ASTM D2990

ASTM D2990 – Standard Test Methods for Tensile, Compressive, and Flexural Creep and Creep-Rupture of Plastics

Description:

Significance and Use

5.1 Data from creep and creep-rupture tests are necessary to predict the creep modulus and strength of materials under long-term loads and to predict any dimensional changes that will potentially occur as a result of such loads.

5.2 Data from these test methods are suitable for use: (1) to compare materials, (2) in the design of fabricated parts, (3) to characterize plastics for long-term performance under constant load, and (4) under certain conditions, for specification purposes.

5.3 Before proceeding with this test method, reference shall be made to the specification of the material being tested. Any specimen preparation, conditioning, dimensions, and/or testing parameters covered in the material specification shall take precedence over those mentioned in this test method, except in cases where to do so would conflict with the purpose for conducting testing. If there are no material specifications, then the default conditions apply.

Scope

1.1 These test methods cover the determination of tensile and compressive creep and creep-rupture of plastics under specified environmental conditions (see 3.2).

1.2 In these test methods three-point loading, as described in Test Methods D790, is used for measurement of creep in flexure. However, four-point loading using the equipment and principles described in D6272 is also permitted as an option.

1.3 For measurements of creep-rupture, tension is the preferred stress mode because for some ductile plastics rupture does not occur in flexure or compression.

1.4 Test data obtained by these test methods are relevant and appropriate for use in engineering design.

1.5 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only.