Abstract
The dynamic propagation behavior of the mode I interlaminar crack in unidirectional carbon/epoxy composites was investigated by using double cantilever beam (DCB)specimens. The dynamic interlaminar propagation toughness was obtained using a hybrid experimental-numerical method. Using a novel electromagnetic Hopkinson bar system, pure mode I fracture was guaranteed by symmetrical opening displacement rates in the range of 10 – 30 m/s. The crack velocities before crack arrest were between 100 and 250 m/s, which was monitored by crack-propagation gauges and high-speed photography. To model the interlaminar crack, a user-defined cohesive element was developed, which integrated the experimentally measured crack propagation history. The propagation toughness was calculated by the energy balance method and the dynamic J-integral technique. Results from extensive studies indicate that the dynamic propagation toughness is not a single-valued function of the crack velocity for mode I interlaminar crack. Both the external dynamic loads and the interaction with the bending waves emanating from the moving crack tip affect the behavior of the crack propagation.
| Original language | English |
|---|---|
| Pages (from-to) | 65-82 |
| Number of pages | 18 |
| Journal | Engineering Fracture Mechanics |
| Volume | 215 |
| DOIs | |
| State | Published - 15 Jun 2019 |
Keywords
- Cohesive zone modelling
- Delamination
- Dynamic fracture
- Finite element analysis
- Polymer matrix composites