The out-of-plane shear behavior can be characterized by short beam shear experiments. Tests such as these, using either a three, four or five-point bending set-up, often suffer from the fact that significant bending is observed in the sample in addition to the shear deformation.
A test set-up developed at EMI, and used successfully in [2], minimizes bending effects resulting in maximized shear deformation (see Figure 5.4: Short Beam Shear Test Setup). The shear force is recorded along with the total displacement using a clip gauge. The shear stress τ and the shear angle γ can then be derived. For full details of this experiment, see [2].
Figure 5.5: Typical Shear Stress - Shear Angle Relationship shows a typical the shear stress–shear strain relationship. The out of plane shear stiffness G13 and the matrix yielding stress τmatrix is derived from the extensometer signals.
