运用通用有限元软件ANSYS对某中承式异形钢管混凝土拱桥进行了动力特性的数值模拟分析,给出了自振频率和振型描述,并对自振特性的影响因素进行了研究。结果表明:主拱肋、竖吊杆、斜撑有助于增强拱桥的竖向刚度;副拱肋对拱桥面外振动影响较大,其外倾角影响结构整体刚度;横撑、斜撑的设置有助于提高拱肋的横向刚度,增强抗风的稳定性;二期恒载集度对竖弯振动影响较大;边界条件对拱桥的动力特性有显著影响。研究结果可以为同类桥梁的抗震设计提供参考。
Using the general finite element software ANSYS,the numerical simulation analysis was performed on a half-through special-shaped concrete-filled steel tubular(CFST) arch bridge to obtain dynamic characteristics.The self-vibration frequencies and vibration mode descriptions were given,and the influence factors on the self-vibration characteristics were also carried out.The results show that main arch rib,vertical boom and braces help to enhance the vertical stiffness of the arch bridge.Vice arch rib has a greater impact on the out-of-plane vibration and camber angle affect the overall stiffness of the structure.Transverse support and braces will improve the lateral stiffness of the arch ribs,and enhance the stability of wind resistance.The boundary conditions have great impacts on dynamic characteristics and degree of second dead load on the vertical vibration.The study results can provide a reference for the seismic design of similar bridges.