船体的极限承载能力

用摄动－迦辽金法求得矩形板的单位轴向缩矩－压缩载荷之间的关系．按照Ｓｍｉｔｈ法得到各单元的平均应力－平均应变曲线和船体梁总纵弯矩与曲率的关系曲线，编制了ＦＵＳＲＡ程序．船舶模型的数值计算表明，结果与试验值相吻合，具有简便、省时等优点．

Ultimate Strength of Ship Hull Girder

The perturbation-Galerkin method is used to study the buckling and postbuckling behavior of simply supported rectangular plate with innal imperfections subjected to inplane uniaxial compression; thereafter the relation between the axial compressive load and unit shortening (load-shortening curve) can be established. According to the Smith method the midship section is discretized into several small elements. Each element is composed of a stiffener and its attaching plate. With the help of the loading-shortening curve of the plate, the average stress-average strain curve of the element can be drawn. Finally, a step by step increase of the vertical curvature of the ship girder hull is applied based on the plane cross section assumption, the position of the instantaneous neutral axis is updated through an iterative process. Then the relationship between the longitudinal bending moment and the curvature of the ship girder hull can be obtained. A computer program FUSRA is compiled for this procedure. A 1/3 scale frigate model under sagging condition as a numerical example is computed by FUSRA. The comparision between the computed results and the test data shows the feasibility of computer program FUSRA with merits of simplicity, less computing time and practical significance.