Biomedical Engineering Reference
In-Depth Information
(a) Fibres in a heart valve.
Courtesy Mrs A. Balguid
(b) Fibres in the intervertebral disc
Figure 4.1
Examples of fibre structures.
Figure 4.2
Fibre reinforcement in a stented valve prosthesis [
5
].
0
F
Figure 4.3
Unloaded and loaded spring.
vertical position and measuring the extension of the spring. However, formulat-
ing the force-extension relation as in Eq. (
4.1
) is, although formally correct, not
very convenient. If another spring was considered with the same intrinsic proper-
ties, while the initial length was different, the coefficient
a
would change as well.
Therefore the relation represented by Eq. (
4.1
) is scaled with the initial, unloaded,
length:
=
c
0
−
1
.
F
=
c
−
0
0
(4.2)
