Table 1.
Finite element results for the components of fracture energy and toughness of the control and deproteinized enamel for the longitudinal direction of crack growth.
| Jtip | JPl | Jbr | Jtotal | KLEFM | Keff | ||
|---|---|---|---|---|---|---|---|
| Control | Sample 1 | 85.8 | 7.8 | 37.2 | 130.8 | 1.68 | 2.08 |
| Sample 2 | 94.0 | 8.3 | 45.3 | 147.6 | 1.76 | 2.20 | |
| Sample 3 | 79.6 | 7.5 | 41.2 | 128.3 | 1.62 | 2.05 | |
|
| |||||||
| Average | 86.5±7.2 | 7.9±0.40 | 41.2±4.1 | 135.5±10.5 | 1.68±0.1 | 2.11±0.1 | |
|
| |||||||
| Deproteinized | Sample 1 | 50.2 | 2.6 | 8.5 | 61.3 | 1.29 | 1.42 |
| Sample 2 | 33.4 | 2.1 | 5.7 | 41.2 | 1.05 | 1.16 | |
| Sample 3 | 26.2 | 1.9 | 4.3 | 32.4 | 0.93 | 1.03 | |
|
| |||||||
| Average | 36.6±12.3 | 2.2±0.40 | 6.2±2.1 | 45.0±14.8 | 1.09±0.2 | 1.2±0.2 | |
Units for J and K are Pa•m and MPa•m1/2, respectively.
I. Jtip is the fracture energy estimated for linear elastic behavior and is used to calculate Kc
II. Jpl accounts for the energy spent in plastic deformation
III. Jbr is the energy stored in the spring elements
IV. Jtotal is the total fracture energy used to calculate Keff