MODELLING OF THIN ANISOTROPIC COLLAGEN-DOMINATED SOFT BIOLOGICAL TISSUE
A new constitutive model for thin,inhomogeneous,anisotropic,soft biologicaltissues is proposed.The thin tissue is modelled as a membrane,and the constitutivebehaviour is characterized by a strain-energy function,which takes the structuralfeatures of soft biological tissue into account.It is assumed that the mechanicalresponse of the tissue is dominated by its fibrous components,elastin and collagen.The proposed model is partly based on constitutive laws proposed by Holzapfel et al.(2000) and Kroon and Holzapfel (2007).The strain-energy of collagen fibres ismodelled by use of a Fung-type strain-energy function,whereas the influence of theelastin fabric and the matrix material is modelled by use of an incompressibleneo-Hookean model.In total the model has five material parameters:μ (the effectiveshear modulus pertaining to the elastin fabric and the matrix material),E1 and E2(the initial stiffness of the collagen fabric in the two principal directions,respectively),α (a parameter describing the level of nonlinearity of the collagenfibres),and β (the angle between the principal directions in the material and thereference coordinate system).A major advantage with the proposed model is,thatthe model parameters have clear physical interpretations.In addition,the totalstrain-energy function is polyconvex,which ensures material stability (Schr(o)der andNeff,2003).The model is fitted to results from inflation/extension tests on anadventitia tube from a femoral artery (Schulze-Bauer et al.,2002).Figure 1 shows acomparison between model predictions and experimental results in terms ofprincipal stretches (λland λc) for different internal pressure loads p.The agreementbetween model predictions and experiments is very good.
M.Kroon G.A.Hoizapfel
Department of Solid Mechanics,Royal Institute of Technology,Stockholm,Sweden. Department of Solid Mechanics,Royal Institute of Technology,Stockholm,Sweden.Institute for Biomechan
国际会议
第二届国际非均质材料力学会议(The Second International Conference on Heterogeneous Material Mechanics)
安徽黄山
英文
614-615
2008-06-03（万方平台首次上网日期，不代表论文的发表时间）