挠度理论是Melan于1888年首次提出的一种相当精确的分析吊桥结构的手算方法。本世纪以来,人们倾向于用刚度相对较弱的加劲桁架修建吊桥。对于这种结构,其它手算方法不太适用,所以挠度理论显得特别重要。过去,挠度理论被用做计算工具,但后来被数字计算机技术代替了。最近出版的两本关于悬索结构的书虽然只就挠度理论作了简单介绍,但仍可用来研究吊桥结 Deflection theory is the first kind of hand-counting method that was first proposed by Melan in 1888 to analyze suspension bridge structure. Since the turn of the century, people have tended to build suspension bridges with stiffer stiffening truss. For this structure, other hand calculations are not suitable, so the deflection theory is of particular importance. In the past, deflection theory was used as a calculation tool, but later replaced by digital computer technology. The two recently published book on the structure of the suspension, although only a brief introduction to the theory of deflection, can still be used to study the suspension bridge