ABSTRACT
Experimental results are presented for elevated temperature (177°C), tension-compression fatigue tests performed on titanium-graphite (TiGr) hybrid laminates containing open holes. The key damage modes were identified as 0° ply splitting, facesheet cracking, and facesheet delamination. The growth of damage during fatigue resulted in large reductions of the local stiffness adjacent to the hole. A one dimensional stiffness model was used to substantiate the role of facesheet delamination in governing the local stiffness. In conjunction with the calculated strain energy release rates it was shown that delamination growth rates vary with the cyclic strain energy release rate raised to the power of 1.9.
