pure shear experiment and simple shear experiment ?

[byhyj]

The pure shear experiment is used for rubber materials; however, the simple shear experiment is used for soft elastomer foam materials. So I think to know why the two materials need different shear experiment to describe the shear capability. And I think to know why we must used pure shear experiment to describe the rubber’s shear capability, and why we must use simple shear experiment to describe the shear capability. What different is there in the two experiment.

[Jorgen]

Both pure shear and simple shear can be used to experimentally test rubber materials.

As you mentioned, the simple shear test is often used for compressible materials, such as foam. And the pure shear can be used for incompressible elastomers. Note, however, that simple shear experiments are also often used for almost incompressible materials.

For incompressible materials, pure shear experiments can be performed by a planar tension test. It turns out that a state of pure shear exists at 45 deg from the loading axis in this test setup.

Simple shear experiments are often performed using a double shear-lap test.

- Jorgen