渐进结构优化法在桥梁找型中的应用

Evolutionary Structural Optimization in Form Finding of Bridges

摘要:

介绍了结构拓扑优化方法的基本理论，详细阐述了双向渐进结构优化法的原理和优化过程，并根据双向渐进结构优化法编制了基于ANSYS平台的结构拓扑优化程序.模拟现有桥梁结构和构件的边界条件，应用该程序求解二维平面拓扑优化问题，分别完成了不同矢跨比拱桥、悬索桥主缆以及斜拉桥桥塔的拓扑优化.拓扑优化过程中结构可经历多种拓扑形态，优化结果表明应力均匀、传力流畅，从而验证了自编程序的有效性.最后，将该程序从二维平面拓展到三维空间，实现一座峡谷桥梁的三维拓扑优化，并基于优化结果的拓扑形式完成了其概念设计方案.研究表明结构拓扑优化技术可以在桥梁概念设计阶段得出合理而富启发性的桥梁结构形式，在桥梁找型方面具有良好的应用前景.

Abstract:

The principle and the procedure of bi directional evolutionary structural optimization (BESO), which is the later version of evolutionary structural optimization (ESO), are stated in detail. A stream of ANSYS Parametric Design Language (APDL) commends based on BESO is programmed. An exploratory research is carried out by applying this program to solving 2D topology optimization problems whose boundary conditions are set according to real bridge structures. The topology optimizations for arch bridges with different rise to span ratios, main cable of suspension bridge and main tower of cable stayed bridge are achieved. The procedures provide several different topological forms and the results show rational structures with well distributed stress and smooth force transmission, which demonstrate the efficiency of the program. The program is then expanded from 2D plane to 3D space and the conceptual design of a canyon bridge is achieved on the basis of topology optimization result. The research indicates structural topology optimization is an effective tool which can be used to draw a reasonable and heuristic layout of a bridge structure in conceptual design phase.