direct stresses and strains of a thick cylinder under internal pressure
| Code | FL140 |
Description:
- In contrast to thin-walled vessels, when designing thick-walled vessels allowance must be made for an uneven distribution of stresses through the thickness of the wall.
- The stress state in a thick-walled vessel under internal pressure is triaxial.
- The direct stresses and strains occur: radial, circumferential, hoop and axial.
- Since the stresses and strains occurring in a vessel are not measured directly, they are determined by measuring strains on the surface.
- Strain gauges are employed to record the strains electrically and the stresses and strains are determined from those measurements.
- The FL 140experimental unit is used to investigate direct stresses and strains occurring on a thick-walled cylinder subjected to internal pressure.
- The oil-filled cylinder is made up of two halves, and is sealed on both sides.
- Internal pressure is generated inside the vessel with a hydraulic pump.
- A pressure gauge indicates the internal pressure. An eccentric groove is cut between the two halves of the cylinder, in which the strain gauges are mounted at various radial points.
- Additional strain gauges are mounted on the inner and outer surfaces of the cylinder.
- Radial, hoop and axial strains are measured, enabling the strain state to be fully recorded.
- The measuring amplifier FL 152displays the recorded signals as measured value readouts.
- To assist and visualise evaluation of the experiment, the measured values can be imported into the application software.
- Mohr’s circle for stress and strain analysis is used to represent the triaxial stress state in the cylinder wall graphically.
- The direct stresses and strains are calculated from the measured strains, applying the appropriate law of elasticity.
Technical Details:
Specification:
- investigation of the stresses and strains in a thick-walled cylinder under internal pressure
- two-part cylinder with flat groove
- strain gauge application at various radial points in the groove and on the cylinder surface
- hermetically sealed hydraulic system, maintenance-free to generate pressure
- hydraulic system with hydraulic pump and manometer
- FL 152 measuring amplifier required
- software for analysing measured values in FL 152
Technical Data:
- Aluminium cylinder
- length: 300mm
- diameter: Ø=140mm
- wall thickness: 50mm
- internal pressure: max. 7N/mm2(70bar)
- Strain gauge application
- 11 strain gauges: half-bridges, 350 Ohm
- gauge factor: 2,00 ±1%
- supply voltage: 10V
- Pressure gauge
- 0…100bar
- accuracy: class 1,0
Dimensions & Weight:
- L x W x H: 700x350x330mm
- Weight: approx. 32kg
Learning Objections/Experiments:
- measurement of elongations by strain gauges
- application of Mohr’s circle for the triaxial stress state
- determination of the distribution of direct stress in
- radial, tangential and axial direction
- investigation of correlations between elongation, pressure and stress in the triaxial stress state
Scope of Delivery:
- 1 experimental unit
- 1 set of instructional material
Features:
- cylinder with strain gauge application on surface and in wall
- triaxial stress state in cylinder wall
Accessories:
Due to the continuous development of our products, the goods supplied may vary in detail to that illustrated on this Website.
