scholarly journals Vibration Analysis of Structures with Rotation and Reflection Symmetry

1996 ◽  
Vol 3 (4) ◽  
pp. 303-311
Author(s):  
Baojian Li ◽  
Xiaozhong Zheng ◽  
Jie Zhao
Keyword(s):  
Theoretical Analysis ◽  
Eigenvalue Problem ◽  
Vibration Analysis ◽  
Group Representation ◽  
Computer Time ◽  
Modal Testing ◽  
Structural Vibration ◽  
Reflection Symmetry ◽  
Analysis Method ◽  
Stiffness Matrices

The article applies group representation theory to the vibration analysis of structures with Cnvsymmetry, and presents a new structural vibration analysis method. The eigenvalue problem of the whole structure is divided into much smaller subproblems by forming the mass and stiffness matrices of one substructure and than modifying them to form mass and stiffness matrices in each irreducible subspace, resulting in the saving of computer time and memory. The modal characteristics of structures with Cnvsymmetry are derived from theoretical analysis. Computation and modal testing are used to verify the validity of the theoretical deductions.

Methodology for Designing Low-Vibration Structures for Movable Mechanisms

1999 ◽  
Author(s):  
Shinobu Yoshida ◽  
Yoshiko Kawabe
Keyword(s):  
Numerical Simulation ◽  
Vibration Analysis ◽  
Simulation Method ◽  
Optimization Method ◽  
Structural Vibration ◽  
Simulation Methods ◽  
Analysis Method ◽  
Module Design ◽  
Numerical Simulation Methods ◽  
Design Steps

Abstract The methodology dealt with here is the way how to use numerical simulation methods corresponding to different design steps. The methods are a budget simulation method for mechanical specification design step, a structural vibration analysis method using a finite element method and an optimization method. The latter two methods are used for the module design and parts design steps. Case studies reviewing the works of authors show the effectiveness of the methodology.

scholarly journals On Dynamics of Spinning Structures

2012 ◽  
Author(s):  
K. K. Gupta ◽  
A. Ibrahim
Keyword(s):  
Finite Element ◽  
Eigenvalue Problem ◽  
Vibration Analysis ◽  
Matrix Eigenvalue Problem ◽  
Matrix Eigenvalue ◽  
Stiffness Matrices ◽  
Simultaneous Iteration ◽  
Line Elements ◽  
Gyroscopic Systems ◽  
Iteration Technique

This paper provides details of developments pertaining to vibration analysis of gyroscopic systems, that involves a finite element structural discretization followed by the solution of the resulting matrix eigenvalue problem by a progressive, accelerated simultaneous iteration technique. Thus Coriolis, centrifugal and geometrical stiffness matrices are derived for shell and line elements, followed by the eigensolution details as well as solution of representative problems that demonstrates the efficacy of the currently developed numerical procedures and tools.

Efficient solution of the fuzzy eigenvalue problem in structural dynamics

2014 ◽  
Vol 31 (5) ◽  
pp. 864-878 ◽  
Author(s):  
Yuying Xia ◽  
M. Friswell
Keyword(s):  
Eigenvalue Problem ◽  
Perturbation Method ◽  
Degrees Of Freedom ◽  
Eigenvalue Problems ◽  
Structural Vibration ◽  
Design Problems ◽  
Content Type ◽  
Analysis And Design ◽  
Stiffness Matrices ◽  
Fuzzy Eigenvalues

Purpose – Many analysis and design problems in engineering and science involve uncertainty to varying degrees. This paper is concerned with the structural vibration problem involving uncertain material or geometric parameters, specified as fuzzy parameters. The requirement is to propagate the parameter uncertainty to the eigenvalues of the structure, specified as fuzzy eigenvalues. However, the usual approach is to transform the fuzzy problem into several interval eigenvalue problems by using the α-cuts method. Solving the interval problem as a generalized interval eigenvalue problem in interval mathematics will produce conservative bounds on the eigenvalues. The purpose of this paper is to investigate strategies to efficiently solve the fuzzy eigenvalue problem. Design/methodology/approach – Based on the fundamental perturbation principle and vertex theory, an efficient perturbation method is proposed, that gives the exact extrema of the first-order deviation of the structural eigenvalue. The fuzzy eigenvalue approach has also been improved by reusing the interval analysis results from previous α-cuts. Findings – The proposed method was demonstrated on a simple cantilever beam with a pinned support, and produced very accurate fuzzy eigenvalues. The approach was also demonstrated on the model of a highway bridge with a large number of degrees of freedom. Originality/value – This proposed Vertex-Perturbation method is more efficient than the standard perturbation method, and more general than interval arithmetic methods requiring the non-negative decomposition of the mass and stiffness matrices. The new increment method produces highly accurate solutions, even when the membership function for the fuzzy eigenvalues is complex.

Research on transformer vibration monitoring and diagnosis based on Internet of things

2021 ◽  
Vol 30 (1) ◽  
pp. 677-688
Author(s):  
Zhenzhuo Wang ◽  
Amit Sharma
Keyword(s):  
Internet Of Things ◽  
Power Distribution ◽  
Vibration Analysis ◽  
Vibration Monitoring ◽  
Power Transformers ◽  
Normal Operation ◽  
Analysis Method ◽  
Power Distribution Network ◽  
Monitoring And Diagnosis ◽  
Distribution Transformers

Abstract A recent advent has been seen in the usage of Internet of things (IoT) for autonomous devices for exchange of data. A large number of transformers are required to distribute the power over a wide area. To ensure the normal operation of transformer, live detection and fault diagnosis methods of power transformers are studied. This article presents an IoT-based approach for condition monitoring and controlling a large number of distribution transformers utilized in a power distribution network. In this article, the vibration analysis method is used to carry out the research. The results show that the accuracy of the improved diagnosis algorithm is 99.01, 100, and 100% for normal, aging, and fault transformers. The system designed in this article can effectively monitor the healthy operation of power transformers in remote and real-time. The safety, stability, and reliability of transformer operation are improved.

The Theoretical Analysis of Performance Evaluation Connotation of Rural Highway Projects

2012 ◽  
Vol 204-208 ◽  
pp. 1848-1856
Author(s):  
Wu Gong Wang ◽  
Rong Guo Ma ◽  
Kun Feng ◽  
Guo Hua Liang
Keyword(s):  
Public Finance ◽  
Performance Evaluation ◽  
Theoretical Analysis ◽  
Swot Analysis ◽  
Project Performance ◽  
Analysis Method ◽  
Highway Projects ◽  
Rural Highway ◽  
Analysis Of Performance ◽  
Highway Project

On the basis of defining the concept of rural highway project performance, the necessity of the project performance evaluation of rural highway is analyzed. According to the theories of government's public function, fiduciary responsibilities accountability and public finance, the relation between rural highway and public finance are made researches on. Furthermore,with the application of the demand level theory of Maslow, the interrelationship among objects of the rural highway project performance evaluation is made an analysis of, and on top of that, combined with SWOT analysis method, the demand and goal of rural highway project performance evaluation are put forward.

A Time-Domain DQ Approach for Vibration Analysis of Beams

2013 ◽  
Vol 631-632 ◽  
pp. 957-961
Author(s):  
Jian She Peng ◽  
Gang Xie ◽  
Liu Yang ◽  
Yu Quan Yuan
Keyword(s):  
Time Domain ◽  
Vibration Analysis ◽  
Differential Quadrature Method ◽  
Boundary Value ◽  
Linear Equations ◽  
Initial Boundary ◽  
Differential Quadrature ◽  
Structural Vibration ◽  
Quadrature Method ◽  
Initial Boundary Value

This paper presents a new time-domain DQ (differential quadrature) method for structural vibration analysis. It adopts differential quadrature method both in space domain and in time domain on the basis of governing partial differential equation and initial-boundary value condition of vibration problems of structures, and gets new differential quadrature linear equations with complete initial-boundary value conditions for solving all parameters of the displacement-field. The examples in this paper show the time-domain differential quadrature method is a useful and efficient tool for structural vibration analysis.

Dynamic analysis of two dimensional simply supported orthotropic bridge decks

1978 ◽  
Vol 5 (1) ◽  
pp. 58-69 ◽  
Author(s):  
G. G. Kulkarni ◽  
S. F. Ng
Keyword(s):  
Theoretical Analysis ◽  
Forced Vibration ◽  
Vibration Analysis ◽  
Bridge Decks ◽  
Two Dimensional ◽  
Amplification Factors ◽  
Simply Supported ◽  
Forced Vibration Analysis ◽  
Critical Sections

Forced vibration analysis of two dimensional bridge deck structures involves complex mathematical procedures and therefore analysis is often based on beam idealization of equivalent plates. This simplification yields close agreement only for long span bridges where plate action is relatively insignificant. However, such a concept of beam idealization cannot be successfully utilized in the case of short span bridges where plate action is predominant and where the determination of the distribution of dynamic deflections and amplification factors at critical sections of such plates is of prime concern. The principal objective of the present investigation is the forced vibration analysis of longitudinally stiffened, simply supported orthotropic bridge decks utilizing a new concept of interconnected beam idealization. The theoretical analysis deals with determination of amplification factors and dynamic deflections along critical sections of the plate treated as a series of interconnected beams. The aspect ratios of the plates under investigation as series of interconnected beams are designed to cover a wide range of plate to beam transition. The theoretical analysis is supplemented by an extensive experimental programme.In conclusion, it is seen that this concept of interconnected beam idealization not only takes into account the plate action of the deck structure but also reduces greatly the complexity of mathematical formulation. A good comparison between the theoretical and the experimental results indicates that this concept can be used to advantage for analysis and, within certain limitations, for design purposes.

scholarly journals Suppression of Vibration Using Passive Receptance Method with Constrained Minimization

2008 ◽  
Vol 15 (6) ◽  
pp. 639-654 ◽  
Author(s):  
Murat Tursun ◽  
Eşref Eşkinat
Keyword(s):  
Vibration Analysis ◽  
Dynamic Stiffness ◽  
Aerospace Engineering ◽  
Graph Representation ◽  
Structural Vibration ◽  
Optimal Parameters ◽  
Combined System ◽  
Receptance Method ◽  
Mass Spring

Structural vibration analysis is used to suppress unwanted vibrations in many areas such as aerospace engineering, manufacturing, defense, automotive, etc. As a result of suppressing the unwanted vibration, the quality of the product is improved. Focusing on the minimization of the vibration amplitudes via a concept of receptance, a new and efficient method for calculating the receptance of a translational mass-spring-damper system with N masses and M absorbers (where N and M are any positive integer) is developed. The receptance of the combined system, in terms of the parameters of the main and absorber systems is derived, separately. The optimal parameters of the absorbers are then found. A methodology is derived using dynamic stiffness and linear graph representation in order to verify the dynamic stiffness, i.e., the inverse of the receptance, of the system.

Oscillation analysis of numerical solution of Nonlinear Operator Equation

2021 ◽  
Vol 7 (5) ◽  
pp. 2111-2126
Author(s):  
Yang Zhou ◽  
Cuimei Li
Keyword(s):  
Numerical Solution ◽  
Operator Equation ◽  
Vibration Analysis ◽  
Nonlinear Operator ◽  
Vibration Spectrum ◽  
Nonlinear Operator Equation ◽  
Analysis Method ◽  
Analysis Model ◽  
Oscillation Analysis ◽  
Analysis Equation

There is a problem of low accuracy in the analysis of the vibration of the numerical solution of the nonlinear operator equation. In this work, the vibration analysis equation is constructed by the step-by-step search method, and the vibration quadrant of the equation is divided by the dichotomy method. The vibration spectrum is determined by the iteration method, and the vibration analysis model of the numerical solution of the nonlinear operator equation is constructed. The vibration analysis of the numerical solution of the nonlinear operator equation is completed based on the solution of the model and the numerical calculation and display of the step-by-step Fourier. The experimental results show that the proposed method has higher accuracy than the traditional vibration analysis method, which meets the requirements of the vibration analysis of the numerical solution of nonlinear operator equation.

Structural Vibration Analysis Caused by Piping Resonance

2007 ◽  
Vol 31 (2) ◽  
pp. 190-196 ◽  
Author(s):  
Dong-Sik Gu ◽  
Hyo-Jung Kim ◽  
Han-Eol Jeong ◽  
Hak-Eun Kim ◽  
Byeong-Keun Choi
Keyword(s):  
Vibration Analysis ◽  
Structural Vibration
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