Standard Test Method for Longitudinal Tensile Properties of “Fiberglass” (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe and Tube

Abstract

4.1 Tensile properties include modulus of elasticity, yield stress, elongation beyond yield point, tensile strength, elongation at break, and energy absorption. Materials possessing a low order of ductility do not necessarily exhibit a yield point. It is permissible to use stress-strain data at several levels of temperature, humidity, time, or other variables to furnish reasonably accurate indications of the behavior of the material. 4.2 Tension tests potentially provide data for research and development, engineering design, quality control, acceptance or rejection under specifications, and for special purposes (Note 3). The tests cannot be considered significant for applications differing widely from the load-time scale of the standard test (Note 4). Such applications require more suitable tests, such as impact, creep, and fatigue. Note 3: It is realized that the method of preparation of a material is one of the many variables that affect the results obtained in testing a material. Hence, when comparative tests of materials per se are desired, the greatest care must be exercised to ensure that all samples are prepared in exactly the same way; similarly, for referee or comparative tests of any given series of specimens, care must be taken to secure the maximum degree of uniformity in details of preparation, treatment, and handling. Note 4: Reinforcements of plastics with glass fiber offer wide opportunities for designing and producing products with markedly different responses to loading even when the basic geometry of the product is similar. For example, a tubular product may be designed to give maximum resistance to torsion loading, but such a product might develop a twist or bow if tested in tension or under internal pressure loading. In the case of pipe for general field use, internal pressure, as well as loads in tension, compression, torsion, and flexure must be resisted to some degree. Different pipe producers have chosen, by design, to offer products having different balances of resistance to such stressing conditions. As a result, it is important that the purchaser and the seller both have a clear understanding and agreement on the significance of this test method relative to the intended use.