塑料管道系统 玻璃增强热固性塑料（GRP）管 测定初始纵向拉伸强度的试验方法

[中文适用范围]： 本文件规定了两种用于测定玻璃纤维增强热固性塑料 (GRP) 管纵向拉伸性能的试验方法（方法 A 和方法 B）。可测定的性能包括： — 纵向拉伸强度，以及 — 极限伸长率。方法 A 使用从管道上切下的纵向条带作为试件。方法 B 使用管道整个横截面的指定长度。方法 A 适用于公称尺寸为 DN 50 或更大、带有圆周缠绕长丝（带或不带短切玻璃和/或编织粗纱和/或填料）的管道，以及离心铸造管道。它适用于公称尺寸为 DN 200 或更大的螺旋缠绕长丝管道。方法 B 适用于所有类型的 GRP 管道。它通常用于公称尺寸不超过 DN 150 的管道。一种方法的结果不一定等于任何替代方法的结果。但是，所有方法都具有同等有效性。附件 A 描述了方法 B 的其他注意事项，这些注意事项对于薄壁螺旋缠绕管的测试非常有用，可用于补充基本文本。注意：本文件未涉及纵向拉伸模量的测定。由于许多 GRP 管具有多层结构，因此模量测定所需的应变的精确测量可能非常困难。如果需要测定纵向模量，请参见 ISO 527-4 和/或 ISO 527-5。 [外文原描述]： This document specifies two test methods (method A and method B) for determining the longitudinal tensile properties of glass-reinforced thermosetting plastics (GRP) pipes. The properties which can be determined are: — the longitudinal tensile strength, and — the percentage ultimate elongation. Method A uses, for the test piece(s), a longitudinal strip cut from a pipe. Method B uses a specified length of the full cross-section of the pipe. Method A is applicable to pipes with a nominal size of DN 50 or greater with circumferentially-wound filaments, with or without chopped glass and/or woven rovings and/or fillers, and to centrifugally-cast pipes. It is applicable to pipes with helically wound filaments with a nominal size of DN 200 or greater. Method B is applicable to all types of GRP pipe. It is usually used for pipes with a nominal size up to and including DN 150. Results from one method are not necessarily equal to the results derived from any of the alternative methods. However, all methods have equal validity. Annex A describes additional considerations for method B that have been found useful for the testing of thin-walled helically-wound pipes and can be used to supplement the basic text. NOTE This document does not address the determination of longitudinal tensile modulus. Due to the multi-layer construction of many GRP pipes, the accurate measurement of strain, necessary for modulus determination, can be very difficult. If it is desired to determine longitudinal modulus, see ISO 527-4 and/or ISO 527-5.