钢桥塔的塔形力学特性分析

采用空间梁单元建立了几种典型钢桥塔的数值分析模型,对不同塔形进行静力和稳定分析,得到了不同塔形、相同塔形采用不同构造的静力和稳定特性.分析结果表明：不同塔型、构造对索塔的稳定性具有显著影响,在抵抗面内失稳、扭转失稳的能力方面,倒V形、A形桥塔具有明显优势;H形桥塔随横梁的上移,其抵抗面内失稳和抗扭转能力明显增加;对于A形桥塔,横梁的上移,降低了抵抗面内失稳能力;可以根据工程要求选择不同塔形.将采用空间梁单元进行第二类稳定分析得到的极限承载力与采用板壳单元分析模型得到的结果进行了对比.结果表明：局部失稳比整体失稳早先发生,局部失稳控制钢桥塔的设计;在稳定极限承载能力状态下,两种模型计算得到的桥塔应力分布规律接近,两者进入塑性区域的位置基本一致.

Mechanics behavior analysis on steel pylons of bridge structures

Analysis models for typical steel pylon styles of bridge structures are established using 3D beam elements, and the static and buckling behaviors of the pylon styles are analyzed. Then the static and buckling mechanics characters of typical pylon styles are gained, which shows that the pylon styles and constitutions have obvious effect on buckling behaviors of the steel pylons. The longitudinal and torsional buckling resistance of inverse V and A pylon style is superior than others. The position of crossbeam of H pylon style is higher, the longitudinal and torsional buckling resistance is larger. However, the position of crossbeam of A pylon style is higher, the longitudinal buckling resistance is lower. Therefore, the different pylon styles can be chosen according to the different design requirements. The ultimate load coefficient of steel pylon models with 3D beam elements is compared with the ones of models using 3D shell elements, which shows that the lost of local stability occur before the lost of total stability, the local buckling will control the design of steel pylons. The regularities of the stress distribution of beam and shell element models for steel pylons are similar, and the positions of the plastic area for different pylons are also similar, which shows the simulation is reasonable. 3 tabs, 15 figs, 14 refs.