimen reach 5% of the estimated failure load, load continuously at the specified loading speed until the total failure load reaches 50%. Record the corresponding deformation value of each load. If the load-deformation data is not obtained at the end, then the specimen is destroyed. If there is an automatic recording instrument, continuous loading is performed and the load-deformation line is recorded. 8.1 For test method A: For specimens that fail at the ends, for test method B, the specimens that fail at the ends shall be loaded at the ends. All the specimens that crack at R are considered as resistance. When there are less than 5 valid specimens in the same batch, they should be tested. 9 Calculation of test results
9.1 The shrinkage strength is calculated according to the formula (13) Www.bzxZ.net
wherein the compressive strength, MP
\. -- Maximum positive shrinkage load or failure load N: h width of specimen. mm
·.-specimen thickness. mm.
9.2 The maximum compressive strain is calculated according to the formula (2):
upper center: E, bottom dimension strain
L——test strain, Tm
: maximum cross section or sample failure time gauge length within the contraction deformation m cut. 9.3 Compressive stress-strain curve.
9.4 The elastic modulus is calculated according to formula (3) or formula (4), E
wherein, &
-compression energy Me:
5 catties·
I load-the increase in load on the initial segment of the deformation line, N: same as formula (1);
read formula (2)
m gauge length 1 corresponding to the load 2. The increase in deformation. mm: GB/T5258—1995
a. : stress-stress increment on the initial straight line of the deformation line, MP: e-strain increment corresponding to the stress increment. 9.5 The positive secant modulus is calculated according to formula <5) or formula (5): -L
wherein:. The compression secant modulus at the specified strain, MPa! P, — load corresponding to the specified strain on the load-deformation curve, N, — same as (23
: 4, — deformation value in the standard curve corresponding to the specified strain, m, — specified compressive strain
— compressive end stress MP9.6 on the stress-strain curve corresponding to the specified compressive strain. The compression test ratio is calculated according to formula (7),
where
compressive heat elimination ratio:
E1+: *m— respectively correspond to the pseudo strain and modal strain in the stress-strain curve starting straight line and the stress increase:. 5.7 Test results Calculations shall be in accordance with Chapter G of GR1446. 1 Test measures
shall be in accordance with Chapter 7 of GE1446, and the test methods and the selected specimen form shall be stated. Additional remarks:
This standard is issued by the State Bureau of Building Materials Industry and is under the jurisdiction of the National Fiber Reinforced Plastics Standardization Technical Committee. (5)
* (6)
This standard was jointly drafted by the Shanghai Guming Steel Research Institute of the State Bureau of Building Materials, the 73rd Research Institute of the Ministry of Aviation and Aeronautical Industry, and the Institute of Primary Schools of the Chinese Academy of Sciences.
The authors of this standard are Zhou Shulin, Zhang Ruimei, Zhang Shuangyin, Yang Yundi, and Dai Mingjun.
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