Instability of critical characteristics of crack propagation

Abstract

The paper presents the numerically evaluated dependence of the stress intensity factor (SIF) on crack velocity ( $$K_{I}-{\dot{a}}$$ dependence) in Homalite-100 specimens subjected to pulse loading. Experiments on crack propagation (Ravi-Chandar and Knauss in Int J Fract 25:247–262, 1984. https://doi.org/10.1007/BF00963460 ; Int J Fract 26:65–80, 1984. https://doi.org/10.1007/BF01152313 ; Int J Fract 26:141–154, 1984. https://doi.org/10.1007/BF01157550 ; Int J Fract 26:189–200, 1984. https://doi.org/10.1007/bf01140627 ) were simulated using the finite element method and incubation time fracture criterion. According to (Ravi-Chandar and Knauss in Int J Fract 26:141–154, 1984. https://doi.org/10.1007/BF01157550 ), experimental data on the SIF–crack velocity dependence exhibit unstable behavior, i.e. considerable scattering of the SIF values: a broad range of SIF values corresponds to a single crack velocity. This way, the conventional approach based on a $$K_{I}-{\dot{a}}$$ dependence being a material property is not applicable in this case. Such a phenomenon is also observed in a numerically obtained $$K_{I}-{\dot{a}}$$ dependence, meaning that the developed approach makes it possible to evade the known ambiguity of the $$K_{I}-{\dot{a}}$$ relation to predict the crack propagation.