Scope:

For product design purposes, the compressive strength of composite materials is a significant property. The combined loading compression (CLC) method using ASTM D6641 is a standard compression test method to determine compressive properties of polymer matrix composite laminates by applying combined end-loading and shear-loading utilizing a combined loading compression fixture. Other polymeric materials can also be tested using this test method.

Test Procedure:

For the ASTM D6641 test, a metallic test fixture is used.A long and narrow specimen without a tab is inserted into the two halves of the test fixture, ensuring that the specimen ends are leveled with the top and bottom ends of the test fixture. All the bolts in the fixture are tightened to a definite torque to hold the test specimen in place. The loaded fixture is placed in a Universal Testing Machine. A strain measuring device can also be used, where strain gauges are attached to both sides of the specimen.The specimen is compressed to failure, and the mean strain from the front and rear sides of the specimen are measured.

Specimen size:

Long and narrow material specimens.

Data:

1. Laminate compressive strength (maximum load / (specimen width × specimen thickness)

2. Laminate compressive modulus (chord modulus from 0.1% to 0.3% strain)

3. Compressive Poisson’s Ratio by chord method (calculated from 0.1% to 0.3% strain)

Conclusion:

Hence, ASTM D6641 is a standard test method that determines compressive properties of polymer matrix composite laminates using a combined loading compression (CLC) test fixture.