Significance and Use

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 dimensional changes that may occur as a result of such loads.

Data from these test methods can be used: ( 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.

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.

1. Scope

1.1 These test methods cover the determination of tensile and compressive creep and creep-rupture of plastics under specified environmental conditions (see 3.1.3).

1.2 While these test methods outline the use of three-point loading for measurement of creep in flexure, four-point loading (which is used less frequently) can also be used with the equipment and principles as outlined in Test Methods D 790 .

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.

1.6 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. A specific warning statement is given in 6.8.2.

Note 1This standard and ISO 899 Parts 1 and 2 address the same subject matter, but differ in technical content (and results cannot be directly compared between the two test methods). ISO 899 Part 1 addresses tensile creep and creep to rupture and ISO 899 Part 2 addresses flexural creep. Compressive creep is not addressed in ISO 899.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

D543 Practices for Evaluating the Resistance of Plastics to Chemical Reagents

D618 Practice for Conditioning Plastics for Testing

D638 Test Method for Tensile Properties of Plastics

D695 Test Method for Compressive Properties of Rigid Plastics

D790 Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materials

D1822 Test Method for Tensile-Impact Energy to Break Plastics and Electrical Insulating Materials

D4000 Classification System for Specifying Plastic Materials

D4065 Practice for Plastics: Dynamic Mechanical Properties: Determination and Report of Procedures

D4968 Guide for Annual Review of Test Methods and Specifications for Plastics

D5947 Test Methods for Physical Dimensions of Solid Plastics Specimens

Keywords

creep; creep-rupture; plastics; Compression testing--plastics; Creep; Creep rupture; Flexural testing--plastics; Tensile properties/testing--plastics;

ICS Code

ICS Number Code 83.080.01 (Plast in general)

DOI: 10.1520/D2990-09

ASTM International is a member of CrossRef.

ASTM D2990