National Research Council Resident Research Associate, NASA Langley Research Center, Hampton, VA
Senior Scientist, NASA Langley Research Center, Hampton, VA
Pages: 21 Published: Jan 1999
The purpose of this paper was to verify the capability of the STAGS (general shell, geometric and material nonlinear) code and the critical crack-tip-opening angle (CTOA) fracture criterion to predict stable tearing in cracked panels that fail with severe out-of-plane buckling. Materials considered in the analyses ranged from brittle to ductile behavior. Experimental test data used in this study are reported elsewhere. The STAGS code was used to model stable tearing using a critical CTOA value that was determined from a cracked panel that was “restrained” from buckling. The STAGS code and the critical CTOA were then used to predict the influence of buckling on stable tearing and failure loads. Parameters like crack-length-to-specimen-width ratio, crack configuration, thickness, and material tensile properties had a significant influence on the buckling behavior of cracked thin-sheet materials. Experimental and predicted results showed a varied buckling response for different crack-length-to-sheet-thickness ratios because different buckling modes were activated. The effects of material tensile properties and fracture toughness on buckling response were presented and discussed. The STAGS code and the CTOA fracture criterion were able to predict the influence of buckling on stable tearing behavior and failure loads on a variety of materials and crack configurations.
cracks, crack growth, crack-tip-opening angle (CTOA), buckling, multiple-site damage cracking, STAGS shell code
Paper ID: STP14946S