样条有限条法分析弯箱梁桥空间内力

PRISMATIC CURVED BOX-GIRDER BRIDGE WITH ARBITRARY RESTRAIN CONDITION ANALYZED BY SPLINE-FINITE-STRIP METHOD

本大讨论用样条有限条法计算有中间支点及内横隔板的两端简支、固定、自由及其他任意组合情况下的等截面弯桥空间内力计算问题。用这种方法计算有内横隔板的连续弯箱梁桥时,不必象一般的有限条法那样借助于力法位移协调方程,而是通过对位移函数的修正,使之完全满足超静定结构的各种约束条件,进而直接算出超静定结构位移函数的最终结果。对于具有任意边界条件(非简支)的弯箱梁桥,其端支承的位移函数也可借变更端部样条函数的简单方法求解,这为有限条法更广泛地用于各种复杂结构开辟了新的途径。

In this paper, a general spline-finite-strip method used to analyze the spaceinternal forces of prismatic curved box-girder bridge is discussed. This methodis especially suitable for analyzing box-girder with internal supports, dia-phragms and arbitrary boundary conditions,such as simply supported, fixed, freeor any combination of them. For analyzing the box-girder bridge with internaldiaphragms with this it does not require to solve the compatibility equations ofdisplacements as usually done in ordinary finite strip method. By modifying dis-placement function to satisfy the restrain conditions of the indeterminate struc-ture, the final displacement founctions can be easily obtained. The displacementfunction of end supports for box-girder bridge with any boundary conditions otherthan simply supported can be casily obtained by modifying the end spline func-tions, so coupling of continuous function in ordinary finite strip method isavoided.Thus the proposed method develops a new way for finite strip methodto analyze any complex structures.A numerical example is given in this paperfor verifying the accuracy of the proposed method as well as the program CBASSwritten in FORTRAN-77 for curved box-girder analysis.