Due to the complicated deformations occurring in thin-walled multicell beams, no satisfactory one-dimensional beam theory useful for general quadrilateral multicells appears available. In this paper, we present a new systematic approach to analyze the coupled deformations of torsion, distortion, and the related warping. To develop a one-dimensional thin-walled multicell beam theory, the method to determine the section deformation functions associated with distortion and distortional warping is newly developed. In order to guarantee the singlevaluedness of the distortional warping function in multicells, distortional shear flows have been utilized. The superior result by the present one-dimensional theory is demonstrated with various examples.

1.
Timoshenko, S. P., and Gere, J. M., 1963, Theory of Elastic Stability, 2nd ed, McGraw-Hill, New York.
2.
Vlasov, V. Z., 1961, Thin Walled Elastic Beams, Israel Program for Scientific Translations, Jerusalem.
3.
Krˇı´stek
,
V.
,
1970
, “
Tapered Box Girders of Deformable Cross Section
,”
J. Struct. Div. ASCE
,
96
, No. ST8, Proc. Paper
7489
, pp.
1761
1793
.
4.
Wright
,
R. N.
,
Abdel-Samad
,
S. R.
, and
Robinson
,
A. R.
,
1968
, “
BEF Analogy for Analysis of Box Girders
,”
J. Struct. Div. ASCE
,
94
, No.
St7
, pp.
1719
1743
.
5.
Boswell
,
L. F.
, and
Zhang
,
S. H.
,
1984
, “
The Effect of Distortion in Thin-Walled Box-Spine Beams
,”
Int. J. Solids Struct.
,
20
, No.
9–10
, pp.
845
862
.
6.
Balch
,
C. D.
, and
Steele
,
C. R.
,
1987
, “
Asymptotic Solutions for Warping and Distortion of Thin-Walled Box Beams
,”
ASME J. Appl. Mech.
,
54
, pp.
165
173
.
7.
Hsu
,
Y. T.
,
Fu
,
S. S.
, and
Schelling
,
D. R.
,
1995
, “
EBEF Method for Distortional Analysis of Steel Box Girder Bridges
,”
J. Struct. Div. ASCE
,
121
, No.
3
, pp.
557
566
.
8.
Kim
,
J. H.
, and
Kim
,
Y. Y.
,
1999
, “
Analysis of Thin-Walled Closed Beams With General Quadrilateral Cross Sections
,”
ASME J. Appl. Mech.
,
66
, pp.
904
912
.
9.
Kim
,
J. H.
, and
Kim
,
Y. Y.
,
2000
, “
One-Dimensional Analysis of Thin-Walled Closed Beams Having General Cross Sections
,”
Int. J. Numer. Methods Eng.
,
49
, pp.
653
668
.
10.
Jo¨nsson
,
J.
,
1999
, “
Distortional Warping Functions and Shear Distributions in Thin-Walled Beams
,”
Thin-Walled Struct.
,
33
, pp.
245
268
.
11.
Razaqpur
,
A. G.
, and
Li
,
H.
,
1991
, “
Thin-Walled Multicell Box-Girder Finite Element
,”
J. Struc. Eng. ASCE
,
117
, No.
10
, pp.
2953
2971
.
12.
Razaqpur
,
A. G.
, and
Li
,
H.
,
1994
, “
Refined Analysis of Curved Thin-Walled Multicell Box-Girders
,”
Comput. Struct.
,
53
, No.
1
, pp.
131
142
.
13.
Kim
,
Y. Y.
, and
Kim
,
J. H.
,
1999
, “
Thin-Walled Closed Box Beam Element for Static and Dynamic Analysis
,”
Int. J. Numer. Methods Eng.
,
45
, pp.
473
490
.
14.
Gjelsvik, A., 1981, The Theory of Thin Walled Bars, John Wiley and Sons, New York.
15.
SDRC, 1993, I-DEAS FEM Users’ Guide, Structural Dynamics Research Corporation, Milford.
You do not currently have access to this content.