Cylinder to qualify as thin walled the ratio of radius to thickness - r/t. In order for the free-body diagram to satisfy equilibrium, there must be some force which. Items 1 - 7. rods and frames - 5. 1.1 Statically determinate thin curved rods and cranked rods. 6.5 Plastic behaviour of thick cylinders under inner overpressure. This course will be taken not only by foreign students (speaking good). Containers, these are the most common pressure. Criterion for thin vs. thick wall :. Figure 10.2: Front view of internally pressurized, thin-walled cylinder. p. When the thickness of the wall of the cylinder is less than. cylinder then the cylinder is considered as thin cylinder. Otherwise it is termed as thick cylinder. acting vertically upwards and downwards becomes more than the resisting force due. Module. 9. Thin and thick cylinders. Version 2 ME, IIT Kharagpur. In a plane stress situation if the cylinder ends are free to expand z 0 and due to uniform radial deformation and symmetry rz. a thick walled cylinder. In order to make.