Accession Number : ADA312780

Title :   Moire for Dynamic Fracture.

Descriptive Note : Final rept. 16 Jan 89-31 Jul 96,

Corporate Author : WASHINGTON UNIV SEATTLE DEPT OF MECHANICAL ENGINEERING

Personal Author(s) : Kobayashi, Albert S.

PDF Url : ADA312780

Report Date : 20 AUG 1996

Pagination or Media Count : 10

Abstract : Geometric Moire and Moire interferometry were used to record the orthogonal displacement fields surrounding stably and rapidly propagating cracks in thin aluminum fracture specimens. The J- and T*-integral values were computed directly, for the first time, from the displacement data. J and T* were also obtained from static/dynamic, elastic-plastic finite element simulations of the fracture tests. While the ASTM far-field J increased, the near-field J precipitously dropped to zero with crack extension. The popular HRR elastic-plastic crack tip field also collapsed with crack extension. In contrast, the near-field T* reached a steady state value with crack extension and was found to be a suitable fracture parameter for characterizing stable and rapid crack growth and arrest.

Descriptors :   *DISPLACEMENT, *FRACTURE(MECHANICS), *INTERFEROMETRY, *CRACK PROPAGATION, *MOIRE EFFECTS, SIMULATION, STEADY STATE, OPTICS, STABILITY, DYNAMICS, FINITE ELEMENT ANALYSIS, ELASTIC PROPERTIES, TEST METHODS, ALUMINUM, PLASTIC PROPERTIES, THINNESS, STATICS, ORTHOGONALITY, J INTEGRALS.

Subject Categories : Mechanics
      Inorganic Chemistry
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE