Flatness roller, system for measuring flatness and line for associated rolling operations

A flatness roller including a body of cylindrical shape extending along an axis of revolution and radially delimited by an outer surface,

• wherein the body includes at least one cavity extending parallel to the axis of revolution,
• each cavity opening radially onto the outer surface through a plurality of slots each extending in a respective plane orthogonal to the axis of revolution, of which two successive slots along an axis parallel to the axis of revolution define a lamella between them,
• each lamella being connected to the body by two opposite circumferential ends of the lamella, each circumferential end forming a connection portion,
• the lamellas aligned in a direction parallel to the axis of revolution forming a generatrix,
• the flatness roller further including at least one optical fibre comprising at least one strain sensor, each strain sensor having a measurement axis, each strain sensor being associated with a lamella,
• each strain sensor being housed in a corresponding cavity and attached to the corresponding lamella at a connection portion of the lamella,
• each strain sensor being arranged so that the angle between the corresponding measurement axis and a plane orthogonal to the axis of revolution is less than or equal to 20°,
• each optical fibre being configured to receive an interrogation signal, each strain sensor of each optical fibre being configured to send, depending on the interrogation signal received by the corresponding optical fibre, an optical response wave representative of a strain of the strain sensor along the corresponding measurement axis.