ASTM D3479 Standard Test Method for Stress-Strain Fatigue of Polymer Matrix Composite Materials

EUROLAB laboratory provides testing and compliance services within the scope of ASTM D3479 standard. The ASTM D3479 standard specifies the fatigue behavior of polymer matrix composite materials subjected to tensile cycling loading. Composite material forms are limited to continuous-fiber or discontinuous fiber-reinforced composites whose elastic properties are particularly orthotropic with respect to the test direction. This test method is limited to unnotched test specimens subjected to constant amplitude uniaxial in-plane loading for which loading is defined as a test control parameter.

This test method offers two procedures, each defining a different test control parameter. Procedure AA system where the test control parameter is load (strain) and the machine is controlled such that the test specimen is subjected to repetitive constant amplitude load cycles. In this procedure, the test control parameter can be defined using either engineering stress or applied load as the constant amplitude fatigue variable.

Procedure BA system in which the machine is controlled such that the test control parameter is strain in the loading direction and the test specimen is subjected to repetitive constant amplitude strain cycles. In this procedure, the test control parameter can be defined using engineering stress in the loading direction as the constant amplitude fatigue variable.

This test method is designed to provide tensile fatigue data for material specifications, research and development, quality assurance, and structural design and analysis. The primary test result is the fatigue life of the test specimen under a given loading and environmental condition. Repeat tests can be used to obtain the fatigue life distribution for certain material types, laminate stacking sequences, environments, and loading conditions. Guidance on statistical analysis of fatigue life data, such as the determination of linearized stress life (SN) or strain life (ε-N) curves, can be found in application E739.

This test method can be used to examine fatigue damage in a polymer matrix composite, such as microscopic cracks, fiber breaks, or delaminations.3 The residual strength or hardness of the sample, or both, may vary due to these damage mechanisms.

The loss in stiffness can be measured by stopping cyclic loading at selected cycle intervals to obtain the quasi-static axial stress-strain curve using the modulus determination procedures found in Test Method D3039/D3039M. The loss of strength associated with fatigue damage can be determined by stopping cyclic loading to achieve static strength using Test Method D3039/D3039M.

This test method can be used as a guide for conducting voltage-voltage variable amplitude loading. This information can be useful in understanding the fatigue behavior of composite structures under spectral loading conditions, but is not covered in this test method.

Values ​​stated in SI units or inch-pound units will be considered standard separately. The values ​​specified in each system are not necessarily exact equivalents; therefore, to ensure compliance with the standard, each system should be used independently of the other and the values ​​obtained from the two systems should not be combined.

This standard does not purport to address all, if any, safety concerns associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health and environmental practices and to determine the applicability of regulatory restrictions prior to use.

Our organization, EUROLAB, provides Standard Test Method services for stress-strain fatigue of polymer matrix composite materials, within the framework of national and international standards, with its trained and expert staff and advanced technological equipment, among numerous test, measurement, analysis and evaluation studies. Provides testing services within the scope of ASTM D3479 standard.