Getting deep into cracks

Physicists at the

, Israel, have developed a new way of studying the way cracks develop which could help predict and prevent engineering catastrophes.

Discovering a better method of modelling and predicting how materials fracture and split apart has great potential. For instance, it is possible engineers could have known ahead of time exactly how much pressure the levees protecting New Orleans could withstand before giving way. It may help predict when and under what conditions material wear and tear will become critical, causing planes to crash or bridges to collapse.

When force is applied to a material, for example a rock hitting a pane of glass, a crack starts to form in the interior layers of that material. In the glass, the force of the striking rock will cause the fracture to progress through the material with gradually increasing speed until the structure of the glass splits apart. The path the forming crack follows and the direction it takes are influenced by the nature of the force and by its shape. As cracking continues, microscopic ridges form along the advancing front of the crack and the fracture path repeatedly branches, creating a lightning bolt or herringbone pattern.