复合材料桁架桥的若干关键问题探讨

Present situation and problems of design and calculation of hybrid FRP-steel truss bridge

由于单向受力的杆件可充分发挥纤维增强复合材料(FRP)在顺纤维方向力学性能优越的特点,因此复合材料桁架结构应用在桥梁工程上得到了重视。本文简要介绍了国内外FRP桁架桥在工程建设中的应用现状,重点对复合材料桁架桥在应用中还存在材料强度发挥程度低、结构可靠度需要提升以及缺乏工程化可靠度设计方法等关键问题进行了分析,指出材料强度发挥程度低导致的建造成本相对较高是限制其应用的主要因素之一,并从复合材料桁架桥多尺度设计的特点出发,对解决以上问题可能的技术路线进行了研讨。

Owing to the fact that the member is in a unidirectional force state,it is possible to give full play to the superior mechanical properties along the fiber direction of fiber reinforced polymer（ FRP）,so the FRP composite truss structure has become much more important. This paper briefly introduces the application of FRP truss bridge in engineering construction. Some key problems still existing in the FRP truss bridge engineering are analyzed,such as the low degree of material strength,structure reliability needs to be improved and lack of engineering methods for structure reliability design.It points out that one of the main factors limiting the application is the relatively high construction costs caused by low degree of material strength. Based on the characteristics of multiscale design of FRP composite truss bridge,the technical route to solve the above problems is discussed.