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为研究空间钢桁架-伞撑空冷支架结构体系的抗震性能,选取轴对称原型结构的1/4,制作1/8缩尺比的试验模型,进行拟动力试验与拟静力试验,分析结构的裂缝开展过程、刚度退化、滞回曲线、骨架曲线以及滞回耗能。采用ABAQUS有限元分析软件对试验模型结构进行非线性地震响应分析,将计算得到的结构位移反应时程曲线及包络曲线与试验结果进行对比,验证了建模方法的合理性。建立原型结构的有限元分析模型,分析结构在不同强度地震作用下的基底剪力时程曲线、位移反应包络曲线以及管柱的损伤演化过程。试验与有限元分析结果表明:空间钢桁架-伞撑空冷支架结构的刚度退化较为缓慢,且在罕遇地震作用下具有较大的剩余刚度;滞回曲线比较饱满,在罕遇地震作用下滞回耗能相对于设防地震作用增幅较大,结构耗能能力较强;骨架曲线比较平缓,无明显拐点,结构在屈服后荷载无明显下降;位移角及结构损伤演化分析表明其变形能力较强,能够满足高烈度地区百万千瓦机组火电厂的抗震设防需求。
In order to study the seismic performance of the steel truss-umbrella stand air-cooled scaffolds, one-fourth of the axial symmetry prototype structure was fabricated and a 1/8 scale-scale test model was made. The pseudo-static test and pseudo-static test were carried out to analyze the structure Crack initiation, stiffness degradation, hysteresis curve, skeletal curve, and hysteresis energy dissipation. The ABAQUS finite element analysis software was used to analyze the nonlinear seismic response of the experimental model structure. The calculated displacement curves and envelope curves were compared with the experimental results to verify the rationality of the modeling method. The finite element analysis model of the prototype structure is established to analyze the time history curve, the displacement response envelope curve and the damage evolution process of the pipe under different seismic intensity. The experimental results and finite element analysis show that the stiffness of the space steel truss-umbrella stand air-cooled supports decelerates slowly and has greater residual stiffness under the rare earthquakes. The hysteresis curve is quite full, and under the effect of rare earthquakes, Compared with fortification seismic effect, the return loss energy is larger than that of fortification seismicity, and the energy dissipation capacity of the structure is relatively strong. The skeleton curve is relatively smooth and has no obvious inflection point. The load of the structure does not decrease obviously after yielding. The evolution of displacement angle and structural damage shows that the deformation capacity is stronger , Which can meet the seismic fortification requirements of 1 million kilowatt thermal power plants in high intensity areas.