The Experimental Modal Analysis of High Speed Machining Tool System Based on Integral Polynomial Recognition Method

2012 ◽  
Vol 723 ◽  
pp. 159-163 ◽  
Author(s):  
Fei Xiao ◽  
Xian Li Liu ◽  
Yan Xin Wang ◽  
Li Jia Liu ◽  
Da Qu
Keyword(s):  
Modal Analysis ◽  
High Speed ◽  
Simulation Method ◽  
Experimental Modal Analysis ◽  
Modal Parameters ◽  
High Speed Machining ◽  
Analysis Method ◽  
Recognition Method ◽  
Element Simulation ◽  
Integral Polynomial

According to the principle of the experimental modal analysis, this study is based on tool system of the MIKRON UCP 710 numerical control machining center as test object for experimental modal analysis. Using the integral polynomial recognition method to identify the modal parameters (natural frequency, structural damping, and modal shape), and finally matching the results with the vector analysis method and the finite element simulation method. The results show that integral polynomial recognition method has higher precision than the vector analysis method to identify the multi-degree of freedom system; the experimental modal analysis can also obtain better modal parameters of the structure system, and a higher precision than the finite element simulation method. Obtained the MIKRON UCP 710 high-speed milling center tool system accurate modal parameters provides the necessary theoretical and experimental basis for the further study of the stability properties in the cutting processing of the high speed machining tool system.

Application of Experimental Modal Analysis Method in Researching of Mechanical Structure Dynamic Characteristics

2013 ◽  
Vol 694-697 ◽  
pp. 370-373
Author(s):  
Zhang Yu ◽  
Wen Zheng Cai
Keyword(s):  
Modal Analysis ◽  
Natural Frequency ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Experimental Modal Analysis ◽  
Analysis Method ◽  
Mechanical Structure ◽  
Vibration Resistance ◽  
Structural Rigidity ◽  
Structure Dynamic

With the purpose of realizing the analysis of mechanical structure dynamic characteristics and inhibit vibration and noise, combined with the analysis of a certain type of high speed sewing machines vibration characteristics, we carry on the concrete experimental modal analysis, and compare the results of the experimental modal analysis with the results of spectrum analysis. The analysis results show that the second order natural frequency of the shell is close to two octaves under the normal working speed of sewing machine and it will lead to resonance. Enhancing the structural rigidity and the natural frequency under this modal to avoid resonance frequency is the key to improve vibration resistance of the structure.

Computation and Analysis of Unbalancing Responses of High Speed Machining Tool System

2010 ◽  
Vol 148-149 ◽  
pp. 40-46 ◽  
Author(s):  
Chun Gen Shen ◽  
Gui Cheng Wang ◽  
Shu Lin Wang ◽  
Wen Wu Nie ◽  
Gang Liu
Keyword(s):  
Modal Analysis ◽  
High Speed ◽  
Natural Frequencies ◽  
Experimental Modal Analysis ◽  
Dynamic Responses ◽  
High Speed Machining ◽  
The Finite Element Method ◽  
Complex Dynamic ◽  
Fem Model ◽  
Integrated Methodology

In this study, an integrated methodology combining computational modal analysis, experimental modal analysis, and computational dynamic analysis was developed to investigate unbalancing dynamic responses of high speed machining tool systems. A linear-elasticity formulation based on the finite element method (FEM) was employed to compute the natural frequencies and obtain the corresponding modal shapes. Experimental modal analysis was then performed to verify the natural frequencies. After the validation, the FEM model was further modified to predict the dynamic responses, with an HSK (a Germany abbreviation of Hohl Schaft Kegel) tool system as a model system. The results indicated that, by validating the computed natural frequencies with experimental ones, an effective simulation model can be established for predicting complex dynamic response of high speed machining tool systems.

scholarly journals Vibration stability analysis of cantilever structure based on symbolic regression algorithm and modal analysis method

2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110212
Author(s):  
Xuchu Jiang ◽  
Hu Zhang ◽  
Ying Li ◽  
Wei Jiang ◽  
Xinyong Mao ◽  
...  
Keyword(s):  
Modal Analysis ◽  
High Speed ◽  
Robustness Analysis ◽  
Symbolic Regression ◽  
Modal Parameters ◽  
Analysis Method ◽  
Response Signal ◽  
Vibration Stability ◽  
Cantilever Structure ◽  
Ema Method

The vibration stability of cantilever mechanism under high-speed rotation directly affects the positioning accuracy. Modal analysis method is usually used to study the vibration stability. However, the traditional experimental modal analysis (EMA) method needs to measure the impulse excitation, while the operational modal analysis (OMA) method needs to satisfy the assumption of white noise. Therefore, the existing modal analysis methods cannot be applied to the study of vibration stability of high-frequency cantilever mechanism. In this paper, the symbolic regression (SR) algorithm is combined with the EMA method, and the robustness analysis and feasibility verification are carried out under the condition of adding noise. The validation of the new method is divided into two parts. In the first part, a three degree of freedom (DOF) linear model is constructed, and the modal parameters identified by SR method and state space method are compared. In the second part, the method is applied to identify the modal parameters of stepped bar. The results are compared with the results of LMS (Siemens’ Testlab). Based on the time-domain response signal only, the modal parameters are extracted by SR, and the main vibration frequency is extracted from the response signal. The system simulation and experimental results show the method provides a possibility to analyze the vibration stability of cantilever structure.

Effect of Bass Bar Tension on Modal Parameters of a Violin's Top Plate

2015 ◽  
Vol 39 (1) ◽  
pp. 145-149 ◽  
Author(s):  
Ewa B. Skrodzka ◽  
Bogumił B.J. Linde ◽  
Antoni Krupa
Keyword(s):  
Modal Analysis ◽  
Experimental Modal Analysis ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Normal Value ◽  
Modal Damping

Abstract Experimental modal analysis of a violin with three different tensions of a bass bar has been performed. The bass bar tension is the only intentionally introduced modification of the instrument. The aim of the study was to find differences and similarities between top plate modal parameters determined by a bass bar perfectly fitting the shape of the top plate, the bass bar with a tension usually applied by luthiers (normal), and the tension higher than the normal value. In the modal analysis four signature modes are taken into account. Bass bar tension does not change the sequence of mode shapes. Changes in modal damping are insignificant. An increase in bass bar tension causes an increase in modal frequencies A0 and B(1+) and does not change the frequencies of modes CBR and B(1-).

scholarly journals An Improved Lagrangian-Inverse Method for Evaluating the Dynamic Constitutive Parameters of Concrete

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1871
Author(s):  
Xinlu Yu ◽  
Yingqian Fu ◽  
Xinlong Dong ◽  
Fenghua Zhou ◽  
Jianguo Ning
Keyword(s):  
High Speed ◽  
Inverse Method ◽  
Image Correlation ◽  
Analysis Method ◽  
Stress Strain ◽  
Optical Techniques ◽  
Element Simulation ◽  
Non Linear ◽  
Constitutive Parameters ◽  
Inverse Analysis Method

The dynamic constitutive behaviors of concrete-like materials are of vital importance for structure designing under impact loading conditions. This study proposes a new method to evaluate the constitutive behaviors of ordinary concrete at high strain rates. The proposed method combines the Lagrangian-inverse analysis method with optical techniques (ultra-high-speed camera and digital image correlation techniques). The proposed method is validated against finite-element simulation. Spalling tests were conducted on concretes where optical techniques were employed to obtain the high-frequency spatial and temporal displacement data. We then obtained stress–strain curves of concrete by applying the proposed method on the results of spalling tests. The results show non-linear constitutive behaviors in these stress–strain curves. These non-linear constitutive behaviors can be possibly explained by local heterogeneity of concrete. The proposed method provides an alternative mean to access the dynamic constitutive behaviors which can help future structure designing of concrete-like materials.

The Use of Modan 3D in Experimental Modal Analysis

2013 ◽  
Vol 486 ◽  
pp. 36-41 ◽  
Author(s):  
Róbert Huňady ◽  
František Trebuňa ◽  
Martin Hagara ◽  
Martin Schrötter
Keyword(s):  
Modal Analysis ◽  
Vibration Analysis ◽  
High Speed ◽  
Mechanical Vibration ◽  
Steel Sample ◽  
Experimental Modal Analysis ◽  
Image Correlation ◽  
Optical Methods ◽  
Mode Shapes ◽  
Vibration Modes

Experimental modal analysis is a relatively young part of dynamics, which deals with the vibration modes identification of machines or their parts. Its development has started since the beginning of the eighties, when the computers hardware equipment has improved and the fast Fourier transform (FFT) could be used for the results determination. Nowadays it provides an uncountable set of vibration analysis possibilities starting with conventional contact transducers of acceleration and ending with modern noncontact optical methods. In this contribution we mention the use of high-speed digital image correlation by experimental determination of mode shapes and modal frequencies. The aim of our work is to create a program application called Modan 3D enabling the performing of experimental modal analysis and operational modal analysis. In this paper the experimental modal analysis of a thin steel sample performed with Q-450 Dantec Dynamics is described. In Modan 3D the experiment data were processed and the vibration modes were determined. The reached results were verified by PULSE modulus specialized for mechanical vibration analysis.

Collision-Free Tool Path Generation for Five-Axis High Speed Machining

2011 ◽  
Vol 474-476 ◽  
pp. 961-966 ◽  
Author(s):  
Li Qiang Zhang ◽  
Min Yue
Keyword(s):  
Image Analysis ◽  
Collision Detection ◽  
High Speed ◽  
Tool Path ◽  
Geometric Model ◽  
High Speed Machining ◽  
Analysis Method ◽  
Geometric Information ◽  
Detection Approach ◽  
Five Axis

Collision detection is a critical problem in five-axis high speed machining. Using a combination of process simulation and collision detection based on image analysis, a rapid detection approach is developed. The geometric model provides the cut geometry for the collision detection and records a dynamic geometric information for in-process workpiece. For the precise collision detection, a strategy of image analysis method is developed in order to make the approach efficient and maintian a high detection precision. An example of five-axis machining propeller is studied to demonstrate the proposed approach. It has shown that the collision detection task can be achieved with a near real-time performance.

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