USING DEAL.II FOR STRUCTURAL ANALYSIS OF A MEDICAL OXYGEN CYLINDER

Abstract

Medical Oxygen Cylinders being convenient containers for transportation and storage of oxygen gas has wide range of applications in industries and hospitals. Storing oxygen at high pressure in cylinders increases the risk of structural failure. This study aims to develop a program based on open source C++ library for Finite Element Analysis (FEA) in thin-walled cylinders and to apply the program to perform structural analysis and safety assessment of medical oxygen cylinders operating below their working pressure. To achieve this goal, a literature review was conducted to identify gaps in the use of open-source software for FEA in thin-walled cylinders. Open source FEA library called deal.ii was used to construct the program. This C++ based program was verified by comparing it with the hoop stress results from theoretical calculation and ANSYS for a simple hollow cylinder. The study then proceeded to create a detailed CAD model of the medical oxygen cylinder for a parametric study for varying wall thickness and material. The model was simplified and meshed for FEA, with pressure and fixity constraints applied during simulation. The parametric simulations were run through the developed program which showed that maximum hoop stress occurs in the region around neck of the cylinder. The methodology involved verification of the program by comparing the results with that of ANSYS and theoretical calculations in case of simple hollow cylinder in which maximum error was found to be 0.875 %. Parametric analysis for variying material and thickness found that the cylinder with larger thickness i.e., 5.6 mm, and material 37MnSi5 undergoes through the smallest deformation. The development of the open-source software will provide a valuable resource for future research and development in this field, as well as contribute to the enhancement of the safety and reliability of medical oxygen cylinders.