Understanding the mechanism of fracture is essential for material and process design. While the initiation of fracture in brittle solids is generally associated with the preexistence of material imperfections, the mechanism for initiation of fracture in viscoelastic fluids, e.g., polymer melts and solutions, remains an open question. We use high speed imaging to visualize crack propagation in e...

Multidirectional composite laminates have been increasingly used as primary load-bearing structures in many applications such as aircraft frames, wings, and turbine or wind-mill blades, owing to their excellent weight-to-strength ratios, better environmental resistance, and much improved long-term durability. Such highperformance polymer matrix composites typically consist of dozens of unidirec...

Cantilever beam is a simplified sample of a lot of mechanical components used in a wide range of applications, including many industries such as gas turbine blade. Due to the nature of the operating conditions, beams are subject to variety of damages especially crack propagates. Crack propagation may lead to catastrophic failure during operation. Therefore, online detection of crack presence an...

We have developed an experiment to study the propagation of laboratory synthesized fatigue cracks under various controlled conditions during Sonic IR inspection. The experiment provides for good repeatability in testing. The parameters of interest include the initial crack length, load history (stress intensity and load ratio) during crack generation, geometry of the crack, material and also th...

The conflict between strength and toughness of Mg matrix composites extremely limits its engineering application. Inspired by nacre, CNTs/Mg bionic laminated were prepared electrophoretic deposition. Compared with Mg, the yield elongation composite was increased 52% 59% respectively. structure intercepts dislocations layers. homogeneous composites, stacked produce higher back stress strengtheni...

Dilatancy associated with fault slip produces a transient pore pressure drop which increases frictional strength. This effect is analysed in steadily propagating rupture model that includes weakening, slip-dependent dilation and fluid flow. shown to increase the stress intensity factor required propagate tip. With increasing speed, an undrained (strengthened) region develops near tip extends be...