2Mechanical Principle


Mechanical Principle: Pressure


The paper demonstrated how variation in pressure results in changes in volume, depending on the type of stress it causes. Elements tend to change in volume upon subjecting them to stress. Upon the practical exercise, it was found that volume that is occupied by elements tends to reduce when subjected to compressive pressure, but the volume increases when tensile is exerted upon them. Therefore, a combination of compressive pressure and tensile would consequent either tension or compression on the element depending on their magnitude and direction of action. In the case of a beam, a theoretical solution would produce results that are close practical or experimental values.

Cylinders, depending on the thickness of their walls, can resist stress to which they are subjected. The paper demonstrated that thick-walled cylinders have increased resistance capabilities against internal pressure through pre-stressing mechanism. Pre-stressing is described as the process of subjecting an element to compressive pressure prior to it supporting any intended applied force (Singh & Singh 2016). This idea is employed in modelling cylinders that are purported to carry fluids or solids that. Any content placed in a cylinder would result in compressive stress on its walls. Therefore, pre-stressing the wall and making them thick are the mechanisms proven to increase the ability of the cylinder to withstand any internal pressure depending on the magnitude of the stress and the degree of resistance of the walls. Pre-stressing the walls of the cylinder increases its ability to accommodate any internal pressure below the pre-stressing force. This mechanism is what Singh & Singh (2016) argue to be applied when modelling a steady state creep.


Singh, T & Singh, I 2016, ‘Modelling of steady state creep in thick-walled cylinders under internal pressure’, International Journal of Mechanical, Aerospace, Mechatronic, and Manufacturing Engineering, Vol. 10, No. 5, pp. 931-936.