ect of ® nite crack length and blunting on dislocation nucleation in mode III
نویسندگان
چکیده
Continuum models, based upon both the Volterra and the Peierls descriptions of a screw dislocation ahead of a mode III crack, are used to evaluate the critical loading for dislocation nucleation at the tip of a ® nite pre-blunted crack. Results are presented for various crack tip root radii, for several crack lengths. Moreover, the e ect of ledge formation at the crack tip is evaluated. It is found that blunt cracks require a substantially larger load to induce dislocation nucleation, and this e ect is ampli® ed by including ledge formation in the analysis. It is also noted that short cracks require a reduced load for dislocation nucleation. §
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Effect of Crack Geometry on Dislocation Nucleation and Cleavage Thresholds
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