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提出了离散截面变量空间桁架形状优化的一个两级算法．在第一级优化中，固定节点的位置，以杆件面积为设计变量，进行离散变量截面优化；在第二级优化中，以节点坐标为设计变量，同时考虑截面变化；形成一系列优化子问题，按目标函数下降方向用Ｆｉｂｏｎａｃｃｉ法搜索出各坐标设计变量的最优变动值，从而形成新的节点位置．两级优化交替进行，直到收敛为止．算例表明本方法简单，收敛平稳，优化效果较好．在算例中讨论了不同的节点坐标初值对优化结果的影响及产生原因．
A two-level algorithm is proposed to optimize the shape of space truss with discrete cross-section variables. In the first level of optimization, the location of fixed nodes, the rod area as the design variables, discrete variable cross-section optimization; in the second level of optimization, the node coordinates for the design variables, taking into account changes in cross-section; to form a series of optimizer Problem, the Fibonacci method is used to search the optimal variation of each coordinate design variable according to the descending direction of the objective function to form a new node location. Two levels of optimization are alternated until convergence. The example shows that this method is simple, the convergence is steady, and the optimization effect is better. In the example, the influence of different initial values of node coordinates on the optimization results and their causes are discussed.