钢筋混凝土D区配筋的拓扑优化设计研究

Research on topological optimization design of reinforcement layouts of reinforced concrete D-regions

钢筋混凝土D区的配筋设计是一个难点。基于试验结果的经验设计方法一直饱受诟病,拉压杆模型等应力方法却又不够成熟,基于整体式模型的遗传演化算法还存在诸多问题。基于分离式模型和非线性分析结果的遗传演化算法可以直观地得到较为分散的配筋设计,利用钢筋分离模型遗传演化结构优化构造了悬臂深梁、异形梁、牛腿等多种钢筋混凝土D区构件的配筋拓扑,验证了钢筋分离模型遗传演化结构优化在钢筋混凝土D区配筋优化方面的普遍能力。还借助有限元软件探讨了一组开洞剪力墙的非线性力学性能,证实了钢筋分离模型遗传演化结构优化设计的构件在比弹性应力方法节省20%左右钢筋用量、比经验方法节省超过75%钢筋用量的前提下,与弹性应力方法设计的构件承载能力基本相当,比经验方法设计的构件极限承载力仅低不到15%;且钢筋分离模型遗传演化结构优化从延性方面对钢筋混凝土D区构件的性能进行了改善。

The design of reinforcement layouts of the D-regions of reinforced concrete(RC) is an arduous problem. The much-maligned empirical design methods based on experiment results have gradually been abandoned. On the other hand, the stress design methods such as strut-and-tie model(STM) are not mature enough, for instance, the genetic evolutionary structural optimization(GESO) based on the integrated elements model still has many problems. A modified GESO method based on the separated-elements model and nonlinear analysis is developed to obtain an intuitive and dispersive reinforcement layout. In this paper, the reinforcement layouts of bracket, shaped beam and other members in RC D-regions are topologically constructed by separated-elements model GESO, in order to verify the general ability of separated-elements model GESO in optimizing RC D-regions. Nonlinear mechanical properties of a group of shear walls with door are also analyzed and compared by using finite element software. The results indicate that the RC D-regions designed by separated-elements model GESO can save the steel, the saving rate of which is nearly 20% compared with elastic stress method and more than 75% compared with empirical method. In that case, the RC D-regions designed by separated-elements model GESO have almost the same bearing capacity with that designed by elastic stress method and their ultimate bearing capacity is only about 15% lower than that designed by empirical method. Meanwhile, separated-elements model GESO also improves the ductility performance of RC D-regions.