Abstract
Experimental investigations are conducted to study dynamic fracture behaviour of sedimentary, igneous and metamorphic rocks. The notched semi-circular bending method (NSCB) has been employed to determine fracture parameters using a split Hopkinson pressure bar (SHPB). The time to fracture, crack speed and velocity of the flying fragments are measured by strain gauge, crack propagation gauge and high-speed photography. Dynamic crack initiation toughness is determined from the dynamic stress intensity factor at the time to fracture, and dynamic crack growth toughness is derived by dynamic fracture energy at a specific crack speed. This study reveals clearly that (i) dynamic crack initiation and growth toughness increase with increasing loading rate and crack speed; (ii) kinetic energy of the flying fragments increases with increasing impact speed of the striker; and, (iii) dynamic fracture energy increases rapidly with increasing crack speed. A semi-empirical rate-dependent fracture model is proposed.
| Original language | English |
|---|---|
| Title of host publication | ISRM VietRock 2015 International Workshop |
| Publication status | Published - 2015 |
| Event | ISRM VietRock 2015 International Workshop - Hanoi, Vietnam Duration: 12 Mar 2015 → 13 Mar 2015 |
Conference
| Conference | ISRM VietRock 2015 International Workshop |
|---|---|
| Country/Territory | Vietnam |
| City | Hanoi |
| Period | 12/03/15 → 13/03/15 |
Keywords
- Dynamic Loading
- Energy
- Failure Mechanisms
- Fracture Toughness
- Rock Dynamics