Dynamic Stress Concentration Analysis in High Velocity Tension of Strips with Notches or Hole by Means of High Speed Photoelasticity

Abstract

The relations of dynamic stress concentration factor f_d varying with time vs static stress concentration factor f_s of very long strips with notches under dynamic tension are analyzed by high speed photoelasticity by means of a multiple spark gap camera using hard epoxy resin specimens and by numerical analysis using FEM and Newmark’s β method. As the shapes of the notches, central circular hole and U-shaped notches at both sides are chosen. The phenomenon of maximum stress position deviation towards incident side at the passage of stress wave front and the behaviour that f_d increases with time and then tends to f_s for all notches, are found. The results of corresponding FEM analyses well support the above mentioned behaviours obtained photoelastically.