Drill Design Research Articles

Study and improvement of surgical drill bit geometry for implant site preparation

During surgical interventions where bone machining operations are involved (drilling, sawing, etc.), bone tissue may be damaged by the mechanical and thermal loads, and thus, working conditions should be selected in order to reduce or avoid this problem. In this study, with the purpose of reducing the damage induced when drilling, an analysis and improvement of the geometry of a surgical drill bit had been done. As baseline, a commercially available stainless steel surgical drill indicated for implant site preparation had been considered. The influence of the rake angle, margin width, and body thinning over the workpiece temperatures, cutting forces, and surface roughness has been determined by a sensitivity study. First, eight drill bits had been fabricated on hard metal and drilling tests on bovine femoral cortical bone were done. These tests showed that the rake angle is the most influential factor among the analyzed, both for temperatures and cutting efforts. The two drill designs which achieved the lowest workpiece temperatures, cutting forces, and surface roughness had been fabricated also in surgical stainless steel and tested at wider cutting condition range of cutting speed and feed rates. These two drill bits reduced workpiece temperatures about 50 %, feed force about 60 %, and cutting torque up to 50 %, while the surface roughness was improved significantly when compared with the commercial surgical drill bit at the same cutting conditions. Comparing stainless steel and hard metal drills, no appreciable effects of the tool material have been detected over the measured output variables. This study shows how remarkable improvements on the design of surgical drills could be achieved by defining the influence of the rake angle, margin width, and body thinning when drilling bone.

Computer Numerical Control Grinding Wheel Pose for Thinned/Notched Drill Points With Specifiable Secondary Cutting Edge and Characteristic Angles

Researchers commonly develop notched drill points with secondary cutting edges that have unusual specifications; however, mathematical models cannot comprehensively specify these thinned/notched drill points. In an earlier work (Lin, P. D., and Tzeng, C. S., 2007, “New Method for Determination of the Pose of the Grinding Wheel for Thinning Drill Points,” Int. J. Mach. Tools Manuf., 47(15), pp. 2218–2229), precise mathematical modeling for drill design and one-wheel grinding of ISO-standard drills with linear secondary cutting edges was presented. That model is expanded herein to drill points with a specifiable secondary cutting edge and characteristic angle distribution. Optionally, the entire cutting edge (primary, secondary, and chisel edges) can be provided with C1 continuity to eliminate stress concentration points. The mathematical background and modeling are summarized in this study. Experimental drills are produced and tested for verification and demonstration. The presented modeling technique allows subsequent researchers to exactly duplicate the drills, including the thinning/notching drill points, a capability that was previously unavailable. This system is useful for improved drill CAD and CNC software for the design, manufacture, reconditioning, and research of novel point design.

Insights from Meta-Analysis of Recent Exercises

ABSTRACT Oil terminals maintain and assess their oil spill response readiness by conducting drills and exercises in general accordance with the Preparedness for Response Exercise Program (PREP) guidelines; however, they often do not realize the full benefits of the time and effort they invest in their exercise programs. Specifically, the way many terminals conduct and evaluate their drill and exercise programs does not provide an in-depth understanding of the capabilities and competencies of their personnel and their response contractors. URS Corporation (URS) recently performed a meta-analysis of tabletop exercises (TTX), equipment deployment exercises (EDX), and unannounced spill equipment deployment drills (UDD) that we facilitated at terminals around the United States. The meta-analysis was performed as a combined review of the after action reports from the various exercises to identify common lessons learned and areas for improvement. Specifically, the objective of the meta-analysis was to develop recommendations, based on an in-depth understanding of the identified common lessons learned and insights from our exercise facilitators, to enhance or improve terminals' oil spill response performance when implemented in the design of future drills and exercises. Based on our study, URS identified and developed recommendations to address the following areas for improvement: training/exercises did not build on previous efforts; TTX were “walk through” or discussion type of exercises and not conducted in “real time”; UDD were conducted in similar ways each time and did not “stress the system”; exercises and drills did not involve upper level (e.g., regional or corporate) personnel who may have significant roles in the response; terminal personnel did not have relationships with staff of industries, contractors, and/or agencies in their area; terminal personnel were not familiar with the Geographic Response Plans or Area Contingency Plans for their area; and exercise programs and post-exercise reviews and critiques did not effectively assess all 15 response plan components. By implementing the recommendations from our meta-analysis, terminals can expect to obtain significantly greater benefits in terms of competence and confidence to respond to oil spills for a modest investment in additional time, cost, and effort.

THEORETICAL MODEL FOR THE RELATIONSHIP BETWEEN THE NUMBER OF TACKLES A PLAYER ENGAGES IN, TACKLE INJURY RISK AND PERFORMANCE IN RUGBY UNION

BackgroundThe tackle in rugby union is a physical contest between opposing players contending for territory and ball possession. During an 80-minute rugby match, a player will physically engage in the...

Heat generated by dental implant drills during osteotomy-a review: heat generated by dental implant drills.

Osseointegration is the more stable situation and results in a high success rate of dental implants. Heat generation during rotary cutting is one of the important factors influencing the development of osseointegration. To assess the various factors related to implant drills responsible for heat generation during osteotomy. To identify suitable literature, an electronic search was performed using Medline and Pubmed database. Articles published in between 1960 to February 2013 were searched. The search is focused on heat generated by dental implant drills during osteotomy. Various factors related to implant drill such effect of number of blades; drill design, drill fatigue, drill speed and force applied during osteotomies which were responsible for heat generation were reviewed. Titles and abstracts were screened, and literature that fulfilled the inclusion criteria was selected for a full-text reading. The initial literature search resulted in 299 articles out of which only 70 articles fulfils the inclusion criteria and were included in this systematic review. Many factors related to implant drill responsible for heat generation were found. Successful preparation of an implant cavity with minimal damage to the surrounding bone depends on the avoidance of excessive temperature generation during surgical drilling. The relationship between heat generated and implant drilling osteotomy is multifactorial in nature and its complexity has not been fully studied. Lack of scientific knowledge regarding this issue still exists. Further studies should be conducted to determine the various factors which generate less heat while osteotomy such as ideal ratio of force and speed in vivo, exact time to replace a drill, ideal drill design, irrigation system, drill-bone contact area.

Effect of formation strength of lithified deposits on stability of wellbore

Wellbore stability is one of the major problems while drilling oil and gas wells. Shale, in turn, makes up about 75% of drilled formations, and over 70% of the borehole problems are related to shale instability [1] costing the industry, accordingly to conservative estimates, $700 million annually [5]. As it was proven in several studies [6] the shale stability problem is related mainly to penetration of drilling fluid into laminations / fractures (between bedding planes and through the microfractures of shale) causing the mechanical failure and thus the loading of the well with cavings. In other words, the fluid invasion clearly weakens the shale making the shale stability very sensitive to the drilling fluid design. If the drilling fluid weight is too low, the risk of wellbore collapse increases. If drilling fluid weight is too high, drilling fluid invasion into these fractures and subsequent shale weakening makes the wellbore prone to instability. As a way to prevent or minimize the loss of wellbore stability the drilling fluid system includes proper bridging agents together with right drilling practices were proposed. At the same time it was noticed that shale in the same interval and formation reacts differently to drilling process. Some of them showing significant washouts and signs of instability and other stay stable and have in gauge hole. It has been suggested that stability of shale formations affected also by formation strength. And there are boundary values after which formations collapse and significant washouts occur. To prove this assumption the analysis of formation strength of shale was performed. The objective of this paper is to show the impact of formation strength to the stability of the wellbore in shale formations. The paper also provides the relation between thickness of layers and depth of washouts, and the boundary values of formation strength when shale loses the stability.

Experimental evaluation of polycrystalline diamond tool geometries while drilling carbon fiber-reinforced plastics

Polycrystalline diamond (PCD) drills are commonly employed in carbon fiber-reinforced plastic (CFRP) drilling to satisfy hole quality conditions with an acceptable tool life and productivity. Despite their common use in industry, only a small number of studies have been reported on drilling CFRPs with PCD drills. In this study, drilling performances of three different PCD drill designs are investigated experimentally using thrust force, torque, and hole exit quality measurements. Results show that work material properties, drilling conditions, and drill design should all be considered together during the selection of process parameters, and the relationships among these factors are quite complex.

DISC drill and replicate coring system: a new era in deep ice drilling engineering

AbstractThe deep ice sheet coring (DISC) drill and replicate coring system (RCS) were designed and manufactured by Ice Coring and Drilling Services/Ice Drilling Design and Operations group of the University of Wisconsin–Madison. The DISC/RCS is an electromechanical system designed to take 122 mm diameter ice cores from the main borehole and 108 mm diameter replicate ice cores to depths of 4000 m. Detailed design of the DISC drill began in 2003, and the completed drill was tested in Greenland in 2006. During five consecutive field seasons at West Antarctic Ice Sheet (WAIS) Divide, 3405 m of ice core were drilled, setting the US deep ice drilling record. The RCS, based on the DISC drill, was developed and built in 2010/11, tested in Antarctica during the 2011/12 WAIS Divide field season and tested further in Madison, WI, during summer–fall 2012. During the 2012/13 Antarctic field season, the system produced five azimuth and depth-controlled deviations at four target depth levels. A total of 285 m of replicate ice core was recovered in the first coring of its kind. The entire main/replicate ice core, including ductile, brittle and warm ice, had excellent quality and satisfied the needs of the ice science community.

Research and Development on Geological Core Drilling Computer Aided Design System

On the request of the current level of the geological core drilling design, refer to oil drilling design software, a geological core drilling computer aided design system was developed by means of advanced web design technology. The system covers all procedures of geological core drilling design, and presets reference value according to system database information, and automatically draws geological column and borehole columnar section according to the user design information, and finally produces overall and standard design report. The development technology is based on ZK and Hibernate framework with MVC and MVVM model. Consequently, the system will be easy to be used and maintained, and will contribute to the geological core drilling design information exchange and share online.

Developing a hot-water drill system for the WISSARD project: 1. Basic drill system components and design

AbstractA new, clean, hot-water drill system (HWDS) was developed by the Science Management Office, University of Nebraska-Lincoln, for use in the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project to gain access to Subglacial Lake Whillans beneath ∼800 m of ice in West Antarctica. One primary borehole was drilled into the basal ice environment of Subglacial Lake Whillans during the initial field season in 2012/13. This paper describes the process of designing, fabricating, assembling, shipping, testing, commissioning and traversing the WISSARD HWDS leading up to the first scientific use of the system.

Research on Informatization of Geological Drilling Construction Management

Along with the continuous development and global application of computer and network technology, the research and application of information technology of geological drilling construction design and management goes deeper. In the paper, on the basis of analysis on the flow and demand of geological drilling information, the overall scheme of drilling construction informatization is presented, and informatization technological plan of computer aided design and construction management on geological drilling is studied and provided. Carrying out those schemes can significantly improve the level of geological drilling design, construction, and management. The paper has given feasible instructions and pointed out problems on informatization of geological drilling.

Waterworks, a Full-Scale Chemical Exposure Exercise: Interrogating Pediatric Critical Care Surge Capacity in an Inner-City Tertiary Care Medical Center

Pediatric Intensive Care Unit (PICU) resources are overwhelmed in disaster as the need to accommodate influx of critically-ill children is increased. A full-scale chlorine overexposure exercise was conducted by the New York Institute for All Hazard Preparedness (NYIAHP) to assess the appropriateness of response of Kings County Hospital Center's (KCHC's) PICU surge plan to an influx of critically-ill children. The primary endpoint that was assessed was the ability of the institution to follow the PICU surge plan, while secondary endpoints include the ability to provide appropriate medical management. Thirty-six actors/patients (medical students or emergency medicine residents) were educated on presentations and appropriate medical management of patients after a chlorine overexposure, as well as lectures on drill design and expected PICU surge response. Victims presented to the hospital after simulated accidental chlorine overexposure at a public pool. Twenty-two patients with 14 family members needed evaluation; nine of these patients would require PICU admission. Three of nine PICU patients were low-fidelity mannequins. In addition to the 36 actor/patient evaluators, each area had two to four expert evaluators (disaster preparedness experts) to assess appropriateness of global response. Patients were expected to receive standard of care. Appropriateness of medical decisions and treatment was assessed retrospectively with review of electronic medical record. The initial PICU census was three of seven; two of these patients were transferred to the general ward. Of the nine patients that required Intensive Care Unit (ICU) admission, six actor/patients were admitted to the PICU, one was admitted to the Surgical Intensive Care Unit (SICU), one went to the Operating Room (OR), and one was admitted to a monitored-surge general pediatric bed. The remaining 13 actor/patients were treated and released. Medical, nursing, and respiratory staffing in the PICU and the general ward were increased by two main mechanisms (extension of work hours and in-house recruitment of additional staff). Emergency Department (ED) staffing was artificially increased prior to the drill. With the exception of ocular fluid pH testing in patients with ocular pruritus, all necessary treatments were given; however, an unneeded albuterol treatment was administered to one patient. Chart review showed adequate discharge instructions in four of 13 patients. Nine patients without respiratory complaints in the ED were not instructed to observe for dyspnea. All patients were in the PICU or alternate locations within 90 minutes. Discussion The staff was well versed in the major details of KCHC's PICU surge plan, which allowed smooth transition of patient care from the ED to the PICU. The plan provided for a roadmap to achieve adequate medical, nursing, and respiratory therapists. Medical therapy was appropriate in the PICU; however, in the ED, patients with ocular complaints did not receive optimal care. In addition, written discharge instruction and educational material regarding chlorine overexposure to all patients were not consistently provided. The PICU surge plan was immediately accessible through the KCHC intranet; however, not all participants were cognizant of this fact; this decreased the efficiency with which the roadmap was followed. An exaggerated ED staff facilitated evaluation and transfer of patients. During disasters, the ability to surge is paramount and each hospital addresses it differently. Hospitals and departments have written surge plans, but there is no literature available which assesses the validity of said plans through a rigorous, structured, simulated disaster drill. This study is the first to assess validity and effectiveness of a hospital's PICU surge plan. Overall, the KCHC PICU surge plan was effective; however, several deficiencies (mainly in communication and patient education in the ED) were identified, and this will improve future response.

Cutting Force and Temperature Variation in Bone Drilling - A Review

Orthopaedic surgery procedure widely utilizes bone drilling in the work for correcting bone fracture and attaching prosthetics. Clean and accurately positioned holes are desired during bone drilling without damaging the surrounding tissues. However, bone temperature rises during drilling. It is always required to keep the temperature during drilling below 47 °C to avoid thermal osteonecrosis (bone cell death), which might lead to a loose of bone-implant interface. Drill design, drill parameters, and coolant delivery were believed to contribute to heat generation. As complex anisotropic biological tissues, determining the bone temperature during drilling is another issue. Complex mechanical and thermological properties are also other problems to be investigated due to the sensitivity to testing and specimen preparation.

The PLC Control System Design of Radial Drilling

Focus on the disadvantages such as complicated circuit , poor reliability, difficulty troubleshooting and etc of the traditional relay-contactor control system of Z3040 radial drilling machine, the PLC control system design plan was proposed, the hardware and software design of electrical control system included the PLC selection, the I/O terminal assignments, the I/O hardware wiring diagram drawing as well as the PLC ladder program design was completed in this thesis based on control theory analysis of radial drilling machine.

Underbalanced drilling technology with air injection connector

Underbalanced drilling technology has been extended deeply into every corner of the industrial productions and processes. In particular, the technology has a wide range of applications in oil and gas industries for the product design, manufacturing and construction process. In this work, a new air injection connector system has been developed for underbalanced drilling. The system development includes five key issues: original design, manufacturing control, experimental method, on-spot drilling design, and field work point control. The air injection connector system plays an important role and can significantly reduce potential losses during the drilling process.

Pressure-Volume-Temperature Property Determination for Fluids at Extreme Pressures

Pressure-volume-temperature (PVT) properties, more commonly known as density data play an important role in various chemical processes and provide a fundamental database for the development and examination of thermodynamic models. For example, ultradeep oil exploration process requires density data at extreme pressure conditions, which are crucial for the design and optimization of drilling and production equipment. This review discusses the current techniques for high-pressure determination. Three most common techniques, vibrating-body, bellows, and floating-piston, are described in detail with presentation of some typical results and advantages and drawbacks are discussed for each method. Other techniques are also briefly introduced at the end of this review.

Design and Test of Drilling and Completion Experimental System with Supercritical Carbon Dioxide

Supercritical Carbon dioxide (SC-CO2) has many excellent properties, such as high rock-breaking efficiency, strong dissolved performance and good displacement efficiency. It is a high-efficiency fluid to exploit coal-bed methane, shale gas, heavy oil, low permeability reservoirs and other unconventional oil and gas reservoirs. Using SC-CO2 jet to break formation rock assisted the drill bit can get several times the penetration rate of conventional drilling and effectively enhance the oil recovery while achieving an initiative reduction of greenhouse gas by storing the CO2 underground in the proper unconventional reservoirs. The functions and process of drilling and completion experimental system are designed based on the SC-CO2 fluid properties and the actual operation conditions. Tests find that the remote control of the system is reliable, pressurization process is steady, sealing and operating performances are excellent. The system can effectively simulate the actual drilling and completion process with SC-CO2. The rock-breaking performance of SC-CO 2 is much better than high pressure water jet which verifies the application superiority of SC-CO 2 in rock-breaking drilling. The research lays basis for the development of SC- CO2 drilling and completion technology.

The Research of Case Matching Algorithm in Drilling Fluid Design Expert System

In the case-based reasoning in drilling fluid design expert system, it selects the corresponding representation method of attributes and matching algorithm according to the characteristics of drilling fluid system and the formulation. The representation methods of attributes in this article include digital, string and range these three methods, therefore, the corresponding matching algorithms also have nearest-neighbor, string matching and range matching these three algorithms. On this basis, and combined with the single parent genetic algorithm to optimize the initial weights combination, we can get the most optimal and realistic drilling fluid system and formula. This design method can greatly improve the efficiency and accuracy of the drilling fluid formula design.

Long-hole destress blasting for rockburst control during deep underground coal mining

The Lazy Colliery in the Ostrava–Karvina Coalfield of the Upper Silesian Coal Basin adopted modern longwall technology for an underground extraction of coal seam No. 504. This coal seam is located at a cover depth of around 700m. The seam thickness varied from 3.1m to 5.0m in the selected longwall panel. Two overlying coal seams, Nos. 512 and 530 experienced mining at average heights of 58m and 75m, respectively, from the planned working horizon of the seam No. 504. The proposed longwall panel was adversely situated below goaf edges of the workings in these two overlying extracted seams. An analysis of the inter-burden rock mass among these coal seams showed the presence of strong, massive strata of sandstones and conglomerates with uniaxial compressive strength values between 70MPa and 120MPa. The stress is measured at different mining stages by Compact Conical-ended Borehole Monitoring (CCBM). A simple laboratory test of the coal sample found a high value of the ratio of the elastic deformation to the total deformation (>0.8), indicating the energy-storing characteristic (prone to burst/bump) of the coal seam. Under the existing geo-mining conditions of the site a suitable destress blasting (long-hole drilling and blasting) design is adopted to pre-fracture the identified competent strata from both gate roads in advance. The total length of the panel could be extracted without any bump/rockburst after the destress blasting. The efficiency of the adopted destress blasting at the different mining stages is evaluated in terms seismic effect (SE), which is calculated through the available seismic monitoring data and weight of the charged explosive. A systematic adoption of the destress rock blasting led the 300m long longwall panel to be smoothly extracted without any further rockbursts.

Tribo-functional design of double cone drill implications in tool wear during drilling of copper mesh/CFRP/woven ply

This article presents an experimental analysis of drilling using carbide drills on carbon fiber reinforced plastic (CFRP) laminates specially made with copper mesh on one side and woven carbon fabric on the other side using carbide drills. The objective of this study was to improve the machining performance during drilling of sandwiched composite using various dimensions of double cone drill. The drill design in terms of its tribological characteristics (i.e. friction, wear) are analyzed including cutting force, life, chip form and hole quality. Results have shown that double cone drills generated less thrust force compared to standard twist drills. No delamination was found in the holes at high feed rates (above 0.1mm/rev). This could be attributed to the presence of thermoplastic nodules between the layers of the CFRP laminate and the presence of woven fabric ply at the bottom of the laminate. Furthermore a relationship between the feed per cutting edge and the thickness of the thermoplastic layer has been developed to promote the formation of continuous chips during drilling. Finally, SEM observations reveal several damage when standard twist drills were used and less damage was observed with double cone drills. These damaged areas were observed in the plies of fibers oriented at −45° and 90° compared with peripheral cutting speed of the drill.