基于修正Park-Ang模型的圆钢管构件地震损伤评估

Research on seismic damage assessment of circular steel tube members based on modified Park-Ang model

为合理评估薄壁圆钢管构件的地震损伤程度,基于Park-Ang地震损伤模型,通过修正相关参数,建立了适用于圆钢管构件的地震损伤模型。利用圆钢管构件在低周反复荷载作用下的骨架曲线,给出了损伤模型中各待定参数的计算方法,在此基础上通过反演构件破坏点损伤因子为1.0时的模型组合系数,并利用曲线拟合法得到模型组合系数与构件轴压比、长细比和径厚比等参数间的关系式,从而建立构件的地震损伤评估模型。结果表明,修正的Park-Ang损伤模型可较好地评估圆钢管构件的损伤程度,构件达到极限破坏时的损伤因子值收敛于1.0且离散性较小,构件的破坏程度可划分为基本完好、轻微与中等破坏、严重破坏和失效破坏,对应的损伤因子界限值分别为0.02,0.41和1.00。

In order to reasonably evaluate the degree of seismic damage of thin-walled circular steel pipe members,a seismic damage model applicable to circular steel pipe members was established based on the Park-Ang seismic damage model by modifying the relevant parameters.Using the skeleton curve of the circular steel pipe component under the action of low-cycle repeated loads,the calculation method of each undetermined parameter in the damage model is given.On this basis,the model combination coefficient when the damage factor of the component failure point is 1.0 is determined through an inverse analysis and used.The curve fitting method provides the relationship between the model combination coefficient and the axial compression ratio,slenderness ratio and diameter-thickness ratio of the components,so as to establish the seismic damage assessment model of the components.The results show that the modified Park-Ang damage model can better evaluate the damage degree of round steel pipe members.When a member starts to fail,the damage factor converges to 1.0 and the dispersion is small.The damage degree of the member can be divided into basically intact,minor damage,moderate and severe damage,and complete damage,the corresponding damage factor threshold values are 0.02,0.41,and 1.00,respectively.