装配式基础隔震框架结构拆分方式研究

Study on the splitting method of prefabricated base-isolated frame structure

地震作用下隔震结构动力响应不同于抗震结构。为研究装配式隔震框架结构的拆分方式,文中针对非线性分析中混凝土损伤因子和装配式基础隔震框架结构进行数值模拟,将残余应变与塑性应变的关系引入考虑塑性应变的损伤因子计算公式中,得到改进的损伤因子计算公式,并对比分析了钢筋混凝土柱数值模拟结果与已有试验结果的骨架曲线特征值,验证改进的损伤因子计算公式的合理性;基于有限元软件ABAQUS对一榀基础隔震框架结构进行模拟,并将验证了的损伤因子输入到该模型中,研究其在地震作用下的损伤特征。结果表明:(1)钢筋混凝土柱屈服荷载、屈服位移、承载力最大值等骨架曲线特征值与试验结果的误差皆在10%以内,改进的损伤因子能够较好地模拟混凝土的非线性特征;(2)一榀基础隔震框架上部结构首层柱柱底1/3处的应力较首层柱其他位置小,其余层的应力较小位置基本位于柱中。本文针对一榀基础隔震框架结构的损伤特征并根据拆分原则提出的结构拆分方式,可为装配式隔震框架结构的拆分方式提供参考。

Since the dynamic response of isolated structure under earthquake is different from that of aseismic structure,numerical simulation is carried out for concrete damage factor in nonlinear analysis and prefabricated base-isolated frame structure in order to study the splitting method of prefabricated isolated frame structure.The relationship between residual strain and plastic strain is introduced into the damage factor calculation formula considering plastic strain so as to obtain an improved formula for calculating the damage factor.The rationality of improved formula is verified by comparing numerical simulation results of reinforced concrete columns and skeleton curve eigenvalues of existing test results;a base-isolated frame structure is simulated based on a finite element software ABAQUS.The verified damage factors are input into the model to study its damage characteristics under earthquake.The results show that:(1)The error is less than 10%between the characteristic values of skeleton curves such as yield load,yield displacement and maximum bearing capacity of reinforced concrete columns and the test results.The improved damage factor can better simulate the nonlinearity characteristics of concrete;(2)The stress at 1/3 of column bottom on the first floor of the superstructure of a base-isolated frame is smaller than that at other positions of the column on the first floor.The positions with smaller stress in other layers are basically located in the column.Structure splitting method is proposed in this paper according to the damage characteristics of a base-isolated frame structure and splitting principle,which can provide a reference for the splitting method of prefabricated isolated frame structure.