基于谱随机有限元法的龙卷风作用下核电常规岛可靠度分析

在核电厂厂址处龙卷风观测记录的基础上,推导了极值III型龙卷风强度概率分布函数。建立了核电常规岛主厂房的计算模型,采用谱随机有限元法,考虑三种荷载工况下龙卷风荷载和结构抗力参数的不确定性,对结构进行龙卷风作用下的随机响应和可靠度分析。分析结果表明:厂房位于龙卷风中心时,龙卷风荷载对厂房的产生明显的扭转效应,结构顶点随机位移对规范限值的超越概率较大;当厂房位于龙卷风最大半径处,龙卷风对结构主要产生侧向推动作用,顶点随机位移对规范限值的超越概率很小。龙卷风位于厂房中心处为三种工况下的荷载最不利位置。

RELIABILITY ANALYSIS OF NUCLEAR POWER PLANT MAIN HOUSE UNDER THE EFFECT OF TRONADO LOAD BASED ON SSFEM

Based on the tornado observation records at a nuclear power plant site, a tornado intensity distribution of extreme value type III was derived. Modelling a computational model for a conventional island main house and taking into account the uncertainty of tornado load and structural resistance parameters, the stochastic response and reliability analysis of a spectral stochastic finite element method (SSFEM) was carried out in three load cases. The results show that: tornado loading produces a strong torsional effect on a structure and the exceeding probability of a top node random displacement to the specification limit is relatively high when the main house locates at the center of tornado; meanwhile, tornado loading produces a pushing effect on a structure and exceeding probability is fairly low when the main house sits at the radius of tornado maximum wind speed. Locating at a tornado center is the most unfavorable load position to the main house in three load cases.