scholarly journals Numerical and Experimental Investigation on Dynamic Behavior in Turning Process of Thin-walled Workpieces made of 42CrMo4 Steel Alloy

2021 ◽  
Author(s):  
Zied Sahraoui ◽  
Nawel Glaa ◽  
Kamel MEHDI
Keyword(s):  
Finite Element ◽  
Dynamic Behavior ◽  
Feed Rate ◽  
Cutting Forces ◽  
Metal Cutting ◽  
Numerical Study ◽  
Steel Alloy ◽  
Turning Process ◽  
42Crmo4 Steel ◽  
Thin Walled

Abstract Machining thin-walled parts is generally cumbersome due to their low structural rigidity. Thus, to better understand the dynamic behavior of thin-walled parts during machining, various engineers and researchers in the field of metal cutting employ the Finite Element Method (FEM) due to its ability to highlight the physics involved in chip formation and the range of force generated in the cutting zone. The results of numerical simulations are evaluated using comparison with experimental data. In this paper, we study the effect of feed rate as well as the thickness of the wall part made of 42CrMo4 steel alloy on the cutting forces and workpiece displacements both experimentally and numerically during roughing and finishing turning process. The numerical study is based on the development of a three-dimensional (3D) Finite Element Model (FEM) in Abaqus/Explicit frame. In the model, the workpiece material is governed by a behavior law of Johnson-Cook. The detachment of the chip is simulated by a ductile fracture law also of Johnson-Cook. Numerical and experimental results show that the cutting forces and the quality of the machined surface depend not only on the choice of cutting parameters but also on the dynamic behavior of thin-walled parts due to their low rigidity and low structural damping during of the machining operation. Indeed, cutting forces are proportional to the feed rate and inversely proportional to the thickness of the part. The largest displacements recorded on the part are mainly along the direction of the tangential component of the cutting force. The flexibility of the part generates instability in the cutting process, but the frequencies of the vibrations are higher than the frequency of rotation of the part.

Experimental Study of the Dynamic Behavior of Thin-Walled Tubular Workpieces in Turning Cutting Process

2020 ◽  
pp. 1-19
Author(s):  
Zied Sahraoui ◽  
Kamel Mehdi ◽  
Moez Ben Jaber
Keyword(s):  
Dynamic Behavior ◽  
Cutting Forces ◽  
Chip Thickness ◽  
Cutting Process ◽  
Machining Process ◽  
Structural Damping ◽  
Turning Process ◽  
Manufactured Products ◽  
Thin Walled ◽  
The Stability

Nowadays, industrialists, especially those in the automobile and aeronautical transport fields, seek to lighten the weight of different product components by developing new materials lighter than those usually used or by replacing some massive parts with thin-walled hollow parts. This lightening operation is carried out in order to reduce the energy consumption of the manufactured products while guaranteeing optimal mechanical properties of the components and increasing quality and productivity. To achieve these objectives, some research centers have focused their work on the development and characterization of new light materials and some other centers have focused their work on the analysis and understanding of the encountered problems during the machining operation of thin-walled parts. Indeed, various studies have shown that the machining process of thin-walled parts differs from that of rigid parts. This difference comes from the dynamic behavior of the thin-walled parts which is different from that of the massive parts. Therefore, the purpose of this paper is to first highlight some of these problems through the measurement and analysis of the cutting forces and vibrations of tubular parts with different thicknesses in AU4G1T351 aluminum alloy during the turning process. The experimental results highlight that the dynamic behavior of turning process is governed by large radial deformations of the thin-walled workpieces and the influence of this behavior on the variations of the chip thickness and cutting forces is assumed to be preponderant. The second objective is to provide manufacturers with a practical solution to the encountered vibration problems by improving the structural damping of thin-walled parts by additional damping. It is found that the additional structural damping increases the stability of the cutting process and reduces considerably the vibrations amplitudes.

Turning Process Modeling and Cutting Force Investigation Based on Finite Element Analysis and Cutting Experiments

2011 ◽  
Vol 314-316 ◽  
pp. 900-903
Author(s):  
Yan Cao ◽  
Hua Chen ◽  
Hai Xia Zhao
Keyword(s):  
Finite Element ◽  
Cutting Force ◽  
Cutting Forces ◽  
Metal Cutting ◽  
Cutting Parameters ◽  
Turning Process ◽  
Rigid Plastic ◽  
Element Analysis ◽  
Fea Model ◽  
Cutting Experiments

On the basis of metal cutting and rigid-plastic finite element theories, taking cutting force in turning process as the research object, a FEA model for turning process using a MDT cutter on a centre lathe CA6140 is constructed to simulate its metal cutting process. Using Deform 3D, cutting forces are calculated according to different cutting parameters. The influences of the cutting parameters on the cutting forces are investigated. In order to validate the FEA model, cutting experiments are conducted. Comparison between simulated cutting forces and experimental forces shows similar trends and reasonable agreement.

Improving the honing accuracy of the holes of stepped thin-walled cylinders

2021 ◽  
pp. 49-54
Author(s):  
V.A. Ogorodov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cutting Forces ◽  
Software Package ◽  
The Finite Element Method ◽  
Radial Forces ◽  
Thin Walled ◽  
Hole Machining ◽  
Deform 3D ◽  
Walled Cylinder

Different ways of fixing of stepped thin-walled cylinders during honing are analyzed. The conditions for increasing the accuracy of hole machining are determined on the basis of unevenness of cylinder deformations from clamping forces and radial forces simulating cutting forces. The studies used the finite element method and the DEFORM-3D V6.1 software package. Keywords: honing, stepped thin-walled cylinder, hole, accuracy, fixing method, deformation, unevenness, DEFORM-3D V6.1 software package. [email protected]

Analytical and experimental stability analysis of AU4G1 thin-walled tubular workpieces in turning process

2020 ◽  
Vol 234 (6-7) ◽  
pp. 1007-1018 ◽  
Author(s):  
Zied Sahraoui ◽  
Kamel Mehdi ◽  
Moez Ben-Jaber
Keyword(s):  
Stability Analysis ◽  
Feed Rate ◽  
Experimental Studies ◽  
Rake Angle ◽  
Machining Process ◽  
Structural Damping ◽  
Turning Process ◽  
Process Stability ◽  
Thin Walled ◽  
The Stability

The development of the manufacturing-based industries is principally due to the improvement of various machining operations. Experimental studies are important in researches, and their results are also considered useful by the manufacturing industries with their aim to increase quality and productivity. Turning is one of the principal machining processes, and it has been studied since the 20th century in order to prevent machining problems. Chatter or self-excited vibrations represent an important problem and generate the most negative effects on the machined workpiece. To study this cutting process problem, various models were developed to predict stable and unstable cutting conditions. Stability analysis using lobes diagrams became useful to classify stable and unstable conditions. The purpose of this study is to analyze a turning process stability using an analytical model, with three degrees of freedoms, supported and validated with experimental tests results during roughing operations conducted on AU4G1 thin-walled tubular workpieces. The effects of the tubular workpiece thickness, the feed rate and the tool rake angle on the machining process stability will be presented. In addition, the effect of an additional structural damping, mounted inside the tubular workpiece, on the machining process stability will be also studied. It is found that the machining stability process is affected by the tubular workpiece thickness, the feed rate and the tool rake angle. The additional structural damping increases the stability of the machining process and reduces considerably the workpiece vibrations amplitudes. The experimental results highlight that the dynamic behavior of turning process is governed by large radial deformations of the thin-walled workpieces. The influence of this behavior on the stability of the machining process is assumed to be preponderant.

scholarly journals Studies of thin-walled parts deformation by gripping force during turning process on an example of bearing ring

2018 ◽  
Vol 244 ◽  
pp. 02010
Author(s):  
Adam Patalas ◽  
Michał Regus ◽  
Katarzyna Peta
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Turning Process ◽  
Turning Operation ◽  
Geometrical Accuracy ◽  
Bearing Ring ◽  
Thin Walled ◽  
Gripping Force ◽  
Element Method

In this paper thin-walled part deformation during finishing turning process caused by gripping force of hydraulic lathe chuck was investigated. Bearing ring was taken as an example of thin-walled part undergo finishing turning operation. Finite Element Method (FEM) was used to define the deformation of examined part. The aim of presented research was to compare the deformation of bearing ring caused by gripping force of hydraulic 3-jaw chuck and 6-jaw chuck for different values of total gripping force. The data obtained from conducted simulations allowed to evaluate the influence of gripping force on machining part deformation which is directly related with its geometrical accuracy.

Analysis of Cutting Technologies for Lightweight Frame Components

2006 ◽  
Vol 10 ◽  
pp. 121-132 ◽  
Author(s):  
Klaus Weinert ◽  
Sven Grünert ◽  
Michael Kersting
Keyword(s):  
Finite Element ◽  
Metal Cutting ◽  
Thermal Stresses ◽  
Machining Process ◽  
Frame Structure ◽  
Experimental Investigations ◽  
Promising Alternative ◽  
Thin Walled ◽  
Process Strategy ◽  
Conventional Drilling

Most technical components applied in industrial practice are subjected to metal cutting operations during their production process. However, this leads to undesirable thermal and mechanical loads affecting the machined workpiece, which can result in an impairment of its serviceability. Due to their small wall thickness lightweight hollow profiles are highly susceptible to the inevitable machining loads and thermal stresses during drilling processes. For the virtual optimization of the machining process and in order to ensure a suitable process strategy, a finite element simulation of cutting operations for thin-walled light metal profiles is conducted. Due to the flexibility within creating drill holes of different diameters without tool changes circular milling represents a promising alternative to the application of conventional drilling tools for variable process strategies to handle batch sizes down to one piece efficiently. Hence, this article gives an insight into the investigations regarding the modeling concepts of the mechanical and thermal loads induced into the thin-walled lightweight frame structure during the circular milling process. Furthermore, process reliability aspects as well as the correlation of the calculated and the measured results will be discussed on the basis of experimental investigations. Finally, this article compares Finite Element Analysis aspects of circular milling processes with conventional drilling processes.

Three-Dimensional Finite Element Analysis on Heavy Cutting for High Strength Steel

2013 ◽  
Vol 274 ◽  
pp. 3-6 ◽  
Author(s):  
Yuan Sheng Zhai ◽  
Xian Li Liu ◽  
Yu Wang
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Feed Rate ◽  
Cutting Forces ◽  
High Strength Steel ◽  
Three Dimensional ◽  
High Strength ◽  
Temperature Fields ◽  
Maximum Temperature ◽  
Element Modeling

The finite element modeling and experimental validation of three-dimensional heavy cutting of high strength steel (2.25Cr-1Mo-0.25V) are presented. The commercial software Deform 3D applied for the finite element modeling is studied the effect of feed rate on the principal cutting forces and the temperature fields. The friction between the tool and the chip is assumed to follow a shear model and the local adaptive remeshing technique is used for the formation of chip. The feed rate significantly affects the cutting forces, but slightly influences the maximum temperature of the chip. The simulation results are compared with experimental data and found to be in good agreement.

Dynamic Behavior of a Thin-Walled Cylindrical Workpiece During the Turning Process, Part 1: Cutting Process Simulation

2002 ◽  
Vol 124 (3) ◽  
pp. 562-568 ◽  
Author(s):  
K. Mehdi ◽  
J.-F. Rigal ◽  
D. Play
Keyword(s):  
Dynamic Behavior ◽  
Process Simulation ◽  
Point Of View ◽  
Cutting Process ◽  
Natural Phenomenon ◽  
Chatter Vibration ◽  
Turning Process ◽  
Chatter Vibrations ◽  
Cylindrical Workpiece ◽  
Thin Walled

From a practical point of view, in machining applications, chatter vibration constitutes a major problem during the cutting process. It is becoming increasingly difficult to suppress chatter during cutting at high speeds. Many investigators have regarded chatter vibrations as a “natural” phenomenon during the cutting process and a part of the process itself. In classical machining operations with thick-walled workpieces chatter vibrations occur when the cutting depth exceeds stability limits dependent on the machine tool. On the other hand, in the case of thin-walled cylindrical workpieces, chatter vibration problems are not so simple to formulate. The main purpose of this study is to qualify the dynamic behavior of a thin-walled workpiece during the turning process. It contains two parts: the cutting process simulation and the definition of experimental stability criteria. In the first part, a numerical model, which simulates the turning process of thin-walled cylindrical workpieces, is proposed. This model also permits obtaining workpiece responses to excitation generated by cutting forces. Finally, the stability of the process is discussed.

scholarly journals An Investigation into the Effect of Electro-Contact Heating in the Machining of Low-Rigidity Thin-Walled Micro-Machine Parts

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4427
Author(s):  
Antoni Świć ◽  
Arkadiusz Gola ◽  
Olga Orynycz ◽  
Karol Tucki
Keyword(s):  
Control System ◽  
Feed Rate ◽  
Cutting Forces ◽  
Flank Wear ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Depth Of Cut ◽  
Contact Heating ◽  
Thin Walled ◽  
Micro Machine

Low-rigidity thin-walled parts are components of many machines and devices, including high precision electric micro-machines used in control and tracking systems. Unfortunately, traditional machining methods used for machining such types of parts cause a significant reduction in efficiency and in many cases do not allow obtaining the required accuracy parameters. Moreover, they also fail to meet modern automation requirements and are uneconomical and inefficient. Therefore, the aim of provided studies was to investigate the dependency of cutting forces on cutting parameters and flank wear, as well as changes in cutting forces induced by changes in heating current density and machining parameters during the turning of thin-walled parts. The tests were carried out on a specially designed and constructed turning test stand for measuring cutting forces and temperature at specific cutting speed, feed rate, and depth of cut values. As part of the experiments, the effect of cutting parameters and flank wear on cutting forces, and the effect of heating current density and turning parameters on changes in cutting forces were analyzed. Moreover, the effect of cutting parameters (depth of cut, feed rate, and cutting speed) on temperature has been determined. Additionally, a system for controlling electro-contact heating and investigated the relationship between changes in cutting forces and machining time in the operations of turning micro-machine casings with and without the use of the control system was developed. The obtained results show that the application of an electro-contact heating control system allows to machine conical parts and semi-finished products at lower cutting forces and it leads to an increase in the deformation of the thin-walled casings caused by runout of the workpiece.

A Numerical Study to Investigate the Influence of Edge Preparation in Vibration Assisted Machining

2018 ◽  
Author(s):  
Salman Pervaiz ◽  
Sathish Kannan ◽  
Wael Abdel Samad
Keyword(s):  
Cutting Forces ◽  
Small Amplitude ◽  
Metal Cutting ◽  
Cutting Tool ◽  
Numerical Study ◽  
Cutting Tools ◽  
Cutting Edge ◽  
Internal Stresses ◽  
Machining Performance ◽  
Edge Preparation

In machining operation, cutting tool performs a central role towards the overall machining performance. A user from metal cutting community always look for better cutting tools that can enhance productivity by reducing tool wear and cost. Modification in the micro-geometry of cutting edge is termed as edge preparation, and it is performed to improve the machining performance by strengthening the cutting edge, reducing internal stresses of coating and lowering the edge chipping etc. Edge preparation has a controlling influence on the formation of deformation zones, cutting temperature, cutting forces and stresses at the cutting interface. Vibration assisted machining (VAM) concept is gaining fame in the metal cutting sector community for machining difficult-to-machine materials. In VAM, cutting tool moves with a small amplitude vibration instead of moving with a constant cutting velocity. This small amplitude vibrational movement provides better machining performance for difficult-to-cut brittle materials. The current numerical study utilized different edge prepared micro-geometries such as sharp edge, round edge and chamfer edge etc. cutting tools, and then these cutting tools were used in the numerical simulations of VAM. The study shows higher magnitude of cutting forces under VAM with tools with modified geometry. The study is beneficial for the metal cutting community and opens new areas of industrial applications.

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