[关键词]
[摘要]
由于建筑高度低、降噪性能好、空间利用率高等优点,U型梁在轨道交通高架桥中广泛应用,但对其结构性能的研究相对较少。基于Abaqus6.14-1的优化模块,依托某实际U型梁项目,首先采用拓扑优化的方法,在保证列车行驶空间等必要功能要求的前提下,以应变能最小为目标函数、体积限值等为约束条件,研究不同支承条件下轨道交通30 m标准跨径简支高架U型梁的最优结构形式。对拓扑优化结果进一步采用形状优化,以消除截面应力集中的影响。结果表明:对于上承式桥梁,当支座间距较小时,优化结果类似于小箱梁,当支座间距较大时,优化结果类似于T梁;对于下承式桥梁,其拓扑优化形态比较接近于实际项目的U型梁设计方案。经形状优化后,局部应力降为原数值的71.39%,应力集中明显改善。结果还表明,连续体结构拓扑优化技术可有效地运用于桥梁结构的方案设计。
[Key word]
[Abstract]
Because of its advantages of low building height, good noise reduction performance, and high space utilization rate, the U-beam has been widely used in rail transit viaducts. However, research on its structural performance has been minimal. Based on the optimization module of Abaqus 6.14-1 and relying on a practical U-beam project, this paper adopts the method of topological optimization to study the optimal structural form of a 30-m standard-span simply supported elevated U-beam in rail transit under different supporting conditions. The minimum strain energy is taken as the objective function, and the volume limit is used as the constraint. The premise is to the necessary functional requirements such as train running space. After that, shape optimization is used to eliminate the stress concentration in the section. The results show that for deck bridges, the optimization results are similar to those of small box girders when the spacing between supports is small. For deck bridges, the optimization results are similar to those of T-beams when the spacing between supports is large. For deck bridges, the topology optimization form is close to the design scheme of U-beams of actual projects. After shape optimization, the local stress drops by 71.39% of the original value, and the stress concentration is obviously improved. The results also show that continuum structure topology optimization technology can be effectively applied to the schematic design of bridge structures.
[中图分类号]
TU997
[基金项目]