Machine Tool Vibrations and Cutting Dynamics (original) (raw)
Related papers
Cutting Tool Vibration in the Metal Cutting Process
2011
Research of machining dynamics have long history i n manufacturing processes with consideration of cutting interruption, intermittenc y and coupled interaction between the tool and workpiece. It gives better understanding of the und erlying physics of material removal. The complex motions in cutting dynamics are mainly caus ed by discontinuities, including chip and tool-workpiece seizure as well as complex stick–sli p motion. Through the application of discontinuous system theory, a comprehensive unders tanding of the grazing phenomena is induced by the boundary of frictional-velocity and the loss of contact between the tool and workpiece are discussed. Significant insights are t o control machine-tool vibration and to develop tool wear free machine-tool concept. The ex periment on the stainless steel machining is presented in the paper and generation of machine to ol vibrations and the associated cutting dynamics is considered.
VIBRATION MEASUREMENT ON CUTTING TOOL UNDER VARIOUS OPERATING CUTTING PARAMETERS
IAEME Publication, 2021
Machining and measuring operations are invariably accompanied by relative vibration between work piece and tool. The effect of vibration is excessive stresses, undesirable noise, looseness of part and partial or complete failure of parts. In this work the cutting tool vibration will be measured by using digital Vibrometer, which can measure displacement velocity, acceleration and frequency. The sensor will be attached with the tool post for sensing the vibration tool during turning operation. Vibration also increases in the cutting tool due to whiling of the job mounted between two stocks of lathe machine. With the increasing feed rate, the surface roughness of work will increase. The feed rate can be considered as a main cutting factor in the machining operation. The mildsteel material will be used for collecting data at various cutting parameters like depth of cut, speed, feed rate etc. on the completion of experimental work data will be analysing using MATLAB. By doing the same we will be able to predict behaviour for the system under any operating cutting parameters.
Archives of Civil and Mechanical Engineering, 2018
New identification and evaluation techniques for machining systems lead to an increase in the efficiency of a production system. This paper presents relationship between tool life, design features, fatigue strength and parameters of vibrations. To cope with this objective, vibration influence on tool wear is assessed, which considers the phase shift of vibration in different coordinates and forces on rake and rear faces of the tool. Tool life is predicted based on fatigue strength of tool material and parameters of tool vibrations. Static and dynamic characteristics of cutting tools during different machining conditions are analyzed using different cutting tools. Test results of cutting tools with different clamping types during static, dynamic and cutting processes, together with the simulation results suggest a relationship between the characteristics of the tool, the elastic system vibrations and tool life.
TJPRC, 2013
In this paper the chatter vibrations in metal cuttings on lathe machine is investigated experimentally. Since the dynamic cutting force is strongly influenced by the variations of cutting parameters, the objective of present paper is to consider the variations of cutting speed, feed and depth of cut on the vibrations of cutting process on the lathe machine, By analyzing experimental results it can be concluded that maintaining appropriate cutting parameter play important role in suppressing vibration that are developed during metal cutting process. For each of cutting conditions, the variations of cutting force component (thrust force) as a function of time are obtained numerically and treated as the input excitation for the lathe machine. The measurement of vibration in terms of acceleration by accelerometer is expressed as a function of time.
TOOL FOR RESEARCHING THE DYNAMIC SYSTEM OF METAL-CUTTING MACHINE
2018
Dynamic characteristics of the system flexibility of the machine affect the accuracy of machining, so the study of this problem is very important. Fluctuations of the machine elements significantly affect the error of the shape of the workpiece. The quality of the processing is determined not so much by the static displacements between the tool and the workpiece but the stability of the machine system as a whole. There are many solutions of vibroacoustic diagnostics devices for machines and machine-tools in the related publications. Defects in the spectrum of vibroacustic signals are found in the process of manufacturing and assembling machines in the form of discrete components, parameters of which are used in vibroacoustic diagnostics as informative diagnostic features. Along with that there is, but not so common, another type of dynamic system analysis of the machine, which can be carried out by experimental methods, or, in particular, by simulating the perturbation of a dynamic system by cutting forces of special type. Imitated disturbance is carried out by using a tool of a special form. During the processing cutting edges of the tool create a pseudorandom process with certain statistical characteristics, in particular, the correlation function. The proposed design of the tool makes it possible to perform the research of frequency parameters of the dynamic system of the machine without complex loading devices.
Oscillations of Cutting Tool as a Useful Effect in Turning and Drillingm
TEM Journal
The paper presents the fixtures with movably mounted turning and drilling cutting tools. The fixtures were developed on the principle of oscillating tooltip similar to the principle of the ultrasonic vibration-assisted machining process. However, presented fixtures do not need an electricity source and utilize mainly forced and self-excited oscillations. In general, the tool vibrations during the cutting process are recognized as a negative phenomenon as it causes a shortening of the tool life and worsens the roughness of the machined surfaces. However, a deeper understanding of the cutting process proposes possible positive effects of tool vibration in terms of chip shapes, flank wear, chip volume coefficient, and quality of the machined surface. Experimentally obtained dependence of mentioned quantities is provided in the paper.
Effects on the Surface Quality in the Machining Processes of the Tool Vibrations
2018
The problem of surface quality and cutting stability in the machining processes is very important and is strictly connected with the final quality of the product. Therefore, this paper describes a new theoretical model for the dynamic cutting forces of orthogonal cutting in turning. A specific advantage for the presented model is the convenience for vibration prediction. The presented dynamic force model is used to predict variable cutting forces with dynamic cutting between cutting tool and workpiece. This model is considered two degree of freedom complex dynamic model of turning with orthogonal cutting system. The complex dynamic system consists of dynamic cutting system force model which is based on the shear angle (φ) oscillations and the penetration forces which are caused by the tool flank contact with the wavy surface.
Cutting Dynamics and Machining Instability
John Wiley & Sons, Ltd eBooks, 2013
Cutting Dynamics and Machining Instability Material removal-as the most significant operation in manufacturing industry-is facing the ever-increasing challenge of increasing proficiency at the micro and nano scale levels of high-speed manufacturing. Fabrication of submicron size three-dimensional features and freeform surfaces demands unprecedented performance in accuracy, precision, and productivity. Meeting the requirements for significantly improved quality and efficiency, however, are contingent upon the optimal design of the machine-tools on which machining is performed. Modern day precision machine-tool configurations are in general an integration of several essential components including process measurement and control, power and drive, tooling and fixture, and the structural frame that provides stiffness and stability. As dynamic instability is inherently prominent and particularly damaging in high-speed precision cutting, design for dynamics is favored for the design of precision machine tool systems [1]. This approach employs computer-based analysis and design tools to optimize the dynamic performance of machine-tool design at the system level. It is largely driven by a critical piece of informationthe vibration of the machine-tool. Due to the large set of parameters that affect cutting vibrations, such as regenerative effects, tool nonlinearity, cutting intermittency, discontinuous frictional excitation, and environmental noise, among many others, the effectiveness of the approach commands that the dynamics of machining be completely established throughout the entire process. This book explores the fundamentals of cutting dynamics to the formulation and development of an innovative control methodology. The coupling, interaction, and evolution of different cutting states are studied so as to identify the underlying critical parameters that can be controlled to negate machining instability and enable better machine-tool design for precision micro and nano manufacturing. The main features that contribute to the robust control of cutting instability are: (1) comprehension of the underlying dynamics of cutting and interruptions in cutting motions, (2) operation of the machine-tool system over a broad range of operating conditions with
2021
Abstract: The performance of the cutting tool subjected to vibration depends upon the operational parameters of the systems. The experimentation is the most reliable means of investigating the vibrational behaviour of the cutting tool during the turning operation on work-piece. However, the empirical expressions developed based on the well-designed experimental observations give much reliable predictions. Hence, the core objective of the present study is to apply design of experiment (DOE) approach on the vibration study of cutting tool considering the four key variables: rotational speed (N) of the spindle i.e. work-piece, feed rate (f), depth of cut (DOC) (dc) and the work-piece diameter (D). Based on the observations, the optimum parameter values identified are: N = 350 RPM, f = 0.15mm/rev, dc = 0.3 mm and D = 40 mm. Moreover, the second order polynomial equation with crossterms has been identified as the more suitable regression expression than the second and third order polynom...
2003
The ability to monitor the behaviour of machine tools and cutting processes is important both from a research perspective as well as in industrial applications such as adaptive control, condition monitoring, process optimization and quality control. The division of Manufacturing Engineering at Lulei University of Technology has been carrying out research in the area of hgh speed and multi axis (5-axis) machming since the mid 1990s. Ths European and nationally funded research, much of it carried out with Nottingham University and Sandvlk Coromant, as well as in manufacturing companies in Sweden and the UK, has focused on understanding the possibilities offered by 5-axishgh-speed machining, as well as understanding the machining process. This initially empirical work has become more qualitative through the development of an instrumented machine tool test bed based on a 5-axis Leichti Turbomill equipped with a 24,000 rpm spindle and fast controller. The machine installation costs appro...