1、PDF外文：http:/ Development and analysis of the large-span FRP woven web structure ABSTRACT: An innovative large-span structural system, namely the FRP woven web structure (FRPWWS), is introduced in this paper. In an FRPWWS, the high-strength FRP strips are “woven” like bamboo strips in a Chinese
2、 bamboo mat to form a plane web. The outer edge of the web is anchored on an outer ring beam, and an inner ring beam is provided to anchor the FRP strips at the center of the web. The stiffness of the web to resist various loads is derived from the initial prestressing during the “weaving” stage and
3、 the additional tensioning as a result of the out-of-plane movement of the inner ring beam. As a result of the high strength-to weight ratio of FRP, this new structural form offers an attractive option for the construction of spatial structures with spans longer than are possible with conventional s
4、tructural materials. In this paper, the basic layout and construction procedure for a simple FRPWWS is first presented. Three basic weaving patterns are next explained. Several variations of the basic structural system are also proposed. A simple mechanical model is presented for the deformation of
5、individual FRP strips. Results from a finite element analysis of an example structure are also given. The results of these analyses confirm the feasibility of the FRPWWS. 1 INTRODUCTION FRP is a new kind of structural material, whose use in civil engineering has been actively explored i
6、n recent years. Due to its favorable properties like 2 corrosion resistance, high strength, low weight, good fatigue performance, and low maintenance cost, it is considered to be an ideal material for constructing long-span structures in the new century. However, its mechanical properties are
7、 distinctly different from those of traditional structural materials in some aspects, such as its anisotropy. Due to the unique properties of FRP, it is necessary to explore new forms of large-span structures for its efficient use and for achieving spans larger than are possible with traditiona
8、l materials. For example, Maeda et al. (2002) have conceived a 5000 meter-span suspension bridge using FRP. The FRP woven web structure, a new large-span structural system, is presented in this paper. This new system represents an attempt aimed at the efficient utilization of the unique charac
9、teristics of FRP in a large-span roof. In an FRPWWS, the high strength FRP strips are woven like bamboo strips in a Chinese bamboo mat to form a plane web. The outer edge of the web is anchored on an outer ring beam, and an inner ring beam is provided to anchor the FRP strips at the center of the we
10、b. A small-scale model of a simple FRPWWS is shown in Figure 1. The FRP strips are initially prestressed to a limited extent to keep them straight during “weaving”. Then, the FRP web is tensioned by a displacement of the inner ring beam in the out-of plane direction, which is effected either by a se
11、t of prestressed tendons or by suspending a heavy mass from the inner ring beam. As a result, a tensioned FRP web, whose geometric stiffness is able to resist a variety of loads, forms a large-span roof system with the two rings. The FRPWWS resembles the cable net structure and the cable-membr
12、ane structure: their members are flexible； and the geometric stiffness resulting from 3 tension is utilized to resist loads. However, the FRPWWS has its unique advantages: (1) the FRP strips are ideal for super large-span structures due to their low self-weight and their superior materia
13、l properties in the lengthwise direction, which are efficiently utilized, while the weakness of inferior properties in the transverse directions is not exposed； (2) significant damping can be expected to arise from friction at joints between FRP strips, which can enhance the resistance of the
14、structure to wind and earthquake loads； (3) the regular weaving pattern leads to an aesthetically pleasing surface； and (4) the corrosion resistance of FRP and the ease of installation because of its lightweight translate into low maintenance costs. In this paper, the basic layout and construction p
15、rocedure for a simple FRPWWS system is presented in detail. The weaving patterns in plane are summarized into three types. Some spatial FRPWWS forms for practical applications are also proposed. A simple mechanical model for individual FRP strips in the web is presented. Results from the finite elem
16、ent analysis of a simple FRPWWS are also described. 2 LAYOUT OF A SIMPLE FRPWWS A simple FRP woven web structure is composed of a FRP woven web, an outer ring beam and an inner ring beam for anchorage, and an additional weight or a set of prestressed tendons, as shown in Figure 1. The web is woven with FRP strips, and CFRP strips or other high-performance hybrid FRP strips are suggested. CFRP strips, which have
