椭圆封头的几何形状与薄膜应力的讨论  

Discussion on the Geometry and Membrane Stresses of the Ellipsoidal Head

作　　者：高炳军[1] 闫文军[1] 王俊宝[1] 

机构地区：[1]河北工业大学化工学院

出　　处：《河北工业大学学报》1999年第1期84-88,共5页Journal of Hebei University of Technology

摘　　要：根据回转壳体的基本概念及回转薄壳的无力矩理论，探讨了椭圆封头的几何形状及其薄膜应力等问题．认为由于中面母线不是椭圆，椭圆封头的椭圆壳部分只能称为近似椭圆壳．对于标准椭圆封头，与根据封头近似椭圆壳中面母线几何形状推导的薄膜应力相比，根据同内径、同长短轴之比的椭圆壳中面母线椭圆推导的薄膜应力，在顶点处两向应力值都稍大，在赤道处，经向应力相同，周向压应力值稍大；根据封头近似椭圆壳内表面母线椭圆推导的薄膜应力，在顶点处两向应力都稍小，在赤道处，经向应力稍小，周向压应力值稍大．而且这种差异随厚径比的增大而增大，当厚径比为０．０４时，在赤道处，周向压应力误差可达２５％左右．Based on the basic concept and nomoment theory of rotational shell,the geometry and membrane stresses of the ellipsoidal head are discussed in this paper. Because the middle surface generatrix is not an ellipse, the socalled ellipsoidal portion of the ellipsoidal head may only be called an approximate ellipsoid.For the standard ellipsoidal head with a/b =2, compared with the membrane stresses derived from the middle surface generatrix of the approximate ellipsoid, the following items are founded.(1)The value of both the hoop and the meridional stresses at the top, the hoop compressive stresses at the equator, derived from the middle surface ellipse of a real ellipsoid with the same inside diameter and ratio of a/b , are a little big. However, the meridional stresses at the equator have a same value. (2) The meridional stresses at both top and equator, the hoop stress at the equator, derived from the inner surface ellipse of the approximate ellipsoid, are a little small. However, the hoop compressive stress at the equator is a little big.(3) The differences increase with the increase of the ratio of the thickness to the diameter, the maximum difference of the hoop compressive stresses at the equator raises up to 25% or so.

关 键 词：化工设备 压力容器 椭圆封头 几何形状 薄膜应力 

分 类 号：TH136[机械工程—机械制造及自动化] TQ051.3[化学工程]