Detail of GB/T 1040.1-2018

Introduction of GB/T 1040.1-2018

Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative. GB/T 1040 consists of the following parts, under the general titel Plastics — Determination of Tensile Properties: — Part 1: General Principles; — Part 2: Test Conditions for Moulding and Extrusion Plastics; — Part 3: Test Conditions for Films and Sheets; — Part 4: Test Conditions for Isotropic and Orthotropic Fibre-reinforced Plastic Composites; — Part 5: Test Conditions for Unidirectional Fibre-reinforced Plastic Composites. This part is Part 1 of GB/T 1040. This part is drafted in accordance with the rules given in the GB/T 1.1-2009. This part replaces GB/T 1040.1-2006 Plastics — Determination of Tensile Properties — Part 1: General Principles in whole. For the purpose of this part, the following technical deviations have been made with respect to the GB/T 1040.1-2006 (the previous edition): — Poisson’s ratio has been modified; — defnitions and methods have been optimized for computer controlled tensile test machines; — the preferred gauge length for use on the multipurpose test specimen has been increased from 50 mm to 75 mm. This is used especially in GB/T 1040.2; — nominal strain of tensile has been modified; — addition of method for calculation of standard strain; — removal of Annex A (Informative) Young's Modulus and Related Calues; — addition of Annex A (Informative) Determination of Strain at Yield; — addition of Annex B (Informative) Extensometer Accuracy for the Determination of Poisson’s Ratio; — addition of Annex C (Informative) Calibration Requirements for the Determination of the Tensile Modulus. This standard is identical with International Standard ISO 527-1:2012 Plastics — Determination of Tensile Properties — Part 1: General Principles. The Chinese documents in consistency with corresponding international normative references in this part, are as follows: GB/T 2918-2018 Plastics — Standard Atmospheres for Conditioning and Testing (ISO 291:2008, MOD) GB/T 2941-2006 Rubber — General Procedures for Preparing and Conditioning Test Pieces for Physical Test Methods (ISO 23529:2004, IDT) This part was proposed by China Petroleum and Chemical Industry Federation. This part is under the jurisdiction of National Technical Committee 15 on Plastic of Standardization Administration of China, Subcommittee 4 on Universal Method Product (SAC/TC 15/SC 4). This part replaces GB/T 1040.1-2006. The previous editions of GB/T 1040.1-2006 are as follows: — GB/T 1039-1979, GB/T 1039-1992; — GB/T 1040-1979, GB/T 1040-1992. Plastics — Determination of Tensile Properties — Part 1: General Principles 1 Scope This part of GB/T 1040 specifies the general principles for determining the tensile properties of plastics and plastic composites under defined conditions. Several different types of test specimen are defined to suit different types of material which are detailed in subsequent parts of this standard. The methods are used to investigate the tensile behaviour of the test specimens and for determining the tensile strength, tensile modulus and other aspects of the tensile stress/strain relationship under the conditions defined. The methods are selectively suitable for use with the following materials: — rigid and semi-rigid (see 3.12 and 3.13, respectively) moulding, extrusion and cast thermoplastic materials, including filled and reinforced compounds in addition to unfilled types; rigid and semi-rigid thermoplastics sheets and films; — rigid and semi-rigid thermosetting moulding materials, including filled and reinforced compounds; rigid and semi-rigid thermosetting sheets, including laminates; — fibre-reinforced thermosets and thermoplastic composites incorporating unidirectional or non-unidirectional reinforcements, such as mat, woven fabrics, woven rovings, chopped strands, combination and hybrid reinforcement, rovings and milled fibres; sheet made from pre-impregnated materials (prepregs), — thermotropic liquid crystal polymers. The methods are not normally suitable for use with rigid cellular materials, for which ISO 1926 is used, or for sandwich structures containing cellular materials. 2 Normative References The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 12160-2002 Calibration of Extensometers Used in Uniaxial Testing (ISO 9513:1999, IDT) GB/T 16825.1-2008 Verification of Static Uniaxial Testing Machines — Part 1: Tension/Compression Testing Machines — Verification and Calibration of the Force-measuring System (ISO 7500-1:2004, IDT) ISO 291 Plastics — Standard Atmospheres for Conditioning and Testing ISO 2602 Statistical Interpretation of Test Results — Estimation of the Mean — Confdence Interval ISO 16012 Plastics — Determination of Linear Dimensions of Test Specimens) ISO 20753 Plastics — Test Specimens ISO 23529 Rubber — General Procedures for Preparing and Conditioning Test Pieces for Physical Test Methods) 3 Terms and Definitions For the purposes of this document, the following terms and definitions apply. 3.1 gauge length L0 initial distance between the gauge marks on the central part of the test specimen Note 1: It is expressed in millimeters (mm). Note 2: The values of the gauge length that are indicated for the specimen types in the different parts of GB/T 1040 represent the relevant maximum gauge length. 3.2 thickness h smaller initial dimension of the rectangular cross-section in the central part of a test specimen Note: It is expressed in millimeters (mm). 3.3 width b larger initial dimension of the rectangular cross-section in the central part of a test specimen Note: It is expressed in millimeters (mm). 3.4 cross-section A product of initial width and thickness, A = bh, of a test specimen. Note: It is expressed in square millimeters, (mm2)   3.5 test speed v rate of separation of the gripping jaws Note: It is expressed in millimeters per minute (mm/min). 3.6 stress σ normal force per unit area of the original cross-section within the gauge length Note 1: It is expressed in megapascals (MPa) Note 2: In order to differentiate from the true stress related to the actual cross-section of the specimen, this stress is frequently called “engineering stress” 3.6.1 stress at yield σy stress at the yield strain Note 1: It is expressed in megapascals (MPa). Note 2: It may be less than the maximum attainable stress (see Figure 1, curves b and c) 3.6.2 strength σm stress at the first local maximum observed during a tensile test Note 1: It is expressed in megapascals (MPa). Note 2: This may also be the stress at which the specimen yields or breaks (see Figure 1). 3.6.3 stress at x% strain σx stress at which the strain reaches the specified value x expressed as a percentage Note 1: It is expressed in megapascals (MPa). Note 2: Stress at x% strain may, for example, be useful if the stress/strain curve does not exhibit a yield point (see Figure 1, curve d). 3.6.4 stress at break σb stress at which the specimen breaks Note 1: It is expressed in megapascals (MPa). Note 2: It is the highest value of stress on the stress-strain curve directly prior to the separation of the specimen, i.e directly prior to the load drop caused by crack initiation. 3.7 strain ε increase in length per unit original length of the gauge. Note: It is expressed as a dimensionless ratio, or as a percentage (%). 3.7.1 strain at yield yield strain εy the first occurrence in a tensile test of strain increase without a stress increase Note 1: It is expressed as a dimensionless ratio, or as a percentage (%). Note 2: See Figure 1, curves b and c. Note 3: See Annex A (informative) for computer-controlled determination of the yield strain. 3.7.2 strain at break εb strain at the last recorded data point before the stress is reduced to less than or equal to 10% of the strength if the break occurs prior to yielding Note 1: It is expressed as a dimensionless ratio, or as a percentage (%). Note 2: See Figure 1, curves a and d. 3.7.3 strain at strength εm strain at which the strength is reached Note: It is expressed as a dimensionless ratio, or as a percentage (%). 3.8 nominal strain εt crosshead displacement divided by the gripping distance Note 1: It is expressed as a dimensionless ratio, or as a percentage (%). Note 2: It is used for strains beyond the yield strain (see 3.7.1) or where no extensometers are used. Note 3: It may be calculated based on the crosshead displacement from the beginning of the test, or based on the increment of crosshead displacement beyond the strain at yield, if the latter is determined with an extensometer (preferred for multipurpose test specimens). 3.8.1 nominal strain at break εtb nominal strain at the last recorded data point before the stress is reduced to less than or equal to 10% of the strength if the break occurs after yielding Note 1: It is expressed as a dimensionless ratio, or as a percentage (%). Note 2: See Figure 1, curves b and c. 3.9 modulus Et slope of the stress/strain curve σ(ε) in the strain interval between ε1 = 0.05% and ε2 = 0.25% Note 1: It is expressed in megapascals (MPa). Note 2: It may be calculated either as the chord modulus or as the slope of a linear least-squares regression line in this interval (see Figure 1, curve d). Note 3: This definition does not apply to films. 3.10 Poisson’s ratio µ negative ratio of the strain increment Δεn, in one of the two axes normal to the direction of extension, to the corresponding strain increment Δεl in the direction of extension, within the linear portion of the longitudinal versus normal strain curve Note: It is expressed as a dimensionless ratio. 3.11 gripping distance L initial length of the part of the specimen between the grips Note: It is expressed in millimeters (mm). 3.12 rigid plastic plastic that has a modulus of elasticity in flexure (or, if that is not applicable, in tension) greater than 700 MPa under a given set of conditions 3.13 semi-rigid plastic plastic that has a modulus of elasticity in flexure (or, if that is not applicable, in tension) between 70 MPa and 700 MPa under a given set of conditions

Contents of GB/T 1040.1-2018

Foreword II 1 Scope 2 Normative References 3 Terms and Definitions 4 Principle and Methods 5 Apparatus 6 Test Specimens 7 Number of Test Specimens 8 Conditioning 9 Procedure 10 Calculation and Expression of Results 11 Precision 12 Test Report Annex A (Informative) Determination of Strain at Yield Annex B (Informative) Extensometer Accuracy for the Determination of Poisson’s Ratio Annex C (Normative) Calibration Requirements for the Determination of the Tensile Modulus Bibliography