Avalanche criticality during compression of porcine cortical bone of different ages.
Crack events developed during uniaxial compression of cortical bones cut from femurs of developing pigs of several ages (4, 12, and 20 weeks) generate avalanches. These avalanches have been investigated by acoustic emission analysis techniques. The avalanche energies are power-law distributed over more than four decades. Such behavior indicates the absence of characteristic scales and suggests avalanche criticality. The statistical distributions of energies and waiting times depend on the pig age and indicate that bones become stronger, but less ductile, with increasing age. Crack propagation is equally age-dependent. Older pigs show, on average, larger cracks with a time distribution similar to those of aftershocks in earthquakes, while younger pigs show only statistically independent failure events.
Departament d'Estructura i Constituents de la Matèria, Facultat de Física. Universitat de Barcelona, Diagonal, 647, E-08028 Barcelona, Catalonia.
Jordi
J
Baró
Department of Bioengineering, University of Illinois, 1270 Digital Computer Laboratory, Urbana, Illinois 61801, USA.
Peter
P
Shyu
Department of Mechanical Science and Engineering, University of Illinois, 1206 West Green Street, Urbana, Illinois 61801, USA.
Siyuan
S
Pang
Department of Bioengineering, University of Illinois, 1270 Digital Computer Laboratory, Urbana, Illinois 61801, USA.|Department of Mechanical Science and Engineering, University of Illinois, 1206 West Green Street, Urbana, Illinois 61801, USA.
Iwona M
IM
Jasiuk
Departament d'Estructura i Constituents de la Matèria, Facultat de Física. Universitat de Barcelona, Diagonal, 647, E-08028 Barcelona, Catalonia.
Eduard
E
Vives
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, United Kingdom.|State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
Ekhard K H
EK
Salje
Departament d'Estructura i Constituents de la Matèria, Facultat de Física. Universitat de Barcelona, Diagonal, 647, E-08028 Barcelona, Catalonia.
Antoni
A
Planes