Force Modeling for Generic Profile of Drills

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Kumar Sambhav ◽  
Puneet Tandon ◽  
Sanjay G. Dhande
Keyword(s):  
Cutting Forces ◽  
Arbitrary Point ◽  
Experimental Results ◽  
Tool Geometry ◽  
Force Model ◽  
Force Modeling ◽  
Surface Patches ◽  
Drill Point ◽  
Twist Drills ◽  
Secondary Cutting

The paper presents a methodology to model the cutting forces by twist drills with generic point geometry. A generic definition of point geometry implies that the cutting lips and the relief surfaces can have arbitrary shapes. Such geometry is easily modeled using Non Uniform Rational B-Spline (NURBS) surface patches which give sufficient freedom to the tool designer to alter the tool geometry. The drill point has three cutting zones: primary cutting lips, secondary cutting lips, and the indentation zone at the center of chisel edge. At the indentation zone, the drill extrudes the workpiece, while at the cutting lips, shearing takes place. At primary cutting lip, the cutting is oblique while at secondary cutting lip, it is predominantly orthogonal. Starting from a computer-aided geometric design of a fluted twist drill with arbitrary point profile, the cutting forces have been modeled separately for all the three cutting zones. The mechanistic method has been employed wherever applicable to have a good correlation between the analytical and the experimental results. The force model has been calibrated and validated for conical drills. Then the model has been evaluated for a drill ground with curved relief surfaces. The theoretical and experimental results are found out to be in good conformity.

Analytical cutting force modelling of micro-slot grinding considering tool-workpiece interactions on both primary and secondary tool surfaces

2021 ◽  
pp. 1-43
Author(s):  
Ashwani Pratap ◽  
Karali Patra
Keyword(s):  
Cutting Force ◽  
Cutting Forces ◽  
Orthogonal Cutting ◽  
Surface Interactions ◽  
Surface Interaction ◽  
Edge Density ◽  
Force Model ◽  
Height Distribution ◽  
Force Modeling ◽  
Tool Surface

Abstract This work presents an analytical cutting force modeling for micro-slot grinding. Contribution of the work lies in the consideration of both primary and secondary tool surface interactions with the work surface as compared to the previous works where only primary tool surface interaction was considered during cutting force modeling. Tool secondary surface interaction with workpiece is divided into two parts: cutting/ ploughing by abrasive grits present in exterior margin of the secondary tool surface and sliding/adhesion by abrasive grits in the inner margins of the secondary tool surface. Orthogonal cutting force model and indentation based fracture model is considered for cutting by both the abrasives of primary tool surface and the abrasives of exterior margin on the secondary surface. Asperity level sliding and adhesion model is adopted to solve the interaction between the workpiece and the interior margin abrasives of secondary tool surface. Experimental measurement of polycrystalline diamond tool surface topography is carried out and surface data is processed with image processing tools to determine the tool surface statistics viz., cutting edge density, grit height distribution and abrasive grit geometrical measures. Micro-slot grinding experiments are carried out on BK7 glass at varying feed rate and axial depths of cut to validate the simulated cutting forces. Simulated cutting forces considering both primary and secondary tool surface interactions are found to be much closer to the experimental cutting forces as compared to the simulated cutting forces considering only primary tool surface interaction.

Integration of On-Machine Measurements in the Force Modeling for Machining of Advanced Nickel-Based Superalloys

2012 ◽  
Author(s):  
Andrew Henderson ◽  
Cristina Bunget ◽  
Thomas Kurfess
Keyword(s):  
Cutting Forces ◽  
Gas Turbines ◽  
High Strength ◽  
Extreme Environment ◽  
Subsurface Damage ◽  
Process Models ◽  
Force Model ◽  
Jet Engines ◽  
Part Quality ◽  
Force Modeling

Nickel-based superalloys are specially designed for applications where high strength, creep resistance, and oxidation resistance are critical at high temperatures. Many of their applications are the hot gas sections of turbo-machinery (e.g. jet engines and gas turbines). With greater demands on the performance and efficiency of these types of machines, the firing temperatures are reaching higher levels and nickel-based superalloys are being utilized more because of their excellent mechanical qualities at extreme temperatures. However, the properties that make them attractive for these applications present difficult challenges for the manufacture, particularly machining, of the components that are made from these materials. Considering the extreme environment that these components operate in, part quality, in particular surface quality, is paramount. The damage and stresses introduced to the surfaces of these components during manufacture needs to be well understood and controlled in order to ensure that premature component and machine failures do not occur. With improved process models and on-machine measurement capabilities, the in-process cutting forces and temperatures can be better understood and therefore subsurface damage can be better controlled. Since cutting forces and temperatures are direct contributors to subsurface damage, better control of these aspects would then lead to better control of subsurface damage. This paper discusses the use of on-machine touch probes to measure wear on milling tools and using those measurements to update a mechanistic force model for more accurate prediction of the cutting forces incurred during the milling of nickel-based superalloys.

scholarly journals A Mathematical Modeling to Predict the Cutting Forces in Microdrilling

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Haoqiang Zhang ◽  
Xibin Wang ◽  
Siqin Pang
Keyword(s):  
Mathematical Modeling ◽  
Cutting Forces ◽  
Chip Thickness ◽  
Cutting Edge ◽  
Force Model ◽  
Cutting Mechanism ◽  
Line Field ◽  
Slip Line Field ◽  
Cutting Model ◽  
Secondary Cutting

In microdrilling, because of lower feed, the microdrill cutting edge radius is comparable to the chip thickness. The cutting edges therefore should be regarded as rounded edges, which results in a more complex cutting mechanism. Because of this, the macrodrilling thrust modeling is not suitable for microdrilling. In this paper, a mathematical modeling to predict microdrilling thrust is developed, and the geometric characteristics of microdrill were considered in force models. The thrust is modeled in three parts: major cutting edges, secondary cutting edge, and indentation zone. Based on slip-line field theory, the major cutting edges and secondary cutting edge are divided into elements, and the elemental forces are determined by an oblique cutting model and an orthogonal model, respectively. The thrust modeling of the major cutting edges and second cutting edge includes two different kinds of processes: shearing and ploughing. The indentation zone is modeled as a rigid wedge. The force model is verified by comparing the predicted forces and the measured cutting forces.

On the Optimized Design of Broaching Tools

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
A. Hosseini ◽  
H. A. Kishawy
Keyword(s):  
Cutting Forces ◽  
Cutting Tool ◽  
Metal Removal ◽  
Removal Rate ◽  
Geometric Model ◽  
Design Procedure ◽  
Tool Geometry ◽  
Manufacturing Cost ◽  
Force Model ◽  
Optimized Design

Among the cutting tools that are utilized in industry broaching tools are the most expensive ones. Unlike other machining operations such as milling and turning in which a cutting tool can be used for producing a variety of shapes, the broaching tools are uniquely designed depending on the desired profile to be produced on the workpiece. Consequently, the shape of broaching tools may be altered from one case to the others. This shape can be a simple keyway or a complicated fir tree on a turbine disk. Hence, a proper design of the broaching tools has the highest priority in broaching operation. Every single feature of these expensive tools must be accurately designed to increase productivity, promote part quality and reduce manufacturing cost. A geometric model of the cutting tool and a predictive force model to estimate the cutting forces are two fundamental requirements in simulation of any machining operation. This paper presents a geometric model for the broaching tools and a predictive force model for broaching operations. The broaching tooth is modeled as a cantilevered beam and the cutting forces are predicted based on the energy spent in the cutting system. A design procedure has been also developed for identification of the optimized tool geometry aiming to achieve maximum metal removal rate (MRR) by considering several physical and geometrical constraints.

scholarly journals Force Prediction in Ultrasonic Vibration-Assisted Milling

2019 ◽  
Author(s):  
Yixuan Feng ◽  
Fu-Chuan Hsu ◽  
Yu-Ting Lu ◽  
Yu-Fu Lin ◽  
Chorng-Tyan Lin ◽  
...  
Keyword(s):  
Ultrasonic Vibration ◽  
Cutting Forces ◽  
Orthogonal Cutting ◽  
Chip Thickness ◽  
Tool Geometry ◽  
Force Model ◽  
Type I ◽  
Vibration Displacement ◽  
Milling Forces ◽  
Instantaneous Uncut Chip Thickness

Force reduction is one of the most important benefit of applying ultrasonic vibration on milling. However, most of studies so far are limited to experimental investigation. In the current study, an analytical predictive model on cutting forces in ultrasonic vibration-assisted milling is proposed. The three types of tool-workpiece criteria are considered based on the instantaneous position and velocity of tool center. Type I criterion indicates that there is no contact if the instantaneous velocity is opposite to tool rotation direction. Type II criterion checks whether the vibration displacement is larger than the instantaneous uncut chip thickness. Type III criterion considers the overlaps between current and previous tool paths due to vibration. If none of these criteria is satisfied, milling forces are nonzero. Then the calculation is performed by transforming milling and tool geometry configuration to orthogonal cutting at each instant. The orthogonal cutting forces are predicted through the exhaustive search of shear angle and calculation of shear flow stress on tool-chip interface. The axial force is then calculated based on tool geometry, and the milling forces in feed, cutting, and axial directions are calculated after coordinate transformation. The proposed predictive force model in ultrasonic vibration-assisted milling is validated through comparison to experimental measurements on Aluminum alloy 2A12. The predicted values are able to match the measured milling forces with high accuracy of average difference of 13.6% in feed direction and 13.8% in cutting direction.

Positional Accuracy of Holes When Drilling in Inclined Workpiece Surfaces Part 1: Experimental Results

1994 ◽  
Vol 208 (2) ◽  
pp. 129-139 ◽  
Author(s):  
J Kaminski ◽  
R Crafoord
Keyword(s):  
Cutting Forces ◽  
Experimental Results ◽  
Positional Accuracy ◽  
Penetration Process ◽  
Twist Drills

The influence of cutting forces on hole positional deviation when drilling with twist drills in workpiece surfaces of 5° inclination and horizontal surfaces has been investigated. An approach to explain the drill tip wandering phenomena is presented. Variations in cutting forces were also investigated when drilling in workpieces of different materials and different feedrates with standard as well as short drills. Results of this investigation show that hole positional deviation has an obvious connection to cutting forces. The standard and the short drills show different wandering paths during the penetration process. Standard drills wander down the slope, while the short ones first move downwards and later begin a motion upwards.

scholarly journals Finite element simulation and experimental validation of the effect of tool wear on cutting forces in turning operation

2019 ◽  
Vol 23 (1) ◽  
pp. 297-302 ◽  
Author(s):  
S. Sai Venkatesh ◽  
T. A. Ram Kumar ◽  
A. P. Blalakumhren ◽  
M. Saimurugan ◽  
K. Prakash Marimuthu
Keyword(s):  
Finite Element ◽  
Tool Wear ◽  
Cutting Forces ◽  
Metal Cutting ◽  
Damage Model ◽  
Friction Model ◽  
Material Behavior ◽  
Experimental Results ◽  
Tool Geometry ◽  
Work Piece

Abstract Machining is the most widely used process in manufacturing, and tool wear plays a significant role in machining efficiency and effectiveness. There is a continuous requirement to manufacture high-quality products at a lower cost. Many past researches show that variations in tool geometry affect the cutting forces significantly. The increase in cutting forces leads to excessive vibrations in the system, giving a poor surface finish to the machined product. In this work, a 2D coupled thermo-mechanical model is developed using Abaqus/Explicit to predict the cutting forces during turning of mild steel. Johnson–Cook material model along with damage model has been used to define the material behavior. Coulomb’s friction model is considered for defining the interaction between the tool and the work piece. Metal cutting process is simulated for different sets of cutting conditions and compared with experimental results. The finite element method results correlate well with the experimental results.

Optimization Design of Drawbead in Drawing Tools of Autobody Cover Panel

2002 ◽  
Vol 124 (2) ◽  
pp. 278-285 ◽  
Author(s):  
Gang Liu ◽  
Zhongqin Lin ◽  
Youxia Bao
Keyword(s):  
Optimization Algorithm ◽  
Optimization Design ◽  
Design Method ◽  
Experimental Results ◽  
Hybrid Optimization ◽  
Force Model ◽  
Hybrid Optimization Algorithm ◽  
Design Plan ◽  
Formed Part ◽  
Restraining Force

In the tooling design of autobody cover panels, design of drawbead will affect the distribution of drawing restraining force along mouth of dies and the relative flowing velocity of the blank, and consequently, will affect the distributions of strain and thickness in a formed part. Therefore, reasonable design of drawbead is the key point of cover panels’ forming quality. An optimization design method of drawbead, using one improved hybrid optimization algorithm combined with FEM software, is proposed in this paper. First, we used this method to design the distribution of drawbead restraining force along the mouth of a die, then the actual type and geometrical parameters of drawbead could be obtained according to an improved drawbead restraining force model and the improved hybrid optimization algorithm. This optimization method of drawbead was used in designing drawing tools of an actual autobody cover panel, and an optimized drawbead design plan has been obtained, by which deformation redundancy was increased from 0% under uniform drawbead control to 10%. Plastic strain of all area of formed part was larger than 2% and the minimum flange width was larger than 10 mm. Therefore, not only better formability and high dent resistance were obtained, but also fine cutting contour line and high assembly quality could be obtained. An actual drawing part has been formed using the optimized drawbead, and the experimental results were compared with the simulating results in order to verify the validity of the optimized design plan. Good agreement of thickness on critical areas between experimental results and simulation results proves that the optimization design method of drawbead could be successfully applied in designing actual tools of autobody cover panels.

ANISOTROPIC CUTTING FORCE CHARACTERISTICS IN MILLING OF MARAGING STEEL PROCESSED THROUGH SELECTIVE LASER MELTING

2021 ◽  
pp. 1-16
Author(s):  
Shoichi Tamura ◽  
Takashi Matsumura ◽  
Atsushi Ezura ◽  
Kazuo Mori
Keyword(s):  
Additive Manufacturing ◽  
Cutting Force ◽  
Maraging Steel ◽  
Selective Laser Melting ◽  
Cutting Forces ◽  
Manufacturing Process ◽  
Laser Scanning ◽  
Force Model ◽  
Laser Melting ◽  
Scanning Direction

Abstract Additive manufacturing process of maraging steel has been studied for high value parts in aerospace and automotive industries. The hybrid additive / subtractive manufacturing is effective to achieve tight tolerances and surface finishes. The additive process induces anisotropic mechanical properties of maraging steel, which depends on the laser scanning direction. Because anisotropy in the workpiece material has an influence on the cutting process, the surface finish and the dimension accuracy change according to the direction of the cutter feed with respect to the laser scanning direction. Therefore, the cutting parameters should be determined to control the cutting force considering material anisotropy. The paper discusses the cutting force in milling of maraging steel stacked with selective laser melting, as an additive manufacturing process. Anisotropic effect on the cutting forces is proved with the changing rate of the cutting force in milling of the workpieces stacked by repeating laser scanning at 0/90 degrees and 45/-45 degrees. The cutting forces, then, are analyzed in the chip flow models with piling up of orthogonal cuttings. The force model associates anisotropy with the shear stress on the shear plane. The changes in the cutting forces with the feed direction are discussed in the cutting tests and analysis.

Statistical Cutting Force Model for Orthogonal Cutting of Polytetrafluoroethylene (PTFE) Composites

2013 ◽  
Author(s):  
Felicia Stan ◽  
Daniel Vlad ◽  
Catalin Fetecau
Keyword(s):  
Friction Coefficient ◽  
Cutting Force ◽  
Feed Rate ◽  
Normal Force ◽  
Polynomial Regression ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Tool Geometry ◽  
Force Model

This paper presents an experimental investigation of the cutting forces response during the orthogonal cutting of polytetrafluoroethylene (PTFE) and PTFE-based composites using the Taguchi method. Cutting experiments were conducted using the L27 orthogonal array and the effects of the cutting parameters (feed rate, cutting speed and rake angle) on the cutting force were analyzed using the S/N ratio response and the analysis of variance (ANOVA). Statistical models that correlate the cutting force with process variables were developed using ANOVA and polynomial regression. The variation of the apparent friction coefficient was analyzed with respect to tool geometry and the cutting process. The results indicated that cutting and thrust forces increase with increasing feed rate, and decrease with increasing rake angles from negative to positive values and increasing cutting speed. A power law relationship between the apparent friction coefficient and the normal force exerted by the chip on the tool-rake face was identified, the former decreasing with an increasing normal force.

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