Purely elastic, partially and fully plastic stress states in a thick-walled spherical pressure vessel with an inner functionally graded material (FG) coating subjected to internal and external pressures are developed analytically in this paper. The modulus of elasticity and the uniaxial yield limit of the FG coating layer are considered to vary nonlinearly through the thickness. Using Tresca’s ...

The past decade has seen increased focus on nanoparticle (NP) based drilling fluid to promote wellbore stability in shales. With the plugging of NP into shale pores, the fluid pressure transmission can be retarded and wellbore stability can be improved. For better understanding of the interaction between shale and NP based drilling fluid based on previous pressure transmission tests (PTTs) on A...

In this paper, a six-stage interactive model is presented for the perforation of metallic plates using blunt deformable projectiles when plastic wave propagation in both target and projectile is considered. In this analytical model, it is assumed that the projectile and target materials are rigid – plastic linear work hardened. The penetration of the projectile into the target is divided into s...

Warpage and shrinkage control are important factors in proving the quality of thin-wall parts in injection modeling process. In the present paper, grey relational analysis was used in order to optimize these two parameters in manufacturing plastic bush of articulated garden tractor. The material used in the plastic bush is Derlin 500. The input parameters in the process were selected according ...

Electrorheological (ER) fluids change their flow properties dramatically when an electric field is applied. These fluids are usually composed of dispersions of polarizable particles in an insulating base fluid or composed of liquid crystal polymer. To build more suitable and complicated designs for application of ER fluid, the simulation of ER fluid as well as experiments are important. First, ...

This study experimentally investigates the effect of multi-walled carbon nanotubes (MWNT’s), as a reinforcing material, on the physical properties of heavy-weight oil well cements. A candidate well is selected and the properties of the cement slurry used in a problematic section of the well are tested in the laboratory. Carbon nanotubes (CNT’s) are added as fibers to the cement slurry and the i...

We have developed a three dimensional numerical model based on the two-phase equations to study the bed-load transport Chauchat and Médale (2009). We have considered two formulations of the model based on a two fluid or a single mixed-fluid description. The governing equations are discretized by a finite element method and a penalisation method is introduced to cope with the incompressibility c...

Two new disposable cannulas for internal drainage of subretinal fluid are described in this article. We describe a curved and a straight version consisting of plastic hubs, 20 gauge proximal and 25 gauge distal stainless steel hypodermic tubing, and soft and flexible silicone tubing overmounts. Both these cannulas facilitate atraumatic drainage of subretinal fluid through pre-existing retinal h...