基于OpenSEES的高强钢组合K形偏心支撑框架精细化建模分析

Accurate modeling of high strength steel composite K-eccentrically braced frames using OpenSEES

为研究高强钢组合K形偏心支撑框架在反复荷载作用下的受力性能,在已有拟静力试验的基础上,利用有限元软件OpenSEES对一个高强钢组合K形偏心支撑框架模型进行了精细化建模研究。首先,探讨了模型的单元选择,纤维截面划分和材料本构参数定义问题。同时,考虑到在地震荷载作用下,高强钢组合K形偏心支撑框架主要依靠消能梁段的剪切变形来耗能,因此,如何模拟结构中消能梁段的剪切效应成为研究的关键。本文采用OpenSEES提供的组合截面和零长度单元两种方法来对消能梁段进行建模,剪切材料分别考虑了Steel 02和滞回材料。将不同消能梁段建模方法的模拟滞回曲线和骨架曲线与试验结果进行比较。结果表明:精细化模型的数值模拟结果和试验结果具有较好的吻合度,验证了数值模型的正确性和可行性;采用零长度单元和Steel 02的组合方式来模拟消能梁段的剪切效应能够同时满足计算效率和计算精度的要求,为进一步利用OpenSEES进行高强钢组合K形偏心支撑框架的动态响应分析和复杂模型分析提供了建模参考依据。

In order to investigate the behavior of high-strength steel composite K-eccentrically braced frame(K-HSS-EBF)under low-cycle loading,an accurate model that corresponded to a quasi-static experimental investigation on K-HSS-EBF was established and analyzed using OpenSEES.First,the selection of element,the division of fiber cross section and the definition of material constitutive parameters were discussed.And then,considering that during an earthquake,the energy dissipation of K-HSS-EBF mainly depends on the shear deformation of the links,the simulation of shear effect of the links become the key problem.In this paper,the link was modeled by the combination section and zero-length element provided in OpenSEES.Steel 02 and hysteretic material were considered as shear materials.The hysteretic loops and skeleton curves of the numerical models were compared with those of the quasi-static test.The results revealed that the numerical simulation results of the accurate model were in good agreement with the experimental results,which verifies the correctness and feasibility of the numerical model.The shear effect of link could be simulated by the combination of zero-length element and Steel 02,which can meet the requirements of both calculation efficiency and accuracy,in addition to serving as a reference for further dynamic response analysis and complex model analysis of K-HSS-EBF using OpenSEES.