load to fracture

Using a plexiglass sample and by means of real-time holographic interferometry and shadow optical method of caustics, the different features of dynamic variation in stress (strain) field, plastic area and nucleation zone (shadow area) when the sample fractures during loading(loading-fracture) and unloading (unloading-fracture) are strdied visually.

加载破裂时的焦散阴影区由慢到快迅速扩展 ;而卸载时的焦散阴影区则扩展较慢 ,并且在尖角形前方有一圆形阴