this study is focused on investigating the parameters of laser percussion drilling process of nickel-base super alloy inconel 718 with thickness of 1 mm. fiber laser with the power of 500 watts was used as the laser source. laser pulse frequency, duty cycle, laser power, focal point position, were assumed as the laser drilling process variables. the hole geometry features, i.e. entrance hole di...

In the present research, the mixed-mode fracture mechanics analysis in a plate with central hole under tensile loading is considered. It is assumed that a plate containing two symmetrical hole-edge cracks is bonded with two dissimilar planes. The stress intensity factors at the crack tips are calculated. The problem is modeled in Casca software and this model is analyzed with Franc software. Th...

the drilling is well known as one of the most common hole making processes in the industry.due to close tolerance requirement for drilled holes in the most of work pieces, onlinecontrolling of the diameter of drilled holes seems to be necessary. in the current work, an onlinedimensional controlling system was developed for drilling process. doing this, drilling processwas executed in different ...

The present work aims at reducing the friction of rubber soles sliding on ceramic floorings. Fitting bored cylindrical protrusions with different diameters on rubber soles was proposed. Experiments were carried out to evaluate the performance of the proposed protrusions in increasing friction coefficient at dry and contaminated floorings. It was found that, at dry sliding, friction coefficient ...

The drilling is well known as one of the most common hole making processes in the industry.Due to close tolerance requirement for drilled holes in the most of work pieces, onlinecontrolling of the diameter of drilled holes seems to be necessary. In the current work, an onlinedimensional controlling system was developed for drilling process. Doing this, drilling processwas executed in different ...

Roll forming process is used for manufacturing sheet metal parts by successive bending and creating the final shape with gradual deformation. In this article, deformation of a pre-punched sheet due to the roll forming process was studied. Two main defects in the roll forming process are ovality of holes and bow defect. The ovality of the hole is influenced by the process parameters including sh...

In the current research work, the problem of fracture mechanics in a plate with a central hole under tensile loading is studied. The stress intensity factors are calculated for a finite plate containing two symmetrical hole-edge cracks. The problem is solved by two different methods, namely the finite element method and the FRANC software analysis. At first the finite element method is used and...

The present study proposes novel micro-jet impingement heat sink with effusion holes for flow extraction. The design consists of impingement nozzles surrounded by multiple effusion holes to take away the spent fluid. A three-dimensional numerical model is used for steady, incompressible, laminar flow and conjugate heat transfer for the performance analysis of the proposed design. The computatio...

Rectangular waveguide is one of the earliest types of transmission lines. Rectangular waveguide can be produced by hot extrusion process. In this paper, the hot extrusion process of CuZn5 rectangular waveguide was investigated by Finite Element Method (FEM). In addition, Genetic Algorithm (GA) was used to optimize the die geometry and process conditions to achieve the lowest magnitude of extrus...