Stick-slip vibrations present at the bottom hole assembly (BHA) of a generic oilwell drillstring subject to dry friction are studied. Different nonlinear differential equations-based models of a drillstring are analyzed. The drillstring models presented are oriented to avoid simulation problems due to the discontinuities originated by the presence of dry friction. The influence of different dri...

Introduction: Commercial drilling, even deep-sea or remote, depends on human teleoperation. Lightspeed delays mean that coring and drilling beyond the Moon requires automation in order to not get stuck or risk mission failure. The Drilling Automation for Mars Exploration (DAME) is a NASA project for developing critical-path drilling software technologies. The DAME project’s purpose was to devel...

This study investigates the effect of focal plane variation using vibration in a femtosecond laser hole drilling process on Invar alloy fabrication quality for the production of fine metal masks (FMMs). FMMs are used in the red, green, blue (RGB) evaporation process in Active Matrix Organic Light-Emitting Diode (AMOLED) manufacturing. The taper angle of the hole is adjusted by attaching the obj...

Here we present a method for high-precision drilling using an industrial robot with high-bandwidth force feedback, which is used for building up pressure to clamp-up an end-effector to the work-piece surface prior to drilling. The focus is to eliminate the sliding movement (skating) of the end-effector during the clamp-up of the end-effector to the work-piece surface, an undesired effect that i...

[1] We report new drillstring packer permeability tests conducted during Integrated Ocean Drilling Program (IODP) Expedition 327 in upper oceanic basement in Hole U1362A on the eastern flank of the Juan de Fuca Ridge. Hole U1362A lies within a closely spaced array (40–2460 m separation) of six holes in well-sedimented 3.5–3.6 m.y. old crust that were drilled, tested, and instrumented with boreh...

Drilling is an hole making process in metal cutting operation performed by extrusion which finds wide application in various industries for manufacturing components using metals and non metals. This process is applied widely in assembly of components or elements, where processing challenges are severe issue such as to maintain surface integrity, ovality, machining time, Metal Removal Rate etc.,...

The drilling and riveting processes are widely used in the assembly of carrier rocket, which makes the efficiency and quality of drilling become the important factor affecting the assembly process. According to the problem existing in the drilling of thick stacked plate (thickness larger than 10mm) of carrier rocket, such as drill break, large noise and burr etc., experimental study of the infl...

This study presents an experimental investigation of the effects of spindle speed, feed rate, and depth of drilling on the temperature distribution during drilling of the cortical section of the bovine femur. In an effort to reduce measurement uncertainties, a new approach for temperature measurements during bone drilling is presented in this study. The new approach is based on a setup for prec...

The bone drilling temperature fields under different cutting parameters and cooling modes were experimental researched by using common twist drill, diamond punching pin, diamond bullet-like grinding head and diamond spherical grinding head. Three cooling modes were applied, namely, natural air cooling, normal saline pouring cooling and normal saline spray cooling. K-thermocouple was used to mea...