Aerospace Engineering Department
BS in Aerospace Engineering
The use of shear keys to help stop or inhibit the face-sheet core delamination of sandwich composite beams under monotonic loading was analyzed in Cal Poly’s structural design lab. The composite beams were treated with the same boundary conditions as the ASTM D5528 double cantilever beam bending in which both faces of the beam remain free; one of the faces would have a debonded side and the other would not. An aluminum tab is attached to the top of the specimens and the load is applied there. Each specimen has piezoelectric sensors that are utilized in the detection of delamination propagation. All the analysis is to be carried out with and without the shear keys. The effects of initial delamlination lengths of 25mm, 50mm, and 75mm were tested with shear keys located at 0.5, 1.0, and 2.0 inches from the start of the delamination. The results found that the closer the shear keys were to the initial delamination, the better they were able to help prevent crack growth and failure. Also, the use of shear keys increased the maximum monotonic load the beam could withstand until it failed compared to samples with no shear keys.