Deformation mechanism in polymers under Berkovich indenter

Hi All

I'm working on thermosetting polymers and use Nanoindentation to characterize various mechanical properties. I use Berkovich indenter for my experiments. I'm confused with deformation in thermosets when compressed with Berkovich indenter. I know that deformation in polymers usually occur due to crazing or shear banding/yielding with crazing usually resulting from tensile force. However, when it comes to compressive as the case under indenter than it might be only shear. Can anybody elaborate it and if possible introduce me to some good book or journal describing this mechanism?