Abstract:

The buckling failure of composite laminates with a surface notch is explored through experiments and analysis. Both strain gauge and acoustic emission techniques are used to observe the mechanical behavior of the laminates with increasing load. For comparison, the unnotched laminate coupons are also tested. Although both notched and unnotched coupons fail in the mode of buckling, there are still some apparent differences in the features of the failure process. A simplified expression for calculating the critical stress is developed according to a stiffness reduction technique. The experimental and theoretical results show good agreement.

Key words: composite material, laminates, surface notch, buckling failure, strain gauge, acoustic emission, stiffness reduction, critical stress