Analytical Solution for Mechanical Stresses Of Multilayered Hollow Spherical Pressure Vessel

• Main Author: Ng, Yee Ping
• Format: Final Year Project / Dissertation / Thesis
• Published: 2020
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://eprints.utar.edu.my/4112/1/1506297_fyp_report_%2D_YEE_PING_NG.pdf; http://eprints.utar.edu.my/4112/

Pressure vessels are enclosed devices typically used to store fluids under very high pressure. Some common applications include BBQ butane grills, LPG tanks, and oil tankers. For the past decades, multilayered and FGM pressure vessels have increased in popularity due to their superior strength without adding bulk to the vessel itself. The design of these pressure vessels has to be complemented with an accurate prediction of its mechanical stress distributions while under load. Over the years, several methods have been proposed to develop solutions to accomplish this, most of which employs the use of numerical methods in the solutions. No study thus far has proposed a fully analytical solution that specializes in the stress behaviour of multilayered spherical pressure vessels. Therefore, for this project, an analytical solution was developed via the recursive method for the displacement and the stress performance of a multilayered hollow sphere. The basis of this solution is adapted from the stress-strain relationship equations for spheres, as well as the equilibrium equation. This analytical solution was then programmed into MATLAB. For verification purposes, the results from this proposed solution was compared to both the results from a Finite Element Analysis, as well as the results published in literature. The proposed solution has generated results that were in nearly complete agreement with the results from the reference paper as well as the FEA outcome. Overall, the average values of the percentage errors are: 0.5% for the comparison with the FEA simulation, and 1.5% for the comparison with the reference paper. It is also found that the optimal number of layers to be modelled for FGM structures is 500 layers.