A phenomenological approach is used to represent the nonlinear viscoelastic behavior of solid propellants. A three dimensional nite strain viscoelastic model, modi ed by a strain softening function that accounts for damage e ects, is considered in the research. Some of the signi cant aspects of high-elongation propellants are incorporated into the constitutive model. The resulting stress-strain...

Cerebrospinal fluid (CSF) pulsations have been proposed as a possible causative mechanism for the ventricular enlargement that characterizes the neurological condition known as hydrocephalus. This paper summarizes recent work by the authors to anaylze the effect of CSF pulsations on brain tissue to determine if they are mechanically capable of enlarging the cerebral ventricles. First a poroelas...

The magnetorheological elastomers (MREs) are novel multifunctional materials which their viscoelastic properties can be varied instantly under an application of applied magnetic field. Due to field-dependent stiffness and damping properties, MREs have been widely used in the development design MRE-based adaptive vibration isolators absorbers also biomedical engineering. Moreover, due inherent m...

The mechanical behaviour of solid biological tissues has long been described using models based on classical continuum mechanics. However, the classical continuum theories of elasticity and viscoelasticity cannot easily capture the continual remodelling and associated structural changes in biological tissues. Furthermore, models drawn from plasticity theory are difficult to apply and interpret ...

AIM To evaluate the etiology and management of elevated intraocular pressure (IOP) following posterior chamber phakic implantable collamer lens (ICL) surgery. METHODS Between 2009 and 2015, 638 eyes of 359 subjects with refractive myopia, underwent V4b and V4c (CentraFLOW) model ICL implantation. Ocular hypertension (OHT) was defined as IOP of ≥ 22 mm Hg on two separate occasions and elevated...

A model to describe the damage state of materials is developed within the framework of Continuum Damage Mechanics. The damage variable is considered as a random variable. To predict the damage state in a body, knowledge of its intrinsic damage distribution is required. After dividing the body into a number of elementary cells, the intrinsic damage distribution can be determined utilizing statis...

In this paper, a general elastoplastic-damage constitutive model considering the effect of strain rate has been developed. The derivation of this model has been cast into the irreversible thermodynamics with internal variables within the fundamentals of Continuum Damage Mechanics (CDM). The rate effect has been involved as an additional term into the plastic yield surface (dynamic plastic yield...

During the last decades glueing became a popular joining technology especially in light weight construction. In order to allow for an appropriate description of glued components in simulations the behaviour of polymer layers hast to be investigated experimentally and theoretically. In this presentation the mechanical behaviour of polyurethan layers is studied in shear experiments. As expected, ...

Though remarkably robust, articular cartilage becomes susceptible to damage at high loading rates, particularly under shear. While several studies have measured the local static and steady-state shear properties of cartilage, it is the local viscoelastic properties that determine the tissue's ability to withstand physiological loading regimens. However, measuring local viscoelastic properties r...