considering the nonlinear hyperelastic or viscoelastic nature of soft tissues has an important effect on modeling results. in medicalapplications, accounting nonlinearity begets an ill posed problem, due to absence of external force. myocardium can be consideredas a hyperelastic material, and variational approaches are proposed to estimate stiffness matrix, which take into account the linearand...

BACKGROUND Cartilage degeneration via osteoarthritis affects millions of elderly people worldwide, yet the specific contributions of matrix biopolymers toward cartilage viscoelastic properties remain unknown despite 30 years of research. Polymer dynamics theory may enable such an understanding, and predicts that cartilage stress-relaxation will proceed faster when the average polymer length is ...

In this work, a fully three-dimensional constitutive model suitable for the macroscopic description of unidirectional fibre-reinforced composites where the matrix exhibits a time-dependent viscoelastic behaviour is developed. Specifically, we consider a coordinate-free formulation where the stress and strain fields can be decomposed into fibre-directional and volumetric parts on the one hand, a...

Viscoelastic effects of the matrix polymer on molecular dynamics dielectric probes were examined using generalized Langevin equation, which was derived to include retardation effect viscous force. By solving we successfully obtained universal relationship between complex relaxation modulus and spectrum probe. When viscoelastic properties are assumed be viscous, is described with Debye function....

In this study, UV-curable urethane acrylate UA synthesized and then characterized by FTIR and HNMR. For better dispersion of nanoparticles in polymeric matrix, nano Al2O3 was modified by silane coupling agent and then its nanocomposites were prepared. The characteristics of synthesized nanocomposites were analyzed by TGA, DMA and infrared thermography. The results signify that adding nano Al2O3...

Characterization and control of the mechanical properties of the extracellular matrix are critical to the interpretation of results of in vitro studies of cultured tissues and cells and for the design of functional engineered constructs. In this work a viscoelastic tensile test system and custom culture chambers were developed and characterized. The system allowed quantification of strain as we...

In the current study the nonlinear viscoelastic response of a polymer matrix composite under multiple creep/creep-recovery loading is presented. The influence of creep/creep-recovery multiple step loading in the overall strain response both viscoelastic and viscoplastic is examined and an attempt for modeling this behaviour is attempted. An increase in the parameters of nonlinearity is observed...

Particulate composites with negative stiffness inclusions in a viscoelastic matrix are shown to have higher thermal expansion than that of either constituent and exceeding conventional bounds. It is also shown theoretically that other extreme linear coupled field properties including piezoelectricity and pyroelectricity occur in layerand fiber-type piezoelectric composites, due to negative incl...

While the matrix/reinforcement load-transfer occurring at the micro- and nanoscale in nonbiological composites subjected to creep deformation is well understood, this topic has been little studied in biological composites such as bone. Here, for the first time in bone, the mechanisms of time-dependent load transfer occurring at the nanoscale between the collagen phase and the hydroxyapatite (HA...