An analytical solution of steady-state dynamic response of a multilayered viscoelastic medium to a moving distributed load is obtained using a novel approach that combines transfer matrix method with Sun’s convolution representation integrated over impulse response function of the layered medium. The layered media under consideration include elastic and viscoelastic media with four different vi...

OBJECTIVES To evaluate the viscoelastic properties of demineralized dentin matrix. Stress-relaxation studies were done on matrices in tension and strain elongation or creep studies were done in both tension and compression. METHODS Mid-coronal dentin disks were prepared from extracted unerupted human third molars. Disks were 0.5 mm thick for stress-relaxation or tensile creep experiments and ...

This paper deals with rigidity percolation in composite materials consisting of a dispersion of mineral particles in a microstructured viscoelastic matrix. The viscoelastic matrix in this specific case is a hydrocarbon refinery residue. In a set of model random composites the mean interparticle surface-to-surface distance was controlled, changing particle volume fraction phi and particle number...

In this paper, a new viscoelastic model is presented to describe the elastic and viscoelastic behaviors of ligaments and tendons during the preconditioning process. The model is formulated by accounting for the mechanical contribution of the main structures of ligaments and tendons, i. e., the collagen fibers, the proteoglycan-rich matrix and the coupling between the collagen fibers and the mat...

In this paper, we present a theoretical analysis of the propagation of acoustic waves through elastic and viscoelastic two-dimensional phononic crystal structures. Numerical calculations of transmission spectra are conducted by extending the finite-difference-time-domain method to account for linear viscoelastic materials with time-dependent moduli. We study a phononic crystal constituted of a ...

Micromechanical models are developed to predict the time and temperature dependent response of woven composite substrates used in multilayer printed circuit boards. In the first part of this study, the elastic–viscoelastic correspondence principle is applied to previously reported elastic micromechanical models. The time-dependent creep compliance of a particular composite substrate (7628 style...

Heterogeneous textures due to phase separation in molten polypropylene (PP)/ ethylene-propylene-rubber (EPR) blends were investigated in relation to their dynamic viscoelastic properties. As characteristic to heterogeneous liquids, slow relaxation mechanisms due to the existence of such phases were found for dynamic moduli of PP/EPR blends. These moduli were analyzed by using the linear viscoel...

Shielding radiation from both x-rays and gamma-rays is important for personnel in medical fields e.g. interventional radiology, nuclear power stations, and other inspection facilities where radiation is involved. Lead is known for its effective shielding property against these high energy radiations, however heaviness and toxicity are its main drawback. In this study effectiveness of non-lead p...

INTRODUCTION: Tendon viscoelastic behaviors are due to frictional losses that may arise from several sources: fluid flow, internal friction between aligned collagen fibers, intrinsic friction in extrafibrillar matrix components (e.g., proteoglycans and glycosaminoglycans), or interactions between the fibers and extrafibrillar matrix (1-4). While it is generally accepted that these are the poten...

Understanding contrast mechanisms and identifying discriminating features is at the heart of diagnostic imaging development. This paper focuses on how pH influences the viscoelastic properties of biopolymers to better understand the effects of extracellular pH on breast tumour elasticity imaging. Extracellular pH is known to decrease as much as 1 pH unit in breast tumours, thus creating a dange...