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.

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.

Experimental and Numerical Investigation of Residual Stress Stiffening Influence on Dynamic Response of Welded Structures

2019 ◽  
Author(s):  
AmirHossein MajidiRad ◽  
Yimesker S. Yihun
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Model Updating ◽  
Experimental Modal Analysis ◽  
Experimental Results ◽  
Welding Residual Stress ◽  
Dynamic Responses ◽  
Mode Shapes

Abstract This paper presents the study of welding residual stress-stiffening effect on the dynamic responses and vibrational parameters of welded aluminum parts through an experimental modal analysis and Center Hole Drilling (CHD) residual stress measurement methods. Having a great corrosion resistance, AA5056 was utilized in this research that has been used in aircraft and ship structures; making the welding assesment of crucial. Natural frequencies and damping factors of several specimens are compared before and after the welding along with verification of experimental modal analysis integrity using Euler-Bernoulli relations. Finite element modeling of welding, cutting and modal/stress analysis of samples are also done to compare the experimental results. The results obtained from the precise modal analysis of all samples show that welding made the structure harder leading to 2% increase in natural frequencies and changing damping factors of different mode shapes. Cutting also reduced the level of residual stresses up to 34%. A good agreement is shown between the modal analysis and the experimental results. The technique used in the experiment and finite element simulation along with modeling assumptions are beneficial to other applications where model updating is required or a prediction of residual stress stiffening influence on modal responses is important.

Stress and Vibration Analysis of a Lathe Bed Made of Aluminum-Copper Alloy for High Speed Machining

2009 ◽  
Vol 15 ◽  
pp. 81-88 ◽  
Author(s):  
R. Torres-Martínez ◽  
G. Urriolagoitia-Calderón ◽  
G. Urriolagoitia-Sosa ◽  
R. Espinoza-Bustos
Keyword(s):  
Cast Iron ◽  
High Speed ◽  
Natural Frequencies ◽  
Mechanical Design ◽  
Parametric Modeling ◽  
High Speed Machining ◽  
The Finite Element Method ◽  
Cu Alloy ◽  
Design Variables ◽  
Machine Tool Structure

The analysis of the rigidity of an Al-Cu alloy lathe bed to be used for high speed machining (HSM) is presented in this work. Mechanical design optimization by means of simulations based on the finite element method (FEM) was applied in order to calculate the lathe bed deflections, the natural frequencies and the corresponding vibration amplitudes. For the parametric modeling, a prototype lathe to be used in conventional speed machining (CSM) with a cast iron bed was considered. The optimized parameter was the stress in the lathe bed, considering as a restriction the allowable deflection in a node of the machine-tool structure. The design variables were the height, the thickness, and the length of the wall of the lathe bed. The lathe bed was loaded with cutting and inertial forces due to HSM in order to demonstrate that the evaluated stresses and vibration amplitudes are in an acceptable level according to ISO Standards (system of limits and fits in workpieces). The results show the feasibility of using an Al-Cu alloy instead of cast iron in the fabrication of lathe beds. This increases the flexibility of manufacture.

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.

scholarly journals Modal analysis of an iced offshore composite wind turbine blade

2021 ◽  
pp. 0309524X2110116
Author(s):  
Oumnia Lagdani ◽  
Mostapha Tarfaoui ◽  
Mourad Nachtane ◽  
Mourad Trihi ◽  
Houda Laaouidi
Keyword(s):  
Wind Turbine ◽  
Modal Analysis ◽  
Turbine Blade ◽  
Natural Frequencies ◽  
Wind Turbine Blade ◽  
Resonance Phenomenon ◽  
Mode Shapes ◽  
The Finite Element Method ◽  
Numerical Work ◽  
Composite Blades

In the far north, low temperatures and atmospheric icing are a major danger for the safe operation of wind turbines. It can cause several problems in fatigue loads, the balance of the rotor and aerodynamics. With the aim of improving the rigidity of the wind turbine blade, composite materials are currently being used. A numerical work aims to evaluate the effect of ice on composite blades and to determine the most adequate material under icing conditions. Different ice thicknesses are considered in the lower part of the blade. In this paper, modal analysis is performed to obtain the natural frequencies and corresponding mode shapes of the structure. This analysis is elaborated using the finite element method (FEM) computer program through ABAQUS software. The results have laid that the natural frequencies of the blade varied according to the material and thickness of ice and that there is no resonance phenomenon.

Experimental Modal Analysis of Fan Vibration Frequency

2011 ◽  
Vol 138-139 ◽  
pp. 395-398
Author(s):  
Li Jun Wang ◽  
Zhi Yang Pan
Keyword(s):  
Modal Analysis ◽  
Vibration Frequency ◽  
Natural Frequencies ◽  
Experimental Modal Analysis ◽  
Resonance Vibration ◽  
Pneumatic Conveying ◽  
Combine Harvester

Fan is used for pneumatic conveying grain in the 4ZTL-1800 combine harvester threshing prior to cutting. In order to decrease power consume of it, the experimental modal analysis of fan was done by using hammer-hitting pulse-inspirit method. The natural frequencies of fan vibration is obtained, which is contrasted with inspirit frequency of fan, then resonance vibration of fan is found and its frequency is at 125Hz, which verifies the result of the experimental modal analysis.The results are beneficial to decrease power consume of fan.

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.

Effect of Weight on the Experimental Modal Analysis of Slender Cantilever Beams

2009 ◽  
Author(s):  
Lawrence Virgin ◽  
David Holland
Keyword(s):  
Modal Analysis ◽  
Natural Frequencies ◽  
Vertical Direction ◽  
Experimental Modal Analysis ◽  
Mode Shapes ◽  
Lateral Stiffness ◽  
Axial Loads ◽  
Horizontal Orientation ◽  
Beam System ◽  
Tensile Forces

It is relatively well known that axial loads tend to influence lateral stiffness and hence natural frequencies of slender structural components. Tensile forces tend to increase the lateral stiffness and compressive forces tend to reduce lateral stiffness, bringing with it the possibility of buckling. In many practical situations this is a negligible effect. But for very slender structures it can be important, including the effect of self-weight. This paper will focus attention on a form of double cantilever beam system, i.e., two cantilevers sharing a common hub. A differential axial load can be applied to this system via orientation in a gravitational field. We shall neglect the effect of gravity when the beams are in their horizontal orientation from a limited theoretical standpoint. It is of course present in the experiments but the cantilevers are much stiffer in one direction than the other, and the beams are clamped with their stiffer resistance in the vertical direction. The focus of the current paper is on the natural frequencies and mode shapes of a two-beam system from an experimental modal analysis perspective.

Performances of HSK Spindle/Toolholder Interface for HSM

2006 ◽  
Vol 532-533 ◽  
pp. 269-272
Author(s):  
Song Zhang ◽  
Xing Ai ◽  
Jian Feng Li ◽  
Xiu Li Fu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Distribution ◽  
Contact Stress ◽  
High Speed ◽  
Rapid Development ◽  
High Speed Machining ◽  
The Finite Element Method ◽  
Axial Movement ◽  
Contact Stress Distribution

With the rapid development of high-speed machining technology, more and more machining centers have been equipped with the HSK toolholders. In this paper, the performances of the HSK spindle/toolholder interface, such as the axial movement, the radial deflection and the contact stress distribution, were simulated by means of the finite element method and compared with the traditional BT interface. From the simulated results, it was pointed out that the performances of the HSK interface were obviously superior to that of the BT interface, and the HSK interface was much more suitable for high-speed machining.

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