Full-Field Measurements of Fracture Initiation and Crack Growth in Superelastic Nitinol

摘要

We present results for full-field measurements of crack tip deformation fields in Nitinol using high sensitivity moire interferometry. Three fatigue loading scenarios are examined illustrating the effect of stress induced martensite transformations at the tip of the crack. Understanding the behavior of fatigue crack growth is paramount to the successful use of this highly complex material response, especially for such application as implant-able medical devices. The results demonstrate the sensitivity of heterogeneous phase transformations on the crack growth behavior.