Abstract: A method for measuring shear load of a fastening tool, which comprises the steps of: positioning an optical fiber sensor on a surface of a fastening tool to be subjected to a measurement, or within the tool but near the surface thereof, so that the optical fiber sensor is positioned along a direction of an axis the fastening tool; and measuring the shear load acting on the fastening tool on the basis of a change in an optical characteristic of the optical fiber sensor that directly corresponds to a deformation of the fastening tool when the shear load is applied to the fastening tool.

Abstract: A method is disclosed wherein a portion of a sensor part of an optical fiber sensor is embedded in an adhesive between two joined members, and peeling in an adhesive joint of the two members is detected on the basis of measuring optical characteristics from the optical fiber sensor when the optical fiber sensor is irradiated with light from a light source while one member is vibrated by vibration means. The method comprises the steps of determining the temperature of the two members during measurement on the basis of the optical characteristics from the sensor part exposed outside of the adhesive; determining, on the basis of the temperature determined during the measurement, the measurement range in which the optical characteristics from the optical fiber sensor are measured; and measuring the variation in the optical characteristics from the optical fiber sensor within the determined measurement range while the member is being vibrated by the vibration means.

Abstract: A method is disclosed wherein a portion of a sensor part of an optical fiber sensor is embedded in an adhesive between two joined members, and peeling in an adhesive joint of the two members is detected on the basis of measuring optical characteristics from the optical fiber sensor when the optical fiber sensor is irradiated with light from a light source while one member is vibrated by vibration means. The method comprises the steps of determining the temperature of the two members during measurement on the basis of the optical characteristics from the sensor part exposed outside of the adhesive; determining, on the basis of the temperature determined during the measurement, the measurement range in which the optical characteristics from the optical fiber sensor are measured; and measuring the variation in the optical characteristics from the optical fiber sensor within the determined measurement range while the member is being vibrated by the vibration means.

Abstract: This invention provides a device or method for measuring vibration with high sensitivity and over a wide bandwidth. A curved section is formed in an optical fiber. The curved section is disposed on a place to be measured. Light is input in the optical fiber, and then variation of frequency between the input light and the output light is detected. Infinitesimal vibration applied to the curved section can be measured as variation of frequency between the input light and the output light. Further, it is possible to measure vibration over a wide bandwidth.

Abstract: A method for measuring shear load of a fastening tool, which comprises the steps of: positioning an optical fiber sensor on a surface of a fastening tool to be subjected to a measurement, or within the tool but near the surface thereof, so that the optical fiber sensor is positioned along a direction of an axis the fastening tool; and measuring the shear load acting on the fastening tool on the basis of a change in an optical characteristic of the optical fiber sensor that directly corresponds to a deformation of the fastening tool when the shear load is applied to the fastening tool.

Abstract: This invention provides a device or method for measuring vibration with high sensitivity and over a wide bandwidth. A curved section is formed in an optical fiber. The curved section is disposed on a place to be measured. Light is input in the optical fiber, and then variation of frequency between the input light and the output light is detected. Infinitesimal vibration applied to the curved section can be measured as variation of frequency between the input light and the output light. Further, it is possible to measure vibration over a wide bandwidth.