Dynamic stress intensity factors for the sharp notch problem with the tip located at the interface

Abstract

This study focuses on determining the dynamic stress intensity factors (DSIF) for sharp notches located at the interface of bi-material structures. Plane elements with single-sided notches subjected to uniaxial tension with a Heaviside-function time dependence were analysed using the finite element method (FEM). The stress fields near the notch tip were computed and the DSIF values were derived through a developed linear extrapolation function. The accuracy of this methodology was verified by comparing the results with data from centrally cracked homogeneous bars. While existing DSIF determination methods largely focus on homogeneous materials and central crack problems, this study introduces an enhanced analytical–numerical method tailored for bi-material interfaces with sharp notches, addressing the specific challenges posed by such configurations. The analysis revealed that the DSIF values oscillated due to the interference and diffraction of mechanical waves at the notch tip, with peak values typically occurring in the third oscillation cycle. These oscillations are influenced by the notch angle, height, and relative stiffness of the bi-material components. The findings underscore the significance of case-specific analyses for accurate fracture behaviour predictions and provide valuable insights for the design of bi-material structures under dynamic loads.