Resistance Change of Strain Gage Bonded to Curved Surface

The strain ε occurring on the resistive element of a strain gage bonded to a curved surface may be expressed by the following equation:

For example, if a uniaxial KFGS gage, of which the gage base including the adhesive layer is 0.015 mm thick, is bonded to a curved surface of r = 1.5 mm, the strain gage already receives strain of approximately 5000 μm/m.
If the gage factor Ks is 2.00,

If the gage resistance is 120 Ω, it increases by approximately 1.2 Ω. If the gage is bonded inside the curve, the resistance decreases.

Strain Gage Bonded on Curved Surface