Strain sensor with measurement discrimination according to the deformation direction

A passive sensor for deformation(s) to which a structure is subjected along a so-called measurement orientation, the sensor comprising a detection system for detecting a variation in a distance between two points or regions of a structure, and a carrier having a first part and a second part configured to be fixed respectively to one of said two points or regions of the structure such that, when one of the first and second parts moves in a direction along the measurement orientation, the other of the first and second parts moves in the opposite direction, the detection system comprising:

• a deformation measuring assembly carried by the first part of the carrier and actuatable only in one direction, so-called measurement direction, of the measurement orientation, in order to measure and store one among the amplitude of the deformation and the number of deformation cycles,
• an actuating device comprising an actuating member which is movable along the measurement orientation and is configured to actuate the deformation measuring assembly when the actuating member is moved in the measurement orientation, as a result of a relative movement between the first and second parts of the carrier,
• wherein the actuating device comprises:
• an intermediary assembly comprising:
• a fixing part using which the intermediary assembly is carried by the second part of the carrier,
• the actuating member, and
• an elastic connection between the fixing part and the actuating member, and
• an actuating assembly which is integral with the first part of the carrier and which has a so-called push part which is directed in the measurement direction, the actuating assembly being configured such that the push part faces the intermediary assembly so as not to exert any action thereon when the second part of the carrier moves in the measurement direction, the actuating member thus being moved together with the second part of the carrier in the measurement direction in order to actuate the deformation measuring assembly, but so as to apply a push on the intermediary assembly when the second part of the carrier moves in the direction opposite the measurement direction, in order to prevent any relative movement between the actuating member and the deformation measuring assembly,
• whereby the deformation measuring assembly will be actuated only when the second part of the carrier moves in the measurement direction, thereby allowing a measurement discrimination between the sensor being subjected to a tension load and the sensor being subjected to a compression load.