冲击荷载下钢管混凝土限高防护架的动力响应

通过采用ANSYS／LS—DYNA有限元软件，分析了钢管混凝土铁路桥限高防护架在汽车碰撞作用下的动力响应，比较了钢管防护架与钢管混凝土防护架的不同动力响应．结果表明：限高防护架碰撞面变形比较明显，发生了较大的内凹现象；立柱的变形最小，能够抵抗更大的冲击荷载；因应力失效而最容易破坏的部位是横梁侧一、侧二支撑管节点处；与钢管防护架相比较，钢管混凝土防护架的碰撞力均值更大，碰撞面位移更小，能够更有效地保护铁路桥的安全，从而为钢管混凝土防护架的结构设计和维护提供依据．

Dynamic Response of Concrete-Filled Steel Tube Height Limit Protective Frame under Impact Loads

We analyze the dynamic response of the railway bridge concrete-filled steel tube height limit protective frame in the crash,and compare different dynamic response of steel tube and concrete-filled steel tube protective frame by using ANSYS/LS-DYNA.The result shows collide surface deformation of the height limit protective frame beam is more obvious,and it undergoes great degree of concave phenomenon;the deformation of column is smallest and it can resist the greater impact load;the most easily damaged parts are tube node locations of side one and side two supporting because of stress failure;compared with steel tube protective frame,the average impact force of concrete-filled steel tube protective frame is bigger,and the displacement of impact surface is smaller,so as to protect the safety of railway bridge more effectively.It provides the reference for structure design and maintenance of railway height limit protective frame.