hemispherical head meaning in Chinese
半球形封头
半球形加压头
半球形燃烧室
Examples
- 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。 - Author thinks that the direction of the maximum plastic distortion along a constant radius around the crack tip may be considered as the direction of shear - mode fracture ( named pmax - criterion ) and the load when located shear band prongs the ligament in the front of crack tip is regarded as the limited load of shear - mode fracture . ( 3 ) the fad ( fracture assessment diagram ) of titled crack is proposed based on achievements of mesomechanics about i - ii complex ductile fracture of metal , and the titled crack is classified two kinds : void - mode fracture is assessed by fracture assessment curve , and shear - mode fracture by limited load . ( 4 ) using a fe program based on plantle - ressue theory to calculate some mesomechanical parameters , a flange joint structure of a high pressure vessel ( design pressure 31 . 4mpa and the thickness of the hemispherical head is half of that of shell . ) is analyzed to determine whether the structure under operation pressure is safe or not , forecast the mode of potential invalidation and argue for the rationality of design of the structure
试件的整体断裂为剪切型，但在试件芯部裂尖钝化区中部出现了韧窝型启裂并有一定的扩展，说明局部较高的应力三轴度也会使韧窝型机制得以发展，但是不改变试件整体的剪切型断裂模式；对韧性断裂的剪切模式的细观机理做了一定的探讨，并且提出了含裂纹构件剪切型断裂的宏观判据：认为裂纹前方的集中剪切带中与裂纹尖端等半径处最大有效塑性应变出现的方向可以作为裂纹剪切断裂的方向(可简称为_ ( pmax )准则) ，集中剪切滑移带贯穿裂纹前方承载韧带时的载荷可以作为极限载荷；本文运用金属韧性断裂细观力学在一复合型韧性断裂方面的研究成果，采用失效评定图的形式，提出了倾斜裂纹的安全性评定方法的基本框架。