Topology of Spade Drills for Wood Drilling Operations Part 2: Spade Drill Point Cutting Geometry Analysis

2005 ◽  
Vol 127 (2) ◽  
pp. 310-318
Author(s):  
Hanxin Zhao ◽  
Kornel F. Ehmann
Keyword(s):  
Software Package ◽  
Geometric Model ◽  
Geometric Analysis ◽  
Analysis Procedure ◽  
Angle Distribution ◽  
Cutting Geometry ◽  
Drilling Operations ◽  
Drill Point ◽  
Geometric Elements ◽  
Geometry Analysis

Based on the spade drill point’s mathematical models established in Part 1 of this paper, a detailed methodology for the analysis of the cutting edges and angle distributions along these edges is given. The analysis addresses the most important geometric elements of the bit including the tip, major cutting edge, and the chisel edge profiles, as well as the rake and clearance angle distribution along these cutting edges. In unison, the geometric model of the spade bit and the analysis procedure described in this part of the paper have laid the foundation for a methodology and a software package for a detailed geometric analysis of all relevant cutting mechanics related geometric entities of the drill. This, in turn, constitutes the first prerequisite for assessing the cutting performance of these tools.

Topology of Spade Drills for Wood Drilling Operations, Part 1: Spade Drill Point Geometry Definition

2005 ◽  
Vol 127 (2) ◽  
pp. 298-309
Author(s):  
Hanxin Zhao ◽  
Kornel F. Ehmann
Keyword(s):  
Mathematical Model ◽  
Construction Industry ◽  
Software Package ◽  
Geometric Analysis ◽  
Analytical Models ◽  
Basic Design ◽  
Technical Literature ◽  
Drilling Operations ◽  
Drill Point ◽  
Geometry And Kinematics

Spade bits, widely and routinely used in the construction industry, have not received any attention in the technical literature, yet there is a pressing need to improve the performance of these bits whose basic design has not changed for decades. To facilitate such improvements, a thorough understanding of the geometric, manufacturing, and cutting mechanics aspects of these tools is necessary. In this two-part paper, the point geometry and manufacturing issues will be discussed. To fundamentally understand the spade drill bit’s behavior, a complete mathematical model of its principal topological elements will be established. In conjunction with this model, the corresponding analytical formulations of the geometry and kinematics of the appropriate manufacturing procedures will also be formulated. In unison, these models will lay the foundation for a methodology and a software package for a detailed geometric analysis of all relevant cutting angle distributions and edge profiles of the spade bit. This will facilitate, at a later point, new point developments rooted in rigorous analytical models.

scholarly journals How realistic are painted lightnings? Quantitative comparison of the morphology of painted and real lightnings: a psychophysical approach

2018 ◽  
Vol 474 (2214) ◽  
pp. 20170859 ◽  
Author(s):  
Mark Stromp ◽  
Alexandra Farkas ◽  
Balázs Kretzer ◽  
Dénes Száz ◽  
András Barta ◽  
...  
Keyword(s):  
Software Package ◽  
Relative Length ◽  
Quantitative Comparison ◽  
Angle Distribution ◽  
Morphological Parameters ◽  
Turning Angle ◽  
Local Maxima ◽  
Time Periods ◽  
Short Time ◽  
Number Of Branches

Inspired by the pioneer work of the nineteenth century photographer, William Nicholson Jennings, we studied quantitatively how realistic painted lightnings are. In order to answer this question, we examined 100 paintings and 400 photographs of lightnings. We used our software package to process and evaluate the morphology of lightnings. Three morphological parameters of the main lightning branch were analysed: (i) number of branches N b , (ii) relative length r , and (iii) number of local maxima (peaks) N p of the turning angle distribution. We concluded: (i) Painted lightnings differ from real ones in N b and N p . (ii) The r -values of painted and real lightnings vary in the same range. (iii) 67 and 22% of the studied painted and real lightnings were non-bifurcating ( N b  = 1, meaning only the main branch), the maximum of N b of painted and real lightnings is 11 and 51, respectively, and painted bifurcating lightnings possess mostly 2–4 branches, while real lightnings have mostly 2–10 branches. To understand these findings, we performed two psychophysical experiments with 10 test persons, whose task was to guess N b on photographs of real lightnings which were flashed for short time periods Δ t  = 0.5, 0.75 and 1 s (characteristic to lightnings) on a monitor. We obtained that (i) test persons can estimate the number of lightning branches quite correctly if N b  ≤ 11. (ii) If N b  > 11, its value is strongly underestimated with exponentially increasing difference between the real and estimated numbers. (iii) The estimation is independent of the flashing period Δ t of lightning photos/pictures. (iv) The estimation is more accurate, if skeletonized lightning pictures are flashed, rather than real lightning photos. These findings explain why artists usually illustrate lightnings with branches not larger than 11.

Shell form in the biconvex articulate Brachiopoda: a geometric analysis

Paleobiology ◽  
1980 ◽  
Vol 6 (1) ◽  
pp. 57-76 ◽  
Author(s):  
George R. McGhee
Keyword(s):  
Geometric Model ◽  
Geometric Analysis ◽  
Small Region ◽  
Shell Morphology ◽  
Shell Surface ◽  
Absolute Size ◽  
Shell Form ◽  
Geometric Space ◽  
Biological Optimization ◽  
Area And Volume

Using a geometric model of shell morphology, it is demonstrated that biconvex brachiopods occupy only a small region of the potential geometric space available to organisms with planispiral exoskeletons composed of two articulated valves. Measurements taken for a sample of 324 genera of the articulate orders Pentamerida, Rhynchonellida, Spiriferida, and Terebratulida were analyzed using a simple geometric model of shell form and ontogeny. The frequency distribution of brachiopod shell morphologies exhibited by the four orders represents the biological optimization of the spatial relationships between area and volume. Biconvex brachiopods develop shells which are designed to minimize shell surface area while maximizing internal shell volume. The means by which optimization is achieved is related directly to the effects of increase in absolute size during ontogeny. The boundaries upon shell geometries utilizable by biconvex brachiopods are determined by (1) limitations of articulation, and (2) limitations of surface and volume.

scholarly journals Cartometric analysis of old maps of Czech Lands: map of Bohemia and map of Moravia by Petrus Kaerius

Geografie ◽  
2009 ◽  
Vol 114 (3) ◽  
pp. 230-243
Author(s):  
Tomáš Bayer ◽  
Markéta Potůčková ◽  
Miroslav Čábelka
Keyword(s):  
Software Package ◽  
Reference Data ◽  
Geometric Analysis ◽  
17Th Century ◽  
Data Set ◽  
Old Maps ◽  
Reference Map ◽  
Suitable Reference ◽  
Czech Lands

The article deals with cartographic assessment of two significant cartographic works from the beginning of the 17th century depicting the territory of Czech lands: map of Bohemia and map of Moravia by Petrus Kaerius (* 1571, † 1646). The map of Bohemia by Petrus Kaerius is based on Aretin’s map of Bohemia. The map of Moravia by Petrus Kaerius is a cartographic work derived from the map of Moravia created by Paulus Fabricius (*1519, †1588). To support these facts, cartometric analysis was carried out in both maps by Petrus Kaerius and their assumed originals. The methodology of map assessment is based on geometric analysis of sets of identical points in an old map and a reference map by means of multiquadratic interpolation. The geographic database DMU 25 was chosen as a suitable reference data set. Results of analyses comprising vectors of residuals on identical points, isolines of scale and rotation were visualized in the software package MapAnalyst.

Mechanistic Model for Spade Drills for Wood Drilling Operations, Part 2: Analysis of Spade Bit Geometry and Performance

2003 ◽  
Vol 125 (2) ◽  
pp. 236-244 ◽  
Author(s):  
Hanxin Zhao ◽  
Kornel F. Ehmann
Keyword(s):  
Performance Measures ◽  
Thrust Force ◽  
Simulation Analysis ◽  
Mechanistic Model ◽  
Geometric Model ◽  
Analytical Models ◽  
Force System ◽  
Topological Features ◽  
Drilling Operations ◽  
And Performance

In this part of the paper the analytical models for the prediction of the force system, established in Part 1, in conjunction with a complete geometric model of the spade bit, will be used in a systematic simulation analysis of the spade drill’s performance. The aim of this analysis is to identify the most desirable geometric characteristics of the different topological features of the spade bit that would result in desirable performance measures expressed in terms of reduced torque and thrust force. The obtained results are intended to guide the development of more efficient tools of this type.

A Study of the Drilling Process

1974 ◽  
Vol 96 (4) ◽  
pp. 1207-1215 ◽  
Author(s):  
R. A. Williams
Keyword(s):  
Feed Rate ◽  
Thrust Force ◽  
Three Dimensional ◽  
Drilling Process ◽  
Two Dimensional ◽  
Twist Drill ◽  
Feed Velocity ◽  
Cutting Geometry ◽  
Drill Point ◽  
Finite Thrust

Drilling is a complex three dimensional cutting process yet it is possible to simulate the action of a two flute twist drill with two dimensional models provided consideration is given to the influence of the feed velocity on the cutting geometry at the drill point. Two models of chip formation and an indentation model are developed to simulate the action of the drill point. From these models equations are derived for the prediction of total torque and thrust given the cutting conditions, drill geometry, and an empirical factor which is related to the work material. Computed values of torque and thrust are shown to compare favorably with those obtained from drilling tests on an 0.45 percent C steel. The shape and magnitude of the wear zone about the chisel edge is estimated and it is shown that the observed finite thrust force as the feed rate approaches zero can be attributed to the “cutting” action of the chisel edge.

An Analysis of Drill Geometry for Optimum Drill Design by Computer. Part I—Drill Geometry Analysis

1970 ◽  
Vol 92 (3) ◽  
pp. 647-656 ◽  
Author(s):  
S. Fujii ◽  
M. F. DeVries ◽  
S. M. Wu
Keyword(s):  
Cross Sections ◽  
Digital Computer ◽  
High Speed ◽  
Comprehensive Analysis ◽  
Twist Drill ◽  
Drill Point ◽  
Geometry Analysis ◽  
Drill Design ◽  
Made In

A comprehensive analysis of the twist drill point geometry is made in order that the high-speed digital computer can be used as an aid in the design of a drill. This subject is treated in two parts. In Part I, the drill geometry is analyzed with respect to the drill flute and flank contours by considering cross sections of the drill cut by planes perpendicular to its axis. Since several important drill angles are defined in planes inclined to the drill axis, the analysis is extended to cover the general case where the drill is cut by any plane inclined to its axis.

scholarly journals Study of Geometric Elements for the Proposed Protecting Dam Reservoir in Al-Fat'ha Area, Iraq

2021 ◽  
Vol 318 ◽  
pp. 01009
Author(s):  
Sabbar S. Abdallah ◽  
Bahaa Al-Din R. Ali ◽  
Muhana M. Ahmed
Keyword(s):  
Geometric Analysis ◽  
Maximum Level ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Analysis Method ◽  
Dam Reservoir ◽  
Flood Level ◽  
Operating Level ◽  
Flooded Area ◽  
Geometric Elements

Partially constructed Makhul dam may collapse after the operation due to the geological and geotechnical background of the foundations zone, and the presence of gypsum layers in this zone, Then the construction of Al-Fat'ha protection dam is one of the proposed solutions. The present study used the geometric analysis method to investigate the ability of Al-Fat'ha planned protecting dam to reduce the disasters of Makhul dam break. The new methodology used to derive the geometric elements of the two dams, and analyze the relations between these elements, and then exam the behavior of Al-Fat'ha proposed dam with and without the studied collapse scenarios. Fourteen collapse scenarios suggested for Makhul dam, from the level 140 m above sea level (a.s.l), to the maximum possible flood level 152 m (a.s.l). A mathematical model was derived to predict the level achieved as a response of cumulative storage in the protecting dam reservoir when the collapse of the Makhul dam occurred. The maximum level in the protecting dam reservoir to face the worst collapse scenario is 147 m (a.s.l), when the corresponding accumulated storage in the reservoir is 3414305769 m3. The results of the geometric analysis indicate that the optimum operating level for Al-Fat'ha dam in the operating conditions without Makhul dam collapse is 118.5 m (a.s.l), which corresponds to the capacity (39243587) m3. The total flooded area between the two dams was calculated for each collapse scenario of Makhul dam; it is about 44 km2 for the worst scenario when nine villages on reservoir banks will submerge. Subsequently, the study confirmed the ability of Al-Fat'ha dam reservoir to contain the direct flood wave caused by the collapse of Makhul dam.

scholarly journals Three dimensional gas-dynamic calculation of nozzle block of small flow-rate centripetal turbine

2019 ◽  
Vol 2019 (4) ◽  
pp. 89-95
Author(s):  
Алексей Крюков ◽  
Aleksei Kriukov
Keyword(s):  
Software Package ◽  
Geometric Model ◽  
Three Dimensional ◽  
Tangential Component ◽  
Low Flow ◽  
Turbine Stage ◽  
Dynamic Calculation ◽  
Gas Dynamic ◽  
Ansys Cfx ◽  
Low Consumption

The article describes the low-consumption turbines as reliable, productive, small-sized actuating mechanisms in various units and machines. Experience in production and use of low-cost turbine stages contributes to improving the efficiency along with simplifying and re-ducing the cost of manufacturing of the blades and the stage in general. Improving the efficiency of low-consumption turbines requires solving the problem of aerodynamic improvement of the flow part and the calculated determination of the optimal geometry and operating modes of the impeller flow. One of the innovative ways to improve the design efficiency of low-consumption turbines is the automation of the development process using modern modeling systems based on the developed software systems. Due to the small size of the design, the design calculations of turbine stages of this type have been made in a one-dimensional formulation with the involvement of various analogies with classical stages. Using three-dimensional gas dynamic calculations based on the ANSYS CFX platform will significantly improve the quality of design of flow parts of low-flow turbines. Implementation of three-dimensional gas-dynamic calculation of the nozzle unit using the software package ANSYS CFX low-consumption turbine stage can solve this problem. The geometric model is built using AutoCAD software, the grid is selected, the boundary conditions are set. The values of the experimental coefficients of the nozzle velocity, neck velocity and the tangential component of velocity at the nozzle outlet have been compared with the coefficients obtained when using the software package. There have been built the velocity fields and made conclusions about feasibility of using the ANSYS CFX software package to determine the main parameters of a three-dimensional flow of the turbine stage.

Analysis and Design of a Drill Grinder and Evaluation of Grinding Parameters

1972 ◽  
Vol 94 (4) ◽  
pp. 1157-1163 ◽  
Author(s):  
S. Fujii ◽  
M. F. DeVries ◽  
S. M. Wu
Keyword(s):  
Factorial Design ◽  
Cutting Condition ◽  
Analysis And Design ◽  
Grinding Parameters ◽  
Computer Aided ◽  
Expected Values ◽  
Drill Point ◽  
Geometry Analysis ◽  
Thrust And Torque

A prototype drill grinder was designed and built based on a computer aided drill point geometry analysis. The new grinder controls all essential drill point grinding parameters. The new grinder was evaluated by grinding drills, measuring their point geometry parameters, and comparing these measurements with their expected values. The effects of five parameters, consisting of three grinding and two cutting condition parameters, on the drill thrust and torque are determined by an experiment using a two-level factorial design.

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