Experimental validation of a microcracking-based toughening mechanism for cortical bone

Area of Science:

• Biomechanics
• Materials Science
• Skeletal Biology

Background:

• Cortical bone toughness may be enhanced by microcrack formation during fracture.
• Previous studies proposed a microcrack-based toughening mechanism in bone.

Purpose of the Study:

• To experimentally validate the proposed microcrack-based toughening mechanism in cortical bone.
• Investigate the role of microcracking in bone fracture toughness.

Main Methods:

• Compact tension tests on cortical bone specimens from red deer antlers.
• Analysis of microcrack formation during crack initiation and propagation.
• Measurement of crack growth resistance and propagation velocity.
• Scanning electron microscopy (SEM) for microstructural analysis.

Main Results:

• More microcracks were observed in specimens with crack propagation compared to initiation.
• Microcrack formation continued after initial fracture crack initiation.
• Crack growth resistance increased with crack extension.
• Crack propagation velocity showed characteristic jumps linked to microcrack formation.

Conclusions:

• Experimental results support the microcrack-based toughening mechanism in cortical bone.
• Bone toughness is significantly influenced by its capacity for microcrack formation during fracture.