The Parametric Resonance Instability in a Drilling Process

2007 ◽  
Vol 74 (5) ◽  
pp. 958-964 ◽  
Author(s):  
Bo-Wun Huang ◽  
Jao-Hwa Kuang
Keyword(s):  
High Speed ◽  
Multiple Scales ◽  
Thrust Force ◽  
Dynamic Instability ◽  
Work Piece ◽  
Drilling Process ◽  
Drilling Depth ◽  
High Speed Drilling ◽  
Instability Regions ◽  
Multiple Scales Perturbation Method

This study investigates dynamic instability in a high-speed drilling process. A pretwisted beam is used to simulate the drill. The time-dependent nature of the thrust force and the drilling depth is considered in the equation of motion of the drill. A moving Winkler-type elastic foundation assumption is applied to the drill tip to approximate the time-varying boundary conditions in the drilling process. Galerkin’s method is used to formulate the characteristic equation in a discrete form. The variation of the instability regions of the drill system is solved and analyzed by employing the multiple-scales perturbation method. The numerical results indicate that the unstable regions suddenly enlarge and shift toward a lower frequency when the drill first contacts the work piece. The effects of the rotational speed, pretwisted angle, and thrust force of the drill on the variation of the dynamic instability in high-speed drilling are also studied and are found to be highly influential.

Dynamic Instability in a High Speed Drilling Process

2005 ◽  
Author(s):  
Bo-Wun Huang ◽  
Jao-Hwa Kuang
Keyword(s):  
High Speed ◽  
Multiple Scales ◽  
Thrust Force ◽  
Dynamic Instability ◽  
Work Piece ◽  
Drilling Process ◽  
Drilling Depth ◽  
High Speed Drilling ◽  
Spinning Speed ◽  
The Galerkin Method

The variation of dynamic instability in a high speed drilling process was investigated in this article. A pre-twisted beam is used to simulate the drill. The time dependent thrust force and drilling depth are considered in the equation of motion. A moving Winkler-Type elastic foundation assumption is employed to the drill tip to approximate the time varying boundary conditions in the drilling process. The Galerkin method is used to formulate the characteristic equation in a discrete form. The variation of instability regions of the drill system is solved and analyzed by employing the multiple scales perturbation method. Numerical results indicate that unstable regions are enlarged and shifted toward a lower frequency suddenly at the moment when the drill attaches the work piece. The effects of spinning speed, pre-twisted angle and thrust force of the drill on the variation of the dynamic instability in a high speed drilling process are also studied.

Dynamic characteristics of a drill in the drilling process

2003 ◽  
Vol 217 (2) ◽  
pp. 161-167 ◽  
Author(s):  
B W Huang
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Thrust Force ◽  
Time Dependent ◽  
Drilling Process ◽  
Improve Quality ◽  
Vibration Model ◽  
High Speed Drilling ◽  
Spinning Speed ◽  
Twisted Beam

The dynamic characteristics of high-speed drilling were investigated in this study. To improve quality and produce a higher production rate, the dynamic characteristics of the drilling process need to be studied. A pre-twisted beam is used to simulate the drill. The moving Winkler-type elastic foundation is used to approximate the drilling process. A time-dependent vibration model for drilling is presented. The spinning speed, pre-twisted angle and thrust force effects of the drill are considered. The numerical analysis indicates that the natural frequency is suddenly reduced as the drill moves into a workpiece.

scholarly journals Biological Drilling: Implant Site Preparation in a Conservative Manner and Obtaining Autogenous Bone Grafts

2018 ◽  
Vol 22 (2) ◽  
pp. 98-101 ◽  
Author(s):  
Eduardo Anitua
Keyword(s):  
Cell Growth ◽  
High Speed ◽  
Bone Cells ◽  
Bone Grafts ◽  
Autogenous Bone ◽  
Drilling Process ◽  
Drilling Depth ◽  
Low Speed ◽  
Aspiration System ◽  
High Speed Drilling

SummaryBackground/Aim: The drilling process for insertion of an implant should be as conservative as possible, as not to damage the future implant bed. If this drilling is conservative additional bone can be obtained to be used afterwards, during the same surgery, as bone graft particulate if needed. The objective of this study was to evaluate the efficiency of a biological low-speed drilling and to analyse the bone obtained in order to ascertain viability and vitality of the contained bone cells. Also, the bone obtained from the low-speed drilling was compared with bone obtained with high speed drilling and irrigation, collected through a filter in aspiration system.Material and Methods: In this pilot study, samples of biological drilling (low speed without irrigation) were collected in five patients undergoing implant surgery. In the same patients a high speed drilling with irrigation was also used. Bone of the drilling was collected through a filter in the aspiration system. Subsequently the samples were analysed by conventional histology and cultivated in order to observe cell growth.Results: The samples of bone obtained by biological drilling showed live cells in the conventional optical microscopy and cell growth after cultivation. The bone obtained with drilling at high revolutions showed no living cells and no cell growth after cultivation.Conclusions: The biological drilling at low speed offered two advantages compared to drilling at high speed with irrigation. The first of these is the perfect control of the drilling depth as the marks of the burs are visible during drilling; the second is possibility of collection of a large number of viable particulate bone grafts without increasing time and complexity of the surgery, which allows immediate augmentation of bone if needed.

Effect of Periodic Drilling Force on Instability in a Drilling Process

2005 ◽  
Vol 219 (8) ◽  
pp. 733-742 ◽  
Author(s):  
B W Huang ◽  
H K Kung ◽  
A W L Yao
Keyword(s):  
Numerical Analysis ◽  
Thrust Force ◽  
Dynamic Instability ◽  
Drilling Process ◽  
Twist Drill ◽  
Unstable Condition ◽  
Drilling Force ◽  
Cutting Geometry ◽  
Drilling Quality ◽  
Spinning Speed

The periodic drilling force effect on the dynamic instability of a drill in a drilling process was investigated. This investigation involves the cutting geometry drilling force from the two active parts of a twist drill subjected to small fluctuations during the drilling process. Theoretically, at some drilling force, this small drilling force fluctuation may lead the system into a dynamically unstable condition. Most hole location errors, reaming, and drill fractures occur in this unstable drilling process phase. The dynamic instability in a drilling process is an important issue in increasing the drilling quality and production rate. In this article, a pretwisted beam with a moving Winkler-type elastic foundation is used to simulate the drill and drilling process. Numerical analysis indicates that the unstable regions are enlarged and shifted to a lower frequency suddenly as the drill bites into a workpiece. It is also observed that the thrust force, spinning speed, and pretwisted angle effects drastically change the dynamic instability of drilling.

scholarly journals Design and Fabrication of Friction Stir Welding Machine

2018 ◽  
Vol 207 ◽  
pp. 03022
Author(s):  
Jithin Ambarayil Joy ◽  
Muhammad Sajjad ◽  
Dong-Won Jung
Keyword(s):  
Friction Stir Welding ◽  
Mass Production ◽  
High Speed ◽  
Work Piece ◽  
Production Time ◽  
Time Production ◽  
Friction Stir ◽  
Welding Machine ◽  
High Speed Drilling ◽  
Working Principle

The aim of the project is to manufacture a welding machine which simplifies the work and improve the accuracy. The working principle of this machine is different other that of other welding machine. The aluminum work piece is held in the vice. The two pieces of aluminum work piece is welded with the help high speed drilling head with friction tool. The working principle is very easy and at the same time production time is very much reduced. This machine is best suitable for mass production

Experimental Research on Microburrs of High Speed Drilling of PCB Using Microdrill

2012 ◽  
Vol 497 ◽  
pp. 215-219 ◽  
Author(s):  
Xiao Hu Zheng ◽  
Zhi Qiang Liu ◽  
Cheng Yong Wang ◽  
Qing Long An ◽  
Ming Chen
Keyword(s):  
High Speed ◽  
Copper Foil ◽  
Great Influence ◽  
Burr Formation ◽  
Drilling Process ◽  
Fiber Plastic ◽  
High Speed Drilling ◽  
Micro Hole ◽  
Three Stages ◽  
Exit Burr

Microburrs have great influence on printed circuit board’s quality. PCB is composed of glass fiber plastic reinforcement material and copper foil. The PCB microburrs are generated in copper foil drilling process. These burrs are generated by copper extrusion and accumulation around the micro-hole. Enter burr and exit burr is quite different. Enter burrs are lower than exit burrs. The burr formation experienced three stages: First, Copper foil extrudes with the feed of microdrill; Second, Most of the Materials are cut off by drill tip and the rest of material; At last, rollover burrs appear when drill enters or exits uncut chip rolls.

Drilling Force and Temperature of Bone by Surgical Drill

2010 ◽  
Vol 126-128 ◽  
pp. 779-784 ◽  
Author(s):  
Yi Xin Yang ◽  
Cheng Yong Wang ◽  
Zhe Qin ◽  
Lin Lin Xu ◽  
Yue Xian Song ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Feed Rate ◽  
High Speed ◽  
Drill Bit ◽  
Twist Drill ◽  
Drilling Speed ◽  
Drilling Force ◽  
Drilling Depth ◽  
High Speed Drilling ◽  
Lower Temperature

Drilling force and temperature of tibia at the high speed drilling for improving the design of surgical drills are very important. In this paper we describe experiments using pig tibia bones, measuring the drilling force and temperature of a new design of drill bit and compare the results against a twist drill. The result shows that the drilling force and temperature are affected by the feed rate and drilling speed, which vary with the drilling depth into the bone. The new surgical drill with three top cutting edges can achieve lower temperature below 47oC and lower drilling force than with the stainless steel twist drill and carbide twist drill.

scholarly journals Determining Optimum Electro Discharge Machining Parameters for Drilling of a Small Hole by Utilizing Taguchi Method

2014 ◽  
Vol 564 ◽  
pp. 481-487 ◽  
Author(s):  
M.K.A.M. Ariffin ◽  
Hazami B. Che Hussain ◽  
Saiful Bahri Mohamed ◽  
S. Sulaiman
Keyword(s):  
Taguchi Method ◽  
Process Parameters ◽  
High Speed ◽  
Removal Rate ◽  
Copper Electrode ◽  
Small Hole ◽  
Work Piece ◽  
Drilling Process ◽  
Machining Parameters ◽  
Electro Discharge Machining

Electro discharge machining (EDM) is a process that uses an electric sparks to generate the high temperature and melt the workpiece. One of the EDM process is drilling. In EDM drilling, an electro thermal mechanism is introduced between the electrode and work piece to create the hole. The hole size is dependent on the diameters of electrode used during the drilling process. The present study performs Taguchi method to investigate the optimal process parameters for high-speed EDM super drill machine that is used to make a small hole. The workpiece used is made from titanium alloy (Ti-6: ASTM B348 Grade 5) and the copper electrode is 2.0 mm in diameter. In this experiment, the process parameters that were selected to be optimised are: current pulse off, maximum current and standard voltage levels. An orthogonal array L9 were employed to analyze the hole enlargement and material removal rate (MRR) depending on 2.0 mm diameter hole penetration. The optimum EDM parameters for hole making process was established and verified with the acquired results.

Drilling Force in High Speed Drilling Carbon Fibre Reinforced Plastics (CFRP) Using Half Core Drill

2010 ◽  
Vol 102-104 ◽  
pp. 729-732 ◽  
Author(s):  
Dong Liu ◽  
Hong Hai Xu ◽  
Chao Ying Zhang ◽  
Hong Juan Yan
Keyword(s):  
High Speed ◽  
Thrust Force ◽  
Air Cooling ◽  
Carbide Tool ◽  
Drilling Force ◽  
Drilling Tool ◽  
Reinforced Plastics ◽  
Drilling Tools ◽  
High Speed Drilling ◽  
Carbon Fibre Reinforced Plastics

The Composites are difficult machining materials which widely used in aerospace industry due to their excellent mechanical properties. Tool wear and delamination are considered the major concern in manufacture the parts and assembly. The thrust force and torque affect the tool life and delamination mostly. This paper investigated the drilling force and torque of carbon fibred composite with carbide drilling tools and half core drilling tool. The experiments were carried out under air cooling cutting conditions and the drilling force using carbide tool and half core tool were compared and the experimental results indicated that the drilling forces using half core drill were smaller than that of using carbide tool.

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