A Critical Examination of a Numerical Fracture Dynamic Code.
WASHINGTON UNIV SEATTLE DEPT OF MECHANICAL ENGINEERING
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After upgrading the energy dissipation algorithm, numerical experiments were conducted to assess the reliability of the explicit dynamic finite element code, HCRACK. Two dynamic fracture specimens, i.e., the wedge-loaded rectangular DCB RDCB specimen and the wedge-loaded tapered DCB TDCB specimen, were then analyzed with this updated fracture dynamic code. Using the experimentally determined dynamic fracture toughness, K sub ID, versus crack velocity, a-dot, relation, the RDCB specimen was analyzed first by the propagation method where good agreements between calculated and measured K sub ID versus a relation were observed. The calculated a versus time, t, relation was then used as input data in the generation method where the resultant K sub ID were virtually identical to those obtained in the propagation method. Error analyses of the generation method were also made first by using the experimentally determined a versus t relation and secondly by artifically perturbing this relation. A TDCB specimen was then analyzed with both the propagation and generation methods by using the K sub ID versus a-dot relation established for this specimen and the measured a versus t relation, respectively. The computed K sub ID obtained by both methods were good agreement with the experimental results, showing that either approach can be used in analyzing fracture.