Abstract

One-dimensional continuous structures include longitudinal vibration of bars, torsional vibration of circular shafts, and transverse vibration of beams. Using the linear time-varying system theory, algorithms are developed in this paper to compute natural frequencies and mode shapes of these structures with nonuniform spatial parameters (mass distributions, material properties and cross-sectional areas) which can have jump discontinuities. A general numerical approach has been presented to include Dirac-delta functions and their spatial derivatives due to jump discontinuities. Numerical results are presented to illustrate the application of these techniques to the solution of different types of spatial variations of parameters and boundary conditions.

References

1.
Rayleigh
,
J. W. S. B.
,
1894
,
The Theory of Sound
, 2nd ed.,
Macmillan
,
London
.
2.
Den Hartog
,
J. P.
,
1956
,
Mechanical Vibrations
, 4th ed.,
McGraw-Hill
, New York (published by Dover Publications in 1984).
3.
Thompson
,
W. T.
,
1992
,
Theory of Vibration With Applications
, 4th ed.,
Prentice Hall
,
Englewood Cliffs, NJ
.
4.
Rao
,
J. S.
, and
Gupta
,
K.
,
1984
,
Introductory Course on Theory and Practice of Mechanical Vibrations
, 1st ed.,
Wiley Eastern Ltd
,
New Delhi, India
.
5.
Rao
,
S. S.
,
2007
,
Vibration of Continuous Systems
,
Wiley
,
Hoboken, NJ
.
6.
Sinha
,
A.
,
2010
,
Vibration of Mechanical Systems
,
Cambridge University Press
,
New York
.
7.
Birman
,
V.
, and
Byrd
,
L. W.
,
2007
, “
Modeling and Analysis of Functionally Graded Materials and Structures
,”
ASME Appl. Mech. Rev.
,
60
(
5
), pp.
195
216
.10.1115/1.2777164
8.
Kirchhoff
,
G.
,
1882
,
Gessammelte Abhandlungen
,
J. A.
Barth
,
Leipzig
,
Germany
(in German).
9.
Ward
,
P. F.
,
1913
, “
The Transverse Vibrations of Rod of Varying Cross-Section
,”
Philos. Mag.
,
25
(
145
), pp.
85
106
.10.1080/14786440108634312
10.
Conway
,
H. D.
, and
Dubil
,
J. D.
,
1965
, “
Vibration Frequencies of Truncated-Cone and Wedge Beams
,”
ASME J. Appl. Mech.
,
32
(
4
), pp.
932
934
.10.1115/1.3627338
11.
Auciello
,
N. M.
, and
Ercolano
,
A.
,
1997
, “
Exact Solution for the Transverse Vibration of a Beam a Part of Which is a Taper Beam and Other Part is a Uniform Beam
,”
Int. J. Solids Struct.
,
34
(
17
), pp.
2115
2129
.10.1016/S0020-7683(96)00136-9
12.
Wu
,
J.-S.
, and
Chiang
,
L.-K.
,
2004
, “
Free Vibrations of Solid and Hollow Wedge Beams With Rectangular or Circular Cross‐Sections and Carrying Any Number of Point Masses
,”
Int. J. Numer. Methods Eng.
,
60
(
3
), pp.
695
718
.10.1002/nme.981
13.
Caruntu
,
D. I.
,
2009
, “
Dynamic Modal Characteristics of Transverse Vibrations of Cantilevers of Parabolic Thickness
,”
Mech. Res. Commun.
,
36
(
3
), pp.
391
404
.10.1016/j.mechrescom.2008.07.005
14.
Li
,
Q. S.
,
2002
, “
Free Vibration Analysis of Non-Uniform Beams With an Arbitrary Number of Cracks and Concentrated Masses
,”
J. Sound Vib.
,
252
(
3
), pp.
509
525
.10.1006/jsvi.2001.4034
15.
Horgan
,
C. O.
, and
Chan
,
A. M.
,
1999
, “
Vibrations of Inhomogeneous Strings, Rods and Membranes
,”
J. Sound Vib.
,
225
(
3
), pp.
503
513
.10.1006/jsvi.1999.2185
16.
Li
,
Q. S.
,
2000
, “
Exact Solutions for Free Longitudinal Vibrations of Non-Uniform Rods
,”
J. Sound Vib.
,
234
(
1
), pp.
1
19
.10.1006/jsvi.1999.2856
17.
Raj
,
A.
, and
Sujith
,
R. I.
,
2005
, “
Closed-Form Solutions for the Free Longitudinal Vibration of Inhomogeneous Rods
,”
J. Sound Vib.
,
283
(
3–5
), pp.
1015
1030
.10.1016/j.jsv.2004.06.003
18.
Yavari
,
A.
,
Sarkani
,
S.
, and
Reddy
,
J. N.
,
2001
, “
Generalized Solutions of Beams With Jump Discontinuities
,”
Arch. Appl. Mech.
,
71
(
9
), pp.
625
639
.10.1007/s004190100169
19.
Myklestad
,
N. O.
,
1944
, “
A New Method of Calculating Natural Modes of Uncoupled Bending Vibration of Airplane Wings and Other Types of Beams
,”
J. Aerosp. Sci.
,
11
(
2
), pp.
163
162
.10.2514/8.11116
20.
Boiangiu
,
M.
,
Ceausu
,
V.
, and
Untaroiu
,
C. D.
,
2016
, “
A Transfer Matrix Method for Free Vibration Analysis of Euler-Bernoulli Beams With Variable Cross Section
,”
J. Vib. Control
,
22
(
11
), pp.
2591
2602
.10.1177/1077546314550699
21.
Yang
,
B.
, and
Fang
,
H.
,
1994
, “
A Transfer-Function Formulation for Nonuniformly Distributed Parameter Systems
,”
ASME J. Vib. Acoust.
,
116
(
4
), pp.
426
432
.10.1016/0022-460X(89)90561-0
22.
Yang
,
B.
,
2005
,
Stress, Strain and Structural Dynamics: An Interactive Handbook of Formulas, Solutions, and MATLAB Toolboxes
,
Elsevier Academic Press
,
San Diego, CA
.
23.
Kailath
,
T.
,
1980
,
Linear Systems
,
Prentice Hall
,
Englewood Cliffs, NJ
.
24.
Matlab
,
2019
, Matlab, The MathWorks, Natick, MA.
25.
Jang
,
S. K.
, and
Bert
,
C. W.
,
1989
, “
Free Vibration of Stepped Beams: Exact and Numerical Solutions
,”
J. Sound Vib.
,
130
(
2
), pp.
342
346
.10.1115/1.2930445
26.
Sinha
,
A.
,
2019
, “
A New Approach to Compute Natural Frequencies and Mode Shapes of Non-Uniform Continuous Bar, Circular Shaft and Beam Vibration
,”
ASME
Paper No. DETC 2019-97263.10.1115/2019-97263
27.
Sinha
,
A.
,
2007
,
Linear Systems: Optimal and Robust Control
,
CRC Press
,
Boca Raton, FL
.
You do not currently have access to this content.