In this paper we describe two numerical methods by which the relaxation modulus and memory function of a polymer can be determined from a set of discrete linear viscoelastic storage and loss moduli measurements. The first method involves expressing the linear viscoelastic data by means of a rational function (with certain constraints) and then taking the Laplace transform of that function. The ...

Linear response theory of thermal fluctuations or driven motion of tracers provides a basis for exploring viscous, elastic and compressible properties of condensed matter. Applications range from atomic physics [1, 24] where the methods were first developed, to recent applications in microrheology [13, 18, 7, 5, 11, 12, 2]. The emphasis here is on hydrodynamics and deformations of incompressibl...

We present a time-dependent finite element model of the human knee joint of full 3D geometric complexity together with advanced numerical algorithms needed for its simulation. The model comprises bones, cartilage and the major ligaments, while patella and menisci are still missing. Bones are modeled by linear elastic materials, cartilage by linear viscoelastic materials, and ligaments by onedim...

Rheological material properties are examples of functionvalued quantities that depend on frequency (linear viscoelasticity), input amplitude (nonlinear material behavior), or both. This dependence complicates the process of utilizing these systems in engineering design. In this article, we present a methodology to model and optimize design targets for such rheological material functions. We sho...

The mechanical testing of thin layers of soft materials is an important but difficult task. Spherical indentation provides a convenient method to ascertain material properties whilst minimising damage to the material by allowing testing to take place in situ. However, measurement of the viscoelastic properties of these soft materials is hindered by the absence of a convenient yet accurate model...

A mathematical model describing the constitutive properties of biofilms is required for predicting biofilm deformation, failure, and detachment in response to mechanical forces. Laboratory observations indicate that biofilms are viscoelastic materials. Likewise, current knowledge of biofilm internal structure suggests modeling biofilms as associated polymer viscoelastic systems. Supporting expe...

Almost all of biological tissues are viscoelastic and their viscoelastic mechanical properties are important in their characteristic functions. This is because constituents of tissues  cells, extracellular matrices, structural proteins, and so on  are viscoelastic. Even hard tissues have been shown to be viscoelastic. For long, main sample material for investigating the viscoelasticity has be...

wall displacements and ground pressure acting on the lining of a tunnel increase with time. these time-dependent deformations are both due to face advance effect and to the time-dependent behavior of the rock mass.  viscoelastic materials exhibit both viscous and elastic behaviors. thorough this study, the effect of different linear viscoelastic models including maxwell, kelvin and kelvin-voigt...