COMPRESSION STRENGTH REDUCTIONS IN COMPOSITE LAMINATES DUE TO MULTIPLE-LAYER WAVINESS

The effects of multiple-layer regions of waviness on static compressio n strength were investigated. A single-step fabrication method was dev eloped for fabricating multiple-nested wavy 0 degrees layers into othe rwise wave-free thermoset crossply laminates. Laminates were fabricate d with varying percentages of 0 degrees layers containing layer wavine ss, but all with a constant layer wave severity. Testing was performed to determine the effects of multiple-layer wave regions on compressio n strength. When no greater than 33% of the 0 degrees layers contained waviness, the percentage reduction in compression strength was approx imately equal to the percentage of wavy 0 degrees layers. However, a c onstant strength reduction of approximately 35% was observed when more than 33% of the 0 degrees layers contained waviness. These results su ggest that under limited conditions, compression strength reductions d ue to layer waviness may be estimated by the percentage of 0 degrees l ayers containing layer waviness.