Tensile Testing of Composite Laminates using Automatic Extensometry (ASTM D3039)

Composite laminates are generally composed of assemblies of layered material. These individual layers often consist of high modulus and high strength fibers in a metallic, ceramic or polymeric matrix. Properties such as tensile strength and modulus are determined by loading specimens to failure.

Tensile testing of composite laminates was performed using 100 kN Hydraulic Wedge grips on a 5900 series frame. To obtain accurate data for measuring modulus and tensile strength an AutoX 750 automatic extensometer was used. It is required to use an extensometer or strain gauge when following ASTM D3039.

ASTM D3039 requires a class B1 extensometer and recommends using a gauge length in the range of 10-50mm. The AutoX can be prompted by the user to move to a specified gauge length. This enables the user to change the gauge length of the extensometer to accommodate a variety of specimens while maintaining a B-1 classification.

Using Bluehill 3 Software, data is recorded and displayed. Parameters such as test control, specimen geometry and calculation can all be added or edited in the software.

After performing these tests, we have concluded that the AutoX 750 is an appropriate extensometer for this application.

Please review ASTM D3039 to ensure a full understanding of the standard.