低屈服点钢偏心支撑框架抗震性能研究

Seismic Performance of Eccentrically Braced Frames Combined with Low Yield Strength Steel

将偏心支撑框架中的消能梁段腹板替换为低屈服点钢材,形成低屈服点钢偏心支撑框架。为实现震后修复的功能,消能梁段与主体结构通过高强螺栓及端板进行连接。建立了单层支撑框架和高宽比为2的高层支撑框架,对比分析了普通钢偏心支撑框架与低屈服点钢偏心支撑框架的抗震性能。有限元分析结果表明,单层支撑框架在相同变形状态下,低屈服点钢偏心支撑框架中的框架柱、支撑轴力显著降低,非消能梁段弯矩和剪力均有降低。高层支撑框架中,中、大震状态下低屈服点钢偏心支撑框架的位移和基底剪力均低于普通钢偏心支撑框架的位移和基底剪力,且抵抗超大震作用的能力更强。可更换消能梁段的抗震性能试验结果同样验证了采用低屈服点钢消能梁段后,相邻构件的内力降低,采用现有规范设计的螺栓和端板能够保证连接部位处于弹性状态,实现震后更换的目的。

The web of the eccentric beam section in the eccentrically braced frame is made of low yield strength steel.In order to repair earthquake-damaged frame,the eccentric beam section and the main structure are connected by high-strength bolts and end plates.A single-story eccentrically braced frame is analyzed under cyclic loading.And the high-rise eccentrically braced frame is calculated by using Pushover method.The height-to-width ratio of the high-rise eccentrically braced frame is 2.The seismic performance of the normal steel eccentrically braced frame and the low yield strength steel eccentrically braced frame are compared and analyzed.The results of finite element analysis show that under the same deformation,the axial forces of columns and braces in the low yield strength steel eccentrically braced frame are significantly reduced,and the bending moment and shear force of non-dissipative beam section are also reduced.In high-rise braced frames,the displacement and base shear force of the low yield strength steel eccentrically braced frame are lower than those of the normal steel eccentrically braced frame,and the resistance to mega earthquake is stronger.The test results of the seismic performance of the replaceable energy dissipation beam are also verified that the internal force of the adjacent members decreases by using the low yield strength energy dissipation beam section.And the bolts and end plates designed according to the existing specifications can ensure the elastic state and achieve the purpose of post-earthquake replacement.