A Mechanistic Dynamic Model of End Milling for Process Controller Simulation

1991 ◽  
Vol 113 (2) ◽  
pp. 176-183 ◽  
Author(s):  
F. M. Kolarits ◽  
W. R. DeVries
Keyword(s):  
Dynamic Model ◽  
Metal Cutting ◽  
Controller Design ◽  
Metal Removal ◽  
End Milling ◽  
Removal Rate ◽  
Digital Simulation ◽  
Surface Geometry ◽  
Cutter Deflection ◽  
On Chip

In an effort to maximize the metal removal rate in end milling while avoiding excessive cutter deflection or breakage, both fixed gain and adaptive controllers have been implemented for on-line feedrate manipulation to maintain a constant cutting force. While such controllers have been able to increase the metal cutting efficiency, they have also exhibited performance problems when large changes in the process dynamics occur. To assist in controller design and evaluation through digital simulation, a new dynamic model of the end milling force response to changes in feedrate and/or spindle speed is presented. This model, based on chip formation mechanics, takes explicitly into account the effect of cutter runout and deflection on the chip load, permits variations in the axial and radial depths of cut to be modeled, and provides surface geometry predictions. Model predictions are shown to correspond well with experimental machining data.

scholarly journals Influence of Chatter of VMC Arising During End Milling Operation and Cutting Conditions on Quality of Machined Surface

1970 ◽  
Vol 2 (1) ◽  
Author(s):  
A.K.M.N. Amin, M.A. Rizal, and M. Razman
Keyword(s):  
Surface Roughness ◽  
Metal Cutting ◽  
Metal Removal ◽  
End Milling ◽  
Cutting Speed ◽  
Cutting Conditions ◽  
End Mill ◽  
Machined Surface ◽  
Operating Cycle ◽  
Wide Range

Machine tool chatter is a dynamic instability of the cutting process. Chatter results in poor part surface finish, damaged cutting tool, and an irritating and unacceptable noise. Exten¬sive research has been undertaken to study the mechanisms of chatter formation. Efforts have been also made to prevent the occurrence of chatter vibration. Even though some progress have been made, fundamental studies on the mechanics of metal cutting are necessary to achieve chatter free operation of CNC machine tools to maintain their smooth operating cycle. The same is also true for Vertical Machining Centres (VMC), which operate at high cutting speeds and are capable of offering high metal removal rates. The present work deals with the effect of work materials, cutting conditions and diameter of end mill cutters on the frequency-amplitude characteristics of chatter and on machined surface roughness. Vibration data were recorded using an experimental rig consisting of KISTLER 3-component dynamometer model 9257B, amplifier, scope meters and a PC.  Three different types of vibrations were observed. The first type was a low frequency vibration, associated with the interrupted nature of end mill operation. The second type of vibration was associated with the instability of the chip formation process and the third type was due to chatter. The frequency of the last type remained practically unchanged over a wide range of cutting speed.  It was further observed that chip-tool contact processes had considerable effect on the roughness of the machined surface.Key Words: Chatter, Cutting Conditions, Stable Cutting, Surface Roughness.

Modelling and Optimization of End Milling Process Using TLBO and TOPSIS Algorithm

2017 ◽  
pp. 54-81 ◽  
Author(s):  
Atul Tiwari ◽  
Mohan Kumar Pradhan
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Metal Cutting ◽  
End Milling ◽  
Removal Rate ◽  
Cutting Parameters ◽  
Optimization Method ◽  
Depth Of Cut ◽  
Multi Objective ◽  
Order Preference

To assure desire quality of machined products at minimum machining costs and maximum material removal rate, it is very important to select optimum parameters when metal cutting machine tool are used. Minimum Surface Roughness (Ra) is commonly desirable for the component; however Material Removal Rate (MRR) should be maximized. This chapter presents an approach for determination of the best cutting parameters precede to minimum Ra and maximum MRR simultaneously by integrating Response Surface Methodology with Multi-Objective Technique for Order Preference by Similarity to Ideal Solution and Teaching and learning based optimization algorithm in face milling of Al-6061 alloy. 30 experiments have been conducted based on RSM with 4 parameters, namely Speed, Feed, Depth of Cut and Coolant Speed and three levels each. ANOVA is performed to find the most influential input parameters for both MRR and Ra. Later the multi-objective attribution selection method TOPSIS and multi objective optimization method TLBO is used to optimize the responses.

Nonlinear Dynamic Model of a Fluidized-Bed Steam Generation System

1980 ◽  
Vol 102 (1) ◽  
pp. 202-208 ◽  
Author(s):  
A. Ray ◽  
D. A. Berkowitz ◽  
V. H. Sumaria
Keyword(s):  
Fluidized Bed ◽  
Dynamic Model ◽  
Controller Design ◽  
Digital Simulation ◽  
Steam Generation ◽  
Generation System ◽  
Nonlinear Dynamic Model ◽  
Continuous Time Model ◽  
Design Data ◽  
Time Model

A dynamic model of an atmospheric pressure fluidized-bed steam generation system is presented which allows digital simulation and analytical controller design. The nonlinear, time-invariant, deterministic, continuous-time model is derived in state-space form from conservation relations, empirical correlations and system design data. The model has been verified for steady-state and transient performance with measured data from experimental test runs. Transient responses of several process variables, following independent step disturbances in coal feed rate and air flow, are illustrated.

scholarly journals Optimization of process parameters on commercial mild steel using taguchi technique

2017 ◽  
Vol 7 (1.1) ◽  
pp. 138 ◽  
Author(s):  
V. Jaiganesh ◽  
B. Yokesh Kumar ◽  
P. Sevvel ◽  
A.J. Balaji
Keyword(s):  
Surface Roughness ◽  
Mild Steel ◽  
Metal Cutting ◽  
Metal Removal ◽  
Removal Rate ◽  
Chip Thickness ◽  
Critical Factor ◽  
Thickness Ratio ◽  
Depth Of Cut ◽  
Versus Input

In the present scenario of bulk manufacturing where Metal Removal Rate (MRR), Chip Thickness Ratio (CTR) and Surface Roughness (SR) is of significant importance in manufacturing the component using CNC (computer numerical controlled) machines. Nine experiments were conducted based on orthogonal array. General linear model has been generated for all the three output parameters such as (MRR, Chip Thickness Ratio surface roughness) versus input parameters (speed, time, depth of cut). The statistical method called the analysis of variance (ANOVA) is applied to find the critical factor. The Main effects of S/N ratio values are found and plotted in the form of graph. The optimized value is found for speed, time, and depth of cut by using “MINITAB” software. By using this optimized value the efficient metal cutting can be done in commercial mild steel.

Dynamic Forces and Hole Quality in Drilling Process

2004 ◽  
Author(s):  
Muge Pirtini ◽  
Ismail Lazoglu
Keyword(s):  
Cutting Forces ◽  
Metal Removal ◽  
Removal Rate ◽  
Drilling Process ◽  
Machining Processes ◽  
Planning Stage ◽  
Cycle Times ◽  
Cutter Deflection ◽  
Home Appliance ◽  
Measured Frequency Response

Drilling is one of the most commonly used machining processes in various industries such as automotive, aircraft and aerospace, dies/molds, home appliance, medical and electronic equipment industries. Due to the increasing competitiveness in the market, cycle times of the drilling processes must be decreased. Moreover, tight geometric tolerance requirements in designs, drilled hole precisions must be increased in production. On the other hand, process engineers have to be conservative when selecting machining conditions with respect to metal removal rate in order to avoid undesirable cases such as drill breakage, excessive cutter deflection and undesirable hole profile problems. In this research, a new mathematical model based on the mechanics and dynamics of the drilling process is developed for the predictions of cutting forces and hole qualities in advance. A new method is also proposed in order to obtain cutting coefficients directly from a set of relatively simple calibration tests. The model is able simulate the cutting forces for various cutting conditions in the process planning stage. In structural dynamics module, measured frequency response functions of the spindle and tool system are integrated into the model in order to obtain drilled hole profiles. Therefore, in addition to predicting the forces, the new model allows to determine and visualize drilled hole profiles in 3D and to select parameters properly under the manufacturing and tolerance constraints. Extensive number of experiments is performed to validate the theoretical model outputs with the measured forces and CMM hole profiles. It is observed that model predictions agree well with the force and CMM measurements. Some of the typical calibration and validation results are presented in this paper.

Optimization of input machining parameters in SBCNC-60 for turning and drilling on P8 (H-13,HSS) material

2021 ◽  
Vol 58 (2) ◽  
pp. 640-663
Author(s):  
Arti Saxena ◽  
YM Dubey ◽  
Manish Kumar ◽  
Abneesh Saxena
Keyword(s):  
Taguchi Method ◽  
Metal Cutting ◽  
Metal Removal ◽  
Removal Rate ◽  
Cutting Speed ◽  
Control Factor ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Cnc Machine ◽  
Input Control

Today’s technology of automobile manufacturing industries depends mainly on a metal cutting operation like turning and drilling. This paper aims to improve turning and drilling operations in industries where necessity is to increase productivity by improving the metal removal rate. This paper-work uses the Taguchi method to analyze the input control parameter and optimize the significant ones to obtain the desired output. Taguchi method is a broadly used technique for experimental design and analysis of experimental data to improve the performance of machining operations like face turning, drilling, etc. in a CNC machine by taking input control factor cutting speed (CS), feed rate (FR), depth of cut (DOC) and then find out the significant ones to optimize machining operation. In this paper, CNMG190616-M5-TM2501 and SD205A-1050–056-12R1-P cutting tool are used for turning and drilling operation respectively for H-13 (P8) material, and then by applying Taguchi L9 array and further analysis using ANOVA and validation test through regression model is done on input control parameters to obtain better optimum performance of SBCNC 60 lathe machine.

Optimization of Cutting Parameters for Desirable Surface Roughness in End-Milling Hardened AISI H13 Steel under a Certain Metal Removal Rate

2011 ◽  
Vol 188 ◽  
pp. 307-313 ◽  
Author(s):  
Tong Chao Ding ◽  
Song Zhang ◽  
Z.M. Li ◽  
Yuan Wei Wang
Keyword(s):  
Surface Roughness ◽  
Metal Removal ◽  
End Milling ◽  
Removal Rate ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Metal Removal Rate ◽  
H13 Steel ◽  
Orthogonal Experiments ◽  
Aisi H13

In this paper, the orthogonal experiments and the optimization experiments with the same metal removal rate are designed to investigate the main effects and primary interaction of cutting parameters on surface roughness and to search the optimal cutting parameter under a certain removal rate when end-milling hardened AISI H13 steel with the PVD coated carbide insert. The empirical model for surface roughness based on the orthogonal experiments and the optimization experiments with the same metal removal rate and the optimal cutting parameter were all verified. Under a certain metal removal rate, the combination of high cutting speed, small axial depth of cut and high feed, small radial depth of cut generates the best surface roughness in hard milling of AISI H13.

scholarly journals Development of Jump Markovian Dynamic Models of Low Cost Digital Duty-Cycle Modulation Drivers For Target System-on-Chip Devices

2020 ◽  
pp. 364-372
Author(s):  
Jean Mbihi ◽  
Léandre Nneme Nneme
Keyword(s):  
Dynamic Model ◽  
Duty Cycle ◽  
Dynamic Models ◽  
Low Cost ◽  
Digital Simulation ◽  
System On Chip ◽  
Target System ◽  
Digital To Analog Converter ◽  
Usb Communication ◽  
On Chip

In this paper, a novel building algorithmic scheme of DDCM (duty-cycle modulation) drivers is presented. It is modelled in the analog domain as a continuous time jump Markovian dynamic model, with a deterministic two-state Markov chain. An equivalent discrete jump dynamic model is computed using pole-zero matching transform. Then, the resulting digital iterative algorithm, consists of simple digital operators and structures. The proposed DDCM algorithm is simulated under Matlab framework, and implemented using Arduino IDE-C++ with uploading into an ESP32 system-on-chip (SoC) device. The monitoring device connected to the ESP32 via an USB communication cable is an Arduino/IDE virtual monitor. It is configured for 230400 bauds communication. A low cost ESP32-based DAC (digital-to-analog converter), is virtually implemented and well tested as a case study of the proposed new generation of DDCM drivers. Matlab digital simulation results and ESP32 processing and virtual monitoring results are presented and discussed, in order to show the realistic nature and the great challenge the proposed DDCM algorithmic scheme for SOC devices.

Prediction and Analysis of Size Tolerances Achievable in Peripheral End Milling

2006 ◽  
Author(s):  
M. N. Islam ◽  
Han Ul Lee ◽  
Dong-Woo Cho
Keyword(s):  
Metal Removal ◽  
End Milling ◽  
Removal Rate ◽  
Size Variation ◽  
Simulation Software ◽  
Surface Generation ◽  
Cutting Condition ◽  
Metal Removal Rate ◽  
Average Size ◽  
Size Tolerance

This paper details the current research on size tolerances of component parts machined through peripheral end milling using a prototype simulation software for virtual end milling based on previously reported cutting force and surface generation models. Firstly, the simulation software was employed for predicting the size tolerances of a prismatic component by varying one controllable variable at a time and then, the relationship between the size tolerance and the variable changed was monitored. When a distinct relationship was noted it was verified both analytically and experimentally. The results indicated that while the average size variation, which contributed to the variation of the basic size of component parts, was always proportional to the metal removal rate, the range of size variations that contributed to the size tolerance was not. Thus, there is scope for increasing the metal removal rate without sacrificing the size tolerances. The knowledge acquired through this research can be applied for selecting an optimum cutting condition using the simulation software when the size tolerances of component parts are specified.

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