In contrast to most fluids, flowing powders do not exhibit viscosity such that a Newtonian rheology cannot accurately describe granular flow. Assuming that the material is incompressible, dry, cohesionless, and perfectly rigid-plastic, generalized Navier-Stokes equations (’Schaeffer Model’) have been derived where the velocity gradient has been replaced by the shear rate, and the viscosity depe...

An anchored sheet wall is commonly used in retaining deep excavations. Anchor force is one of the critical design parameters in practice. Based on the kinematical admissible failure mechanism, a limit analysis approach to determine the anchor force is presented. The explicit formula for the anchor force is given, which makes it easy to calculate using a simple calculation program such as MS Off...

in this study, some seed physical properties of two sugar beet varieties, shirin and gadouk (436), were evaluated as a function of moisture content. physical properties included length, width, thickness, arithmetic and geometric mean diameters, sphericity, thousand seed weight, angle of repose, terminal velocity, true density, bulk density, porosity, and coefficient of friction. four moisture c...

Equal-channel angular pressing (ECAP) combined with the Conform process provides a solution for the continuous production of ultrafine-grained materials. In the present study finite element method was executed to investigate the effects of die channel angle and friction on the strain homogeneity and the required torque in ECAP-Conform process. Deformation behaviour of Al 6061 wires was analyzed...

uniaxial compressive strength (ucs) and internal friction coefficient (µ) are the most important strength parameters of rock. they could be determined either by laboratory tests or from empirical correlations. the laboratory analysis sometimes is not possible for many reasons. on the other hand, due to changes in rock compositions and properties, none of the correlations could be applied as an ...

Dissimilar joint with good quality and mechanical properties is one of the major problems the industries. One of the most commonly used methods to solve this problem is friction stir welding process. In this paper two different tool pin with simple cylindrical and screwed profile were used to finding optimization of friction stir welding parameters to reach best mixing flow, composite structure...

In this paper, flow and heat transfer of nanofluid through a converging or diverging channel with porous medium is investigated. The fluid constantly flows under the effect of magnetic field through the channel. The diverging/converging fluid motion is modeled using the momentum and energy equations. The influence of some parameters such as opening channel angle, Reynolds number and Darcy’s num...

It i s emphasized t h a t a d i s t r i b u t i o n func t ion i n both the d i s l o c a t i o n loop lengths and obstac le s t rengths must be considered t o develop a q u a n t i t a t i v e theory f o r the h y s t e r e t i c d i s s i p a t i o n o f energy. That i s when d i s l o c a t i o n surmounts an undulat ing i n t e r n a l s t ress f i e l d and t h e break-away i s r e s t r i...

Micro-stamping process is one of the most cost-effective methods to manufacture metallic bipolar plates (BPPs). This research investigates the forming of titanium thin sheet as a potential candidate for BPPs in proton exchange membrane fuel cell (PEMFC). In this regard, the process was first simulated using finite element (FE) code Abaqus. Afterward, experimental tests were implemented and the ...

In this research work, a 3D numerical modeling technique is proposed based on the 3D particle flow code in order to investigate the failure mechanism of rock foundations. Two series of footings with different geometries and areas are considered in this work. The failure mechanism obtained is similar to that of the Terzaghi’s but there is a negligible difference in between. Lastly, one equation ...