What is the thickness of the shell of a bomb calorimeter of spherical form of 10 cm inside diameter if the working stress is σMPa and the internal pressure is σ/2 MPa? [Take 21/3 = 1.26]
at r = a, σθ is maximum
Thickness of bomb shell
The radial stress in a thin spherical pressure vessel is
Hoop stress in a thin cylinder of diameter dand thickness t subjected to pressure p will be
Due to fluid pressure p in the cylinder bursting force = p x d x L
This is resisted by thickness of cylinder Resisting force = σh(2t x L).
Resisting force = Bursting force
where σh = hoop stress
p = internal fluid pressure
d = Diameter of cylinder
t = Thickness of cylinder
Longitudinal stress in a thin cylinder of diameter d and thickness t subjected to pressure p will be
A thin cylindrical shell of internal diameter d and thickness ‘t’ is subjected to internal pressure ‘p’. The change in diameter is given by
In above case the longitudinal strain is
A thin cylindrical shell of diameter d, length L and thickness t is subjected to an internal pressure p. What is the ratio of longitudinal strain to hoop strain in terms of Poisson’s ratio (1/m)?
The volumetric strain in case of a thin cylindrical shell of diameter d, thickness t, subjected to internal pressure p is
The design of thin cylindrical shells is based on
Since hoop stress (σh) > Longitudinal stress (σL). Hence to have safe design, hoop stress is considered.
The commonly used technique of strengthening thin pressure vessels is