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

The effects of multiple-layer regions of waviness on static compression strength were investigated. A single-step fabrication method was developed for fabricating multiple-nested wavy 0 degrees layers into otherwise wave-free thermoset crossply laminates. Laminates were fabricated with varying percentages of 0 degrees layers containing layer waviness, but all with a constant layer wave severity. Testing was performed to determine the effects of multiple-layer wave regions on compression strength. When no greater than 33% of the 0 degrees layers contained waviness, the percentage reduction in compression strength was approximately equal to the percentage of wavy 0 degrees layers. However, a constant strength reduction of approximately 35% was observed when more than 33% of the 0 degrees layers contained waviness. These results suggest that under limited conditions, compression strength reductions due to layer waviness may be estimated by the percentage of 0 degrees layers containing layer waviness.