نتایج جستجو برای: central hole drilling method

تعداد نتایج: 2115195  

2017
Zhiqiang Liang Suyan Zhang Xibin Wang Haixin Guo Tianfeng Zhou Li Jiao Pei Yan

During the micro-drilling process of stainless steel, the wear, fracture, and breakage of the micro-drill easily occur. Micro-drill geometry parameters have significant influence on the drilling performance of the micro-drill. Nowadays, the helical point micro-drill is proposed and its improved drilling performance is validated by some researchers. In this study, to analyze the effect of geomet...

The fracture and crack growth of mechanical structures is a usual phenomenon which is due to the application of tensile, cyclic loading or thermal stresses on the structure. So introducing of methods to prevent the crack growth is useful. Afterward, one of the repairing methods of crack growth, consisting to make a hole in the crack tip to elimi-nate the sharp corners, was explained. This metho...

Calculation of the specific charge and specific drilling before a blasting operation plays a significant role in the design of a blasting pattern and the reduction of the final extraction cost of minerals. In this work, the information from the Sungun, Miduk and Chah-Firouzeh copper mines in Iran was assessed, and it was found that there was a significant relationship between the specific charg...

2015
D. Sui

Since Dual Gradient Drilling (DGD) is a new and advanced drilling technology, currently its methods, procedures, simulations and experiments are still underdeveloped. It requires more study, research and advanced methods on DGD systems. The motivation of the paper is to study DGD systems, design good operational drilling parameters, and work on automated DGD systems to further realize safe and ...

2009
Samad Valipour Shokouhi Agnar Aamodt Pål Skalle Frode Sørmo

Oil well drilling is a complex process which frequently leads to operational problems. In order to deal with some of these problems, knowledge intensive case based reasoning (KiCBR) has clearly shown potential. An important problem in drilling is hole cleaning, in which a high number of observed parameters and other features are involved. This paper presents how to determine the root causes of ...

2008
Luís M. Durão António G. Magalhães António T. Marques João Manuel R. S. Tavares

Hole drilling operations are common in fibre reinforced plastics FRP’s to facilitate fastener assembly to other parts in more complex structures. As these materials are non-homogeneous, drilling causes some damages, like delamination, for example. Delamination can be reduced by a careful selection of drilling parameters, drill material and drill bit geometry. In this work two types of laminates...

2017
Jialing Zou

Pressure control drilling technology through the precise control of the entire wellbore annular pressure profile, the bottom of the pressure can always maintain the safety density window, so as to achieve the purpose of safe operation. In the drilling process, the use of conventional drilling technology for drilling operations, easily lead to well, overflow and other drilling accidents. In this...

1998
Terry Plank Roger Larson James Gill Robert Stern Julie Morris Tim Elliott Peter Floyd Jeffrey Alt Lew Abrams John Ludden

During Leg 185 two deep-water sites will be drilled, one seaward of the Mariana Trench (Ocean Drilling Program Hole 801C) and one seaward of the Izu-Bonin Trench (Site BON8A). The primary objectives are to investigate sediment subduction along this arc-trench system and to characterize the chemical fluxes during alteration of the oceanic crust. Despite the simple setting and shared subducting p...

2016
Bruna Aparecida Rezende Michele L. Silveira Luciano M. G. Vieira Alexandre M. Abrão Paulo Eustáquio de Faria Juan C. Campos Rubio

Composite materials are widely employed in the naval, aerospace and transportation industries owing to the combination of being lightweight and having a high modulus of elasticity, strength and stiffness. Drilling is an operation generally used in composite materials to assemble the final product. Damages such as the burr at the drill entrance and exit, geometric deviations and delamination are...

2016
Satheesh Kumar

Advanced Ceramics find wide range of industrial applications. Cutting of advanced ceramic (SiC) is very difficult using conventional machining methods due to its low fracture toughness. In the past few years, researchers have claimed successful machining of ceramic composites using EDM process. Furthermore, increasing trend, necessity of miniaturization, micro components in MEMS and semiconduct...

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