Determination of prestress and construction order of cable-supported frames.

1.建立了大跨度索支承框架的优化设计方法。最优索力在最终状态下，通过求解一个数学规划问题的应力和位移的约束下，由于服务负载和外部负载，代表静态地震荷载和风荷载。目标函数为最大值或索力偏差。计算结果表明，采用精确重分析方法，得到最优索力的计算量很小。2.提出了一种近似的方法来求解索力引入和临时支撑拆除的最优顺序（时间表），其中施工过程中的中间状态是从最终状态反向追踪的。采用启发式目标函数来表示设备的最大能力和施工总能量。3.采用动态规划方法求解调度问题的精确最优解。结果表明，用近似方法可以得到较好的近似解。由于近似方法的计算量很小，因此该方法可以有效地用于实际应用。4.已经找到了各种类型的索支承框架的最佳张拉时间表，开发了一个接口程序，实现了本项目开发的工具与商用分析软件NASTRAN之间的数据转换。在实际应用中充分利用这些工具。

1.An optimization method has been developed far long-span frames supported by cables. The optimal cable forces at the final state are found by solving a mathematical programming problem under constraints on the stresses and displacements due to service loads and the externa1 loads that represent static earthquake loads and wind loads. The objective functions are maximum value or the deviation of the cable farces. It has been demonstrated that the computational cost for obtaining the optimal cable forces is very small if an exact reanalysis method is used.2.An approximate to method has been presented for finding optimal order (schedule) of introducing cable farces and removing temporary supports, where the intermediate states during construction is traced inversely from the final state. Heuristic objective functions are used to represent the maximum capacity of the equipments and the total energy for construction.3.The exact optimal solution has been found for the scheduling problem by a dynamic programming approach. It has been shown, by comparing the results by the approximate and exact methods, that a good approximate solution can be found by the approximate method. Since the computational cost of the approximate method is very small the proposed method can be effectively used for practical application.4.Optimal tensioning schedules have been found for cable-supported frames of various types, and the characteristics of the optimal solution have been discussed.5.An interface program has been developed for converting the data between the tools developed in this project and the commercial analysis package (NASTRAN) to fully utilize the tools in practical application.