Experiments

  • Measurement of strain using strain gauges.
  • Application of Mohr’s Circle for stress and strain analysis, determination of the principal strains.
  • Determination of the Poisson’s ratio.
  • Investigation of correlations between strain, pressure and stress in the plane bi axial stress state.
  • Determination of the principal stresses: Axial and circumferential stresses in magnitude and direction
    * on an open vessel (pipe)
    * on a closed vessel (boiler tank)
  • Comparison of open / closed vessels.

Specification

  • Investigation of the stresses and strains in a thin-walled cylinder under internal pressure.
  • Cylinder usable as open pipe or as closed tank.
  • Strain gauge application on cylinder surface at various angles.
  • Hydraulic cylinder with spindle to generate pressure.
  • Hermetically sealed hydraulic system, maintenance-free.

An apparatus set on a bench for measuring the stress and strain in a cylinder with thin walls under internal pressures On the hand pump, a pressure release valve is pre-set and tested at the factory. This benchtop unit’s main part is a cylinder made of aluminium with thin walls. A piston that can be moved using a hand wheel seals one side of it. As a result, it is possible to produce either the single-axis stress state of a tube or the dual-axis stress state of a sealed container. Oil is placed inside the sealed cylinder. An easily readable pressure gauge shows the internal pressure, which is produced by a hydraulic hand pump. To measure deformation, five strain gauges are fastened to the cylinder’s outside edge at angles of 0°, 30°, 45°, 60°, and 90° to the cylinder’s axis. The measuring amplifier is used in conjunction with the unit. The results of the tests with thin-walled cylinders show how to calculate and design pipelines and pressure vessels using techniques that are frequently used in practice. When calculating and designing steam tanks, pressure vessels, and pipes, the major stresses are important factors. In order to identify the stresses and strains that are present in a vessel, strain gauges are used to measure the strains on the surface. The tool is used to investigate stresses and strains in a cylinder with thin walls that is under internal pressure. The oil-filled cylinder has a moveable piston at one end and a closed end. This enables the unit to be open-ended or closed-ended conveniently. A bolt with a threaded spindle is used to move the piston. There are two load situations represented: the uniaxial stress condition of an open vessel, such as a pipe, and the biaxial stress state of a closed cylinder, such as a boiler tank. An hydraulic cylinder and a spindle work together to produce internal pressure inside the cylinder. The internal pressure is displayed by a pressure gauge. To keep track of the strains, strain gauges are attached to the cylinder’s surface. The measured strains are directly read out by the measuring amplifier. The measurement data can be entered into the application programme to aid and facilitate visual evaluation of the experiment. To show the conversion of the strain graphically and identify the main strains, Mohr’s Circle is used in stress and strain analysis. By using the appropriate elasticity equations, the primary stresses can be computed from the principal strains.