Modeling Bioactive Materials

Abstract

Abstract. In this chapter we examine the mechanical properties of the ventral interior lateral muscle of the tobacco hornworm caterpillar, Manduca sexta. Uniaxial loading-unloading shows that the tissue is capable of large nonlinear pseudo-elastic deformations, has a hysteretic behavior and displays stress softening during the first few cycles of repeated loading. The data are used to develop a constitutive model that accounts for the observed material response, including a continuous transition from passive to active states. We consider the material initially incompressible, pseudo-elastic and transversely isotropic with preferred orientation parallel to the longitudinal direction of the muscle. The constitutive formulation is then generalized to account for slightly compressible materials and adapted for finite element implementation. The corresponding incremental equations and the associated isochoric and volumetric parts of the elasticity tensor are derived. To account for pseudoelasticty, the isochoric part is modified accordingly. The simulation of a bio-actuated micro-pump is used to validate and demonstrate the capability of the model.

Anisotropic Subcutaneous Response During Fingertip Normal and Tangential Loadings

“…The famous HGO hyperelastic model [22] accounts for the asymmetry of the fiber response under, respectively, compressive and tensile axial loads. It also predicts the anisotropic macroscopic response resulting from the preferential alignment of the collagen fiber network, and it fulfills volume preservation as expected in soft biological tissues [23], [24].…”

A Cosserat Model of Elastic Solids Reinforced by a Family of Curved and Twisted Fibers

“…Industrial applications of the mechanics of composite materials reinforced by curvilinear fibers are thoroughly treated in [13]. Further applications to bioelasticity are described in [14]. In this literature, the fibers confer anisotropy to the composite but their instrinsic flexural and torsional elasticities are not taken into account.…”