ωp.
Fig. 17(a) indicated that when ωp was constant
and inclusion was stiffer than the medium, transientαηDSCF decreased with the
reduction in elliptical axial ratio, gradually declined from 1.928 to
0.897. This demonstrated that at the inclusion stiffer than the medium,
unlike steady-state αηDSCFalways less than 1, the transient incident aggravated the angular stress
concentration. Moreover, the angular stress concentration as shape of
inclusion approaching crack was more significant than that approaching
circle. In Fig. 17(b), for the
inclusion softer than the medium, transientαηDSCF increased with the
decrease in the elliptical axial ratio, from 2.712 to 3.705. Numerical
results demonstrated that for the inclusion softer than the medium, the
angular stress concentration at shape of inclusion approaching circle
was more significant than that when shape of inclusion approaching
crack. This phenomenon was contrary to Fig. 17(a), indicated that the
difference of material properties between the inclusion and medium
affected the changes in transientαηDSCF with elliptical axial
ratio.
Fig. 18 illustrated that when elliptical axial ratio andωp were constant, transientαηDSCF for the inclusion
stiffer than the medium was always smaller than that for the inclusion
softer than the medium. This phenomenon indicated that the angular
stress concentration of the soft inclusion was more significant than
that of the stiff inclusion, and the softer the inclusion was, the
greater the possibility of failure at both ends of the minor axis. The
value of transient αηDSCF in
case 2 was smaller than that in case 3, which proved that the greater
the difference in the material properties between the medium and
inclusion, the more significant the dynamic stress concentration. This
phenomenon was consistent with the changes of steady-stateαηDSCF .