The Experts below are selected from a list of 11502 Experts worldwide ranked by ideXlab platform
Christopher David Cook - One of the best experts on this subject based on the ideXlab platform.
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Drilling of carbon composites using a one shot Drill Bit part ii empirical modeling of maximum thrust force
International Journal of Machine Tools & Manufacture, 2006Co-Authors: Marta A Fernandes, Christopher David CookAbstract:Abstract In order to extend tool life and improve quality of hole Drilling in carbon composite materials, a better understanding of ‘one shot’ hole Drilling is required. This paper describes the development of an empirical model of the maximum thrust force and torque produced during Drilling of carbon fiber with a ‘one shot’ Drill Bit. Shaw's simplified equations are adapted in order to accommodate for tool wear and used to predict maximum thrust force and torque in the Drilling of carbon composite with a ‘one shot’ Drill Bit. The mathematical model is dependent on the number of holes Drilled previously, the geometry of the Drill Bit, the feed used and the thickness of the workpiece. The model presented here is verified by extensive experimental data.
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Drilling of carbon composites using a one shot Drill Bit part i five stage representation of Drilling and factors affecting maximum force and torque
International Journal of Machine Tools & Manufacture, 2006Co-Authors: Marta A Fernandes, Christopher David CookAbstract:Abstract The thrust force and torque produced during Drilling contain important information related to the quality of the hole and the wear of the Drill Bit [1] . In this paper, the force and torque produced during Drilling of carbon fibre using a ‘one shot’ Drill Bit is investigated. The signals in the time domain were divided into stages and common problems and defects associated with each stage discussed. It is also shown how tool wear and thickness of the workpiece affect the thrust force and torque throughout the Drilling process. The findings of this paper are used to develop a mathematical model of the maximum thrust force and torque as described on Part II of this paper and are a valuable reference for future optimisation of Drilling carbon composites with a ‘oneshot’ Drill Bit.
Flavio Poletto - One of the best experts on this subject based on the ideXlab platform.
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Drill Bit seismic monitoring while Drilling by downhole wired pipe telemetry
Geophysical Prospecting, 2014Co-Authors: Flavio Poletto, Piero Corubolo, F. Miranda, Andrea Schleifer, Paolo ComelliAbstract:ABSTRACT Drill‐Bit seismic while Drilling provides reverse vertical seismic profiles with large configurations of surface seismic sensors. This seismic while Drilling technique makes it possible to predict the formation changes ahead of the Bit and to image 2D and 3D structures without interfering with the Drilling activity. The method is based on the recording of reference (pilot) signals which enable us to recognize and process the signal of the downhole Drill‐Bit source, thus obtaining impulsive seismograms after the crosscorrelation and deconvolution of the pilot signals and the seismic data recorded by surface or crosswell geophones. One issue in the application of this methodology can be the loss of the transmitted energy for the reference signal propagated from the Bit to the surface through the Drill string, when the pilot signals are recorded at the surface, at the top of the Drill string. It is well known that with polycrystalline diamond compact Bits, the pilot signal recorded at the surface may be weak and consequently the seismic while Drilling results are poor. This may also happen during Drilling in the sliding mode without pipe rotation, and in highly deviated or horizontal wells. A solution to improve the Drill‐Bit seismic while Drilling method in these conditions is to record the reference signal in the proximity of the Bit source, using downhole near‐Bit tools to get good‐quality measurements of the pilot signal. We present Drill‐Bit seismic while Drilling results obtained in a Drilling test using wired pipes for high‐rate communication from bottom hole to the surface. The results demonstrate the applicability of this integrated approach as a standard procedure. The advantage of this is to provide real‐time synchronized reverse vertical seismic profiles, as well as high‐resolution and good‐quality data in terms of S/N and high‐frequency content. The method improves the use of the working Drill Bit as a downhole seismic source with different types of Bit and Drilling conditions.
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Drill Bit As a Seismic Source For Near-well Imaging
Seg Technical Program Expanded Abstracts, 2012Co-Authors: F. Miranda, Piero Corubolo, Andrea Schleifer, Flavio PolettoAbstract:We analyze the performance of the Drill-Bit seismic source for near-well investigation purposes. We test two different configurations, crosshole and single-well-imaging (SWI). The crosshole results are used to characterize the high-frequency content and to observe the radiation pattern of the Drill Bit source. These results are also used to analyze the stability in the signature of the Drill-Bit signal. We obtain appreciable results up to 350 Hz. The Drill-Bit data are used for SWI purposes by reference signal analysis in a Drilled depth interval of approximately 140 m. The method allows us to detect reflections for prediction of the interfaces to be Drilled, and the results are in agreement with other geophysical results and geological evidences.
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Drill-Bit seismic interferometry with and without pilot signals
Geophysical Prospecting, 2010Co-Authors: Flavio Poletto, Piero Corubolo, Paolo ComelliAbstract:We use different interferometry approaches to process the seismic signals generated by a Drill-Bit source in one well and recorded by seismic receivers located both in a second borehole and at the surface near the source well. We compare the standard interferometry results, obtained by using the raw Drill-Bit data without a pilot signal, with the new interferometry results obtained by using the Drill-Bit seismograms correlated with a reference pilot signal. The analysis of the stationary phase shows that the final results have different S/N levels and are affected by the coherent noise in the form of rig arrivals. The interferometry methods are compared by using different deconvolution approaches. The analysis shows that the results agree with the conventional Drill-Bit seismograms and that using the reference pilot signal improves the quality of the Drill-Bit wavefields redatumed by the interferometry method.
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Drill-Bit displacement-source model: Source performance and Drilling parameters
Geophysics, 2006Co-Authors: Flavio Poletto, Cinzia BellezzaAbstract:The emission properties of a Drill-Bit source and the signature of the Drill-Bit seismograms depend on the dynamic action of the Drill Bit, which in turn is a function of the geological conditions, rock properties, and Drilling parameters. In fact, Drilling is a variable dynamic process, in which the vibrations produced by the Drill Bit are transmitted into the Drillstring and formation with a partition of energy determined by the impedances at the Bit. In this analysis, we study Drill-Bit performance and calculate the forces produced by an ideal Drill Bit to determine the variations in the signal signature and, ultimately, the conditions of source repeatability as a function of average Drilling parameters and signal frequency. The model includes near-field effects and assumes the Drill Bit acts as a displacement source, producing axial Bit forces with relative Bit/formation displacement and vertical penetration in the formation. The analysis shows that the expected Bit signature, which is equivalent to the ground force in Vibroseis, depends on average tooth impact area, percussion frequency, rate of penetration, formation strength, Bit wear, and downhole pressure. In particular, the results show that larger amplitudes of the axial forces are expected at a lower rate of penetration, higher formation strength, and lower formation pressure.
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Energy balance of a Drill-Bit seismic source, part 2: Drill-Bit versus conventional seismic sources
Geophysics, 2005Co-Authors: Flavio PolettoAbstract:The radiation properties of a downhole Drill-Bit seismic source are related to the amplitude and frequency of the forces exerted by the working Bit. The main vibration modes of roller-cone and polycrystalline diamond compact (PDC) Bits are investigated under different Drilling conditions. The analysis includes vibrations produced by teeth indention, multilobed patterns, bouncing with periodic and random effects, single-cutter forces, stick-slip and whirling effects, mud-pressure modulation forces, and Bit wear. Drill-Bit radiation properties are calculated using the results obtained in part 1 of this paper and are numerically compared to the radiation of conventional vertical seismic profiling (VSP) sources.
Marta A Fernandes - One of the best experts on this subject based on the ideXlab platform.
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Drilling of carbon composites using a one shot Drill Bit part ii empirical modeling of maximum thrust force
International Journal of Machine Tools & Manufacture, 2006Co-Authors: Marta A Fernandes, Christopher David CookAbstract:Abstract In order to extend tool life and improve quality of hole Drilling in carbon composite materials, a better understanding of ‘one shot’ hole Drilling is required. This paper describes the development of an empirical model of the maximum thrust force and torque produced during Drilling of carbon fiber with a ‘one shot’ Drill Bit. Shaw's simplified equations are adapted in order to accommodate for tool wear and used to predict maximum thrust force and torque in the Drilling of carbon composite with a ‘one shot’ Drill Bit. The mathematical model is dependent on the number of holes Drilled previously, the geometry of the Drill Bit, the feed used and the thickness of the workpiece. The model presented here is verified by extensive experimental data.
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Drilling of carbon composites using a one shot Drill Bit part i five stage representation of Drilling and factors affecting maximum force and torque
International Journal of Machine Tools & Manufacture, 2006Co-Authors: Marta A Fernandes, Christopher David CookAbstract:Abstract The thrust force and torque produced during Drilling contain important information related to the quality of the hole and the wear of the Drill Bit [1] . In this paper, the force and torque produced during Drilling of carbon fibre using a ‘one shot’ Drill Bit is investigated. The signals in the time domain were divided into stages and common problems and defects associated with each stage discussed. It is also shown how tool wear and thickness of the workpiece affect the thrust force and torque throughout the Drilling process. The findings of this paper are used to develop a mathematical model of the maximum thrust force and torque as described on Part II of this paper and are a valuable reference for future optimisation of Drilling carbon composites with a ‘oneshot’ Drill Bit.
Lianyu Fu - One of the best experts on this subject based on the ideXlab platform.
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On‐line temperature measurement of a micro Drill Bit
Circuit World, 2012Co-Authors: Lianyu FuAbstract:Purpose – The purpose of this paper is to present a method and a system for measuring Drill Bit temperature on‐line in the micro Drilling process and to characterize Drilling processes via Drill Bit temperature.Design/methodology/approach – The Drill Bit temperature measurement system was first established by the utilization of an infrared camera. Then the Drill Bit temperature in a Drilling cycle was characterized. The temperatures of an ultra‐small micro Drill Bit and a coated Drill Bit were measured and compared.Findings – The temperature of an ultra‐small Drill Bit can be measured on‐line via the proposed temperature measurement system. The Drilling process can be characterized by the Drill Bit temperature. The Drill Bit temperature decreased when a coated Drill Bit was used.Originality/value – The paper highlights key points for measuring the Drill Bit temperature on‐line by an infrared camera and characterizes PCB Drilling processes by measuring the Drill Bit temperature.
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development of a micro Drill Bit with a high aspect ratio
Circuit World, 2010Co-Authors: Lianyu Fu, Xueguang LiAbstract:Purpose – The purpose of this paper is to present key points relating to the development of micro Drill Bits with high aspect ratios and to provide a solution for high aspect ratio hole Drilling.Design/methodology/approach – Based on the analysis of challenges in high aspect ratio hole Drilling, key points for the development of micro Drills Bit with high aspect ratio are discussed. A design example of a micro Drill Bit with 0.3 mm diameter and a 7.2 mm flute length is presented. Experiments are conducted to verify the performance of the developed micro Drill Bit.Findings – Helix angle, web thickness and flute land ratio are three key parameters that significantly influence the behaviour of micro Drill Bits with high aspect ratios. Large helix angle, web thickness and flute land ratio are beneficial in terms of improving the performance of high aspect ratio micro Drill Bits. Step Drilling is essential to prevent Drill breakage and to ensure smooth debris evacuation. Meanwhile, proper steps and Drilling pa...
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development of an ultra small micro Drill Bit for packaging substrates
Circuit World, 2010Co-Authors: Lianyu FuAbstract:Purpose – The paper aims to present key points regarding the development of an ultra‐small micro Drill Bit for packaging substrate hole processing.Design/methodology/approach – Key points for the development of ultra‐small Drill Bits are presented. These are based on a study of the influential mechanisms of micro Drill Bit material properties, key parameters and coating techniques on the behaviours of micro Drill Bit. Experiments were conducted to verify the Drilling capability of the developed ultra‐small micro Drill Bits.Findings – The material properties of micro Drill Bits are of great importance in ensuring the performance. Helix angle, primary face angle and point angle are three key parameters that significantly influence Drill Bit behaviour. Computer‐aided engineering analysis, temperature monitoring and video monitoring techniques in high‐speed Drilling are useful tools for achieving the optimal design of ultra‐small Drill Bits. Using coating technology on ultra‐small Drill Bits can improve their...
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Development of an ultra‐small micro Drill Bit for packaging substrates
Circuit World, 2010Co-Authors: Lianyu FuAbstract:Purpose – The paper aims to present key points regarding the development of an ultra‐small micro Drill Bit for packaging substrate hole processing.Design/methodology/approach – Key points for the development of ultra‐small Drill Bits are presented. These are based on a study of the influential mechanisms of micro Drill Bit material properties, key parameters and coating techniques on the behaviours of micro Drill Bit. Experiments were conducted to verify the Drilling capability of the developed ultra‐small micro Drill Bits.Findings – The material properties of micro Drill Bits are of great importance in ensuring the performance. Helix angle, primary face angle and point angle are three key parameters that significantly influence Drill Bit behaviour. Computer‐aided engineering analysis, temperature monitoring and video monitoring techniques in high‐speed Drilling are useful tools for achieving the optimal design of ultra‐small Drill Bits. Using coating technology on ultra‐small Drill Bits can improve their...
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Method and system of automated measurement of micro Drill Bit wear
Circuit World, 2009Co-Authors: Lianyu Fu, Jian Li, Fan YangAbstract:Purpose – The purpose of this paper is to provide a method and system to achieve automated measurement of micro Drill Bit wear.Design/methodology/approach – A method and system of automated measurement of micro Drill Bit wear on the basis of machine vision are presented. Experiments are conducted to verify the developed method and system.Findings – The worn area of the primary face is an appropriate index to reflect the wear condition of a micro Drill Bit. A machine vision based technique is an applicable tool for capturing and characterising images of worn micro Drill Bit. The developed system can accurately measure and characterise the wear performance of micro Drill Bits with different materials and different parameter designs.Originality/value – The paper highlights the method and the system for achieving automated measurement of micro Drill Bit wear. The developed method and system can provide fast and precise evaluation of micro Drill Bit wear.
Hsun-heng Tsai - One of the best experts on this subject based on the ideXlab platform.
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Thermal Contact Simulation of Drill Bit and Bone during Drilling
2010 4th International Conference on Bioinformatics and Biomedical Engineering, 2010Co-Authors: Yuan-kun Tu, Li-wen Chen, Yung-chuan Chen, Wei-hua Lu, Chun-hui Chiang, Hsun-heng TsaiAbstract:In this study, a dynamic elastic-plastic finite element model is used to simulate the bone temperature rise during Drilling process. Various rotating speeds and applied forces of the Drill Bit are investigated to explore the effects of these parameters on the temperature rise within the bone. The results indicate that a Drill Bit with a higher rotating speed or a higher applied force can have noticeable reductions on the bone temperature rise as well as the size of thermal effective zone.
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Finite Element Simulation of Drill Bit and Bone Thermal Contact During Drilling
2008 2nd International Conference on Bioinformatics and Biomedical Engineering, 2008Co-Authors: Yuan-kun Tu, Li-wen Chen, Ching-chieh Huang, Yung-chuan Chen, Hsun-heng TsaiAbstract:Drilling is an essential part of internal fixation in orthopaedic and trauma surgery. The temperature rise during bone Drilling is an important index to the damage of bone. In this study, an elastic-plastic dynamic finite element model is used to simulate the process of a Drill Bit Drilling through the bone. Various initial temperatures of Drill Bit are investigated to explore the effects of this parameter on the temperature rise and on the contact stress distribution of the bone during Drilling. The results indicate that a Drill Bit with a lower initial temperature can reduce the temperature rise in bone during Drilling. A relationship between the initial temperature of Drill Bit and temperature rise is proposed.
