Types of Pressure Vessels Pressure vessels are mainly of two type:
- Thin shells
If the thickness of the wall of the shell is less than 1/10 to 1/15 of its diameter, then shell is called thin shells.
- Thick shells
- Hoop stress/circumferential stress will be tensile in nature.
- Longitudinal stress/axial stress will be tensile in nature
- Radial stress will be compressive in nature.
- Circumferential Stress /Hoop Stress
Where, p = Intensity of internal pressure
d = Diameter of the shell
t = Thickness of shell
η = Efficiency of joint
- Longitudinal Stress
- Hoop Strain
- Longitudinal Strain
- Ratio of Hoop Strain to Longitudinal Strain
- Volumetric Strain of cylinder
Stresses in Thin Spherical Shell:- Hoop stress/longitudinal stress
- Hoop stress/longitudinal strain
- Volumetric strain of sphere
Lame’s Theory
Lame’s theory is based on the following assumptions
Assumptions
- Homogeneous material.
- Plane section of cylinder, perpendicular to longitudinal axis remains under plane and pressure. Hoop stress at any section
Radial pressure
Subjected to Internal Pressure (p)
- At
- At
Subjected to External Pressure (p)
- At
- At
Note: Radial and hoop stresses vary hyperbolically.
Comments
write a comment