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.

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.

Assessment of Plasma Enhanced Machining for Improved Machinability of Inconel 718

1997 ◽  
Vol 119 (1) ◽  
pp. 125-129 ◽  
Author(s):  
J. W. Novak ◽  
Y. C. Shin ◽  
F. P. Incropera
Keyword(s):  
Experimental Study ◽  
Surface Roughness ◽  
Tool Life ◽  
Cutting Forces ◽  
Inconel 718 ◽  
Experimental Results ◽  
Hybrid Machining ◽  
Machining System ◽  
Conventional Machining

An experimental study has been performed to assess the feasibility of using a hybrid machining system to improve the machinability of Inconel 718. An assembled plasma enhanced machining (PEM) system is described, and experimental results obtained from both conventional and plasma enhanced machining of Inconel 718 are compared. Several advantages of PEM over conventional machining are demonstrated, including improvement of surface roughness, lower cutting forces and extended tool life.

Matrix Representation and Prediction of Three-Dimensional Cutting Forces

1977 ◽  
Vol 99 (4) ◽  
pp. 828-834 ◽  
Author(s):  
J. A. Kirk ◽  
D. K. Anand ◽  
C. McKindra
Keyword(s):  
Cutting Forces ◽  
Metal Cutting ◽  
Present Model ◽  
Cutting Tool ◽  
Matrix Representation ◽  
Three Dimensional ◽  
Experimental Results ◽  
Analytical Models ◽  
Two Dimensional ◽  
The Matrix

Matrix geometry techniques are applied to predicting three-dimensional cutting forces. In the present model a specific cutting plane is located and two-dimensional metal cutting theory is applied. Force predictions in this plane are then matrix transformed to three orthogonal forces acting on the cutting tool. Experimental results show the matrix model accurately predicts three-dimensional cutting forces in turning of long slender workpieces. Experimental results are also compared to other analytical models described in the literature.

Finite Element Simulation of Cutting Forces in Turning Ti6Al4V Using DEFORM 3D

2013 ◽  
Author(s):  
Kosaraju Satyanarayana ◽  
Anne Venu Gopal ◽  
Popuri Bangaru Babu
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Cutting Forces ◽  
Experimental Results ◽  
Shear Friction ◽  
Shear Friction Factor ◽  
Deform 3D

Titanium alloys are widely used in aerospace industry due to their excellent mechanical properties though they are classified as difficult to machine materials. As the experimental tests are costly and time demanding, metal cutting modeling provides an alternative way for better understanding of machining processes under different cutting conditions. In the present work, a finite element modeling software, DEFORM 3D has been used to simulate the machining of titanium alloy Ti6Al4V to predict the cutting forces. Experiments were conducted on a precision lathe machine using Ti6Al4V as workpiece material and TiAlN coated inserts as cutting tool. L9 orthogonal array based on design of experiments was used to evaluate the effect of process parameters such as cutting speed and feed with a constant depth of cut 0.25 mm and also the tool geometry such as rake angle on cutting force and temperature. These results were then used for estimation of heat transfer coefficient and shear friction factor constant, which are used as boundary conditions in the process of simulation. Upon simulations a relative error of maximum 9.07% was observed when compared with experimental results. A methodology was adopted to standardize these constants for a given process by taking average values of shear friction factor and heat transfer coefficient, which are used for further simulations within the range of parameters used during experimentation. A maximum error of 9.94% was observed when these simulation results are compared with that of experimental results.

Experimental Analysis of the Effect of Cutting Conditions on the Initial Penetration in Drilling: A Comparative Study Between Conventional and Split Chisel Drills

2009 ◽  
Author(s):  
Sungwoo Park ◽  
Issam Abu-Mahfouz ◽  
Amit Banerjee
Keyword(s):  
Time Domain ◽  
Drilling Process ◽  
Drill Bit ◽  
Penetration Process ◽  
Initial Penetration ◽  
Split Point ◽  
The Time Domain ◽  
Twist Drills ◽  
Skewness And Kurtosis ◽  
Peak Value

To improve the performance and the capability of the drilling process, it is necessary to understand the mechanics of drilling. In particular, drill bit vibrations lead to undesirable effects such as chatter, hole location and roundness errors. In this study, the wandering motion during initial penetration in drilling is experimentally investigated. Four quantities, namely, mean, peak-to-peak value, skewness, and kurtosis are calculated for the time-domain orbital signals. The orbital signals were obtained using proximity probes. The drilling was performed in plates of aluminum, brass, steel, and stainless steel using conventional point and split-chisel symmetrical twist drills. The conventional and split-point drills show different wandering paths during the penetration process. In general, split-point drills produced larger size orbits with more chatter during initial penetration, but showed better centering. On the other hand, conventional drills were found to produce holes that were more offset with smaller size and smoother wandering motion around the actual centers.

scholarly journals Numerical and experimental investigation of Johnson–Cook material models for aluminum (Al 6061-T6) alloy using orthogonal machining approach

2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879779 ◽  
Author(s):  
Sohail Akram ◽  
Syed Husain Imran Jaffery ◽  
Mushtaq Khan ◽  
Muhammad Fahad ◽  
Aamir Mubashar ◽  
...  
Keyword(s):  
Coefficient Of Friction ◽  
Cutting Forces ◽  
High Speed ◽  
Material Model ◽  
Material Behavior ◽  
Experimental Results ◽  
Model Parameters ◽  
Al 6061 ◽  
Orthogonal Machining ◽  
Cutting Speeds

This research focuses on the study of the effects of processing conditions on the Johnson–Cook material model parameters for orthogonal machining of aluminum (Al 6061-T6) alloy. Two sets of parameters of Johnson–Cook material model describing material behavior of Al 6061-T6 were investigated by comparing cutting forces and chip morphology. A two-dimensional finite element model was developed and validated with the experimental results published literature. Cutting tests were conducted at low-, medium-, and high-speed cutting speeds. Chip formation and cutting forces were compared with the numerical model. A novel technique of cutting force measurement using power meter was also validated. It was found that the cutting forces decrease at higher cutting speeds as compared to the low and medium cutting speeds. The poor prediction of cutting forces by Johnson–Cook model at higher cutting speeds and feed rates showed the existence of a material behavior that does not exist at lower or medium cutting speeds. Two factors were considered responsible for the change in cutting forces at higher cutting speeds: change in coefficient of friction and thermal softening. The results obtained through numerical investigations after incorporated changes in coefficient of friction showed a good agreement with the experimental results.

scholarly journals Effects of Turning Parameters and Parametric Optimization of the Cutting Forces in Machining SiCp/Al 45 wt% Composite

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 840 ◽  
Author(s):  
Rashid Ali Laghari ◽  
Jianguang Li ◽  
Mozammel Mia
Keyword(s):  
Mathematical Model ◽  
Cutting Force ◽  
Feed Rate ◽  
Cutting Forces ◽  
Desirability Function ◽  
Interactive Effect ◽  
Cutting Speed ◽  
Experimental Results ◽  
Machining Process ◽  
Depth Of Cut

Cutting force in the machining process of SiCp/Al particle reinforced metal matrix composite is affected by several factors. Obtaining an effective mathematical model for the cutting force is challenging. In that respect, the second-order model of cutting force has been established by response surface methodology (RSM) in this study, with different cutting parameters, such as cutting speed, feed rate, and depth of cut. The optimized mathematical model has been developed to analyze the effect of actual processing conditions on the generation of cutting force for the turning process of SiCp/Al composite. The results show that the predicted parameters by the RSM are in close agreement with experimental results with minimal error percentage. Quantitative evaluation by using analysis of variance (ANOVA), main effects plot, interactive effect, residual analysis, and optimization of cutting forces using the desirability function was performed. It has been found that the higher depth of cut, followed by feed rate, increases the cutting force. Higher cutting speed shows a positive response by reducing the cutting force. The predicted and experimental results for the model of SiCp/Al components have been compared to the cutting force of SiCp/Al 45 wt%—the error has been found low showing a good agreement.

High Precision Hydrostatic Actuation Systems for Micro- and Nanomanipulation of Heavy Loads

2005 ◽  
Vol 128 (4) ◽  
pp. 778-787 ◽  
Author(s):  
Saeid Habibi ◽  
Richard Burton ◽  
Eric Sampson
Keyword(s):  
High Precision ◽  
Experimental Results ◽  
Positional Accuracy ◽  
Large Load ◽  
Actuation System ◽  
Heavy Loads ◽  
Actuation Systems ◽  
Laboratory Prototype ◽  
Electrohydraulic Actuator

In this paper reports on an important finding, that is, hydrostatic actuation systems are able to manipulate heavy loads with submicron precision and a large stroke. In this relation, the design of a high-precision hydrostatic actuation system referred to as the ElectroHydraulic Actuator (EHA) is presented. A laboratory prototype of this system has achieved an unprecedented level of performance by being able to move a large load of 20Kg with a precision of 100nm and a stroke of 12cm. This level of performance places the hydrostatic actuation concept in competition with piezoelectric platforms in terms of positional accuracy. Experimental results from this prototype are reported and analyzed.

Modeling of Forces for Drills With Chip-Breaking Grooves

2004 ◽  
Vol 126 (3) ◽  
pp. 555-564 ◽  
Author(s):  
Sushanta K. Sahu ◽  
Richard E. DeVor ◽  
Shiv G. Kapoor
Keyword(s):  
Cutting Forces ◽  
High Speed ◽  
Low Carbon Steel ◽  
High Speed Steel ◽  
Mechanistic Modeling ◽  
Design Parameters ◽  
Low Carbon ◽  
Workpiece Material ◽  
Chip Breaking ◽  
Twist Drills

In this paper, a mechanistic modeling approach to predicting cutting forces for conical twist drills with chip-breaking grooves has been developed. The model is based on force principles for restricted contact cutting extended to take into account the presence of a groove on the drill rake face. The applicability of the model for arbitrary groove geometries has been ensured by eliminating the use of grooved drills in the calibration process. Four different combinations of groove geometries have been used for validating the model using high speed steel drills and low carbon steel workpiece material. The force predictions from the model were found to be in good agreement with the measured forces. The model was then employed to determine groove orientation and design parameters that minimize cutting forces, subject to the condition that chip breaking is satisfactory.

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