Analysis of Dynamic Stress Responses in Structural Vibration

1997 ◽  
Author(s):  
Liping Huang
Keyword(s):  
Stress Response ◽  
Frequency Response ◽  
Normal Mode ◽  
Stress Responses ◽  
Dynamic Stress ◽  
Complex Stress ◽  
Structural Vibration ◽  
Mode Shapes ◽  
Response Analysis ◽  
Shell Elements

Abstract This paper describes basic concepts and finite element method of dynamic stress response analysis. It provides basics of stress modal analysis and frequency response analysis. The paper defines concepts of normal mode stresses and complex stress frequency response functions for shell elements and shows that element stress responses in both time and frequency domains can be expressed as superposition of normal mode stresses. It demonstrates that element stress response solutions have the similar forms to those of node displacement responses and that normal mode stresses in stress analysis play the same role as mode shapes in normal vibration analysis.

Experimental Study for Extraction of Normal Modes

1995 ◽  
Author(s):  
S. Y. Chen ◽  
M. S. Ju ◽  
Y. G. Tsuei
Keyword(s):  
Frequency Response ◽  
Normal Mode ◽  
Normal Modes ◽  
Measurement Data ◽  
Mode Shapes ◽  
Complex Frequency ◽  
Response Functions ◽  
Frequency Response Functions ◽  
Incomplete System ◽  
Coupled Structures

Abstract A frequency-domain technique to extract the normal mode from the measurement data for highly coupled structures is developed. The relation between the complex frequency response functions and the normal frequency response functions is derived. An algorithm is developed to calculate the normal modes from the complex frequency response functions. In this algorithm, only the magnitude and phase data at the undamped natural frequencies are utilized to extract the normal mode shapes. In addition, the developed technique is independent of the damping types. It is only dependent on the model of analysis. Two experimental examples are employed to illustrate the applicability of the technique. The effects due to different measurement locations are addressed. The results indicate that this technique can successfully extract the normal modes from the noisy frequency response functions of a highly coupled incomplete system.

Transient Process Response Analysis of Forced Synchronous Elliptical Vibrating Screen

2010 ◽  
Vol 118-120 ◽  
pp. 962-966
Author(s):  
Lian Wan Zhang ◽  
Zhong Jun Yin ◽  
Xin Sun ◽  
Zhi Chao Tang
Keyword(s):  
Steady State ◽  
Harmonic Analysis ◽  
Transient Process ◽  
Stress Level ◽  
Stress Responses ◽  
Large Scale ◽  
Dynamic Stress ◽  
Response Analysis ◽  
Vibrating Screen ◽  
Existing Structure

This paper is based on the scientific modeling of large-scale elliptical vibrating screen which is widely used in many fields. Through the tool of harmonic analysis in ANSYS, the dynamic stress responses during steady state and transient process are studied. The results confirmed that the existing structure can fulfill the requirement of dynamic stress level. Another contribution of this paper is to provide a new idea to analyze the transient process response, especially when the motor data are not sure.

Dynamic Characteristics Analysis and Topology Optimization of Column Based on Finite Element Method

2013 ◽  
Vol 721 ◽  
pp. 541-544
Author(s):  
Jing Chen ◽  
Ze Long Yang ◽  
Xian Xuan Li
Keyword(s):  
Finite Element ◽  
Topology Optimization ◽  
Frequency Response ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Response Analysis ◽  
Response Curves ◽  
Element Analysis ◽  
Column Structure

Aiming to improve the dynamic and static characteristics of a type of machining center column, the finite element modal analysis and harmonic response analysis of the column are performed, and this paper analyzes the dynamic characteristics of the column based on the first five mode shapes and natural frequencies of the column and the displacement - frequency response curves of the column. Topology optimization analysis of the column is performed with ANSYS, and the finite element analysis is performed on the column again after the column structure is improved based on the optimal distribution of material of the column structure and the design experience of column. The result shows that the first five natural frequencies of the column increase, the peak of the displacement - frequency response of the column decrease, and the dynamic characteristics are improved significantly.

A Simple Method for Extracting Normal Modes

1993 ◽  
Author(s):  
S. Y. Chen ◽  
M. S. Ju ◽  
Y. G. Tsuei
Keyword(s):  
Frequency Response ◽  
Normal Mode ◽  
Response Function ◽  
Frequency Response Function ◽  
Normal Modes ◽  
Mode Shapes ◽  
Phase Information ◽  
Simple Method ◽  
Resonant Frequencies ◽  
Complex Modes

Abstract A simple method for extracting the normal modes of structures is developed. The frequency response function relation between the complex and the normal modes is derived and a technique is developed to calculate the normal modes from the identified (damped) complex modes. In this method, only the magnitude and phase information at resonant frequencies are needed for extracting the normal mode shapes. A numerical example is employed to illustrate the theory. The results indicate that this method is more robust than other methods when the frequency response measurements are contaminated with noise.

Transient Response Analysis of Damped Rotor Systems by the Normal Mode Method

1975 ◽  
Author(s):  
A. J. Dennis ◽  
R. H. Eriksson ◽  
L. H. Seitelman
Keyword(s):  
Steady State ◽  
Normal Mode ◽  
Transient Response ◽  
Transient Analysis ◽  
Equations Of Motion ◽  
Forced Response ◽  
Mode Shapes ◽  
Response Analysis ◽  
Rotor Systems ◽  
Incremental Formulation

A method to determine the transient response of damped single or multi-shaft rotor systems is presented. The rotor systems are idealized as rotating concentrated masses connected by massless beams, discrete springs, and dampers. The springs may have piecewise constant springs rates to simulate the stiffening effect of parts coming in contact after displacement through an initial offset. Arbitrary forcing functions are allowed. The method employs an incremental formulation in which damping gyroscopic and nonlinear terms are treated as external loads which are lagged in time. The equations of motion are uncoupled by performing a normal mode expansion of the response solution in terms of the non-rotating, undamped eigenvectors and their associated eigenvalues; modes and natural frequencies are obtained from a standard Prohl analysis. An analytical solution is used for each step of the incremental analysis. This technique has been used to study the response of a number of rotor systems to the sudden application of a rotating imbalance load. The systems studied include a dual shaft model of a rig, a single-shaft case from the written literature and a large multi-line (multi-shaft) system. The transient analysis was run out to steady-state and close agreement obtained with results from an independent steady-state forced response analysis. Orthogonality relations between the mode shapes were observed to be critical to the quality of the results. It was observed that transient analysis of multi-line systems can be accurately predicted only if the higher frequency modes which are participating in the response are included in the normal mode solution.

Dynamic Mechanical Analysis of Automotive Gearbox Casing

2011 ◽  
Vol 230-232 ◽  
pp. 539-543 ◽  
Author(s):  
Guang Yao Zhao ◽  
Peng Fu ◽  
Shu Wen Zhou ◽  
Shan Ge Tong
Keyword(s):  
Frequency Response ◽  
Three Dimensional ◽  
Response Characteristic ◽  
Harmonic Excitation ◽  
Structural Vibration ◽  
Weak Links ◽  
Response Analysis ◽  
Element Analysis ◽  
Harmonic Response ◽  
The Impact

After the three-dimensional solid modeling of the SG135 automobile gearbox, finite element analysis models of static, transient and harmonic response load are built based on correlation theory. On the basis of ADAMS dynamic simulation of different gearbox gears, transient load of the gearbox casing at different working gears is found out. With frequency response characteristic of gearbox casing analyzed at typical working conditions of first gear and reverse gear, the evaluation of some factors such as strength and stiffness are given out, which provides theory basis for further improvement of gearbox casing structure and strengthening weak links. Based on harmonic response analysis, the impact on gearbox casing structural vibration by harmonic excitation of the engine is imitated, and the match relation of frequency response between the gearbox and the engine is analyzed. Improvements about engine operational limits matching and gearbox structural design are proposed.

Estimation and Reduction of Motor Input Surge Voltage using Frequency Response Analysis

2012 ◽  
Vol 132 (8) ◽  
pp. 630-637
Author(s):  
Toru Wakimoto ◽  
Yoshimitsu Takahashi ◽  
Norihito Kimura ◽  
Yukitoshi Narumi ◽  
Naoki Hayakawa
Keyword(s):  
Frequency Response ◽  
Response Analysis ◽  
Frequency Response Analysis

Identification of Trouble of Transformer by Frequency Response Analysis

2009 ◽  
Vol 129 (4) ◽  
pp. 517-525 ◽  
Author(s):  
Satoru Miyazaki ◽  
Yoshinobu Mizutani ◽  
Hiroshi Suzuki ◽  
Michiharu Ichikawa
Keyword(s):  
Frequency Response ◽  
Response Analysis ◽  
Frequency Response Analysis

Diagnosis Criterion of Abnormality of Transformer Winding by Frequency Response Analysis (FRA)

2016 ◽  
Vol 136 (7) ◽  
pp. 654-662
Author(s):  
Satoru Miyazaki ◽  
Yoshinobu Mizutani ◽  
Akira Taguchi ◽  
Junichi Murakami ◽  
Naokazu Tsuji ◽  
...  
Keyword(s):  
Frequency Response ◽  
Response Analysis ◽  
Frequency Response Analysis ◽  
Transformer Winding ◽  
Diagnosis Criterion
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