Research on Weld Seam Models for Hydro-forming of Ellipsoidal Shell

Abstract

In order to study the effect of weld seam models on hydro-forming of ellipsoidal shell, three kinds of models, i.e., comprehensive model rough model and no weld seam model were built and the influence was discussed on variation of axis length. An experiment for hydro-forming of ellipsoidal shell with initial axis length ratio 1.8 was first carried out, and the axis length varying with the increasing of internal pressure was obtained. Simulation on three kinds of finite element model was conducted, and the effect of weld seam models on the simulation accuracy was deeply discussed by a comparison of axis length variation between simulation and experiment. It is shown that little difference happens among the three kinds of weld seam models at the early stage of deformation, and the axis length deviation is less than 4%. However, there is worse simulation accuracy for the no weld seam model at the middle and late stage of deformation, and the axis length deviation is up to 15%. While both the comprehensive model and the rough model can successfully predict the axis length variation with the deviation no more than 5%. Finally, the rough model is selected on the basis of better simulation accuracy and simple weld seam model.

Keywords

• weld seam model
• ellipsoidal shell
• hydro-forming