Dynamic and Modal Analysis of a Snake like Robot

2020 ◽  
Vol 896 ◽  
pp. 203-210
Author(s):  
Leonard Marius Ciurezu-Gherghe ◽  
Nicolae Dumitru ◽  
Ionuţ Daniel Geonea ◽  
Cristian Copiluși
Keyword(s):  
Dynamic Analysis ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Vibration Modes ◽  
Time Frequency

In this paper a modal and dynamic analysis of a snake like robot is performed. Modal analysis consist in determination of own vibration modes and natural frequencies. The proposed dynamic analysis was performed in order to determine the variation time/frequency laws for the cinematic and dynamics parameters.

Dynamic Analysis of the Structure of Automobile Components, Obtained by Powder Metallurgy

2020 ◽  
Vol 896 ◽  
pp. 119-126
Author(s):  
Anca Didu ◽  
Nicolae Dumitru ◽  
Cristina Ileana Pascu ◽  
Violeta Cristina Contoloru
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Models ◽  
Combustion Engine ◽  
Practical Interest ◽  
Wide Field ◽  
Connecting Rod ◽  
Time Frequency ◽  
Different Types ◽  
Automobile Components

The analysis of the dynamic behavior of parts from the structure of the cationing mechanism of an internal combustion engine in 4 steps is followed. Thus, kinetic and dynamic models were developed for the motor mechanism considered as an assembly consisting of crankshaft, connecting rods, bearings and pistons. Dynamic models were built mainly in the Ansys program, based on the finite element method. The following problems were addressed, namely the dynamic analysis, with the determination of the response in time for displacements, stresses and deformations and also the vibration analysis in order to analyze the frequency response for the kinematic parameters of the whole system, but also of the component elements. Dynamic models for the numerical processing of the two types of analyzes were designed in a parameterized system with multiple possibilities of working on different time, frequency or different types of loadings and connection conditions. The purpose of this paper is to study the dynamic response of the main elements of the mechanism, for different types of materials. Given the wide field of applicability in automobiles, the technology for obtaining parts from sintered powders, the studies were realized for the cases when the connecting rod and the bearings are made of metallic powders, respectively of steel, to be extended for more complex cases, when we consider the influence of lubricant and temperature distribution in areas of practical interest.

scholarly journals Dynamic Modal Analysis of Vertical Machining Centre Components

2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
Anayet U. Patwari ◽  
Waleed F. Faris ◽  
A. K. M. Nurul Amin ◽  
S. K. Loh
Keyword(s):  
Modal Analysis ◽  
Mode Shape ◽  
Modal Testing ◽  
Machine Component ◽  
Vibration Modes ◽  
Structural Dynamic ◽  
Element Simulation ◽  
Analysis Technique ◽  
Design Software

The paper presents a systematic procedure and details of the use of experimental and analytical modal analysis technique for structural dynamic evaluation processes of a vertical machining centre. The main results deal with assessment of the mode shape of the different components of the vertical machining centre. The simplified experimental modal analysis of different components of milling machine was carried out. This model of the different machine tool's structure is made by design software and analyzed by finite element simulation using ABAQUS software to extract the different theoretical mode shape of the components. The model is evaluated and corrected with experimental results by modal testing of the machine components in which the natural frequencies and the shape of vibration modes are analyzed. The analysis resulted in determination of the direction of the maximal compliance of a particular machine component.

Determination of Natural Frequencies of Spherical Cells

2008 ◽  
Author(s):  
Marjan Molavi ◽  
Ali Bonakdar ◽  
Ion Stiharu
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Living Cells ◽  
Health Condition ◽  
Comprehensive Analysis ◽  
Yeast Cells ◽  
Spherical Cells

In this paper, a finite element (FE) and scaled-up experimental modal analysis are employed to estimate the natural frequencies of the baker’s yeast cells. It is apparent the mechanical properties of the living cells and particularly the natural frequencies are highly related to the health condition of cells, and therefore a comprehensive analysis is carried out to determine the natural frequencies of individual cells.

scholarly journals Computation of Rayleigh damping coefficient of a rectangular submerged floating tunnel (SFT)

2020 ◽  
Vol 2 (5) ◽  
Author(s):  
Md. Hafizur Rahman ◽  
Chhavi Gupta
Keyword(s):  
Dynamic Analysis ◽  
Modal Analysis ◽  
Fundamental Frequency ◽  
Significant Role ◽  
Analytical Study ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Damping Coefficients ◽  
Rayleigh Damping ◽  
Submerged Floating Tunnel

Abstract The dynamic behaviors of the submerged floating tunnel, a buoyant structure of high slenderness, are a matter of concern since it is surrounded by the huge hazardous effects called hydrodynamic, seismic and functional action. Modal analysis and Rayleigh damping coefficients play a significant role in dynamic analysis, but it is not sufficiently simple to predict the reasonable damping coefficients named α and β. The present paper outlines the modal analysis and the calculation of Rayleigh damping coefficients that provide the natural frequencies, mode shapes, mode’s motion as well as coefficients α and β. To compute the Rayleigh damping coefficients, 2–10% damping to the critical damping has been assumed for this analytical study. For the analysis, an FEA-based software ANSYS is utilized successfully. It has been seen that the fundamental frequency and Rayleigh damping coefficients (α = 0.946 and β = 0.00022) of the SFT are reasonably high and it is under noticeable damping.

Experimental and Numerical Modal Analysis of Gearbox Casing in a Polishing Machinery

2009 ◽  
Vol 69-70 ◽  
pp. 560-564
Author(s):  
Yang Yu Wang ◽  
Shi Ming Ji ◽  
Dong Hui Wen ◽  
Xian Zhang
Keyword(s):  
Modal Analysis ◽  
Natural Frequencies ◽  
Test System ◽  
Structural Vibration ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Vibration Test ◽  
3D Fem ◽  
Fem Model

Vibrations in polishing machinery may affect the manual or automatic controls and reduce the efficiency of the operations to be carried out. In this article, an experimental and numerical analysis on the dynamic characteristic of a gearbox casing in polishing machinery have been carried out. The numerical investigation was achieved with NASTRAN based on a 3D FEM model and the experimental modal analysis for the determination of the natural frequencies and the associated eigenmodes of the gearbox casing with LMS structural vibration test system was performed. The fundamental modal parameters including the first 10-order natural frequencies, damping ratios and mode shapes were estimated and identified. Analytical and experimental results have been compared and discussed. Agreement between measurements and calculations is satisfactory and the results can be used as reliable reference for improving the dynamic behavior of the gearbox casing.

Modal Analysis of a Drilling Machine for Blades of Wind Turbines

2011 ◽  
Vol 308-310 ◽  
pp. 1850-1854
Author(s):  
Yong Shu Jiao ◽  
Yong Liang Zhang ◽  
Mu Hui Fan
Keyword(s):  
Modal Analysis ◽  
Wind Turbines ◽  
Software Package ◽  
Natural Frequencies ◽  
Position Angle ◽  
Simplified Model ◽  
Drilling Machine ◽  
Structural Stress ◽  
Specific Working

In this paper, the authors conducted a modal analysis of a drilling machine for blades of wind turbines. A simplified model of the machine was established with a commercial FEM software package, Ansys. At a specific working position the first six order natural frequencies were calculated and the results obtained from two different contacting manners were compared. The influence of static structural stress induced by gravitational load on natural frequency was also evaluated. The variations of the natural frequencies of the machine with the position angle of the rotary box were subsequently obtained. This is helpful for the determination of range of the excitation frequencies.

scholarly journals Component Mode Synthesis Method Applied to Acoustic Resonators in Ducts for Structural Vibration Analysis

2020 ◽  
Vol 25 (4) ◽  
pp. 498-503
Author(s):  
Jose Manuel Bautista Ordóñez ◽  
Maria Alzira de Araújo Nunes
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Component Mode Synthesis ◽  
Structural Vibration ◽  
Structural Systems ◽  
Vibration Modes ◽  
The Finite Element Method ◽  
Element Method

Tubular structural systems appear in many industrial applications, such as heating, ventilation, and air conditioning systems, which are responsible for making any enclosed environment remain within a temperature, humidity, and cleanliness range. This kind of system has its applications in the internal environmental comfort of industrial spaces, buildings, and vehicles. Several of these spaces have industrial processes that generate high sound frequencies and mechanical vibrations that need to be adequately controlled to meet both environmental and health norms. With the intention to analyze the structural vibration of tubular systems, the modal analysis technique is a classical methodology for the extraction of natural frequencies and vibration modes. Among the various techniques of modal analysis, numerical methodologies such as the finite element method, and also analytical methodologies such as the Component Mode Synthesis (CMS) can be found. CMS is one of the leading modeling tools for complex systems that are applied to large systems. The method uses a modal superset and consists of separately modeling individual components of a structure and coupling them into a single system. The objective of this work is to demonstrate the application of the CMS technique through the estimation of natural frequencies and vibration modes in a simplified tubular structural system formed by two substructures, using MATLAB and ANSYS. The validation of the results was done through numerical modeling using the finite element method using and ANSYS software. The results obtained were satisfactory, thus demonstrating the feasibility of applying the CMS technique to an analysis of structural vibration in tubular structural systems.

Modal analysis of violin bodies with back plates made of different wood species

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 7687-7713
Author(s):  
Vasile Ghiorghe Gliga ◽  
Mariana Domnica Stanciu ◽  
Silviu Marian Nastac ◽  
Mihaela Campean
Keyword(s):  
Modal Analysis ◽  
Quality Factor ◽  
Wood Species ◽  
Natural Frequencies ◽  
Musical Instrument ◽  
Experimental Modal Analysis ◽  
Acoustic Properties ◽  
Spectral Components ◽  
The Impact

This research investigated the potential of some European wood species for use in the manufacturing of the back plates of violins as an alternative to the quite rare curly maple wood. An experimental modal analysis was employed for this purpose using the impact hammer method. The modal analysis was performed both on the top and back plates, as individual structures, and then after being integrated into the violin body. The modal analysis envisaged the determination of the eigenfrequencies (natural frequencies), the number of spectral components, and the quality factor, as important indicators of the acoustic performances of a musical instrument. A multi-criteria analysis based on the values obtained for these indicators allowed interesting findings concerning the acoustic properties of the selected wood species (hornbeam, willow, ash, bird-eye maple, walnut, and poplar). Same as curly maple, they all have special aesthetics, but only hornbeam, willow, and ash wood proved to have acoustic potential as well.

Experimental Modal Analysis of a First Stage Blade in ALSTOM Gas Turbine

2014 ◽  
Vol 624 ◽  
pp. 303-307 ◽  
Author(s):  
Arash Rahmani ◽  
Ahmad Ghanbari ◽  
Ali Mohammadi
Keyword(s):  
Modal Analysis ◽  
Gas Turbine ◽  
Natural Frequencies ◽  
Turbine Blades ◽  
Vibration Modes ◽  
Ansys Software ◽  
Critical Problems ◽  
The Subject ◽  
Laser Digitizer ◽  
Acceptable Agreement

Failures of turbine blades are one of the most critical problems in power generating industry. Among the different failure mechanisms, resonant vibration of blades has a major role and therefore is the subject of many recent research works. Therefore, in this paper, modal analysis of a first stage blade in ALSTOM gas turbine is investigated and natural frequencies and vibration modes of blade are found in various conditions. For this purpose, a cloud-point model of a gas turbine blade has been created using 3D Laser Digitizer. Then the numerical calculation by finite element method using ANSYS software based on experimental test conditions is utilized and Experimental natural frequencies have been obtained. The results show acceptable agreement between the experimental and FEM results.

Dynamic Analysis and Structure Improvements on Machine Tool Bed

2012 ◽  
Vol 605-607 ◽  
pp. 1541-1544
Author(s):  
Lei Sun ◽  
Ming Hai Wang ◽  
Bao Feng Shan ◽  
Jin Lan Bai ◽  
Hai Zhou
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Machine Tool ◽  
Dynamic Analysis ◽  
Modal Analysis ◽  
Natural Frequencies ◽  
Vibration Modal ◽  
Element Method

The modal analysis of machine tool bed was done by means of finite element method. Find out its characteristics of vibration modal. Then structure improvements on arrangement of tool bed reinforcing plates were done. After the structure improvements the natural frequencies of the tool bed were improved.

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