PSI - Issue 5

M.H. Hebdon et al. / Procedia Structural Integrity 5 (2017) 1027–1034 Liu et al. / Structural Integrity Procedia 00 (2017) 000 – 000

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mm (0.2 ″ ). Each suspension chain consists of a set of four parallel closed eyebars, which are connected by pins with a diameter of 292.1 mm (11.5 ″ ). To facilitate assembly of the eyebar chain, the eyelet was designed in an oval format, formed by two circles with different diameters. Besides, the main towers are made up of structural steels and lattice bracings, serving to support the eyebar chain of the suspension bridge. The towers are 68.78 m (225.64 ′ ) in height, and the columns are outwardly inclined. The distance between centerlines of the steel columns is 10.21 m ( 33.5′ ) at the top, and 16.92 m ( 55.5′ ) at the bottom. The tower columns are connected by lattice bracings.

Fig. 2. Cross-section of the central span ( 1″=0.025m ).

U18

a

c

U20

U16

Joint with hanger

Joint with eyebar

Diagonal

Upper chord

Joint with tower

U4

U2

Lower chord

Upright

U1

L19 L18

L20

L16 L17

L3 L4

L0 L1 L2

b

Fig. 3. (a) Side view of truss; (b) Lower part of L0-L4; (b) Stinger-to-floor-beam connection (Unit: mm).

2.2. Finite element modelling

A global finite element (FE) model of the HLB was established, as shown in Fig. 4(a). The trusses, main towers, floor-beams and stringers were modeled using Beam188 elements with respective real cross-section, where lacing bars in lattice members were respectively built. Eyebars were built with Beam188 elements and the z -axis rotation degrees of freedom (DOF) of the end elements were released to simulate the movement of the eyebar joint. The hangers were modeled using the tension only Link180 element with three DOFs for each node. The floor slab was created using Shell181 elements. The material properties, stiffness and geometric constants (i.e. areas of cross-section, moments of inertia, etc.) were calculated and assigned to the corresponding elements. In order to accurately obtain critical information, refined 3D shell elements (i.e. Shell181) were used to build the connections of concern, as shown in Fig. 4(b). The coupling interface between 3D shell elements and beam element as a rigid region allowed both displacement compatibility and stress equilibrium (Li et al., 2009). Mixed-dimensional modeling has been previously used to simulate performance of complex structures, whose effectiveness has been confirmed by many large-scale simulations (Chan et al., 2009). Boundary conditions of the FE model were set as follows: the bottoms of the main towers and ends of eyebar chains were restrained with all DOFs; the trusses were coupled with the columns of the main towers in the z-direction (i.e. transverse direction) at two ends by coupling elements.