Vibrational and acoustic response of ribbed plates

236 Pages·2016·4.54 MB·English

Iowa State University Capstones, Theses and
Retrospective Theses and Dissertations
Dissertations
1993
Vibrational and acoustic response of ribbed plates
Ten-Bin Juang
Iowa State University
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Recommended Citation
Juang, Ten-Bin, "Vibrational and acoustic response of ribbed plates " (1993).Retrospective Theses and Dissertations. 10458.
https://lib.dr.iastate.edu/rtd/10458
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Vibrational and acoustic response of ribbed plates
Juang, Ten-Bin, Ph.D.
Iowa State University, 1993
U M I
SOON.ZeebRd.
Ann Aibor, MI 48106

Vibrational and acoustic response of ribbed plates
by
Ten-Bin Juang
A Dissertation Submitted to the
Graduate Faculty in Partial Fulfillment of the
Requirements for the Degree of
DOCTOR OF PHILOSOPHY
Department: Aerospace Engineering and Engineering Mechanics
Major: Engineering Mechanics
Approved:
Signature was redacted for privacy.
In Charge of Major Work
Signature was redacted for privacy.
For the Major Department
Signature was redacted for privacy.
For the Graduate College
Iowa State University
Ames, Iowa
1993
u
TABLE OF CONTENTS
Page
LIST OF FIGURES vii
LIST OF TABLES xviii
GENERAL INTRODUCTION 1
Motivation 1
Explanation of Dissertation Organization 3
Explanation of Dissertation Format 6
PAPER I. VIBRATIONAL RESPONSES OF A SINGLE-RIBBED INFINITE
PLATE IN AIR: DISPLACEMENT AND STRUCTURAL
INTENSITY 7
ABSTRACT 8
ANALYSIS AND DISCUSSION 9
Introduction 9
I. Mathematical Analysis 10
A. Formulation of displacement response 10
1. Plate response to convected pressure excitation 11
2. Plate response to general forcing excitation 16
3. Plate response to line force excitation 18
4. Plate response to point force excitation 20
B. Structural intensity in plates 22
n. Numerical Results and Discussions 22
A. Verification of the mathematical model 22
1. Verification of the numerical scheme 23
2. Verification of driving point input impedance function on
a ribbed plate 24
m
B. Simulations and validations 25
1. Displacement response due to a plane wave incident pressure 25
2. Displacement response due to a line or point force 29
3. Structural intensity response due to a line or point force 34
4. Structural power due to a point force 39
Conclusions 43
ACKNOWLEDGEMENTS 44
APPENDIX A: PRESENTATION OF RIB STIFFENER 45
APPENDIX B: VERIHCATION OF DISPLACEMENT RESPONSE 46
REFERENCES 48
PAPER n. ACOUSTIC RESPONSES OF A SINGLE-RIBBED INFINITE
PLATE IN AIR: PRESSURE, INTENSITY, AND POWER 49
ABSTRACT 50
ANALYSIS AND DISCUSSION 51
Introduction 51
I. Mathematical Analysis 52
A. Formulation of acoustic pressure response 52
1. Nearfield acoustic pressure 54
2. Farfield acoustic pressure 55
B. Formulation of acoustic intensity response 57
C. Formulation of farfield acoustic power 58
n. Numerical Results And Discussions 58
A. Verification of the mathematical model 58
1. Verification of the numerical scheme 58
iv
2. Acoustic pressure response due to a line or point force 61
3. Acoustic intensity response due to a line or point force 65
4. Acoustic power due to a point force 73
Conclusions 79
ACKNOWLEDGEMENTS 82
REFERENCES 83
PAPER in. VIBRATIONAL RESPONSES OF A MULTIPLE-RIBBED INHNITE
PLATE IN WATER: DISPLACEMENT AND STRUCTURAL
INTENSITY 85
ABSTRACT 86
ANALYSIS AND DISCUSSION 87
Introduction 87
I. Mathematical Analysis 88
A. Formulation of displacement response 88
1. Plate response to a line force excitation 92
2. Plate response to a point force excitation 94
B. Formulation of branch-cut contour integral 95
n. Numerical Results And Discussions 99
A. Verification of the mathematical model 99
1. Verification of the numerical scheme 99
2. Verifications of natural frequency for clamped-ribbed plates 102
3. Verifications of structural intensity in ribbâd plates 104
B. Simulations and validations 104
1. Frequency response function and mode shape 105
2. Structural intensity 114
Conclusions 117
V
REFERENCES 118
PAPER IV. ACOUSTIC RESPONSES OF A MULTIPLE-RIBBED INHNITE
PLATE : PRESSURE AND POWER 119
ABSTRACT 120
ANALYSIS AND DISCUSSION 121
Introduction 121
I. Mathematical Analysis 122
A. Formulation of acoustic pressure response 122
n. Numerical Results And Discussions 127
A. Verification of the mathematical model 127
1. Acoustic pressure response due to a line or point force 127
2. Acoustic power response due to a point force 136
3. Acoustic power calculation and radiation pattern 139
Conclusions 141
REFERENCES 147
PAPER V. MODE LOCALIZATION PHENOMENA ANALYSIS ON INFINITE
RIBBED PLATES AND FINITE STIFFENED BEAMS 149
ABSTRACT 150
ANALYSIS AND DISCUSSION 151
1. Introduction 151
1.1. Periodic structures 151
1.2. Disordered structures 152
2. Formulation of Transfer Matrix Method 155
3. Results and Discussions on Finite Beams 160
3.1. Verifications of mathematical and experimental models 160