The dislocation group dynamics emitted from a stressed source was analyzed under the stress singularity at a crack tip. From this analysis, the mechanical significance of the dislocation a free zone was clarified. That is, the length of dislocation-free zone (DFZ) is a function of the applied stress rate, and inverse pile up against the back tip of the occurs. The maximum dislocation density at the tip of DFZ was represented by a double logarithmic linear function of the length of the DFZ. From this analysis, it was shown that fracture occurs within the DFZ and the dynamic fracture strength decreases with increasing applied stress rate. Furthermore, the scattering of the trigger point for brittle fracture in the region of the brittle-ductile transition was clarified by this model and the proposed model of dislocation pile-up. This analysis makes it possible to distinguish brittleness of materials.
|ジャーナル||Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals|
|出版ステータス||Published - 1991 1 1|
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanics of Materials
- Metals and Alloys
- Materials Chemistry