The rheological properties of four different Kuwaiti crude oils in the presence of polyacrylamide (PAA) were investigated. PAA was varied at three different concentrations of 25, 50, and 75 ppm to study the viscoelastic properties in the untreated samples. Four different temperatures (25, 30, 35, and 40 °C) were used to evaluate different viscoelastic parameters of the treated and untreated Kuw...

Dynamic viscoelastic properties of bamboo were determined in torsion and bending. Damping, measured by tan δ, in dry bamboo was relatively small, about 0.01 in bending and 0.02 to 0.03 in torsion, with little dependence on frequency in the audio range. In wet bamboo, damping was somewhat greater: 0.012 to 0.015 in bending and 0.03 to 0.04 in torsion. The anisotropy in damping implies a purely c...

In this paper, the dynamic response of a viscoelastic beam subjected to a moving distributed load has been studied. The viscoelastic properties of the beam have been considered as linear standard model in shear and incompressible in bulk. The stress components have been separated to the shear and dilatation components and as a result the governing equations in viscoelastic form has been obtaine...

The properties of composite materials including those of biological origin depends very much upon structure. We consider here viscoelastic properties in which the stiffness depends on time or frequency, and microelastic properties in which there is dependence of stress upon spatial gradients of strain. The complex structural hierarchy of composite materials, particularly biological ones, gives ...

Linear and non-linear rheological properties of wheat gliadin and glutenin suspensions were investigated at various concentrations. Linear dynamic viscoelastic properties for both gliadin and glutenin were strongly dependent on concentration. For gliadins, the storage moduli (G 0), loss moduli (G00), and phase shifts dramatically changed within a narrow concentration range, indicating that glia...

The Rayleigh wave propagation problem in the elastic halfspace — viscoelastic layer interface was analysed in the paper. The problem was formulated in the Fourier–Laplace space using the Biot viscoelastic solid model. The characteristic equation has taken the Rayleigh equation form with correction term describing viscoelastic layer properties influence on the wave velocity. The approach present...

We examine the question of whether fluids and crystals are differentiated on the basis of their zero frequency shear moduli or their limiting zero frequency shear viscosity. We show that while fluids, in contrast with crystals, do have a zero value for their shear modulus, in contradiction to a widespread presumption, a crystal does not have an infinite or exceedingly large value for its limiti...

soil is a nonrenewable source that needs considerable management to prevent physical deteriorationby erosion and compaction. compacted soil causes low fertility and yield. the purpose of this study isto investigate the effect of viscoelastic properties of soil and to determine important factors oncompaction. furthermore, stress distribution, prediction of soil compaction and simulation of its e...

one of the most important factors that affect tire friction is surface roughness, which determines the size of the real contact area, real pressure distribution on the contact interface, and scales of mechanical engagement between viscoelastic rubber and a rough substrate. the need to predict coefficient of friction (cof) for rubber on rough surfaces for applications such as traction of tires o...

coeffcient of  friction  (cof)  for  rubber parts  is one of  the key parameters in their interaction with solid rough surfaces (micrometer to millimeter scales),  such  as  tire-road  interactions. cof  of  rubber  depends  on  viscoelastic properties of rubber, roughness characteristics of the counter-part surface, and process variables such as contact nominal pressure and sliding speed. due ...