Open-Hole Shear Fixture
Standard Test Method for Open-Hole Compressive Strength of Polymer Matrix Composite Laminates
ASTM D6484 specifies a compression shear testing procedure for composites. The open hole is used as a weak spot in the sample which causes the rupture to occur near it. The shear fixtures tend to be used either with compression platens or with fatigue rated wedge grips.
The sample is a long bar, about a foot in length. A hole is drilled in the center to create an area of weakness that is the focus for the test.
This procedures calls for a open hole compression shear fixture. The fixture is end loaded, and both sides exert a compressive force onto the sample.
Maximum shear stress tend to be the most common result value, however other, more sophisticated calculations can be made with the stress/strain data.