高强混凝土框架边节点抗震性能分析

Analysis of anti-seismic capability of peripheral joints in high-strength concrete frame

在四榀高强混凝土框架边节点试件的抗震性能试验研究工作基础上,用有限元非线性方法建立了计算模型并进行了简化.对高强混凝土采用等效单轴应变的增量正交异性模型,且考虑裂面效应的反复加载本构关系,对反复荷载下的应力 应变关系作了适当修改;钢筋的应力 应变关系中考虑了反复荷载下的Baushinger效应,同时对其软化段作了相应的简化;在粘结滑移模型中引用了斜压杆单元和反复荷载下的粘结滑移关系.根据以上模型编制了二维非线性有限元程序,并用所编程序对四榀高强混凝土框架边节点进行了分析,计算结果与试验结果符合良好.

Based on experiment, antiseismic capability of peripheral joint samples of four highstrength concrete frame is analyzed with nonlinear finite element method, where certain calculation models are quoted and modified to simplify the calculation. The result shows that the calculated conclusion is close to practical situation. An incremental orthotropic model with equivalent uniaxial strain is taken as one for the highstrength concrete, the isomorphism of cyclic loading with the cracking effect is taken into consideration, and the relationship of stress to strain under cyclic loading is properly modified, also. The Baushinger effect is taken into consideration for the stressstrain relation within the reinforcing steel under cyclic loading and, meantime, a corresponding simplification is made upon the softened segment of the relationship. In addition, an element of oblique compressive rod and the bondslip relationship under cyclic loading are used in bondslip modeling. Therefore, a twodimensional nonlinear finit element program is developed on the basis of abovementioned model, with which the analysis of antiseismic capability of peripheral joints in the concrete frame is conducted, resulting in a conclusion having a fine agreement with the experimental one.