钢安全壳椭球封头极限承载力敏感性分析

Ultimate Capacity Sensitivity Analyses of SCV Ellipsoidal Head

针对极限内压作用下钢安全壳的屈曲失效和屈服失效，研究初始缺陷、径高比、事故温度、缩尺比、封头厚度以及筒身有效高度和厚度等关键参数对椭球封头极限承栽力的影响。建立多个代表性结构模型，计算采用几何与材料双重非线性分析，给出后屈曲阶段的局部屈曲变形以及颈缩应变下结构变形．并根据屈曲点或顶点处的荷载一位移曲线得到屈曲失效或屈服失效的极限承载力。敏感性分析结果表明．初始缺陷、径高比、事故温度和封头厚度对极限承载力均有不同程度影响，其中径高比最为关键。

Considering the SCV buckling failure and yielding failure under ultimate internal pressure, the initial imperfection, radius-height ratio, accident temperature, scaled ratio, head thickness, effective height and thickness of cylindrical shell are all studied on the influence of the ellipsoidal head ultimate capacity. The multiple structures are modeled, and both geometric and material double nonlinear analysis is adopted. The post-buckling deformation and the deformation at elongation failure are shown, and the ultimate capacities are obtained by the load-displacement curves of buckling point in buckling failure or the top point in yielding failure. The results of sensitivity analyses indicate that initial imperfection, radius-height ratio, accident temperature and head thickness have their own certain influences, and especially radius-height ratio is the most significant factor.