Below is a short summary and detailed review of this video written by FutureFactual:
Pressure Vessels Demystified: Hoop Stress, Cylindrical vs Spherical Shapes, and Design Formulas
Short Summary
This video explains the core mechanics behind pressure vessels, focusing on cylindrical and spherical shapes. It derives the hoop stress for thin-walled cylinders using equilibrium of forces, showing sigma_hoop = PD/(2T) and noting that hoop stress is twice the longitudinal stress. Through a numerical example (D = 0.4 m, t = 0.01 m, P = 50 bar), it shows how 100 MPa hoop stress arises and how reductions in pressure, diameter, or increases in thickness reduce stress. The discussion extends to the orientation of reinforcing fibers in hoses, the concept of minimum wall thickness using an allowable hoop stress, and joint efficiency. A comparison with spherical vessels highlights how curvature distributes stress uniformly, reducing maximum wall requirements, though cylindrical vessels are more economical. The video also explains simplifying assumptions like constant hoop stress through thickness and when thick-walled theory is needed.
