Investigation of the role of crimps in collagen fibers in tendon with a microstructually based finite element model.

Tendon has a hierarchical structure that links tendon, fascicle, fibre and fibrils. In particular tendon fibres are made up of fibrils that have distinctive wavy forms called crimps. Experimental and imaging studies have shown that this crimp pattern plays an important role in mechanical properties of tendon but its exact influence has not been identified. We have developed a micro finite element model of tendon that contains accurate crimp patterns embedded in the model. This model utilizes a unique material coordinate system that is aligned in the direction of fibres. The crimp was implemented by performing fibre fitting procedure, which aligns the material coordinate system according to the crimp angle. FE analysis study was performed to identify the influence of crimp morphology on stress distribution pattern in tendon. Introduction of crimp angle to the model produced heterogeneous deformation and stress transfer patterns whereas the one without any crimp patterns predicted a uniform stress pattern. Future works include parametric studies on the influence of crimp pattern and morphology on stress distribution pattern in the tissue.