Experimental and Numerical Study of a Shunt Structure for Large Dynamic Strain Measurement

Cost-effective and energy-saving sensor for large dynamic strain measurement is still lacking for wireless sensor networking application. In this paper, a shunt structure is proposed to measure large dynamic strain using metal foil strain gauge without fatigue failure. This shunt structure is made of single metal sheet for convenient installation. The working principle of the strain shunt with one shunt sheet bridging two strain relieving units is illustrated. The strain measured on the shunt sheet surface is proportionally lower than that on the target surface where the strain shunt is attached, and the ratio of strain level reduction is derived analytically from shunt structure dimension. The constancy and stability of the shunt ratio is validated through tensile and bending load tests for both static and dynamic loads. Furthermore, the stress concentration and shunt ratio sensitivity to compound load are investigated numerically.