Authors: D. Caseiro, S. Santos, C. Ferreira

This work presents a mechanical strain amplifier to be installed between the surface to be monitorized and a strain gauge, allowing the sensitivity factor of the strain gauge to be amplified by a factor of 6. The geometry of the proposed amplifier was designed and optimized using the finite element method and experimentally verified. The experimental analysis consisted on the application of a load cycle to a steel specimen with the mechanical strain amplifier coupled and, at the same time the specimen strain was also measured with a strain gauge placed directly on its surface. The experimental tests performed on an Instron servohydraulic actuator, showed the functionality and applicability of the proposed mechanical strain amplifier. The strain gauge installed on the mechanical amplifier presented a higher sensitivity than the specimen strain. The high sensitivity achieved with the proposed device enables a new range of applications since it allows exploring wider measuring ranges.

D. Caseiro¹ | S. Santos² | C. Ferreira^3,4
1 Departamento de Engenharia Mecânica, ESTG, Instituto Politécnico de Leiria
2 Departamento de Engenharia Mecânica, ESTG, CDRSP, Instituto Politécnico de Leiria
3 Departamento de Engenharia Eletrotécnica, ESTG, Instituto Politécnico de Leiria
4 INESC Coimbra, Rua Antero de Quental 199, 3000-033 Coimbra, Portugal