基于累积损伤的钢骨超高强混凝土框架节点承载力退化模型研究

RESEARCH ON STRENGTH DEGRADATION MODEL OF STEEL REINFORCED SUPER-HIGH-STRENGTH CONCRETE FRAME JOINT BASED ON THE CUMULATIVE DAMAGE

为研究地震作用下钢骨超高强混凝土框架节点的承载力退化规律,通过对12个节点试件的低周往复荷载试验,在分析已有承载力退化模型的基础上,引入强度退化函数,从累积损伤方面建立了钢骨超高强混凝土框架节点承载力退化模型,确定了节点损伤变量与承载力退化的函数表达式,并讨论了试验参数对承载力退化的影响。结果表明:所建立的退化模型能够反映节点的承载力退化现象,与试验结果吻合较好。构件的承载力衰减与加载制度有关,在同级控制位移下,承载力退化程度基本相等,节点构件发生破坏时,仍具有一定的承载力。该模型能反映地震作用下钢骨超高强混凝土框架节点受力机理,可对该类节点的抗震设计和地震后的加固提供理论参考。

In order to research the degradation rule of the bearing capacity of steel reinforced super-high-strength concrete frame joint under the earthquake,through quasi-static tests of 12 specimens,on the basis of analyzing the existing strength degradation models,a strength degradation model of steel reinforced high strength concrete frame joint based on the cumulative damage was established by introducing the strength degradation function,the function expression of damage variable and strength degradation were determined,and the influence of experimental parameters on the strength degradation was discussed in the paper. The results showed that the established degradation model could reflect the bearing capacity of the joint degradation phenomenon,and the results agreed well with the test results. The bearing capability of the members was related to loading system. The degradation of bearing capacity was basically equal under the equivalent control displacement. Components still had a certain bearing capacity when the joints were destroyed. The model could reflect the stress mechanism of steel reinforced high strength concrete frame joint under the earthquake. It also could provide a theoretical reference for the seismic design and the reinforcement of this kind of joints after the earthquake.