Figure 3. 6AL10a-b-c specimen images obtained after 5 Joules of impact energy
Fatigue Tests
Fatigue tests were conducted using Shimadzu Servo-Hydraulic Fatigue test equipment with a 100 kN load cell. First, the fatigue behaviors of the materials used in producing the sandwich composites were determined using a 5 Hz frequency. Load was applied to specimens as a sine wave and R (σminmax) of 0.1 was used. Fatigue tests were performed for aluminum, the 3M 2216 adhesive and the composite materials, for values below static damage loads. Figure 4 shows stress vs. cycles to failure graphs for the Al 5754 face sheet, the 3M 2216 adhesive and the CFRP.