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Gage Pattern

Gage pattern commonly refers to the number of the grid (uniaxial/multi-axial) and the layout of the grid (planar/stacked).

  • Select a uniaxial strain gage, if
  - Only one direction of strain needs to be investigated.
  - Cost is an issue. Two or three single uniaxial gages are usually less expensive than a bi-axial or tri-element strain gage.
  • Select a bi-axial strain rosette (0°-90° Tee rosette), if
  - The principal stresses need to be investigated and the principal axes are known.
  • Select a tri-element strain rosette (0°-45°-90° rectangular rosette or 0°-60°-120° delta rosette), if
  - The principal stresses need to be investigated but the principal axes are unknown.
 

There are two different layouts in multi-axial strain rosettes: planar and stacked.

  • Select a strain rosette with planar layout, if
  - Heat dissipation is an issue.
  - Accuracy and stability are critical. Planar layout has each gage closer to the measuring surface and no interference in between.
  • Select a strain rosette with stacked layout, if
  - The strain gradient is large. Stacked layout measures strain at the same point.
  - Space for mounting is limited.