ASTM D4476-09

Flexural properties determined by this test method are especially useful for quality control and specification purposes.

The maximum axial fiber stresses occur on a line under the loading nose. The use of the semicircular cross section eliminates premature compression shear that has been noted in three-point flexure tests on full-round rods.

Flexural properties may vary with specimen depth, temperature, atmospheric conditions, and differences in rate of straining.

Before proceeding with this test method, reference should be made to the specification of the material being tested. Any test specimen preparation, conditioning, dimensions, or testing parameters, or combination thereof, covered in the materials specification shall take precedence over those mentioned in this test method. If there are no material specifications, then the default conditions apply.

1.1 This test method covers the determination of the flexural properties of fiber-reinforced pultruded plastic rods. The specimen is a rod with a semicircular cross section, molded or cut from lengths of pultruded rods (see Fig. 1). This test method is designed for rods with a diameter of ¹/₂ in. or greater.

Note 1—There is no known ISO equivalent for this test method.

1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.

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 and health practices and determine the applicability of regulatory limitations prior to use.

FIG. 1 Cross Section of Test Specimen