3-D Finite Element Modeling of Ductile Crack Growth in Thin Aluminum Materials

摘要: This work describes the development and verification of a 3-D model to predict stable, Mode I crack growth in thin, ductile aluminum alloys. The extends standard 2-D form tip opening angle (CTOA) methodology, which determines extension based on obtaining critical at tip. When CTOA reaches value, all nodes along current, front are released simultaneously, thereby growing self-similar manner. Evaluation occurs specified distance behind tip; this decouples evaluation from mesh refinement. CTOA-based also includes adaptive load control strategies minimize effects discrete increments response. To evaluate effectiveness described approach, validation study using load-crack data 2.3-mm-thick Al 2024-T3 specimens tested NASA-Langley. test matrix C(T) M(T) specimens, with varying widths (50 600 mm), a/W ratios, levels constraint suppress out-of-plane bending. Comparisons curves experiments analyses constrained 150-mm specimen provide calibrated value 5.1°. Analyses for unconstrained predictions peak good agreement experimental values.