The dynamic stiffness matrix of a uniform isotropic beam element based on trigonometric shear deformation theory is developed in this paper. The theoretical expressions for the dynamic stiffness matrix elements are found directly, in an exact sense, by solving the governing differential equations of motion that describe the deformations of the beam element according to the trigonometric shear deformation theory, which include the sinusoidal variation of the axial displacement over the cross section of the beam. The application of the dynamic stiffness matrix to calculate the natural frequencies and normal mode shapes of two rectangular beams is discussed. The numerical results obtained are compared to the available solutions wherever possible and validate the accuracy and efficiency of the present approach.

1.
Timoshenko
,
S. P.
, 1922, “
On the Transverse Vibration of Bars With Uniform Cross-Section
,”
Philos. Mag.
0031-8086,
43
, pp.
125
131
.
2.
Mindlin
,
R. D.
, and
Deresiewicz
,
H.
, 1954, “
Timoshenko’s Shear Coefficient for Flexural Vibrations of Beams
,”
Proc. of 2nd U.S. National Congress of Applied Mechanics
,
ASME
, New York, pp.
175
178
.
3.
Cowper
,
G. R.
, 1966, “
The Shear Coefficient in Timoshenko’s Beam Theory
,”
ASME J. Appl. Mech.
0021-8936,
33
, pp.
335
340
.
4.
Hutchinson
,
J. R.
, 2004, “
On Timoshenko Beams of Rectangular Cross-Section
,”
ASME J. Appl. Mech.
0021-8936,
71
, pp.
359
367
.
5.
Murthy
,
A. V.
, 1970, “
Vibrations of Short Beams
,”
AIAA J.
0001-1452,
8
, pp.
34
38
.
6.
Soler
,
A. I.
, 1968, “
Higher Order Effects in Thick Rectangular Elastic Beams
,”
Int. J. Solids Struct.
0020-7683,
4
, pp.
723
739
.
7.
Leech
,
C. M.
, 1977, “
Beam Theories: A Variational Approach
,”
Int. J. Mech. Eng. Educ.
,
5
, pp.
81
87
.
8.
Stephen
,
N. G.
, and
Levinson
,
M.
, 1979, “
A Second Order Beam Theory
,”
J. Sound Vib.
0022-460X,
67
, pp.
293
305
.
9.
Levinson
,
M.
, 1981, “
A New Rectangular Beam Theory
,”
J. Sound Vib.
0022-460X,
74
, pp.
81
87
.
10.
Bickford
,
W. B.
, 1982, “
A Consistent High-Order Beam Theory
,”
Dev. Theor. Appl. Mech.
0070-4598,
11
, pp.
137
150
.
11.
Levinson
,
M.
, 1985, “
On Bickford’s Consistent Higher Order Beam Theory
,”
Mech. Res. Commun.
0093-6413,
12
, pp.
1
9
.
12.
Murty
,
A. V. K.
, 1985, “
On the Shear Deformation Theory for Dynamic Analysis of Beams
,”
J. Sound Vib.
0022-460X,
101
, pp.
1
12
.
13.
Kant
,
T.
, and
Gupta
,
A.
, 1988, “
A Finite Element Model for a Higher Order Shear Deformable Beam Theory
,”
J. Sound Vib.
0022-460X,
125
, pp.
193
202
.
14.
Bhimaraddi
,
A.
, and
Chandrashekhara
,
K.
, 1993, “
Observations on Higher-Order Beam Theory
,”
J. Aerosp. Eng.
0893-1321,
6
, pp.
408
413
.
15.
Petrolito
,
J.
, 1995, “
Stiffness Analysis of Beams Using a Higher-Order Theory
,”
Comput. Struct.
0045-7949,
55
, pp.
33
39
.
16.
Wang
,
C. M.
,
Reddy
,
J. N.
, and
Lee
,
K. H.
, 2000,
Shear Deformable Beams and Plates
,
Elsevier
, New York.
17.
Reddy
,
J. N.
,
Wang
,
C. M.
,
Lim
,
G. T.
, and
Ng
,
K. H.
, 2001, “
Bending Solutions of the Levinson Beams and Plates in Terms of the Classical Theories
,”
Int. J. Solids Struct.
0020-7683,
38
, pp.
4701
4720
.
18.
Ghugal
,
Y. M.
, and
Shimpi
,
R. P.
, 2001, “
A Review of Refined Shear Deformation Theories for Isotropic and Anisotropic Laminated Beams
,”
J. Reinf. Plast. Compos.
0731-6844,
20
, pp.
255
272
.
19.
Eisenberger
,
M.
, 2003, “
An Exact High Order Beam Element
,”
Comput. Struct.
0045-7949,
81
, pp.
147
152
.
20.
Stein
,
M.
, 1989, “
Vibration of Beams and Plate Strips With Three-Dimensional Flexibility
,”
ASME J. Appl. Mech.
0021-8936,
56
, pp.
228
231
.
21.
Ghugal
,
Y. M.
, and
Shimpi
,
R. P.
, 2000, “
A Trigonometric Shear Deformation Theory for Flexure and Free Vibration of Isotropic Thick Beams
,” Structural Engineering Convention, SEC-2000, IIT Bombay, India.
22.
Rao
,
G. V.
,
Saheb
,
K. M.
, and
Janardhan
,
G. R.
, 2006, “
Concept of Coupled Displacement Field for Large Amplitude Free Vibrations of Shear Flexible Beams
,”
ASME J. Vibr. Acoust.
0739-3717,
128
, pp.
251
255
.
23.
Ramezani
,
A.
,
Alasty
,
A.
, and
Akbari
,
J.
, 2006, “
Effects of Rotary Inertia and Shear Deformation on Nonlinear Free Vibration of Microbeams
,”
ASME J. Vibr. Acoust.
0739-3717,
128
, pp.
611
615
.
24.
Burden
,
R. L.
, and
Faires
,
J. D.
, 1989,
Numerical Analysis
,
PWS-Kent Publishing
, Boston.
25.
Char
,
B. W.
,
Geddes
,
K. O.
,
Gonnet
,
G. H.
,
Monagan
,
M. B.
, and
Watt
,
S. M.
, 1990, Maple Reference Manual, Symbolic Computation Group and Waterloo Maple Publishing, Department of Computer Science, University of Waterloo, Canada.
26.
Cowper
,
G. R.
, 1968, “
On the Accuracy of Timoshenko’s Beam Theory
,”
J. Engrg. Mech. Div.
0044-7951,
94
, pp.
1447
1453
.
27.
Senthilnathan
,
N. R.
, and
Lee
,
K. H.
, 1992, “
Some Remarks on Timoshenko Beam Theory
,”
ASME J. Vibr. Acoust.
0739-3717,
114
, pp.
495
497
.
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