Hard magnetics in ultra-soft magnetorheological elastomers enhance fracture toughness and delay crack propagation

Fracture Toughness of Wood and Wood Composites during Crack Propagation

The mode I fracture toughness as a function of crack length of medium density fiberboard (MDF), particle board (PB), and Douglas-fir (DF) were all measured using a new energy-based method. PB and MDF are examples of composites that develop fiber bridging during crack propagation, which causes their toughness to increase with crack length. Longitudinal cracks in DF also displayed fiber bridging ...

Buoyancy-driven crack propagation: the limit of large fracture toughness

Fracture toughness and fatigue-crack propagation in a Zr–Ti–Ni–Cu–Be bulk metallic glass

The recent development of metallic alloy systems which can be processed with an amorphous structure over large dimensions, specifically to form metallic glasses at low cooling rates ~;10 K/s!, has permitted novel measurements of important mechanical properties. These include, for example, fatigue-crack growth and fracture toughness behavior, representing the conditions governing the subcritical...

Evaluation of mode I fracture toughness of cortical bone tissue in the RL crack propagation system

In this work the mode I fracture properties of bone tissue were determined for the RL propagation system. With this aim, Double Cantilever Beam (DCB) fracture tests were performed using specimens of cortical bone tissue harvested from bovine femurs with an age of approximately 8 months. In order to overcome the difficulty associated to the monitoring of crack length during propagation in the co...

Magnetorheological elastomers – possibilities and limitations

The mechanical properties of magnetorheological (MR) materials can be changed continuously, rapidly and reversibly by an applied magnetic field. Solid MR materials consist of magnetically polarisable particles, generally iron, in an elastomer matrix. The required iron concentration is high, about 30% by volume. Problems and solutions will be discussed related to MR-technology. Finally long-term...