Abstract Scope |
Many engineering materials of importance can be mechanically characterized as brittle or quasi-brittle solids. A technique has been developed for observing and studying the process of macroscopic crack initiation and propagation using digital image correlation (DIC), and using linear elastic fracture mechanics (LEFM), determination of fracture toughness has been made. Specimen design, loading configuration, and diagnostics for identifying crack initiation and location, and scheme for extracting the stress intensity factor at the moving crack tip will be described. An interesting characteristic of this techniques is that it can be applied to the characterization of materials as a function of loading rate with the only limitation on its application being the resolution and rate at which images can be captured. It is known that the crack speed is a material characteristic that is associated loading rate and fracture toughness. This investigation will also show the relationship between loading rate and fracture. |