Affine kinematics in planar fibrous connective tissues: an experimental investigation
- 354 Downloads
The affine transformation hypothesis is usually adopted in order to link the tissue scale with the fibers scale in structural constitutive models of fibrous tissues. Thanks to the recent advances in imaging techniques, such as multiphoton microscopy, the microstructural behavior and kinematics of fibrous tissues can now be monitored at different stretching within the same sample. Therefore, the validity of the affine hypothesis can be investigated. In this paper, the fiber reorientation predicted by the affine assumption is compared to experimental data obtained during mechanical tests on skin and liver capsule coupled with microstructural imaging using multiphoton microscopy. The values of local strains and the collagen fibers orientation measured at increasing loading levels are used to compute a theoretical estimation of the affine reorientation of collagen fibers. The experimentally measured reorientation of collagen fibers during loading could not be successfully reproduced with this simple affine model. It suggests that other phenomena occur in the stretching process of planar fibrous connective tissues, which should be included in structural constitutive modeling approaches.
KeywordsAffine transformation Constitutive modeling Fibrous connective tissue Collagen fibers orientation Liver capsule Skin
The authors wish to thank Pr Mathias Brieu for useful discussions. This work was supported by the Programme Avenir Lyon Saint-Etienne (ANR-11-IDEX-0007) of Université de Lyon, within the program “Investissements d’Avenir” operated by the French National Research Agency (ANR), and by grants from Ecole Polytechnique (interdisciplinary project) and from Agence Nationale de la Recherche (ANR-13-BS09-0004-02 and ANR-10-INBS-04).
Conflict of interest
None of the authors have any professional or financial conflict of interest.
- Jayyosi C (2015) Caractérisation mécanique et microstructurale du comportement à rupture de la capsule de Glisson pour la prédiction du risque de lésions des tissus hépatiques humains. Université Claude Bernard Lyon 1Google Scholar
- Lanir Y, Salant EL, Foux A (1988) Physico-chemical and microstructural changes in collagen fiber bundles following stretch in-vitro. Biorheology 25:591–603Google Scholar
- Mauri A, Ehret AE, Perrini M et al (2015) Deformation mechanisms of Human amnion: quantitative studies based on second harmonic generation microscopy. J Biomech. doi: 10.1016/j.jbiomech.2015.01.045