In drilling of composite laminates, it is important to minimize or reduce occurrences of delaminations. In particular, a peel-up delamination at entrance and push-out delamination at exit are common. Delaminations may be avoided by regulating the drill thrust force can be controlled by adjusting the feedrate of the drill. Dynamics involved in drilling of composite laminates is time varying and ...

Bone drilling is an essential part of many orthopaedic surgery procedures, including those for internal fixation and for attaching prosthetics. Estimation and control of bone drilling forces are critical to prevent drill breakthrough, excessive heat generation, and mechanical damage to the bone. This paper presents a 3D finite element (FE) model for prediction of thrust forces experienced durin...

Yinghui Liu, Brian Weinberg, Constantinos Mavroidis* Department of Mechanical & Industrial Engineering, Northeastern University 360 Huntington Avenue, Boston MA 02115, Tel: 617-373-4121, Fax: 617-373-2921 Email: [email protected], Webpage: http://www.coe.neu.edu/~mavro * Associate Professor, Corresponding Author Abstract Deep space drilling is necessary for appropriate chemical and biological s...

fluid properties with constant improvement in efficiency have been noticeable as important criteria in drilling operation. the main drilling fluid properties highly depend on utilization of new polymers with high efficiency in drilling fluid composition. in this paper, the performance of a new polymer, called partially hydrolyzed polyacrylamide polymer (phpa), is studied which has recently ente...

It is not possible to directly measure the total mass of gas and liquid in the annulus and geological properties of the reservoir during petroleum exploration and production drilling. Therefore, these parameters and states must be estimated by online estimators with proper measurements. This paper describes a nonlinear Moving Horizon Observer to estimate the annular mass of gas and liquid, and ...

Drilling-induced delamination is among the major concerns of applying the fiber-reinforced composite materials in various industries. Core drill ossesses the advantage for reducing the delamination by distributing the drilling thrust force toward the drill periphery. The thrust force of core rill varying with the conditions in drilling carbon fiber reinforced plastic (CFRP) is experimentally in...

Methodological development and tests were carried out in the Savukoski-Pelkosenniemi area and eastern Rovaniemi during the project ‘Novel technologies for greenfield exploration’ funded by Tekes. The aims were to develop or provide recommendations for suitable drilling equipments and methods that would enable the sampling of both basal till and bedrock at the same time, as well as stratigraphic...

With respect to the problem of big volume, large weight and high power consumption of lunar sampler nowadays, the paper firstly described a novel flexible mini lunar regolith sampler. Then the vibration model of it is established while drilling. The drilling efficiency can be improved more effectively by controlling the lunar regolith sampler always in the resonance state. But the dynamical mod...

Background & objectives: Oil well drilling operations are subject to various occupational hazards because of their nature and type of activities, which causes illnesses, loss of workforce as well as a lot of financial losses to the economic system of the community. Therefore, it is essential for all employees to observe safety in order to protect manpower and equipment. The purpose of this stud...

K e y w o r d s F o u r t h g r a d e fluid, Unsteady flow, Lie symmetries. 1. I N T R O D U C T I O N In recent years, considerable efforts have been usefully devoted to the s tudy of flow of nonNewton ian fluids. This is ma in ly due to their m a n y appl icat ions in pe t ro leum drilling, manufactu r ing of food and paper, and other similar activities. A vast a m o u n t of l i te ra ture i...