安全壳静水中的屈曲临界深度分析

摘要

A critical safety depth for sunken accident is required in the process of desig-ning the safety shell,which acts as a significant safety guarantee for the offshore nuclear power plant.Since the size of safety shell is large and several kinds of angles will appear when the safety shell is sunk,a method of the critical buckling depth coefficient was developed here for safety shell working under hydrostatic pressure,which can be well applied in the engineering design of safety shell.With the current code computation for safety shell buckling,the process of safety shell working under hydrostatic pressure was carefully simulated and the effects of structural geometric defects on the critical buckling depth coefficient were analyzed.The results show that the critical buckling depth coeffi-cient increases with safety shell's thickness,yet the increase rate of critical buckling depth coefficient decreases.In addition,the sensitivity of critical buckling depth coeffi-cient on structural geometric defect increases with the decrease of safety shell's thick-ness.Without the buckling experiments of safety shell under hydrostatic pressure,this method is a compromised way based on the current buckling design code for pressure vessel under uniform external pressure.%安全壳作为海上核电站的一道重要安全保障,需设计其发生沉没事故时的临界安全深度.由于安全壳尺寸较大,且在沉没时会呈现各种姿态角,为便于安全壳结构的工程设计,本文提出了一种安全壳在静水中的屈曲临界深度系数法.结合目前已成熟的安全壳屈曲规范计算,对安全壳进行了静水压力下的屈曲安全设计,并分析了结构几何缺陷对屈曲临界深度系数的影响.结果表明:随着安全壳厚度的增加,其屈曲临界深度系数逐渐增加,但增加率逐渐变小;安全壳的厚度越小,屈曲临界深度系数对几何缺陷敏感性越强.该方法是在目前压力容器均匀外压下的屈曲安全设计规范的基础上以及在缺乏相应的安全壳静水中的屈曲试验情况下的一种折中方案.