Abstract :

This Study Presents A Comprehensive And Systematic Design Methodology For Cylindrical Vacuum Chambers Operating Under Full Vacuum Conditions, With Primary Emphasis On Ensuring Structural Stability Against External Atmospheric Pressure In Accordance With ASME Section VIII, Division 1. Unlike Internally Pressurized Vessels That Are Governed By Tensile Stresses, Vacuum Chambers Are Subjected To Compressive Stresses Where Elastic Buckling Becomes The Dominant Mode Of Failure, Particularly In Thin Shells Characterized By High Diameter-to-thickness Ratios And Extended Unsupported Lengths. To Address These Challenges, The Shell Thickness And Geometric Parameters Were Determined Using UG-28 Provisions For External Pressure Design, While The Adequacy Of Stiffening Rings Was Verified Based On UG-29 Requirements To Ensure Sufficient Moment Of Inertia And Reduction In Effective Unsupported Length. In This Work, A Comparative Analysis Was Carried Out Using Different Stiffening Configurations, Namely No Stiffening Ring, One Stiffening Ring, Two Stiffening Rings, And Three Stiffening Rings, To Evaluate Their Influence On Structural Stability, Critical Buckling Pressure, And Allowable External Pressure Limits. The Results Clearly Indicate That The Absence Of Stiffening Rings Leads To Reduced Load-carrying Capacity And Higher Susceptibility To Buckling, Whereas The Introduction Of Stiffening Rings Progressively Enhances Stability By Decreasing The Effective Unsupported Length And Increasing Resistance To External Pressure. A Dual-validation Approach Was Employed By Integrating Manual Calculations Derived From ASME External Pressure Charts With PV Elite Simulations, Ensuring Consistency And Compliance With Design Codes. Furthermore, The Study Incorporates Optimization Of Ring Spacing, Appropriate Material Selection, And Sensitivity Analysis Of Geometric Variations To Establish A Robust And Reproducible Design Workflow Adaptable To Various Chamber Configurations. The Results Demonstrate That The Strategic Incorporation Of Stiffening Rings Enables The Safe Use Of Thinner Shells Without Compromising Structural Integrity, Thereby Providing A Cost-effective And Reliable Design Solution. This Work Effectively Bridges The Gap Between Empirical ASME Methodologies And Computational Tools Such As PV Elite, Offering A Structured, Code-compliant Approach That Enhances Predictive Accuracy, Improves Safety In Vessel Construction, And Contributes A Validated Framework For Modern Pressure Vessel Engineering Applications.

Published:

11-4-2026

Issue:

Vol. 26 No. 4 (2026)

Page Nos:

1336 - 1345

Section:

Articles

License:

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

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