【国外标准】 Standard Test Method for Tensile Properties of Pultruded Glass-Fiber-Reinforced Plastic Rod

4.1 The high axial-tensile strength and the low transverse-compressive strength of pultruded rod combine to present some unique problems in determining the tensile strength of this material with conventional test grips. The high transverse-compressive forces generated in the conventional method of gripping tend to crush the rod, thereby causing premature failure. In this test method, aluminum-alloy tabs contoured to the shape of the rod reduce the compressive forces imparted to the rod, thus overcoming the deleterious influence of conventional test grips.4.2 Tensile properties are influenced by specimen preparation, strain rate, thermal history, and environmental conditions at the time of testing. Consequently, where precise comparative results are desired, these factors must be carefully controlled.4.3 Tensile properties provide useful data for many engineering design purposes. However, due to the high sensitivity of these properties to strain rate, temperature, and other environmental conditions, data obtained by this test method shall not, by themselves, be considered for applications involving load-time scales or environmental conditions that differ widely from the test conditions. In cases where such dissimilarities are apparent, the sensitivities to strain rate, including impact and creep, as well as to the environment, shall be determined over a wide range of conditions as dictated by the anticipated service requirements.1.1 This test method describes a procedure for determining the tensile properties of a pultruded, glass-fiber-reinforced thermosetting plastic rod of diameters ranging from 2.03 mm (0.08 in.) to 12.7 mm (0.5 in.). Test Method D7205/D7205M is an alternative test method to determine tensile properties of fiber-reinforced composite rods of diameters bigger than 12.7 mm (0.5 in.).1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific hazards statements are given in 6.1 and 8.4.3.NOTE 1: There is no known ISO equivalent to this standard.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.