【正文】 elastic modulus is E, the difference between the radii of the inner and the outer ring beams is L, and the self weight and flexural stiffness of the FRP strip are neglected because they are very small. In the first state as shown in Figure 13(a), a horizontal initial prestressing force H0 is applied to the end of the strip. Then the strain of the strip is EAH00 ?? (1) The initial length of the strip is 00 1 ???LL (2) In the second state as shown in Figure 13(b), two vertical loads V are applied on the inner ring beam to move it down to tension the strips. The tensile force in the strip is T1, whose horizontal ponent is H1, and the displacement of the inner ring beam is on equilibrium consideration, there is 2211 VHT ?? (3) If the strain of the strips at this time is ε1, then 1? EAT1? (4) 9 021201 LLL ????? ?? (5) From the geometric relationship, there is LHV 11 ?? (6) Combining these equations, T1, Δ1, ε1 can be found. In the third state, the strips are required to support a service load q(x) which is symmetrically placed with respect to the centre of the inner ring beam. The reaction at the fixed end can be deposed into the horizontal force H2 and the vertical force R. The total deflection of a point at a distance x from the fixed point is denoted by z(x), the deflection due to the service load is denoted by w(x), and the total displacement of the inner beam is denoted by Δ2. Hen, ? ?? L VdxxqR 0 )( (7) The deflected shape is governed by the following cable equation (Sheen 1997): 0)(222 ?? xqdx zdH (8) If q(x) is a uniform load, the deflection curve can be found easily by double integration to be: 22 )(2)( ???? LxxxLHqxz (9) and Equation (7) bees R=qL+V (10) The slopes at the strip ends are 20 HRdxdzx ?? (11) 10 2HVdxdzLx ?? (12) Based on deformation patibility, the total length change of each strip in the second stage is given by dxLdxdzLs ? ???????? ?????? ?????????? 0 21221 (13) but the second stage elongation found from strains is ? ????????? ??????????? 2112 1 LEA LHHs (14) Thus, H2 and Δ2 can be found from Equations 1014. As an example, a pair of strips for a model FRPWWS as shown in Figure 13 is considered, where L=80m and the properties of the strips are the same as those of product 2 in Table 1. In the first stage, an initial stress of 500MPa is induced in the strips, then ε0=, L0=, and H0=84kN. In the second stage, an outofplane force V=30kN is applied. As a result, Δ1=, ε1=, H1= and the stress in the strips is 1344MPa. Finally, a uniform load q=, and consequently Δ2=, H2=, and the maximum stress in the strips is 2352MPa and occurs near the outer fixed end. From this simple analysis, the key parameters for an FRPWWS can be identified. These include the initial control stress or the prestressing force H0, the outofplane force V or the deflection of the inner beam Δ1. They control the deformation of the web under loading and the stress level in the FRP strips. A simple FRPWWS A simple FRPWWS as shown in Figure 14 was analyzed by the finite 11 element method using the finite element package ANSYS (2021). It has a 150m span, and the radius of the inner ring is 30m. Product 2 listed in the Table 1 is employed in this structure, which is assumed to have a design value of 2021 Map for the tensile strength. Only the radiated pattern is adopted. There are 360 repeated sets altogether, each of which is posed of three strips. Thus, there are 1,080 FRP strips in the structure. The geometric nonlinearity from large deformation was considered in the finite element analysis, while interaction between strips was neglected. The self weight of the FRP web is ignored as it is only 177kN which is much smaller the total load acting on the structure. The stress level in the initial prestressed web is controlled to be no more than 210MPa, while that after the downward movement of the inner ring beam no more than 1000 Map. From the finite element analysis, under a vertical force of 14,400 ken for the second stage operation, the inner ring beam moves down by m and the maximum stress in the strips reaches 995MPa. The construction of the FRPWWS is now plete. As the weight of each strip in this FRPWWS is less than 18kg, which can be carried by an adult, the construction of this structure is expected to be easy. The total weight of the strips in the FRPWWS is estimated to be about 19,440 kg. The pleted FRPWWS was next subject to a factored uniform load of , which is intended to include the selfweight of the roofing material, wind loading and snow loading. Under this loading, the maximum deflection increase is and the total maximum stress in the FRP