Abstract: Displacement measuring means are fixed onto the structural element. A hole is drilled in the measurement zone and a supply pressure is applied to a flat actuator introduced into the hole. The displacements measured are analyzed as a function of the supply pressure to determine the stress from a supply pressure which roughly compensates for the deformation of the element due to the drilling of the hole. The measuring means comprise two arms that are fixed to the element at two respective anchoring points aligned parallel to a measuring direction, and at least two displacement sensors mounted on the arms on each side of the anchoring points to measure the variations in separation between the anchoring points. The arms leave between them a gap through which the hole is drilled at a central position with respect to the anchoring points.

Abstract: Displacement measuring means (15, 16) are fixed onto the structural element. A hole (20, 21) is pierced in the measurement zone and a supply pressure is applied to a flat actuator introduced into the hole. The displacements measured are analyzed as a function of the supply pressure to determine the stress from a supply pressure which roughly compensates for the deformation of the element due to the piercing of the hole. The measuring means comprise two arms (15) that are fixed to the element at two respective anchoring points (X) aligned parallel to a measuring direction, and at least two displacement sensors (16) mounted on the arms on each side of the anchoring points to measure the variations in separation between the anchoring points. The arms (15) leave between them a gap through which the hole is pierced at a central position with respect to the anchoring points.