a plain strain analysis of frictional rolling contact on an elastic graded coating is presented in this paper. finite element method is applied to gain an understanding of the stresses and contact zone properties caused during rolling contact. the effects of friction, material stiffness ratio and coating thickness on stresses in contact zone and coating/substrate interface are studied. shear mo...

We introduce a simple variational principle for coherent material vortices in twodimensional turbulence. Vortex boundaries are sought as closed stationary curves of the averaged Lagrangian strain. Solutions to this problem turn out to be mathematically equivalent to photon spheres around black holes in cosmology. The fluidic photon spheres satisfy explicit differential equations whose outermost...

in classical mechanics, considering hook’s law stress is a linear function of strain. while in strain gradient theory stress is a function of strain and strain differentials. in this paper, novel formulation relating stress and strain and also new boundary conditions are derived based on minimum potential energy principle. in strain gradient theory a length coefficient parameter is defined. thi...

in this research, the possibility of using high percentage of lignocellulosic fibers in making natural fiber-thermoplastic composite was studied. three weight percentages of bagasse flour namely 40, 55 and 70 percents were chosen. mapp was used as coupling agent at two weight percentages of pp, namely 0, 4 and 6 percents. tensile strength was measured applying instron 6025. the results showed t...

In this study postmortem changes in the character of the stress-strain limit cycle were analyzed for cat extensor communis and extensor lateralis tendons maintained in a stream of Ringer’s solution and loaded with a short series of symmetrical triangular-wave stress cycles. The mechanical behavior of these tendons was compared with that of similar tendons which had been preserved by freezing. I...

Pressure vessel is a kind of special equipment which involved in various industries. Once it damaged, will cause great loss to people's life and property. The traditional elastic modulus reduction method for upper bound limit analysis pressure vessels adopts the elastic-perfectly plastic material model. This result waste materials without considering strain hardening effect. So effect introduce...

Delamination fracture of a two-dimensional functionally graded multilayered four-point bending beam that exhibits non-linear behaviour of the material is analyzed. The fracture is studied analytically in terms of the strain energy release rate. The beam under consideration has an arbitrary number of layers. Each layer has individual thickness and material properties. A delamination crack is loc...

Beeswax is a multicomponent material used by bees in the genus Apis to house larvae and store honey and pollen. We characterized the mechanical properties of waxes from four honeybee species: Apis mellifera L., Apis andreniformis L., Apis dorsata L. and two subspecies of Apis cerana L. In order to isolate the material effects from the architectural properties of nest comb, we formed raw wax in ...