Plastics- Determination of Charpy impact properties
Non-instrumented impact test
1.1 This part of ISO 179 specifies a methid for determining the Charpy impact strength of plastics under defined conditions. A unmber of different types of specimen and test configurations are defined. Different test parameters are specified according to the type of material, the type of test specimen and the type of notch.
1.2 The method can bu used to investigate yje behaviour of specified types of specimen under the impact conditions defined and for estimating the brittleness or toughness of specumens within limitations inherent in the test conditions. It can also be used for the detemination of comparative data from similar types of material.
1.3 The method has a greater range of applicability then that given in ISO180［1］and is more suitable for the testing of material showing interiaminar sheer fracture or of material exhibiting surface effects due to environmental factors.
1.4 The method is suitable for use with the following range of material:
--rigid thermoplastic moulding and extrusion materials(including filled and reinforced compounds in addition to unfilled types) and tigid thermoplastics sheets;
--rigid thermosetting moulding materials(including filled and reinforced compounds) and rigid thrtmosetting sheets(including laminates)
--fiber-reinfoced thermosetting and thermoplastic composites incorporating unidirectional or milti-directional reinforcements(such as mars, woven fabrics, woven roving, chopped strands, cimbination and hybrid reinfocements, roving and milled fibers) or incorporating sheets made friom pre-mpregnated material(prepregs),including filled and reinforced compounds;
--thermotropic liquid-crystal polymers.
1.5 Notched samples are not normally suitable for us with rigid cellular materials, ling-fiber-reinforced compsities or thermotropic liquid-crystal polymers. In these cases. unnotched may be used.
1.6 The method is suited to the use of specimens moulded to the chosen dimensions, machined from the central portion of a standard multipurpose test specimen(see ISO3176) or machined from finished or semifished products such as moudingd, laminatesd and extrudded or cast sheet.
1.7 The method specifies preferred dimensions for the test specimen. Test which are carried out on specimens of differentdimensions or with different notches, or specimens which are prepared under different conditions, might produce results which are nor cpmparable. other factorsm such as the energy capacity of the apparatus, the impact velocity and the conditioning of the speximens can also influence the results. Cinsequently, when comparative data are required, these factors must be carefully controlled and recorder.
1.8 The method should not be used as a source of data for design calculations. Information on the typical behaviour of a material can be obtained, however. by testing at different temperatures,
by varying the notch radius and/or the specimen thickness and by testing specimens prepared under different conditions.
2 Normative references
The following reference documents are indispensable for the application of this document. For datad references, only the edition cited applies. For undatad references， the latest edition of the referenced document(including any amendments) applies.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.