Structural Design Considering Spatial Variation of Input Seismic Motions

1.建立了考虑输入运动空间变化的有限维结构平均-最大地震反应灵敏度分析方法。建立了平均-最大地震反应应变约束下结构体积最小的优化设计问题。找出了拱型桁架和框架的最佳截面积。结果表明，最优结构体积由于输入运动的空间变化引起的准静态响应而增大。研究了优化后分析中最优解对参数的稳健性，并通过拱型框架算例验证了参数灵敏度系数的准确性。针对考虑土-结构相互作用的大跨度结构，提出了一种用弹簧模拟的反应谱方法。通过时程分析对计算结果进行了验证。对不同类型的三维大跨度结构进行了优化设计，并讨论了相互作用的影响。大跨度穹顶结构通常由墙体支撑。在到达结构基础之前，基岩水平上的地震运动会被土体放大。因此，很自然地假定大跨度屋盖结构是由土支撑的次要结构，边界结构被认为是主要结构。为了推广本文提出的方法，提出了一种基于频域分析的二次结构优化方法。

1. sensitivity analysis method has been developed for mean-maximum seismic responses of finite dimensional structures considering spatial variation of input motions.2. An optimum design problem has been formulated for minimizing the structural volume under constraints on mean-maximum seismic response strains. Optimum cross-sectional areas have been found for arch-type trusses and frames, It. Has been shown that the optimal structural volume increases due to quasi-static responses resulted from spatial variation of input motions3. It is important to investigate robustness of the optimal solutions against the parameters for postoptimal analysis has been presented, and the accuracy of the parametric sensitivity coefficients has been verified by the examples of arch-type frames.4. A response spectrum method has been developed for long-span structures considering soil-structure interactions, which are modeled by springs. The results have been verified by time-history analysis. Optimum designs have been found for various types of three-dimensional long-span structures, and the effect of interaction has been discussed.5. Long-span dome structures are often supported by walls. The seismic motions at the bedrock level are magnified by the soils before arriving the foundations of the structure. Therefore, it is natural to assume that the long-span roof structures are secondary structures supported by soils and boundary structures which are considered as primary structures. To extend the method developed in this study, an optimization method based on frequency-domain analysis has been presented for secondary structures.