Analysis of Chatter Vibration Through Step-Function Response

1972 ◽  
Vol 94 (4) ◽  
pp. 985-990
Author(s):  
H. Takeyama ◽  
O. Sakata
Keyword(s):  
Machine Tool ◽  
Step Function ◽  
Response Analysis ◽  
Chatter Vibration ◽  
First Approximation ◽  
Machine Tool Structure ◽  
On Line ◽  
Cutting Zone ◽  
Simple Evaluation ◽  
Cutting System

This paper deals with a challenge to apply the method of indicial response analysis for obtaining the frequency characteristics of total cutting system, tool system, and cutting zone. The feasibility of this method has been verified by simulation tests. Furthermore, linearity in cutting zone has been demonstrated to a first approximation by utilizing the proposed method. As examples of its application, on-line prediction or prevention of chatter vibration and simple evaluation of machine tool structure have been proposed.

Monitoring of the Machine Elements in Drilling Machine Using Vibration Signals by FEM

2008 ◽  
Author(s):  
G. V. Naveen Prakash ◽  
H. V. Ravindra
Keyword(s):  
Finite Element ◽  
Machine Tool ◽  
Spindle Speed ◽  
Vibration Velocity ◽  
Response Analysis ◽  
Drilling Machine ◽  
Machine Condition ◽  
Outer Race ◽  
Machine Tool Structure ◽  
Machine Elements

Deterioration in the machine running conditions always produces a corresponding increase in the vibration level. By monitoring vibration level it is possible to obtain information about the machine condition. Here, drilling machine was considered for the analysis. Spindle bearings and gearbox are found to be the critical elements of the machine tools on which condition monitoring has to be concentrated. To analyze the condition of the existing machine elements, finite element method has been used. An attempt has been made by modeling drilling machine to find out the response of the structure for various defects in machine elements. The finite element model of the machine tool was developed by using finite element package ANSYS. Modal analysis has been carried out to determine the natural frequencies and mode shapes of the structure. Frequency response analysis was used to determine the response of the structure due to the unbalance forces. Transient response analysis was used to study the effect of assumed defects on the machine tool structure. A defect was assumed on the outer race of the spindle bearing and on the gear and responses were observed at the spindle bearings location. From the analysis for the assumed defect in the outer race of the bearing, it was observed that the vibration velocity increases with the increase in depth of defect and depends on location of the defect. From the vibration signature resulting due to assumed destructive pitting defect in all teeth of the driven gear, it was observed that the vibration velocity level decreases with increase in spindle speed. This is because, at lower speeds time taken by each tooth to mesh with its counterpart is more, and hence persistence of disturbing force due to defect in meshing gear is more at lower speeds. Experimentation was carried out on the drilling machine by using the instrument Machine Condition Tester T-30. The experimental data obtained were used to analyze the condition of the machine elements. The vibration velocity was measured on the spindle bearings location for different spindle speed. From the Experimental analysis it was observed that with the increase in spindle speed, the vibration velocity also increases. Finally, theoretical results were judged against the experimental results. Thus the present work shows that the FEM is a valuable tool in finding sources of undesirable vibrations from various defects present in the machine elements of the machine tool structure.

Research Situation Analysis of On-line Detection Technology for Power Transformer Winding Deformation

2020 ◽  
Vol 13 (6) ◽  
pp. 823-832
Author(s):  
Zhenhua Li ◽  
Weihui Jiang ◽  
Li Qiu ◽  
Zhenxing Li ◽  
Yanchun Xu
Keyword(s):  
Detection Method ◽  
Theoretical Research ◽  
Line Detection ◽  
Response Analysis ◽  
Advantages And Disadvantages ◽  
Detection Technology ◽  
The Future ◽  
Transformer Winding ◽  
On Line ◽  
Winding Deformation

Background: Winding deformation is one of the most common faults in power transformers, which seriously threatens the safe operation of transformers. In order to discover the hidden trouble of transformer in time, it is of great significance to actively carry out the research of transformer winding deformation detection technology. Methods: In this paper, several methods of winding deformation detection with on-line detection prospects are summarized. The principles and characteristics of each method are analyzed, and the advantages and disadvantages of each method as well as the future research directions are expounded. Finally, aiming at the existing problems, the development direction of detection method for winding deformation in the future is prospected. Results: The on-line frequency response analysis method is still immature, and the vibration detection method is still in the theoretical research stage. Conclusion: The ΔV − I1 locus method provides a new direction for on-line detection of transformer winding deformation faults, which has certain application prospects and practical engineering value.

Dynamic Analysis of Helical Milling Unit Based on Virtual Machine Tool

2011 ◽  
Vol 188 ◽  
pp. 463-468 ◽  
Author(s):  
Xu Da Qin ◽  
Qi Wang ◽  
H.Y. Wang ◽  
Song Hua
Keyword(s):  
Machine Tool ◽  
Virtual Machine ◽  
Dynamic Stiffness ◽  
Three Dimensional ◽  
Geometrical Model ◽  
Helical Milling ◽  
Response Analysis ◽  
Computer Simulation Model ◽  
Element Analysis ◽  
Virtual Machine Tool

The virtual prototype is a computer simulation model of the physical product that can be analyzed like a real machine. This paper studies the helical milling unit based on the virtual machine tool. The helical milling unit is first designed according to the kinematics of the helical milling. The main parts of the equipment include rotating mechanism, orbital agency and radial offset organization. Based on the feasibility analysis of the structure, the three-dimensional geometrical model is built in the Solidworks software. The key parts in the model are separated from the device and introduced into the finite element analysis (FEA) software, according to the cutting loads tested from experiment, static and dynamic modal analysis and harmonic response analysis are carried out for the key parts of this device. The results show that the static and dynamic stiffness can meet design requirement.

A Stochastic Approach to Characterization of Machine Tool System Dynamics Under Actual Working Conditions

1976 ◽  
Vol 98 (2) ◽  
pp. 614-619 ◽  
Author(s):  
F. A. Burney ◽  
S. M. Pandit ◽  
S. M. Wu
Keyword(s):  
Machine Tool ◽  
Working Conditions ◽  
Stochastic Approach ◽  
Relative Displacement ◽  
Process Dynamics ◽  
Actual Working ◽  
Machine Tool Structure ◽  
Vertical Milling ◽  
Vertical Milling Machine ◽  
Tool Dynamics

The machine tool dynamics is evaluated under actual working conditions by using a time series technique. This technique develops mathematical models from only one signal, viz., the relative displacement between the cutter and the workpiece. Analysis of the experimental data collected on a vertical milling machine indicates that the new methodology is capable of characterizing the machine tool structure and the cutting process dynamics separately. Furthermore, it can also detect and quantify the interaction between these two subsystems.

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