TY - JOUR
T1 - Ultimate strength of horizontally curved steel I-girders with equal end moments
AU - Lee, Keesei
AU - Davidson, James S.
AU - Choi, Junho
AU - Kang, Youngjong
N1 - Funding Information:
This research was supported by the Basic Science Research Program ( NRF-2015R1C1A1A01052250 ) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning.
Publisher Copyright:
© 2017 Elsevier Ltd
PY - 2017/12/15
Y1 - 2017/12/15
N2 - Even under gravitational loading alone, horizontally curved girders experience not only bending moment but also torsional moment. The torsional moment acting on open sections simultaneously produces shear and normal stress due to pure and warping torsion respectively. Consequently, bending moment, pure torsion and warping torsion are coupled, which results in a very complicated stress state that makes it difficult to calculate the ultimate strength of horizontally curved members. This study revealed that the initial curvature can reduce the ultimate strength of horizontally curved members by up to 50%. Although current design specifications such as the AASHTO LRFD Bridge Design Specifications, suggest some alternatives, the exact behavior of a curved member cannot be considered well with those provisions. While it is true that the one-third rule is convenient to apply and gives good results, there is no strength equation for curved members. In order to derive an adequate strength equation for curved members, this research suggests a new concept of ultimate state. Finite element analysis using ABAQUS is used to consider the effects of sectional rigidities for bending, pure torsion and non-uniform torsion separately. Finally, an ultimate strength equation is suggested for simply supported curved girders that are subjected to equal end moments.
AB - Even under gravitational loading alone, horizontally curved girders experience not only bending moment but also torsional moment. The torsional moment acting on open sections simultaneously produces shear and normal stress due to pure and warping torsion respectively. Consequently, bending moment, pure torsion and warping torsion are coupled, which results in a very complicated stress state that makes it difficult to calculate the ultimate strength of horizontally curved members. This study revealed that the initial curvature can reduce the ultimate strength of horizontally curved members by up to 50%. Although current design specifications such as the AASHTO LRFD Bridge Design Specifications, suggest some alternatives, the exact behavior of a curved member cannot be considered well with those provisions. While it is true that the one-third rule is convenient to apply and gives good results, there is no strength equation for curved members. In order to derive an adequate strength equation for curved members, this research suggests a new concept of ultimate state. Finite element analysis using ABAQUS is used to consider the effects of sectional rigidities for bending, pure torsion and non-uniform torsion separately. Finally, an ultimate strength equation is suggested for simply supported curved girders that are subjected to equal end moments.
KW - Finite element analysis
KW - Horizontally curved girder
KW - Lateral torsional buckling
KW - Nonlinear
KW - Torsion
KW - Ultimate strength
UR - http://www.scopus.com/inward/record.url?scp=85033588816&partnerID=8YFLogxK
U2 - 10.1016/j.engstruct.2017.09.047
DO - 10.1016/j.engstruct.2017.09.047
M3 - Article
AN - SCOPUS:85033588816
SN - 0141-0296
VL - 153
SP - 17
EP - 31
JO - Engineering Structures
JF - Engineering Structures
ER -