椭圆形封头大开孔结构强度分析

Structural Strength Analysis of an Elliptic Head with a Large Opening

根据椭圆形封头的结构特点和工作条件,运用有限元分析方法,对大开孔椭圆形封头结构进行了应力分布计算与分析;进行了缩比模拟试验件静态应力实测及实验验证分析。计算和实验结果表明,该结构的危险部位为薄壁大接管与封头相贯顶部内侧,可作为设计的主要控制点;有限元计算外侧高应力区应力与实测结果相符,误差仅为0.7%,焊缝及内表面计算值与实测值误差大一些,但不超过11.3%。表明了利用三维有限元分析方法解决大开孔封头的结构设计是可行、可靠的。误差较大的原因分析可以为实际产品的设计、加工及实验提供一定的参考。

In the light of the structural features and operating conditions of elliptic heads,by employing a finite-element analysis method,a calculation and analysis has been performed of the stress distribution on an elliptic head structure with a large opening.Measurements of static stress and experimental verification analyses have also been undertaken on a reduced-scale simulation test piece.The calculation and test results show that the dangerous part of the structure is located at the inner top side of the connected portion between the thin-walled large nozzle and the head,which can be taken as the design main control point.The stresses in the external-side high stress zone calculated by using the finite element method correspond with the actually measured stress results with an error of only 0.7% being recorded.A slightly bigger error exists between the calculated and actually measured values in the welding seams and the inner surface but it does not exceed 11.3%.This shows that the use of the three-dimensional finite-element analytic method to resolve the structural design of heads with a large opening is feasible and reliable.The analysis of causes leading to a relatively great error can serve as a helpful reference for the design,manufacture and tests of real products.