16mnr and 45 # steel are taken as examples . the obtained results have been applied to analyze the safety of operation pressure and rationality of design of a kind of engineering structure - a flange joint of hemispherical head to cylindrical shell . try to seek a sort of new method to assessment the capability of structure to load beyond the traditional method which regards stress and strain as main parameters 本文以45 ~ #调质钢和压力容器常用钢材16mnr为研究对象，对金属材料韧性断裂的断裂模式进行细观机理上的研究，进而分析一种工程结构? ?采用与筒体厚度不同的半球形封头的压力容器的筒体连接结构? ?的静载变形特点和破坏形式，尝试在以应力应变为主要参数的传统方法之外，寻求一种新的结构承载能力分析的方法。
