Analysis of the Effect of Machining Sequence on Machining Error Considering Workpiece Rigidity Change

2020 ◽  
Author(s):  
Yutaro Nakao ◽  
Koji Teramoto
Keyword(s):  
Cutting Force ◽  
Value Added ◽  
Numerical Control ◽  
Machining Process ◽  
Generation Process ◽  
Machining Error ◽  
Machine Error ◽  
Estimation Of Error ◽  
Error Factor ◽  
Physical Phenomena

Abstract The objective of this research is to investigate relations between individual physical phenomena and machining error from the measured machined error. Small lot production using numerical control machine tools is widely applied to high quality and high value-added products. In such production, agile and flexible machining is required. Thus, there have been many researches which investigate the effect of specific phenomena such as cutting force, thermal expansion, tool wears, chattering vibration and so on, which is to realize high precision machining. However, there have been some unsolved problems. The first problem is focused phenomena are mostly cutting force and/or machine tool deflection. Accordingly, other effects such as the results by workpiece rigidity change have not been investigated enough. The second problem is that the generation process of machining error is complicated and there is no proper method to compensate. Because of those complicate process, it is difficult to determine the dominant error factor of a new machining case in advance. Therefore, on-machine error measurement and estimation of error factors are essential technologies in order to achieve accuracy assurance. Recently, machining for rib-structured and thin-walled workpiece becomes important because of their higher structure efficiency and light weight characteristic. In this paper, the effect of workpiece rigidity to the machining error is investigated. Depend on the machining sequence, workpiece rigidities change differently during the machining process. Two different machining cases with different machining sequences are conducted and difference between the cases are investigated.

Modelling and real-time compensation of cutting-force-induced error on a numerical control twin-spindle lathe

2009 ◽  
Vol 224 (4) ◽  
pp. 567-577 ◽  
Author(s):  
H Wu ◽  
H J Chen ◽  
P Meng ◽  
J G Yang
Keyword(s):  
Neural Network ◽  
Cutting Force ◽  
Real Time ◽  
Bp Neural Network ◽  
Machine Tools ◽  
Error Model ◽  
Numerical Control ◽  
Machining Process ◽  
Nc Machine ◽  
Nc Machine Tools

Cutting-force-induced errors are one of the major sources of error in numerical control (NC) machine tools. The error compensation technique is an effective way to improve the manufacturing accuracy of NC machine tools. Effective compensation relies on an accurate error model that can predict the errors exactly during the machining process. In the present paper a robust and accurate cutting-force-induced error model is built using a back-propagation (BP) neural network and a genetic algorithm (GA) for an NC twin-spindle lathe. The GA—BP neural network modelling technique not only enhances the prediction accuracy of the model but also reduces the training time of the BP neural network. A real-time compensation system of the cutting-force-induced error on the lathe is developed based on the cutting-force-induced error model. The errors were reduced by about 38 per cent after real-time compensation in a machining experiment.

Influence of Nonlinear Friction and Disturbance in the Control of a Mechatronic System: CNC Machine Tool Application

2011 ◽  
Author(s):  
Liz K. Rincon ◽  
Joa˜o M. Rosario
Keyword(s):  
Machine Tool ◽  
Cutting Force ◽  
Viscous Friction ◽  
Numerical Control ◽  
Machining Process ◽  
Contour Error ◽  
Nonlinear Friction ◽  
Cnc Machine ◽  
Mechatronic Systems ◽  
High Speeds

The CNC (Computer Numerical Control) machine tools are complex mechatronic systems applied to the manufacture with high precision and high speeds. To achieve high accuracy and operational efficiency, the disturbance and friction, which occur during machining process, should be reduced as low as possible. This paper develops an analysis of influence by cutting force and friction effect in the control of machine tool based on the CNC dynamic model and parameters identification. For this purpose, the study focuses on Coulomb and Viscous nonlinear friction and the external disturbances. The analysis uses control position error, contour error, and stability to determine the influence of friction and disturbance. The results show that Viscous friction has more critical influence on system than the Cutting force and Coulomb. The work contributes in recognizing which parameters have greater influence on the machine behavior through dynamic analysis with the identification strategy, in order to design and improve the control structure for a real CNC system.

Development of Web-Based Virtual CNC Milling Machine Tool With Mechanistic Cutting Force Models for Education and Learning

2010 ◽  
Author(s):  
A. Chukwujekwu Okafor ◽  
Vinay R. Talekar ◽  
V. Irigireddy ◽  
R. Gulati
Keyword(s):  
Machine Tool ◽  
Cutting Force ◽  
Cutting Tools ◽  
Numerical Control ◽  
Machining Process ◽  
Work Piece ◽  
Milling Machine ◽  
Cnc Milling ◽  
Long Distance ◽  
Web Based

This paper presents the results of the development of Virtual Computer Numerical Control Milling Machine Tool (VCNC-MMT) with cutting force models for web-based education and learning. This research is divided into five parts: 1) Virtual modeling of the machine parts, work-piece, cutting tools, and fixtures. 2) Assembly of the virtual components and assignment of the kinematics to the VCNC-MMT. 3) Development of virtual controller and offline simulation of machining process. 4) Implementation of the VCNC-MMT and simulation on the internet using X3D modeling language for long distance education, learning and training. 5) Development of the mechanistic cutting force models and incorporation with the VCNC-MMT. Mechanistic cutting force models for helical end mills with corner radius has been completed and simulated using MATLAB.

scholarly journals Adaptive CNC Machining Process Optimization of Near- net- shaped Blade based on Machining Error data Flow Control

2021 ◽  
Author(s):  
Dongbo Wu ◽  
wang hui ◽  
he lei ◽  
Jie Yu
Keyword(s):  
Flow Control ◽  
Process Optimization ◽  
Error Control ◽  
Data Flow ◽  
Cnc Machining ◽  
Numerical Control ◽  
Machining Process ◽  
Machining Error ◽  
Fixture System ◽  
Data Flow Control

Abstract Adaptive CNC machining process is one of the efficient processing solution for near- net- shaped blade, this study proposes an adaptive computer numerical control (CNC) machining process optimization scheme based on multi-process machining errors data flow control. The geometric and mechanical models of the multi-process adaptive CNC machining process are firstly constructed. The multi-process machining error data flow and the process system stiffness of near- net- shaped blade are then experimentally explored. The machining error flow collaborative control of the near- net- shaped blade multi-process CNC machining is finally realized by the adaptive CNC machining process under the premise of sufficient stiffness of the blade- fixture system. The results show that the dynamic displacement response of the blade multi-process CNC machining process is controlled within 0.007mm. The optimized adaptive CNC machining process based on the multi-process geometric machining error data flow control and the sufficient stiffness of blade- fixture system can realize the multi-process machining error control and high-precision machining of near- net- shaped blade. The process chain of the optimized adaptive CNC machining process is reduced by 87% compared with the low melting point alloy pouring process and 50% compared with adaptive CNC machining process of the twice on-machine measurement on the blade body.

Iterative Algorithm for Establishing the Optimal Compensation Model of Blade Cutting Path Based on Finite Element Analysis

2014 ◽  
Vol 556-562 ◽  
pp. 6085-6088
Author(s):  
Yan Cao ◽  
Li Wei Jia ◽  
Hui Yao ◽  
Zhi Jie Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cutting Force ◽  
Iterative Algorithm ◽  
Machining Process ◽  
Machining Error ◽  
Element Analysis ◽  
Compensation Model ◽  
Blade Machining ◽  
Cutting Path

Blade deformation during its machining is a key problem in aviation manufacturing. Machining error of a low rigidity blade caused by cutting force reduces its processing precision. And this kind of error is difficult to predict and control. In the paper, Finite Element Analysis is used to simulate blade machining process. The errors at sample points are gotten and used to evaluate the change of tool path. An optimal compensation model of blade machining path is put forward to consider the coupling effect between blade deformation and cutting force in multiple feeds. And an iterative algorithm is also presented to solve the optimal model. Thus, the object is achieved to reduce the blade machining error to a satisfying extent.

scholarly journals Serrated Chips Formation in Micro Orthogonal Cutting of Ti6Al4V Alloys with Equiaxial and Martensitic Microstructures

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 197 ◽  
Author(s):  
ZeJia Zhao ◽  
Suet To ◽  
ZhuoXuan Zhuang
Keyword(s):  
Cutting Force ◽  
Unit Length ◽  
Orthogonal Cutting ◽  
Machining Process ◽  
Orthogonal Machining ◽  
Large Yield ◽  
Power Spectral ◽  
Straight Line ◽  
Serrated Chips ◽  
Electropulsing Treatment

The formation of serrated chips is an important feature during machining of difficult-to-cut materials, such as titanium alloy, nickel based alloy, and some steels. In this study, Ti6Al4V alloys with equiaxial and acicular martensitic microstructures were adopted to analyze the effects of material structures on the formation of serrated chips in straight line micro orthogonal machining. The martensitic alloy was obtained using highly efficient electropulsing treatment (EPT) followed by water quenching. The results showed that serrated chips could be formed on both Ti6Al4V alloys, however the chip features varied with material microstructures. The number of chip segments per unit length of the alloy with martensite was more than that of the equiaxial alloy due to poor ductility. Besides, the average cutting and thrust forces were about 8.41 and 4.53 N, respectively, for the equiaxed Ti6Al4V alloys, which were consistently lower than those with a martensitic structure. The high cutting force of martensitic alloy is because of the large yield stress required to overcome plastic deformation, and this force is also significantly affected by the orientations of the martensite. Power spectral density (PSD) analyses indicated that the characteristic frequency of cutting force variation of the equiaxed alloy ranged from 100 to 200 Hz, while it ranged from 200 to 400 Hz for workpieces with martensites, which was supposedly due to the formation of serrated chips during the machining process.

scholarly journals Modeling of Cutting Force in the Turning of AISI 4340 Using Gaussian Process Regression Algorithm

2021 ◽  
Vol 11 (9) ◽  
pp. 4055
Author(s):  
Mahdi S. Alajmi ◽  
Abdullah M. Almeshal
Keyword(s):  
Gaussian Process ◽  
Cutting Force ◽  
Predictive Accuracy ◽  
Gaussian Process Regression ◽  
Machining Process ◽  
Support Vector ◽  
Process Data ◽  
Cutting Force Prediction ◽  
Artificial Neural Network Ann ◽  
Aisi 4340

Machining process data can be utilized to predict cutting force and optimize process parameters. Cutting force is an essential parameter that has a significant impact on the metal turning process. In this study, a cutting force prediction model for turning AISI 4340 alloy steel was developed using Gaussian process regression (GPR), support vector machines (SVM), and artificial neural network (ANN) methods. The GPR simulations demonstrated a reliable prediction of surface roughness for the dry turning method with R2 = 0.9843, MAPE = 5.12%, and RMSE = 1.86%. Performance comparisons between GPR, SVM, and ANN show that GPR is an effective method that can ensure high predictive accuracy of the cutting force in the turning of AISI 4340.

Optimization of turn-milling process in roughing and finishing regimes: Trade-off between productivity, cutting force and surface integrity

2021 ◽  
pp. 095440892199851
Author(s):  
Ebrahim Hosseini ◽  
Shafiqur Rehman ◽  
Ashkan Alimoradi
Keyword(s):  
Cutting Force ◽  
Desirability Function ◽  
Milling Process ◽  
Machining Process ◽  
Hybrid Machining ◽  
Trade Off ◽  
Hybrid Machining Process ◽  
Process Factors ◽  
Turn Milling ◽  
Selection Of

Turn-milling is a hybrid machining process which used benefits of interrupted cutting for proceeding of round bars. However, number of controllable parameters in the hybrid process is numerous that makes optimizing the process complicated. In the present study, an optimization work has been proposed to investigate the trade-off between production rate and cutting force in roughing regime as well surface roughness and tensile residual stress in finishing regime. Number of 43 experiments based on response surface methodology was designed and carried out to gather required data for development of quadratic empirical models. Then, the adequacy and importance of process factors were analyzed using analysis of variances. Finally, desirability function was used to optimize the process in rough and finish machining regimes. The obtained results showed that selection of eccentricity and cutter speed at their maximum working range can effectively enhance the quality characteristics in both the roughing and finishing regimes.

Surface Roughness and Cutting Force Components Evaluation in Hard Turning by Differently Shaped Cutting Tools

2016 ◽  
Vol 862 ◽  
pp. 26-32 ◽  
Author(s):  
Michaela Samardžiová
Keyword(s):  
Surface Roughness ◽  
Cutting Force ◽  
Hard Turning ◽  
Cutting Tool ◽  
Single Point ◽  
Machining Process ◽  
Tool Geometry ◽  
Machined Surface ◽  
Cutting Force Components ◽  
Force Components

There is a difference in machining by the cutting tool with defined geometry and undefined geometry. That is one of the reasons of implementation of hard turning into the machining process. In current manufacturing processes is hard turning many times used as a fine finish operation. It has many advantages – machining by single point cutting tool, high productivity, flexibility, ability to produce parts with complex shapes at one clamping. Very important is to solve machined surface quality. There is a possibility to use wiper geometry in hard turning process to achieve 3 – 4 times lower surface roughness values. Cutting parameters influence cutting process as well as cutting tool geometry. It is necessary to take into consideration cutting force components as well. Issue of the use of wiper geometry has been still insufficiently researched.

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