Topic
Chatter mark
About: Chatter mark is a research topic. Over the lifetime, 156 publications have been published within this topic receiving 1232 citations.
Papers published on a yearly basis
Papers
TL;DR: In this article, the quality of the machined surface after broaching and the output signals obtained from multiple sensors, namely acoustic emission, vibration, and cutting forces, were estimated in terms of geometrical accuracy, burr formation, chatter marks and surface anomalies.
Abstract: The paper reports on research which attempts to correlate the quality of the machined surface after broaching and the output signals obtained from multiple sensors, namely acoustic emission, vibration, and cutting forces. The quality of the machined surface was estimated in terms of geometrical accuracy, burr formation, chatter marks and surface anomalies. Cutting conditions were varied based on an orthogonal array with cutting speed, coolant conditions, and tool settings as factors. Each orthogonal array was repeated at three levels of the tool wear. The results show that the cutting force signals are sensitive enough to detect the geometrical deviation of the machined profile, burr formation and to a lesser extent the chatter marks. The vibration signals were found sensitive to detect the chatter marks while the acoustic emission signal proved to be efficient for the detection of small surface anomalies such as pluckings, laps, and smeared material. However, up to now, no clear distinction between the different types of the surface anomalies could be made using the analysis of the acoustic emission signal. Time and frequency domain analysis of the output signals were carried out in order to develop appropriate techniques for qualitative/quantitative evaluation of the machined surface quality. It was found that each sensory signal is rather limited to a narrow field of application where certain surface features are detectable. The limitations of the employed sensory signals/analysis methodologies used to assess the workpiece surface quality, and their applicability in the industrial machining conditions are also discussed.
120 citations
TL;DR: In this paper, a new approach for chatter modelling in micro-milling is presented, which takes into account: the nonlinearity of the uncut chip thickness including the run-out effect; velocity dependent micromilling cutting forces; the dynamics of the tool-holder-spindle assembly.
Abstract: This paper presents a new approach for chatter modelling in micro-milling. The model takes into account: the nonlinearity of the uncut chip thickness including the run-out effect; velocity dependent micro-milling cutting forces; the dynamics of the tool-holder-spindle assembly. The uncut chip thickness is determined after considering the full kinematics of the cutting tool including the run-out effect. The micro-milling cutting forces are determined by: (i) a finite element (FE) prediction of the cutting forces in orthogonal cutting at different cutting velocities and uncut chip thicknesses; (ii) describing the relationship between cutting forces, cutting velocities and uncut chip thicknesses into a nonlinear equation; (iii) incorporating the uncut chip thickness model into the relationship of the cutting forces as function of the cutting velocity and the uncut chip thickness. The modal dynamic parameters at the cutting tool tip are determined for the tool-holder-spindle assembly and used for solving the equation of motion. The micro-milling process is modelled as two degrees of freedom system where the modal dynamic parameters for the tool-holder-spindle assembly and the micro-milling cutting forces are considered. Due to nonlinearities in the micro-milling cutting forces, the equation of motion is integrated numerically in the time domain using the Runge–Kutta fourth order method. The displacements in the x and y directions are obtained for one revolution-per-tool. Statistical variances are then employed as a chatter detection criterion in the time-domain solution. Scanning electron microscope (SEM) inspection is carried out to observe potential chatter marks on the micro-milled AISI 4340 steel surfaces at different spindle speeds and depths of cut. The predicted stability lobes and the experimentally obtained stability limits resulted in satisfactory agreement. The influence of the run-out effect on the stability lobes at different feed rates was investigated, which demonstrated the capability of the developed chatter model to consider quantitatively the run-out phenomenon. The results showed that the stability limits decrease by increasing the run-out length.
100 citations
TL;DR: The effectiveness of the proposed method is verified with cutting tests, and the results show that the chatter can be detected successfully before severe chatter marks are left on the workpiece.
Abstract: Chatter is a self-excited vibration between the workpiece and tool. In view of the non-stationarity of the chatter signal, the synchrosqueezing transform (SST) is used to process vibration signals during cutting, which can enhance the energy ratio of chatter. In order to eliminate the interference of tooth passing frequency and its harmonics, a time-frequency filtering method is applied to filter these frequency components out. Then, the vibration signal is reconstructed by inverse SST and statistical indexes in time and frequency domains are calculated. The cutting tests are carried out to select statistical indexes which are sensitive to chatter. The effectiveness of the proposed method is verified with cutting tests, and the results show that the chatter can be detected successfully before severe chatter marks are left on the workpiece.
52 citations
TL;DR: In this article, a technique for detecting chattering on ground cylindrical parts is presented, which is a defect caused by vibration during the grinding process and is best described as waviness in the surface of a workpiece.
Abstract: This paper presents a technique for chattering detection on ground cylindrical parts. Chattering is a defect caused by vibration during the grinding process and is best described as waviness in the surface of a workpiece. In this work, such waviness is measured with a mechanical stylus profiler featuring a diamond tip, and then converted into height values with the help of a precision displacement transducer. The output signal is later converted to digital form and transformed to the time–frequency domain by means of the wavelet transform, allowing its coefficients to grow as a function of surface defects and highlighting chatter marks. The method was validated experimentally with actual production parts and it was found to adequately measure the amplitude and to give location information of the chatter marks on the analyzed surface. Results show that this method can be used objectively to identify and quantify surface quality and that it is feasible to effectively integrate it into production processes for manufacturing control.
49 citations
TL;DR: In this paper, a literature review, the development and deployment of mathematical models, and a rigorous analysis of plant observations were conducted to investigate the causes of severe vibrations in hot and cold rolling of steel.
43 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 6 |
| 2020 | 1 |
| 2019 | 4 |
| 2018 | 11 |
| 2017 | 7 |
| 2016 | 5 |