deflection and strain of a membrane under compressive load

Description:

• In experimental stress and strain analysis, strain gauges are used to determine stresses and strains in components and structures.
• The maximum stresses and strains are key variables in terms of its structure, and ultimately dictate the dimensions of a component.
• Strain gauges provide the means required to evaluate mechanical stress and strains.
• The FL 120experimental unit can be used to measure the deflection and strain of a disk under different compressive loads.
• For this purpose, a thin disk, also called a membrane or diaphragm, is clamped into place and subjected to pressure.
• A cylinder with a hand-operated piston generates pressure in a maintenance-free hydraulic system.
• This pressure is indicated on a manometer.
• Strains on the surface of the membrane are recorded by strain gauges.
• The layout of the strain gauges at optimally selected points provides a comprehensive view of the stresses and strains over the entire disk.
• The maximum stresses and strains are calculated by applying the law of elasticity.
• The strain gauge measurements are recorded and displayed by means of the FL 152measuring amplifier.
• The measured values can be imported into the application software for visualisation to evaluate the experiment.
• At the same time, the deflection of the membrane is measured by a dial gauge.
• The dial gauge can be moved along a cross-member, enabling measurements to be taken at any radius.

Technical Details:

Specification:

• investigate the deflection and strain of a thin disk under compressive load
• strain gauges measure in the radial and tangential direction
• strain gauge configured as half-bridge
• possible to measure the deflection at any radius
• measure the deflection via adjustable dial gauge, scale indicates position along the radius
• hermetically sealed hydraulic system, maintenance-free, for generating the compressive load
• hydraulic system with hydraulic pump and manometer
• FL 152 measuring amplifier required
• software for analysing measured values in FL 152

Technical Data:

• Aluminium disk:
  • outer diameter: Ø 230mm
  • diameter used in the experiment: Ø 200mm
  • thickness: 3mm
• Strain gauge application:
  • 8 strain gauges: half-bridges, 350 Ohm
  • gauge factor: 2,00 ±1%
  • power supply: 10V
• Dial gauge:
  • 0…20mm
  • graduation: 0,01mm
• Manometer:
  • 0…1bar
  • accuracy: class 1,0
• System pressure:
  • 0,6bar

Dimensions & Weight:

• L x W x H: 700x350x350mm
• Weight: approx. 25kg

Learning Objections/Experiments:

• measure radial and tangential strain using strain gauges
• measure deflection using a dial gauge
• calculate the stresses from the measured strains: radial stress, tangential stress
• determine direction of principal stress
• application of Mohr’s strain circle to determine the principal strains
• fundamental principle: using strain gauge technology to measure strains

Scope of Delivery:

• 1 experimental unit
• 1 set of instructional material

Features:

• membrane with strain gauge application
• determine radial and tangential stress profiles from measured strains

Accessories:

• Required: FL 152 multi-channel measuring amplifier
• Optional: WP 300.09 Laboratory trolley

Due to the continuous development of our products, the goods supplied may vary in detail to that illustrated on this Website.