Experimental Modal Research on the Cutting System of EBZ-75 Type Boom-Roadheader

2013 ◽  
Vol 278-280 ◽  
pp. 295-298
Author(s):  
Song Yong Liu ◽  
Chen Xu Luo
Keyword(s):  
Modal Analysis ◽  
Vibration Frequency ◽  
Vibration Analysis ◽  
Reference Data ◽  
Vertical Direction ◽  
Harmonic Excitation ◽  
Main Mechanism ◽  
Simulation Results ◽  
Cutting System ◽  
Response Rule

Based on the virtual prototype technology, using the ADAMS vibration analysis module, the displacement response rule of the main mechanism of the cutting system excited by sinusoidal harmonic excitation is obtained. And through the analysis of the results, the fact that 20HZ, 29HZ, 120HZ and 134 HZ are the sensitive frequency of the main mechanism is found out. Using the hammer test modal analysis methods to analysis cutting system of EBZ-75 type boom-roadheader, and compared with simulation results, the sensitive vibration frequency in vertical direction of the cutting system is achieved, which provides a test reference data for the optimize design of the cutting system.

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.

Schwingungsanalyse an Industrierobotern*/Vibration analysis of industrial robots

2019 ◽  
Vol 109 (09) ◽  
pp. 656-661
Author(s):  
A. Karim ◽  
C. Michalkowski ◽  
A. Lechler ◽  
A. Verl
Keyword(s):  
Modal Analysis ◽  
Active Control ◽  
Normal Mode ◽  
Vibration Analysis ◽  
Industrial Robots ◽  
Vibration Exciter ◽  
Dynamic Vibration ◽  
Vibration Behavior ◽  
Working Space ◽  
Electromagnetic Vibration

Dieser Beitrag untersucht experimentell das dynamische Schwingverhalten eines „KR-500–3 MT“ von Kuka mittels eines elektromagnetischen Schwingerregers (Shaker) an insgesamt 28 Messposen im Arbeitsraum. Diese Untersuchungsmethode ist neuartig, da die Ergebnisse mit einer Modalanalyse mit Impulshammeranregung verglichen werden. Ab der vierten Eigenmode entstehen Unterschiede aufgrund der Anregungsform. Zudem wird an jeder Pose eine Messung mit angezogener Motorbremse und eine mit aktiver Regelung durchgeführt und miteinander verglichen.   This paper explores experimentally the dynamic vibration behavior of a Kuka KR-500 MT, using an electromagnetic vibration exciter (shaker) on a total of 28 measuring poses in the working space. As such studies are not known, the results are compared to a modal analysis with impulse hammer excitation. Starting from the fourth normal mode, differences arise due to the form of excitation. Both measurements are performed and compared with each other on each pose with brakes applied as well as with active control.

Design and vibration analysis of a self-adaptive piston in a novel nanoimprint system

2017 ◽  
Vol 69 (4) ◽  
pp. 591-597
Author(s):  
Chaoran Liu ◽  
Yufeng Su ◽  
Jinzhao Yue ◽  
Junjie Wang ◽  
Weiwei Xia ◽  
...  
Keyword(s):  
Nanoimprint Lithography ◽  
Vibration Analysis ◽  
Design Methodology ◽  
The Self ◽  
Ball Screw ◽  
Piston Rings ◽  
Content Type ◽  
Simulation Results ◽  
The One ◽  
Self Adaptive

Purpose A self-adaptive piston is designed for the compressional gas cushion press nanoimprint lithography system. It avoids the lube pollution and high wear of traditional piston. Design/methodology/approach The self-adaptive piston device consists of symmetrical piston bodies, piston rings and other parts. The two piston bodies are linked by a ball-screw. The locking nut adjusts the distance between two piston bodies to avoid the piston rings from being stuck. The piston rings are placed between two piston bodies. Findings The simulation results based on COMSOL indicate that cylinder vibration caused by self-adaptive piston is 15.9 times smaller than the one caused by a traditional piston. Originality/value The self-adaptive piston is superior to the traditional piston in decreasing cylinder vibration.

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.

Vibration Analysis for NDE of Ceramic Components

2021 ◽  
Author(s):  
Bernd Köhler ◽  
Kilian Tschöke ◽  
Mareike Stephan ◽  
Sergey Gartsev ◽  
Martin Barth
Keyword(s):  
Modal Analysis ◽  
Simultaneous Measurement ◽  
Vibration Analysis ◽  
Microphone Array ◽  
Acoustic Measurements ◽  
Laser Doppler Vibrometry ◽  
Mode Identification ◽  
Vibration Excitation ◽  
Ceramic Components ◽  
Signal Evaluation

Abstract In this contribution we study vibration testing for ceramic parts on the example of an electrolyte cup, used in a prospective power cells design. An adapted experimental arrangement for the vibration excitation and the acoustic measurements was built and tested. In parallel, extensive numerical modal analysis simulations were performed using ANSYS. The resonance spectra obtained by modelling agree with the experimentally determined spectra in such a way that the experimentally determined eigenfrequencies can be assigned to the cup modes. The correctness of this identification was verified by direct mode visualization with scanning laser doppler vibrometry. A much faster and potentially in-line capable method for experimental mode identification is the simultaneous measurement at several points using a microphone array and subsequent signal evaluation with operational modal analysis. This procedure was successfully tested. Features in the spectra connected with the presence of flaws are discussed. These features include the drop of some eigenfrequencies and the splitting of degenerated modes.

Large Amplitude Forced Vibration Analysis of Stiffened Plates under Harmonic Excitation

2012 ◽  
pp. 26-61
Author(s):  
Anirban Mitra ◽  
Prasanta Sahoo ◽  
Kashinath Saha
Keyword(s):  
Free Vibration ◽  
Forced Vibration ◽  
Large Amplitude ◽  
Vibration Analysis ◽  
Mathematical Formulation ◽  
Free Vibration Analysis ◽  
Harmonic Excitation ◽  
Stiffened Plates ◽  
Backbone Curve ◽  
Forced Vibration Analysis

Large amplitude forced vibration behaviour of stiffened plates under harmonic excitation is studied numerically incorporating the effect of geometric non-linearity. The forced vibration analysis is carried out in an indirect way in which the dynamic system is assumed to satisfy the force equilibrium condition at peak excitation amplitude. Large amplitude free vibration analysis of the same system is carried out separately to determine the backbone curves. The mathematical formulation is based on energy principles and the set of governing equations for both forced and free vibration problems derived using Hamilton’s principle. Appropriate sets of coordinate functions are formed by following the two dimensional Gram-Schmidt orthogonalization procedure to satisfy the corresponding boundary conditions of the plate. The problem is solved by employing an iterative direct substitution method with an appropriate relaxation technique and when the system becomes computationally stiff, Broyden’s method is used. The results are furnished as frequency response curves along with the backbone curve in the dimensionless amplitude-frequency plane. Three dimensional operational deflection shape (ODS) plots and contour plots are provided in a few cases.

scholarly journals Hybrid Method of Modal Analysis and Laser Shock Scanning to Visualize the Pyroshock Propagation in a Tension Joint

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Yong-Woon Kim ◽  
Jae-Kyeong Jang ◽  
Jung-Ryul Lee ◽  
Hak-Seong Gim
Keyword(s):  
Modal Analysis ◽  
Hybrid Method ◽  
Response Spectrum ◽  
Near Field ◽  
Low Frequency ◽  
Simulation Method ◽  
Experimental Simulation ◽  
Laser Shock ◽  
Simulation Results ◽  
Tension Joint

The use of pyrodevices in the aerospace industry has been increasing because of their ability to implement separation missions with a small weight, for example, space launchers, spacecrafts, and missiles. During operation, pyrodevices generate pyroshock, which causes failures of electronic devices. Recently, a pyroshock simulation method using laser shock has been developed to evaluate the risk of pyroshock before flight mission. However, depending on the structure, the laser shock showed some difficulty simulating pyroshock in the low-frequency regime accompanying vibration. Therefore, in this study, we developed a hybrid method of numerical modal analysis and laser shock-based experimental simulation to visualize the pyroshock propagation in all the relevant frequency regimes. For the proof of concept of the proposed method, we performed experiments of explosive bolt-induced shock and pyrolock-induced shock in the open-box-type tension joint and compared the hybrid simulation results with actual pyroshock. From the results, we obtained the simulated time-domain signal with an averaged peak-to-peak acceleration difference (PAD) of 11.2% and the shock response spectrum (SRS) with an averaged mean acceleration difference (MAD) of 28.5%. In addition, we were able to visualize the simulation results in the temporal and spectral domains to compare the pyroshock induced by each pyrodevice. A comparison of the simulations showed that the pyrolock had an impulse level of 1/12 compared to the explosion bolt. In particular, it was confirmed that the pyrolock-induced shock at the near field can cause damage to the electronic equipment despite a smaller impulse than that of the explosive bolt-induced shock. The hybrid method developed in this paper demonstrates that it is possible to simulate pyroshock for all the frequency regimes in complex specimens and to evaluate the risk in the time and frequency domain.

Operational modal analysis of a nonlinear oscillation system under a harmonic excitation

2020 ◽  
pp. 095440622097755
Author(s):  
Xuchu Jiang ◽  
Feng Jiang ◽  
Biao Zhang
Keyword(s):  
Modal Analysis ◽  
Nonlinear Oscillation ◽  
Normal Modes ◽  
Nonlinear Normal Modes ◽  
Harmonic Excitation ◽  
Forced Response ◽  
Operational Modal Analysis ◽  
Single Frequency ◽  
Modal Parameters ◽  
Oscillation System

Operational modal analysis (OMA) is a procedure that allows the modal parameters of a structure to be extracted from the measured response to an unknown excitation generated during operation. Nonlinearity is inevitably and frequently encountered in OMA. The problem: The traditional OMA method based on linear modal theory cannot be applied to a nonlinear oscillation system. The solution: This paper aims to propose a nonlinear OMA method for nonlinear oscillation systems. The new OMA method is based on the following: (1) a self-excitation phenomenon is caused by nonlinear components; (2) the nonlinear normal modes (NNMs) of the system appear under a single-frequency harmonic excitation; and (3) using forced response data, the symbolic regression method (SR) can be used to automatically search for the NNMs of the system, whose modal parameters are implicit in the expression structure expressing each NNM. The simulation result of a three-degree-of-freedom (3-DOF) nonlinear system verifies the correctness of the proposed OMA method. Then, a disc-rod rotor model is considered, and the proposed OMA method’s capability is further evaluated.

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