Development of Force Control Mechanism for Dished End Forming of Pressure Vessel

Abstract

Today many manufacturing industries prefer metal forming process over other manufacturing process. The reason behind this is their better characteristics observed during cold working. The heavy and large size components are formed as it imparts strength, toughness and wear resistance to the material. Cold metal forming processes are used in pressure vessel manufacturing, automobile industries, aviation and locomotive industries, etc. where precise performance characteristics are desired. No literature is directly throwing lights on thick plate dish end forming so therefore it is necessary to critically develop a proper procedure of controlling forces during thick plate dish-end forming. Aim of present work is to develop a force control mechanism for dished end forming of pressure vessel. To find the limiting force to form a petal (a piece of plate from crown and petal type dished end) Single Point Pressing method is used. Forming is done with use of different die and punch which depends on shape and type of dish end (i.e. elliptical). Analytical method of forming is very complex and time consuming compared to that FEA results, because that are quite satisfactory which can be further validate with experimental trial results. In order to achieve the result Finite Element Analysis for forming elliptical dish end is being done, for the determination of limit force ABAQUS/CAE is used which is more promising FE package available in market for nonlinear analysis. This analysis is carried out by pressing number of points on a petal to achieve final dish end profile. From analysis plots, force required to form a petal has been found. It has been seen that stresses are coming within safe forming limit. The analysis results are then implemented for experimental trial and it has been found that the results are fruitful and product formed satisfactory.