Design Analysis and Optimization of Head for Large size UHV Vessel

Abstract

To reduce stress and increase smoothness of dome curvature for large size UHV chambers with help of space curve like cubic spline & Bezier curve and compere and reduce 1) Discontinuity effect at Junction of Crown and Knuckle 2) Stress at junction of crown and knuckle of torispherical head shape, 3) Bending moment 4) Hoop force at end of dome. A Design of Vacuum Chamber is the same process of designing of pressure vessel, but with pressure is applied on external surface of chamber wall. That’s why ASME developed different codes and procedure for designing of externally pressurized vessel. During project work, I was designing dome for vacuum chamber for Ultrahigh Vacuum (10-9 torr) application with help of ASME VIII Div-1 UG-32, 33, 33.1,44 for designing of shell and dome of for pressure and vacuum vessel. Also selection of material for vacuum application is tedious process, because it involves vacuum science and vacuum metallurgy and much different vacuum terminology to take care for during working condition of system. Dome curvature has mathematical discontinuity because of there are two type of radius involved in torispherical dome meridional 1) Knuckle, 2) Crown, and there is a joint connection between this radius, but we can reduce this mathematical discontinuity with help of space curve like Bezier curve for dome meridional. So, we convert this two radius of dome meridional into single curvature in the form of Bezier curve of 5th degree of polynomial with C2 (Curvature Continuity) level of continuity. During this project work development of Stress base Geometrically Discontinuity in Dome Curvature and Cylindrical Shell Meridian is carry out.