结构地震碰撞分析的线性粘弹性碰撞模型

LINEAR VISCOELASTIC MODEL OF EARTHQUAKE-INDUCED STRUCTURAL POUNDING

针对结构地震碰撞模拟问题,该文中结合Kelvin模型和Hertz-damp模型构造了新的碰撞阻尼函数,提出了线性粘弹性碰撞模型,并基于现有的碰撞试验数据检验了其正确性和碰撞模拟精度。研究结果表明:线性粘弹性碰撞模型可以消除Kelvin模型中出现的撞击力跳跃和拉力的缺陷;相比其他常用的结构地震碰撞分析模型而言,线性粘弹性碰撞模型和Hertz-damp模型都具有较高的碰撞模拟精确度,且线性粘弹性碰撞模型的表达形式比Hertz-damp模型的更为简单易用。分析对比中还发现,如在碰撞模型中忽略碰撞过程中的耗能,数值模拟结果将会高估碰撞对结构的破坏效应。

In order to study the earthquake-induced pounding on structural responses, based on a new damping function, a linear viscoelastic pounding model is proposed, which absorbs the advantages of Kelvin and Hertz-damp models. Then the effectiveness of the proposed model is verified by comparing the results of numerical analysis with results of two impact experiments. The results of the study indicate that the initial jump of the pounding force and negative pounding force before separation in a Kelvin model can be thoroughly eliminated in the proposed model. Both the linear viscoelastic and Hertz-damp models can give relatively precise results in simulating the pounding force time histories compared to other commonly used pounding models. Moreover, an advantage of the proposed model is that it has a simpler expression compared to the Hertz-damp model. This implies that the proposed model can be much easier to be used in the pounding simulation. It is also found that it will lead to overestimation of damage effects if the energy loss is neglected during pounding simulation.