ISO/TC 61/SC 2/WG 1 - Static behavior

1.1 This document 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 ISO 527. 1.2 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. 1.3 The methods are selectively suitable for use with the following materials: — rigid and semi-rigid 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.

This document specifies a method for determining the flexural properties of rigid and semi-rigid plastics under defined conditions. A preferred test specimen is defined, but parameters are included for alternative specimen sizes for use where appropriate. A range of test speeds is included. The method is used to investigate the flexural behaviour of the test specimens and to determine the flexural strength, flexural modulus and other aspects of the flexural stress/strain relationship under the conditions defined. It applies to a freely supported beam, loaded at midspan (three-point loading test). The method is suitable for use with the following range of materials: — thermoplastic moulding, extrusion and casting materials, including filled and reinforced compounds in addition to unfilled types; rigid thermoplastics sheets; — thermosetting moulding materials, including filled and reinforced compounds; thermosetting sheets. In agreement with ISO 10350-1[5] and ISO 10350-2[6], this document applies to fibre-reinforced compounds with fibre lengths ≤7,5 mm prior to processing. For long-fibre-reinforced materials (laminates) with fibre lengths >7,5 mm, see ISO 14125[7]. The method is not normally suitable for use with rigid cellular materials or sandwich structures containing cellular material. In such cases, ISO 1209-1[3] and/or ISO 1209-2[4] can be used. NOTE 1 For certain types of textile-fibre-reinforced plastic, a four-point bending test is used. This is described in ISO 14125. The method is performed using specimens which can be either moulded to the specified dimensions, machined from the central section of a standard multipurpose test specimen (see ISO 20753) or machined from finished or semi-finished products, such as mouldings, laminates, or extruded or cast sheet. The method specifies the preferred dimensions for the test specimen. Tests which are carried out on specimens of different dimensions, or on specimens which are prepared under different conditions, can produce results which are not comparable. Other factors, such as the test speed and the conditioning of the specimens, can also influence the results. NOTE 2 Especially for injection moulded semi-crystalline polymers, the thickness of the oriented skin layer, which is dependent on the moulding conditions, also affects the flexural properties. The method is not suitable for the determination of design parameters but can be used in materials testing and as a quality control test.

ISO 899-1 specifies a method for determining the tensile creep of plastics in the form of standard test specimens under specified conditions such as those of pretreatment, temperature and humidity. The method is suitable for use with rigid and semi-rigid non-reinforced, filled and fibre-reinforced plastics materials in the form of dumb-bell-shaped test specimens moulded directly or machined from sheets or moulded articles. The method is intended to provide data for engineering-design and research and development purposes. Data for engineering-design purposes requires the use of extensometers to measure the gauge length of the specimen. Data for research or quality-control purposes may use the change in distance between the grips (nominal extension). Tensile creep can vary significantly with differences in specimen preparation and dimensions and in the test environment. The thermal history of the test specimen can also have profound effects on its creep behaviour (see Annex A). Consequently, when precise comparative results are required, these factors are intended to be carefully controlled. If tensile-creep properties are used for engineering-design purposes, the plastics materials are intended to be tested over a broad range of stresses, times and environmental conditions.

ISO 527-2:2012 specifies the test conditions for determining the tensile properties of moulding and extrusion plastics, based upon the general principles given in ISO 527‑1.

ISO 18872:2007 specifies procedures for determining the tensile properties of moulding and extrusion plastics over a wide range of strain rate, including high rates appropriate to impact-loading situations. Properties are determined through a combination of measurements at low and moderate strain rates, the use of mathematical functions to model these results, the rate-dependence of parameters and the determination of parameters at high strain rates by extrapolation. Tensile properties at high strain rates are then derived by calculation. In this way, the experimental problems and associated errors with the measurement of properties at high rates are avoided.

ISO 899-2:2003 specifies a method for determining the flexural creep of plastics in the form of standard test specimens under specified conditions such as those of pretreatment, temperature and humidity. It applies only to a simple freely supported beam loaded at mid-span (three-point-loading test). The method is suitable for use with rigid and semi-rigid non-reinforced, filled and fibre-reinforced plastics materials (see ISO 472 for definitions) in the form of dumb-bell-shaped test specimens moulded directly or machined from sheets or moulded articles. NOTE The method may be unsuitable for certain fibre-reinforced materials due to differences in fibre orientation. The method is intended to provide data for engineering-design and research and development purposes. Data for engineering-design purposes requires the use of extensometers to measure the gauge length of the specimen. Data for research or quality-control purposes may use the change in distance between the grips (nominal extension). Flexural creep may vary significantly with differences in specimen preparation and dimensions and in the test environment. The thermal history of the test specimen can also have profound effects on its creep behaviour (see Annex A). Consequently, when precise comparative results are required, these factors must be carefully controlled. If flexural-creep properties are to be used for engineering-design purposes, the plastics materials should be tested over a broad range of stresses, times and environmental conditions. The method may not be suitable for determining the flexural creep of rigid cellular plastics (attention is drawn in this respect to ISO 1209-1, Cellular plastics, rigid -- Flexural tests -- Part 1: Bending test, and ISO 1209-2, Cellular plastics, rigid -- Flexural tests -- Part 2: Determination of flexural properties).

This International Standard specifies a method for determining the compressive properties of plastics under defined conditions. A standard test specimen is defined but its length may be adjusted to prevent buckling under load from affecting the results. A range of test speeds is included. The method is used to investigate the compressive behaviour of the test specimens and for determining the compressive strength, compressive modulus and other aspects of the compressive stress/strain relationship under the conditions defined. The method applies to the following range of materials:  rigid and semi-rigid [1] thermoplastic moulding and extrusion materials, including compounds filled and reinforced by e.g. short fibres, small rods, plates or granules in addition to unfilled types; rigid and semi-rigid thermoplastic sheet;  rigid and semi-rigid thermoset moulding materials, including filled and reinforced compounds; rigid and semirigid thermoset sheet;  thermotropic liquid-crystal polymers. In agreement with ISO 10350-1 and ISO 10350-2, this International Standard applies to fibre-reinforced compounds with fibre lengths u 7,5 mm prior to processing. The method is not normally suitable for use with materials reinforced by textile fibres (see references [2] and [5]), fibre-reinforced plastic composites and laminates (see [5]), rigid cellular materials (see [3]) or sandwich structures containing cellular material or rubber (see [4]). The method is performed using specimens which may be moulded to the chosen dimensions, machined from the central portion of a standard multipurpose test specimen (see ISO 3167) or machined from finished or semifinished products such as mouldings or extruded or cast sheet. The method specifies preferred dimensions for the test specimen. Tests which are carried out on specimens of different dimensions, or on specimens which are prepared under different conditions, may produce results which are not comparable. Other factors, such as the test speed and the conditioning of the specimens, can also influence the results. Consequently, when comparable data are required, these factors must be carefully controlled and recorded.

ISO 527-1:2012 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 ISO 527. 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 not normally suitable for use with rigid cellular materials, for which ISO 1926 is used, or for sandwich structures containing cellular materials.

ISO 178:2010 specifies a method for determining the flexural properties of rigid and semi-rigid plastics under defined conditions. A standard test specimen is defined, but parameters are included for alternative specimen sizes for use where appropriate. A range of test speeds is included. The method is used to investigate the flexural behaviour of the test specimens and to determine the flexural strength, flexural modulus and other aspects of the flexural stress/strain relationship under the conditions defined. It applies to a freely supported beam, loaded at midspan (three-point loading test). The method is suitable for use with the following range of materials: thermoplastic moulding, extrusion and casting materials, including filled and reinforced compounds in addition to unfilled types; rigid thermoplastics sheets; thermosetting moulding materials, including filled and reinforced compounds; thermosetting sheets. ISO 178:2010 applies to fibre-reinforced compounds with fibre lengths less than or equal to 7,5 mm prior to processing. For long-fibre-reinforced materials (laminates) with fibre lengths greater than 7,5 mm, see ISO 14125. The method is not normally suitable for use with rigid cellular materials or sandwich structures containing cellular material. In such cases, ISO 1209‑1 and/or ISO 1209‑2 can be used. Contrary to the previous editions of this International Standard, this edition specifies two methods, method A and method B. Method A is identical to the method in previous editions of this International Standard, i.e. it uses a strain rate of 1 %/min throughout the test. Method B uses two different strain rates: 1 %/min for the determination of the flexural modulus and 5 %/min or 50 %/min, depending on the ductility of the material, for the determination of the remainder of the flexural stress-strain curve.

ISO 899-1:2003 specifies a method for determining the tensile creep of plastics in the form of standard test specimens under specified conditions such as those of pretreatment, temperature and humidity. The method is suitable for use with rigid and semi-rigid non-reinforced, filled and fibre-reinforced plastics materials (see ISO 472 for definitions) in the form of dumb-bell-shaped test specimens moulded directly or machined from sheets or moulded articles. The method is intended to provide data for engineering-design and research and development purposes. Data for engineering-design purposes requires the use of extensometers to measure the gauge length of the specimen. Data for research or quality-control purposes may use the change in distance between the grips (nominal extension). Tensile creep may vary significantly with differences in specimen preparation and dimensions and in the test environment. The thermal history of the test specimen can also have profound effects on its creep behaviour. Consequently, when precise comparative results are required, these factors must be carefully controlled. If tensile-creep properties are to be used for engineering-design purposes, the plastics materials should be tested over a broad range of stresses, times and environmental conditions.

Specifies a method for determining the flexural creep of plastics in the form of standard test specimens under specified conditions such as those of pretreatment, temperature and humidity. The method is suitable for use with rigid and semi-rigid non-reinforced, filled and fibre-reinforced plastics materials in the form of rectangular bars moulded directly or cut from sheets or moulded articles. It is intended to provide data for engineering-design and research and development purposes.

Specifies a method for determining the tensile creep of plastics in the form of standard test specimens under specified conditions such as those of pretreatment, temperature and humidity. The method is suitable for use with rigid and semi-rigid non-reinforced, filled and fibre-reinforced plastics materials in the form of dumb-bell-shaped test specimens moulded directly or machined from sheets or moulded articles. It is intended to provide data for engineering-design and research and development purposes.

Specifies a method for determining the compressive properties of plastics in the form of standard test specimens when tested under defined conditions of pretreatment. temperature, humidity and testing machine speed. The compressive properties determined by this method include compressive yield stress, compressive strength, offset yield stress, percentage compressive strain at rupture and compressive stress at specified compressive strain.

Several different types of test specimen are defined to suit different types of material. The methods specified are selectively suitable for use with the following range of materials: rigid and semirigid thermoplastics moulding, including filled and reinforced compounds in addition to unfilled types, sheets and films, rigid and semirigid thermosetting moulding naterials including filled and reinforced compounds, and sheets including laminates, as well as fibre-reinforced thermoset and thermoplastics composites.

The methods specified are selectively suitable for use with the following range of materials: rigid and semirigid thermoplastics moulding, extrusion and cast materials, including compounds filled and reinforced by e.g. short fibres, small rods, plates or granules but excluding textile fibres in addition to unfilled types, rigid and semirigid thermosetting moulding and cast naterials, including filled and reinforced compounds but excluding textile fibres as reinforcement, and thermotropic liquid crystal polymers.

The principle of the method specified is to deflect the test specimen, supported as a beam, at constant rate at the midspan until the specimen fractures or until the deformation reaches some predetermined value. During this procedure the force applied to the specimen is measured. The method is applicable to rigid thermoplastics moulding and extrusion materials, rigid thermosetting moulding materials, fibre-reinforced thermoset and thermoplastics composites, thermotropic liquid-crystal polymers.