预应力混凝土薄壁曲线梁空间分析的刚度法──Ⅰ．薄壁曲线梁空间分析的刚度法

THREE-DIMENSIONAL STIFFNESS ANALYSIS OF P.C. CURVED THIN-WALLED GIRDERS I .TGREE-DIMENSIONALSTIFFNESS ANALUSIS OF CURVED THIN- WALLED GIRDER

本文在曲线格子梁理论基础上，通过能量法推导出了空间薄壁曲线梁考虑翘曲作用的单元刚度矩阵与在各种均布荷载作用下单元的等效节点力算式，从而为用刚度法进行预应力混凝土薄壁曲线架空间结构分析提供了理论基础。在分析中考虑了截面形心与剪心不重合对内力的影响，为了验证计算方法的正确性，通过几个实例与Ｄｅｂｒｏｗｈ按薄壁曲线梁翘曲扭转理论的解析解比较十分吻合．说明本文方法与其程序的可靠性。

From a,general expression for strain energy, the derivation of threedemensional curved thin- walled member stiffness matrix,which is based on the curved grillage theory in consideration of warping effect, is presented in terms of girder geometry The equivalent space nodal forces due to equally distributed loadings are also described In the analysis,the effect of eccentricity between centroid and shear centre ofsection is taken into account.This enables an arbitrarily acting prestressing tendon of P.C.curved bridge to be analysis by the stiffness method. Nuerical examples and comparisons are precented for some typical girder configuratious,given by the warping torsion theory of Dabroweki.They are in good agreement,indicating the accuracy and reliability of the method.The three-dimensional analysis for the prestressing of the curved thin- Walled girder and its application to the analysis of P.C.curved box girder bridge in Da - Lian will be developed in part of this paper.