School of Civil and Environmental Engineering, Amirkabir University of Technology, Tehran, Iran.
Sci Rep. 2022 Oct 6;12(1):16784. doi: 10.1038/s41598-022-21247-8.
The seismic design of conventional structures is mainly addressed considering the direct construction cost; the life cycle costs (LCCs) are often neglected. This paper proposes a performance-based framework for optimal seismic design of irregular steel structures; the LCC is involved as an optimization criterion. Two regular 7- and 10-story structures are first designed based on the design earthquake; their geometries are then changed to make them setback irregular having in overall four cases to investigate. Nonlinear analyses are performed to estimate the target displacement for annual exceedance probabilities, different specified acceleration levels, and, accordingly, the extent of the structural damage. The LCCs of the cases studied are calculated to achieve two objectives: an LCC-based optimal design of steel structures, and evaluating the extent of irregularity on the structures' LCCs. Results indicate that in the regular and irregular 7-story structures, a 40% and a 50% increase in the seismic loads can respectively reduce the LCCs by 31.3% and 34.9%. In the same vein, in the 10-story regular and irregular structures, increasing the seismic loads by 50% can reduce the LCCs by 33.4% and 31.7%, respectively. The results highlight the point that irregular structures, overall, require a higher initial cost than regular structures when the LCC is taken into account as an optimization criterion.
传统结构的抗震设计主要考虑直接建设成本；往往忽略了生命周期成本（LCC）。本文提出了一种基于性能的不规则钢结构抗震优化设计框架，将 LCC 作为优化准则。首先根据设计地震对两个规则的 7 层和 10 层结构进行设计，然后改变它们的几何形状，使其成为后退不规则结构，总共研究了四种情况。进行非线性分析以估计年超越概率、不同指定加速度水平的目标位移，从而评估结构的损坏程度。计算了所研究案例的 LCC，以实现两个目标：基于 LCC 的钢结构优化设计，以及评估结构 LCC 不规则性的程度。结果表明，在规则和不规则的 7 层结构中，地震荷载分别增加 40%和 50%可以分别降低 31.3%和 34.9%的 LCC。同样，在规则和不规则的 10 层结构中，地震荷载增加 50%可以分别降低 33.4%和 31.7%的 LCC。结果强调了这样一个观点，即当将 LCC 作为优化准则时，不规则结构通常比规则结构需要更高的初始成本。
