On the Dependence of the Dynamic Crack Tip Temperature Fields in Metals upon Crack Tip Velocity and Material Parameters
Abstract
Although various approximations have been used to analytically predict the temperature rise at a dynamic crack tip and its relation to the crack tip velocity or the material properties, few experimental investigations of these effects exist. Here, the method of using a high speed infrared detector array to measure the temperature distribution at the tip of a dynamically propagating crack tip is outlined, and the results from a number of experiments on different metal alloys are reviewed. First the effect of crack tip velocity is reviewed, and it is seen that the maximum temperature increases with increasing velocity and that a significant change in the geometry of the temperature distribution occurs at higher velocities in steel due to the opening of the crack faces behind the crack tip. Next, the effect of thermal properties is examined, and it is seen that, due to adiabatic conditions at the crack tip, changes in thermal conductivity do not significantly affect the temperature field. Changes in density and heat capacity are more likely to produce significant differences in temperature than changes in thermal conductivity. Finally, the effect of heat upon the crack tip deformation is reviewed, and it is seen that the generation of heat at the crack tip in steel leads to the formation of a shear band at 45 deg to the surface of the specimen. In titanium, no conclusive evidence of shear band formation is seen.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1992
- Accession Number
- ADA253657
Entities
People
- Ares J. Rosakis
- James J. Mason
Organizations
- California Institute of Technology