反弯点高度比对强梁弱柱钢框架混合试验影响分析

Analysis of influence of height ratio of inflection points on hybrid test of SBWC steel frame

为了进一步研究大震下试验子结构进入弹塑性阶段时采用基于反弯点边界条件模拟方法的适用性,建立OpenSEES有限元数值模型,通过施加不同强度的地震荷载,建立反弯点高度比位置与构件损伤指标D的关系,并采用振动台试验进行验证。结果表明:强梁弱柱钢框架中底层框架柱弹性反弯点位置在柱中上方,其中边柱的反弯点高度比更偏离柱中位置;随着构件损伤程度的加深,反弯点位置逐渐趋于柱中。混合试验中将试验子结构加载边界取在取在柱中位置时的试验加载误差小于4%,满足边界条件模拟精度的要求。

In order to further study the applicability of the simulation method based on the inflection point boundary condition when the test substructure enters the strong plastic stage under a huge earthquake,an OpenSEES finite element numerical model is established and verified by a shaking table test.By applying seismic loads of different intensities,the relation between the height ratio of the inverted point and the component damage index D is established.The results show that in the steel frame with strong beams and weak columns,the position of the elastic inflection point of the bottom frame column is above the middle of the column,and the height ratio of the inflection point of the side column is more deviated from the middle of the column.As the damage degree of the component deepens,the position of the inflection point gradually moves to the middle of the column.In the seismic hybrid test,when the test substructure loading boundary is taken in the middle of the column,the test loading error is less than 4%,which meets the requirements of boundary condition simulation accuracy.