预应力混凝土核电厂安全壳结构扭转地震效应影响因素分析

ANALYSIS ON TORSIONAL SEISMIC RESPONSE INFLUENCE FACTOR OF PRESTRESSED CONCRETE NUCLEAR POWER PLANT CONTAINMENT VESSELS STRUCTURE

为探究扭平分量比、扭转周期比、层间位移角、扭转位移比及扭转效应系数指标对地震作用下核电厂安全壳结构弹性扭转效应的影响,确定结构最不利扭转损伤薄弱部位。基于El Centro波、Taft波和南京地震波作用,利用有限元分析软件ANSYS,对核电厂安全壳结构在自重、自重和预应力共同作用两种工况下的弹性扭转地震效应进行分析。结果表明:层间位移角和扭转效应系数越大,且扭转位移比大于1.2时,核电厂安全壳结构的弹性扭转效应更为剧烈,扭转损伤不利部位发生在筒壁中间附近区域以及筒壁与穹顶相接处周围的区域;控制核电厂安全壳结构扭转效应指标与扭转动力参数密切相关,提高抗扭刚度及阻尼,将有利于降低扭转振动的幅度,从而增强结构的抗扭安全。研究结果可为在役核电站安全评估提供技术参考。

To study the influence of torsional component ratio, torsional period ratio, inter-story drift angle, torsional displacement ratio and effect coefficient on the elastic torsional effect of nuclear power plant containment vessels structure under earthquake, and determine the weak part of the most adverse torsion damage for the design, meanwhile the effective methods to control torsional vibration of nuclear power plant containment were proposed. Based on the El Centro wave, Taft wave and Nanjing earthquake wave, the finite element analysis software ANSYS was used to analyze elastic torsional seismic response of nuclear power plan containment structure under two working conditions, the weight, the weight and the prestress. As inter-story drift angle and torsion effect coefficient were getting bigger, and torsional displacement ratio was greater than 1.2, the elastic torsional effect was more severe. Torsion damage unfavorable positions would not only occur in the middle of the tube wall near the area, but also around the connection of the tube wall and the dome. The control indexes on torsional effect of nuclear power plant containment vessels structure were closely related to torsional dynamic parameters, improving layer torsional rigidity and damping would be beneficial to reduce the torsional vibration amplitude, so as to enhance the anti-torsion security of structure. The results could provide technical reference for safety evaluation of nuclear power plant in service.