桥梁结构地震碰撞分析模型的碰撞刚度计算方法研究

摘要

In order to study the earthquake-induced bridge pounding,the computation methods of impact stiffness for Kelvin model and Hertz-damp model were theoretically derived based on equating the maximum pounding deformation calculated with the collinear impact model of two rods to that calculated with the rigid-body impact model.Then,the effectiveness of the proposed calculation methods was verified,respectively.The results indicated that the impact stiffness of Kelvin model is obviously smaller than the axial stiffness of the shorter bridge girder,this fact supports previous researchers' comments obtained from the measured data.The numerical analysis results indicated that Hertz-damp model can raise the pounding simulation accuracy with the proposed impact stiffness calculation method.%针对桥梁结构地震碰撞模拟问题,文中分别推导了基于波动理论的直杆共轴碰撞模型和基于接触单元法的刚体碰撞模型中相应的最大碰撞变形的计算式,并基于二者相等的关系给出了Kelvin模型和Hertz-damp模型中相应碰撞刚度的计算方法,并对所建议方法的合理性和精确度进行了验证分析.研究结果表明,文中建立方法计算的Kelvin模型的碰撞刚度数值明显小于较短主梁的轴向刚度,这一点与以前学者基于实测数据分析得到的结论相一致.数值分析结果表明,相比以前的碰撞刚度计算方法,采用本文建议的方法确定Hertz-damp模型的碰撞刚度时,可以显著提升其碰撞模拟精确度.