On the determination of the å-K relationship for birefringent polymers

Dynamic stress-intensity factors for unsymmetric dynamic isochromatics

“…The difference between the resultant static K I , KII, and aox and the corresponding dynamic values then constitute the theoretical errors involved in using the static near-field isochromatics for data reduction. is in agreement with that of Reference [7]. The lack of systematic changes in errors,i.e.…”

“…Note that the sign conventions of a is negative of that used in References [2,7,8,11,12]. (0e) Obviously Fk = 0 when the theoretical and measured isochromatic coincides.…”

“…A commonly used data reduction procedure for this purpose is to fit a theoretical, near-field, static isochromatics to the recorded experimental dynamic isochromatics and to then equate the resultant static stress intensity factor of the former to the unknown dynamic stress intensity factor of the latter [2][3][4][5]. Error estimates for using a static near-field stress to extract the dynamic stress intensity factor have been made by several investigators [6][7][8] and in particular, exhaustively by Rossmanith and Irwin [8].…”

Instability in dynamic fracture

“…Irwin et al [123], Ravi-Chandar and Knauss, 4.2.10) and Hauch and Marder [121] observed that microbranches are initiated in Homalite beyond 0.37v 0 , which is within 2% of the critical velocity observed in PMMA.…”

Qualitative analysis of the fast brittle fracture

“…For example, the dependence of crack velocity ~i on dynamic stress intensity factor K~ has been a subject of experimental [5][6][7][8][9][10][11] and theoretical work [12,13]. The uniqueness of Kl --~i relation was specifically considered in this issue and the applicability of the experimental methods employed in the measurement was discussed [14] and the experimental difficulty associated with the fast brittle fracture was demonstrated.…”