We analyze the focusing properties of Fresnel zone plates fabricated over steel tapes using laser ablation. Our intention is to implement the use of micro-optical elements when the use of conventional chrome-glass elements is not indicated. Because of the manufacture process, the surface presents a certain anisotropic roughness, which reduces the focusing properties. First, we develop numerical...

BACKGROUND In the internal fixation of fractured bone by means of bone-plates fastened to the bone on its tensile surface, an on-going concern has been the excessive stress-shielding of the bone by the excessively-stiff stainless-steel plate. The compressive stress-shielding at the fracture-interface immediately after fracture-fixation delays callus formation and bone healing. Likewise, the ten...

in this research, mesoporous silica was applied as the host of corrosion inhibitor (molybdate). the loaded mesoporous silica was dispersed in an epoxy matrix. the composite was then coated on the mild steel plate. results showed that the corrosion resistance of the scratched epoxy/mesoporous silica loaded by molybdate was better than the one without molybdate or neat epoxy. on the other hand, e...

1.0 Introduction It is now reasonably well established that reinforced concrete (RC) structural elements can be strengthened/retrofitted/repaired by bonding high-strength fibre reinforced polymer (FRP) composites. Such reasons include steel reinforcement corrosion, construction flaws, change in loading or structure usage, or damage from impact or seismic events. Traditional methods of repair ca...

In the present research, friction stir welding (FSW) process was used for butt joining of pure copper plate to 316L stainless steel plate. Mechanical properties and microstructural characteristics of the joint were evaluated by microhardness and tensile tests as well as optical and scanning electron microscope (SEM). It was found that microstructure of the weld nugget (WN) has fine grains where...

This paper presents a low cycle fatigue life curve by simulating a crack in a cover plate welded moment connection. Initiation of ductile fracture in steel is controlled by growth and coalescence of micro-voids. This research used a numerical method using finite element modeling and simulation of ductile crack initiation by a micromechanical model. Therefore, a finite element model of a cover p...

We investigate experimentally the behavior of a thin sheet of polytetrafluoroethylene between a steel plate and a cylindrical steel indenter under combined action of high normal force and torsion. Under these actions, the polytetrafluoroethylene layer is partially squeezed out of the contact area. The thickness of the remaining layer is studied as function of the applied normal force, the torsi...

The strengthening and repair of existing structures using bonded carbon fiber reinforced polymer, CFRP, laminates has attracted a great deal of attention in the past two decades. Investigations clearly indicate the great potential of this method for restoring the capacity of corroded steel beams and improving their fatigue life. One important issue regarding the use of this technique in strengt...