caa a22 4500 465742130 CHVBK 20180323111811.0 cr unu---uuuuu 170327e19900601xx s 000 0 eng 10.1007/BF00035087 doi (NATIONALLICENCE)springer-10.1007/BF00035087 Dynamic fracture initiation and propagation in 4340 steel under impact loading [Elektronische Daten] [Alan Zehnder, Ares Rosakis] Dynamic fracture initiation and propagation in 4340 steel was investigated experimentally using the optical method of reflected caustics combined with high speed photography. A new crack propagation testing configuration consisting of a three point bend specimen loaded in a drop weight tower was used. It was found that prior to crack initiation the stress intensity factor time record calculated using the dynamic tup load and a static formula disagrees with the actual stress intensity factor measured by caustics. During crack propagation, the crack tip velocity and stress intensity factor time records varied smoothly and repeatably allowing for a straightforward interpretation of the data. The experiments show that for the particular heat treatment of 4340 steel used, the dynamic fracture propagation toughness depends on crack tip velocity through a relation that is a material property. Kluwer Academic Publishers, 1990 Zehnder Alan Graduate Aeronautical Laboratories, California Institute of Technology, 91125, Pasadena, CA, USA aut Rosakis Ares Graduate Aeronautical Laboratories, California Institute of Technology, 91125, Pasadena, CA, USA aut International Journal of Fracture Kluwer Academic Publishers 43/4(1990-06-01), 271-285 0376-9429 43:4<271 1990 43 10704 https://doi.org/10.1007/BF00035087 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00035087 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zehnder Alan Graduate Aeronautical Laboratories, California Institute of Technology, 91125, Pasadena, CA, USA aut NATIONALLICENCE 700 1- Rosakis Ares Graduate Aeronautical Laboratories, California Institute of Technology, 91125, Pasadena, CA, USA aut NATIONALLICENCE 773 0- International Journal of Fracture Kluwer Academic Publishers 43/4(1990-06-01), 271-285 0376-9429 43:4<271 1990 43 10704 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer