Valid

GB/T 1041-2008Plastics -- Determination of compressive properties (English PDF)

Preview PDF

This is a limited preview

Buy now to download the full PDF (10 pages)

Need quotation for your management?

Get a formal quotation for GB/T 1041-2008 in 30 minutes.

Issued by

General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China

Level / Type

National · Recommended

Issue date

September 4, 2008

Implementation date

April 1, 2009

Scope

GB/T 1041-2008 (Plastics -- Determination of compressive properties) is available as an English-translated PDF.

GB/T 1041-2008 — This standard specifies the method for determining the compressive properties of plastics under standard conditions. A standard specimen is specified, but its length can be adjusted in case Prevent its compression warpage from affecting the test results, as well as the range of test speed.

This standard is used to study the compressive behavior of samples and to determine the compressive stress-strain and compressive strength, compressive modulus and relationship to other properties.

This standard applies to the following materials. --- Rigid and semi-rigid thermoplastic molding and extrusion materials, including reinforced composites filled with short fibers, strips, flakes or granules and unfilled composite or semi-rigid thermoplastic sheets; --- Rigid or semi-rigid thermosetting molding materials, including filled or reinforced composite materials, rigid or semi-rigid thermosetting sheets; ---Thermotropic liquid crystal polymer.

According to ISO 10350-1:1998 and GB/T 19467.2-2004, this standard is applicable to fibers whose fiber length before processing is <=7.5mm. Dimensional reinforced composite materials.

This standard does not generally apply to textile fiber reinforced composite plastics and laminates, rigid foams and materials containing foam or foam Rubber sandwich construction material.

Specimens used in this standard may be molded of selected dimensions or may be machined from the middle of a standard multipurpose specimen. (GB/T 11997-2008) or machined from finished or semi-finished products such as molded, extruded or cast into sheets.

This standard specifies preferred specimen dimensions. The results of tests carried out on different specimens or on specimens prepared under different conditions are incomparable.

Other factors, such as test speed and state conditioning, can also affect test results. therefore. When needed for test data when making comparisons, these factors should be strictly controlled and recorded.

Found what you need?

Document preview — GB/T 1041-2008

National Standard of the People's Republic of China

ICS: 83.080.01
Classification: G 31
Replacing: GB/T 1041-1992; GB/T 14694-1993

Issued by: General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, Standardization Administration of the People's Republic of China

1 Scope
2 Normative references
4 Principles
5 Equipment
5.1 Testing machine
5.2 Device for measuring sample size
6 Samples
6.1 Shape and size
6.2 Preparation
6.3 Sample
6.4 Anisotropic materials
7 Number of samples
8 Condition adjustment of the sample
9 Test steps
9.1 Test environment
9.2 Measurement of sample size
9.3 Sample loading
9.4 Preload
9.5 Test speed
9.6 Data recording
10 Calculation and presentation of results
10.1 Stress
10.3 Compression modulus
10.4 Statistical parameters
10.5 Significant figures
11 Precision
12 Test report

1 Scope

This standard specifies the method for determining the compressive properties of plastics under standard conditions. A standard specimen is specified, but its length can be adjusted in case Prevent its compression warpage from affecting the test results, as well as the range of test speed.

This standard is used to study the compressive behavior of samples and to determine the compressive stress-strain and compressive strength, compressive modulus and relationship to other properties.

This standard applies to the following materials.

--- Rigid and semi-rigid thermoplastic molding and extrusion materials, including reinforced composites filled with short fibers, strips, flakes or granules and unfilled composite or semi-rigid thermoplastic sheets;

--- Rigid or semi-rigid thermosetting molding materials, including filled or reinforced composite materials, rigid or semi-rigid thermosetting sheets;

---Thermotropic liquid crystal polymer.

According to ISO 10350-1:1998 and GB/T 19467.2-2004, this standard is applicable to fibers whose fiber length before processing is <=7.5mm.

Dimensional reinforced composite materials.

This standard does not generally apply to textile fiber reinforced composite plastics and laminates, rigid foams and materials containing foam or foam Rubber sandwich construction material.

Specimens used in this standard may be molded of selected dimensions or may be machined from the middle of a standard multipurpose specimen.

(GB/T 11997-2008) or machined from finished or semi-finished products such as molded, extruded or cast into sheets.

This standard specifies preferred specimen dimensions. The results of tests carried out on different specimens or on specimens prepared under different conditions are incomparable. Other factors, such as test speed and state conditioning, can also affect test results. therefore. When needed for test data when making comparisons, these factors should be strictly controlled and recorded.

2 Normative references

The clauses in the following documents become the clauses of this standard through the reference of this standard. For dated references, all subsequent Amendments (not including errata content) or revised editions do not apply to this standard, however, encourage the parties to the agreement based on this standard to study Whether the latest versions of these files are available. For undated references, the latest version applies to this standard.

4 Principles

Compress the specimen at a constant velocity along the major axis of the specimen until failure occurs or a certain load or reduction in specimen length is reached value reaches the predetermined value. Measure the load on the sample during this process.

5 Equipment

5.1 Testing machine

5.1.1 Overview

The testing machine shall comply with the provisions of GB/T 17200-1997 and shall also meet the provisions of 5.1.2 to 5.1.5.

5.1.2 Test speed

The testing machine should be able to maintain the test speed specified in Table 1.If other speeds are used, when the speed is lower than 20mm/min, the speed of the testing machine the speed tolerance should be within ±20%; and when the speed is greater than 20mm/min, the tolerance should be within ±10%.

5.1.3 Compression appliances

The two hardened steel compression plates that apply deformation load to the sample shall be able to load the sample in the axial direction, and the deviation from the axial direction shall be within 1.1000.

At the same time, the load is transmitted through the polished platen surface. The flatness of these plates is within 0.025mm. The two plates are parallel to each other and perpendicular to the load shaft.

NOTE. Self-aligning equipment may be used if required.

5.1.4 Load indicator

The load indicator shall be provided with a device capable of indicating the total compressive force to which the specimen is subjected, which is substantially inertialess at the specified test speed.

hysteresis, the accuracy of the indicated total value shall be at least within ± 1 % of the indicated value.

NOTE. The use of a commercially available circular strain gauge system can compensate for lateral forces that may arise due to misalignment (see 9.3).

5.1.5 Strain gauges

Strain gauges are used to measure the change in length of the corresponding portion of the specimen. If the compressive strain epsilon is determined (priority research), then this length is the standard in addition, for the nominal compressive strain epsilonc, this length is the distance between the two contact surfaces of the compression device. It would be nice to automatically log this distance.

The instrument shall be substantially free of inertial hysteresis at the specified test speed. For the measurement of modulus, type A specimens shall be used to the required accuracy.

Use at least ±1% of the strain span. As a measure of compressive modulus, it is equivalent to ±1 µm of 50 mm gauge length and 0.2% strain spacing.

When the strain gauge is added to the sample, avoid any slight deformation or damage to the sample, and ensure that there is no gap between the strain gauge and the sample.

How to slide.

The specimens may also be fitted with longitudinal strain gauges whose accuracy shall be at least 1% of the strain interval used. For modulus measurements this is equivalent to strain the precision is 2.0×10-5.The strain gauges used, the method of specimen preparation and the adhesive used shall be selected so as not to affect the test results.

Note. Slight misalignment and inherent warping of the specimen may cause differences in strain between opposite sides of the specimen, resulting in errors at low strains. In this kind of in this case, the average strain on two opposite surfaces of the specimen can be measured. However, when using the data collected separately by strain gauges on each side of the sample, warping of the sample will be found.

warping and bending much faster than the average strain of two opposing surfaces.

5.2 Device for measuring sample size

5.2.1 Hard materials

Use a micrometer or equivalent instrument to measure the thickness, width and length of the sample to the nearest 0.01mm.

The size and shape of the sample measuring platform should be suitable, and the force applied should not change the size of the sample.

5.2.2 Semi-rigid materials

Measure the thickness of the sample with a flat circular presser foot micrometer or an equivalent instrument capable of applying a pressure of (20 ± 3) kPa to the sample, accurate to 0.01mm.

6 Samples

6.1 Shape and size

6.1.1 Overview

Specimens shall be prismatic, cylindrical or tubular. The dimensions of the specimen shall satisfy the following inequality (1) (see also Appendix B).

6.1.2 Preferred samples

Table 2 gives preferred sample dimensions.

The sample is preferably cut from a multi-purpose sample (see GB/T 11997-2008).

When the optimal sample cannot be used due to insufficient or geometric constraints of the product under test, two small samples introduced in Appendix A can be used.

6.2 Preparation

6.2.1 Molded and extruded plastics

Specimens should be prepared in accordance with the relevant material standard. Unless otherwise agreed by the parties concerned, the samples shall be in accordance with GB/T 9352-2008, GB/T 17037.1-1997, GB/T 5471-2008 or ISO 10724-1:1998 The material is directly molded or directly injected.

6.2.2 Sheet

The test specimen shall be machined from sheet material according to the method specified in ISO 2818:1994.

6.2.3 Machining

All machining operations should be carried out carefully to produce a smooth surface. Special attention should be paid to machining so that the end surface of the sample is flat and smooth, the edge is sharp and clear, and the end surface is perpendicular to the longitudinal axis of the sample, and its perpendicularity is within 0.025mm.

The final surface of the specimen is recommended to be machined on a lathe or milling machine.

6.2.4 Marking line

If optical strain gauges are used, add two marking lines of specified length to the specimen. The distance between these markings and the center of the specimen shall be approximately equal, and the distance between the two markings shall be measured with an instrument having an accuracy of at least 1%.

GB/T 1041-2008/ISO 604:2002 Do not scratch, die cut, or emboss marking lines on the specimen to cause damage to the specimen. It should be ensured that the medium of the marking line will not bring harm to the tested material.

, and ensure that the two parallel marking lines should be as narrow as possible.

6.3 Sample

Specimens shall be free from warping, surface and edges free from scratches, pits, sink marks, flashing or other visible defects that would affect the results. Two sides facing the platen the surfaces should be parallel and at right angles to the longitudinal axis.

Compliance with these requirements is checked visually with the aid of rulers, and flat plates and measured with a screw micrometer.

Before the test, one or more samples that do not meet the above requirements should be rejected, or processed to a suitable size and shape.

Note. Injection molded specimens usually have a chamfer angle between 1° and 2° for easy demoulding, so the sides of molded specimens are generally not parallel.

6.4 Anisotropic materials

6.4.1 When testing anisotropic materials, the compressive force shall be applied to those products (moldings, sheets, pipes, etc.) in use (if known) in the same or similar direction.

6.4.2 The preferred sample can determine the relationship between the sample size and the product size, if the preferred sample is not used, it is determined according to the product size Specimen size, different from the specimen size selected in 6.1.The orientation and size of the specimen sometimes have a great influence on the test results, so it should be Indicate orientation.

6.4.3 When a material exhibits significant differences in compressive properties in two principal directions, tests shall be carried out in both directions. if the material is subjected to compressive forces not in any principal direction but in a specific direction in the intended use, then the test is carried out in that direction test. The orientation of the specimen with respect to the principal direction shall be recorded.

7 Number of samples

7.1 For isotropic materials, test at least 5 specimens for each sample.

7.2 For anisotropic materials, test at least 10 specimens for each sample. Five of them are perpendicular to the main axis of anisotropy, and the other five parallel to it.

7.3 If the sample fails at an obvious defect, it shall be discarded and the sample shall be replaced for testing.

8 Condition adjustment of the sample

The sample should be conditioned according to the requirements of the national standard for the material. When there is no such requirement, unless otherwise agreed by the parties concerned, should be carried out in accordance with the most suitable conditions specified in GB/T 2918-1998.

The optimal condition is 23/50.If the compression properties of the material are known to be insensitive to humidity, the humidity may not be controlled.

9 Test steps

9.1 Test environment

One of the standard environments specified in GB/T 2918-1998 should be selected for the test, preferably the same as the environment used for state regulation.

9.2 Measurement of sample size

Measure the width of the specimen along its length the thickness and diameter are three points, and the average value of the cross-sectional area is calculated. Measure the length of each specimen should be accurate to 1%.

9.3 Sample loading

Place the sample between the two pressure plates so that the center line of the sample is consistent with the line connecting the centers of the two pressure plates.

OK. Adjust the testing machine so that the end face of the sample is just in contact with the pressure plate.

During compression, the end face of the specimen may slide along the platen, the extent of which varies depending on the surface structure of the specimen and platen. this Will lead to different degrees of barrel deformation, affecting the measured results. The less rigid the material, the more pronounced this effect is.

For more accurate measurement, it is recommended to use appropriate lubricant on each end of the sample to facilitate sliding; or place fine sand between the sample and the pressure plate paper to prevent sliding. Regardless of the method used, it should be noted in the test report.

9.4 Preload

Basically, no load should be applied to the sample before the test, but in order to avoid the bending region at the beginning of the stress-strain curve, such a load is necessary. When measuring the modulus, the compressive stress sigma0 (see Figure 2) at the start of the test should be within the following range.

0<=sigma0 <=5×10-4Ec (2) the corresponding pre-strain epsilonc0<=0.05%. Whereas when measuring properties such as sigmaM, it shall be within the range of.

0<=sigma0<=102sigmaM (3)

9.5 Test speed

Adjust the test speed v (see 3.2) according to the material specification, expressed in millimeters per minute (mm/min). When there is no material specification, adjust to the value given by Table 1 that is closest to the following relation.

For preferred specimens (see 6.1.2), the test speed is.

9.6 Data recording

During the test, the force (stress) and corresponding compression (strain) of the specimen are determined, preferably using an automated recording system to obtain a complete the stress-strain curve system.

From the stress-strain data recorded during the test, determine the relevant stress and strain as defined in Chapter 3: If in the stress-strain diagram Find the bending zone at the beginning, check whether it exceeds the prestressing range given in 9.4.If the compression cannot be measured directly on the specimen, then the the deformation of the testing machine should be corrected according to Appendix C.

10 Calculation and presentation of results

10.1 Stress

Calculate the stress parameter defined in 3.3 by formula (4).

10.2.2 Nominal strain (measured by movement of the crosshead)

10.3 Compression modulus

10.4 Statistical parameters

Calculate the arithmetic mean of 5 test results. If necessary, calculate the standard deviation and Mean with 95% confidence interval.

10.5 Significant figures

Stress and compressive modulus are calculated to three significant figures, and compressive strains are calculated to two significant figures.

11 Precision

The precision of this test method is unknown because interlaboratory data are not yet available. After receipt of interlaboratory data, wait for next revision when ordering, a statement about the precision will be added.

12 Test report

The test report should include the following.

a) Note that this standard is adopted, and add the sample type and test speed according to the following pattern.

b) Identify the complete identification instructions of the known materials to be tested, including type, source and manufacturer;

c) A description of the nature and shape of the material to be tested, that is, whether it is a finished product or a semi-finished product, whether it is a test panel or a sample. This should include the main dimensions Size, shape, manufacturing method, number of layers, pretreatment, etc.;

d) if applicable, the average, minimum and maximum values of the width, thickness and length of the test specimen;

e) details of the method used to prepare the test specimen;

f) if the material is a finished or semi-finished product, indicate the orientation from which it was cut;

g) the number of samples tested;

h) Conditioning and testing environment, if necessary, plus special conditioning performed by the standard for the material or product condition;

i) The accuracy grade of the testing machine (see GB/T 17200-1997);

j) the type of strain gauge used;

k) the type of compression device used;

l) whether lubricant or sandpaper is used on the end face;

m) Measured individual test data for the compression properties defined in Clause 3;

n) the average value of each property measured to be used as an indicative value for the material under test;

o) (optional) standard deviation and/or coefficient of variation and/or confidence interval for the mean;

p) Whether any samples were rejected or replaced, and if so, why;

q) The date of the test.

......
This preview omits tables, figures, formulas and parts of the technical clauses. The complete document — 10 pages — is available in the English PDF.

Referenced standards

Cited by

How to Download GB/T 1041-2008

1
Add to cart
Click "Download PDF" on this page and choose "Buy this standard". You can add more standards before checkout.
2
Checkout
Enter your email and billing details. Payment is processed securely by Stripe (cards or bank transfer). Prefer bank details? Request a quotation (min. order $300).
3
Instant delivery (0–9 sec)
Delivery is automatic: within seconds of payment you'll receive an email with a secure download link. The link stays valid for 72 hours.
4
Invoice included
A tax invoice is attached to the confirmation email. Need a custom invoice? Contact us.

Related Standards