地震中桥梁碰撞刚度取值的修正

Bridge Impact Stiffness Values of Correction in the Earthquake

摘要: 在桥梁碰撞研究中，一般采用接触单元来分析碰撞机理，其中碰撞刚度合理取值方法一直没有统一的结论。目前所采用的碰撞刚度建议取0.5倍较短主梁的轴向刚度。该取值存在一定的局限性与主观性。本文根据桥梁碰撞变形机理，认为碰撞刚度在碰撞过程中是不断变化的，通过柔度法和应力应变公式反推碰撞刚度，用应力应变等参数描述碰撞刚度的变化。分析参数表明：碰撞刚度和邻梁比对碰撞力、碰撞持续时间影响最大。

Abstract: Generally, the analysis mechanism of collision is based on the contact element method in the collision study of the bridge, which impacting stiffness has been controversial. Currently, it adopted by the colliding stiffness suggest take 0.5 times short axial stiffness of the beam, which has limitations and department of subjective. In this paper, the author believes that collision stiffness is changing in the collision process according to collision deformation mechanism on the bridge. Collision stiffness derived by flexibility method and stress strain formula and the change of impact stiffness described by parameters such as stress and strain. Results of analyzing the parameters show that collision stiffness and adjacent beam ratio have a significant affect on the impacting force and duration.