Please login to view this media
- Talk
- 15/06/2021
- Canada
The Effect of Loading Rate on the Micro-Damage Process Zone Formed During Fracture of Human Cortical Bone
Description
The video transcript features Daniel Dapaah discussing his research on the effects of loading rate on microdamage process zone formation during human cortical bone fractures. He highlights the global challenge of bone fragility and its socioeconomic implications, citing that Canada experiences 30,000 hip fractures annually, costing approximately $1.1 billion. Dapaah emphasizes the necessity for better fracture risk prediction tools and understanding the mechanisms of bone fractures, which start with initial cracks that propagate to lead to bone separation.
He introduces the concept of the microdamage process zone, a network of microcracks that occurs during fracture and plays a critical role in energy dissipation and stress blunting at crack tips. The study aims to compare quasistatic and impact loading rates to observe differences in the formation of this microdamage zone.
The methodology includes conducting three-point fracture tests on cadaveric femurs, utilizing high-speed cameras for detailed imaging. Through data image correlation, the research investigates strain field distributions and calculates the area of the microdamage process zone, along with measuring material resistance to crack growth.
Results indicate that impact load tests yield higher peak loads but smaller microdamage zones compared to quasistatic rates. This suggests that microdamage plays a less significant role at higher loading rates, implying a rate-dependent mechanism critical to understanding fracture resistance. Dapaah concludes by acknowledging his co-authors, funding sources, and references, thanking the audience for their attention.