This paper focuses on the effect of member geometric imperfection on nonlinear geometrically buckling and seismic performance of a new style of space steel structure, suspen-dome, which is composed of a reticulated shell and cable-strut system. By supposing the initial curvature of members as half-wave sinusoids, a stiffness equation of imperfect truss elements is derived for the struts, while that of imperfect beam elements is derived for the reticulated shell members. The proposed imperfect elements are implanted into ANSYS finite element program. Three numerical examples are employed to validate the proposed imperfect elements and analysis method. An ellipsoidal suspen-dome of Changzhou gymnasium is taken as an example. The results show that the imperfection value has relatively great influence on the structural stiffness. With the increase of member imperfection, the critical load decreases in a basically linear way. Under different prestress states, the relation curves between the critical load and imperfection are basically parallel. The nonlinear seismic analysis results show that when imperfection is included, the initial state responses are different, namely, the seismic displacement increases while the stress in rods and cables decreases. The proposed imperfection analysis method can be widely used in not only suspen-dome structures, but also other kinds of prestressed space grid structures. In this way, the influence of member imperfection on structural buckling and seismic performance can be estimated.
[1]
Y. P. Liu,et al.
SECOND-ORDER ANALYSIS FOR DESIGN OF GLASS-SUPPORTING AND PRE-TENSIONED TRUSSES
,
2009
.
[2]
S. Remseth,et al.
Nonlinear static and dynamic analysis of framed structures
,
1979
.
[3]
Hongbo Liu,et al.
Structural behavior of the suspen-dome structures and the cable dome structures with sliding cable joints
,
2012
.
[4]
Heung-Fai Lam,et al.
Analysis and design of the general and outmost-ring stiffened suspen-dome structures
,
2003
.
[5]
Siu Lai Chan,et al.
SECOND-ORDER ELASTIC ANALYSIS OF FRAMES USING SINGLE IMPERFECT ELEMENT PER MEMBER
,
1995
.
[6]
R. Adman,et al.
Exact shape functions of imperfect beam element for stability analysis
,
2007,
Adv. Eng. Softw..
[7]
Amr S. Elnashai,et al.
Eulerian formulation for large-displacement analysis of space frames
,
1993
.
[8]
Jian-Xin Gu,et al.
Exact Tangent Stiffness for Imperfect Beam-Column Members
,
2000
.
[9]
Heung-Fai Lam,et al.
Factors affecting the design and construction of Lamella suspen-dome systems
,
2005
.