A procedure is presented for simulating the sequential impoundment process of concrete-faced rockfill dam using nonlinear finite element method. The parameters of constitutive relationship of stress and strain are determined by tri-dimensional compression test in laboratory. The model applied in this study adopts the technique of element birth and death to simulate the sequential impoundment pr...

where J(t) is the creep compliance as it depends on time t, and E(t) is the relaxation modulus. Many constitutive models have been developed to describe the nonlinear viscoelastic behavior of materials; see Schapery (1969) and Findley et al. (1976). Models described by Johnson et al. (1996) are for large deformations and Pioletti et al. (1998) take into account the strain rate. In the present s...

In this study, nonlinear bending of functionally graded (FG) circular sector plates with simply supported radial edges subjected to transverse mechanical loading has been investigated. Based on the first-order shear deformation plate theory with von Karman strain-displacement relations, the nonlinear equilibrium equations of sector plates are obtained. Introducing a stress function and a potent...

Nonlinear effects in the coupling of polarization with elastic strain have been predicted to occur in ferroelectric materials subjected to high electric fields. Such predictions are tested here for a PbZr0.2Ti0.8O3 ferroelectric thin film at electric fields in the range of several hundred MV/m and strains reaching up to 2.7%. The piezoelectric strain exceeds predictions based on constant piezoe...

A combined nonlinear optical microscopy (NLOM) and optical coherence microscopy (OCM) imaging system has been assembled in order to simultaneously capture co-registered volumetric images of corneal morphology and biochemistry. Tracking of cell nuclei visible in the OCM volume enabled the calculation of strain depth profile in response to changes in intraocular pressure for rabbit cornea stroma....

We present a systematic study of strain effects on the electronic band structure of the group-IIInitrides (AlN, GaN and InN). The calculations are based on density functional theory (DFT) with band-gap-corrected approaches including hybrid functional and quasiparticle G0W0 methods. We study strain effects under realistic strain conditions, hydrostatic pressure and biaxial stress. The strain-ind...

PURPOSE The purpose of this study was to create synthetic vocal fold models with nonlinear stress-strain properties and to investigate the effect of linear versus nonlinear material properties on fundamental frequency (F0) during anterior-posterior stretching. METHOD Three materially linear and 3 materially nonlinear models were created and stretched up to 10 mm in 1-mm increments. Phonation ...

Accurate joint models require the ability to predict soft tissue behavior. This study evaluates the ability of constitutive equations to predict the nonlinear and viscoelastic behavior of tendon and ligament during stress relaxation testing in a porcine model. Three constitutive equations are compared in their ability to model relaxation, recovery and reloading of tissues. Quasi-linear viscoela...

A finite strain nonlinear viscoplastic constitutive model for polyurethane (PU)–Montmorillonite clay (MTM) nanocomposites is developed with the goal of characterizing the mechanical response under different strain rates and strain amplitudes. In this model, both the elastic and viscous responses are considered to be nonlinear. It is shown that a simple mathematical extension of the model used t...