A crack-type fatigue detecting sensor comprises: a foil substrate having a first surface and a second surface fixed to a member to be tested; and a foil fracture piece having a slit formed in a central portion between opposite end portions in a longitudinal direction thereof such that the slit extends from one side portion toward the other side portion in a width direction thereof perpendicular to the longitudinal direction, wherein the opposite end portions of the fracture piece are respectively fixed to the first surface of the substrate and a portion including the central portion having the slit has a thickness smaller than a thickness of the opposite end portions over a whole width. IMAGE
展开▼
