基于等增量敏感性的高层建筑结构反向约束优化设计方法研究

以高层建筑结构为背景，提出了一种降级反向约束优化设计方法。降级反向约束优化设计方法根据工程设计习惯，按照整体、组件、构件、截面、构造的顺序逐级收紧设计约束条件，在每一轮设计中采用等增量敏感性分析方法，以最小的结构材料增量弥补本级冗余不足的设计准则，在满足规范安全性的同时，减少结构材料浪费。应用反向约束优化设计方法，对一个10层钢框架结构和一幢实际超高层钢结构进行了基于等增量敏感性的优化设计，并与正向约束优化设计方法的结果进行对比。研究结果表明，结构能够满足规范各项设计准则的要求，在充分满足安全性要求的同时，有效减少了结构材料用量，两个案例材料用料分别减少了14.2%和7.8%，且在优化过程中没有出现约束条件偏离限值的情况，提高了优化效率。

Reversely constrained optimal design method for tall buildings based on constant incremental sensitivity

A descending order reversely constrained optimal design method (DO-RCOD) was proposed in this paper with tall buildings as engineering background. DO-RCOD method tightened design constraints gradually in descending order according to common design habits, i.e., global, assembly, component, sectional and detailing constraint grades. The constant incremental sensitivity analysis (CISA) method developed by the authors was applied in the structural design of each constraint grade to compensate the under-constrained design criteria with minimum material premium, and thus the structural material wastes were reduced with enough structural safety specified by the codes. The reversely constrained optimal design (RCOD) method was applied to a 10-story frame structure and a real super tall steel structure. The case studies show that the structures can satisfy the code requirements, while the structural material consumption was effectively reduced. In two case studies, 14.2% and 7.8% of the structural materials are saved. And in the process of optimization, there is no constraint value far from the limit value, which improves efficiency.