Shear damped fiber optic sensor

A fiber optic sensor that includes a flexural disk having a pair of fiber optic coils mounted on opposite sides thereof and connected together to form part of an interferometer that produces a sensor output signal in response to acceleration of the flexural disk, comprising:

• a housing that includes a first housing member that includes a first end plate, a first sidewall extending from an outer edge of the first end plate and a first post extending from a central region of the first end plate and a second housing member that includes a second end plate, a second sidewall extending from an outer edge of the second end plate and a second post extending from the second end plate, the first and second sidewalls each having inward facing notches at end edge portions thereof, the first and second housing members being arranged end-to-end such that the inward facing notches define an inward-facing groove, the flexural disk having an outer edge portion mounted in the inward-facing groove and having a central passage therethrough;
• the first post having a first end face, the second post having a second end face, the first and second posts being aligned with the first and second end faces being adjacent to define a support member extending between oppositely facing portions of the first and second end plates and extending through the central passage in the flexural disk with an inner edge of the central passage being spaced apart from the support member;
• and
• a damping member mounted on a central region of the support member and arranged to exert a radial force on the inner edge of the flexural disk to dampen vibrations of the flexural disk and thereby control the sensor output signal amplitude over a selected frequency range.

A method for forming a fiber optic sensor that includes a flexural disk having a pair of fiber optic coils mounted on opposite sides thereof and connected together to form an interferometer that produces a sensor output signal in response to movement of the flexural disk, comprising the steps of:

• forming a housing to have first and second end plates with a sidewall extending therebetween, the sidewall being formed to have an inwardly facing groove therein;
• mounting the flexural disk in the inwardly facing groove, the flexural disk having a central passage therethrough;
• forming a support member that extends between oppositely facing portions of the first and second end plates and that extends through the central passage in the flexural disk with an inner edge of the central passage being spaced apart from the support member;
• mounting a damping member on the central support member;
• and
• arranging the damping member to exert a radial force on the inner edge of the flexural disk to dampen vibrations of the flexural member and thereby control the sensor output signal amplitude over a selected frequency range.

A method for forming a fiber optic sensor that includes a flexural disk having a pair of fiber optic coils mounted on opposite sides thereof and connected together to form part of an interferometer that produces a sensor output signal in response to acceleration of the flexural disk, comprising:

• forming a housing that includes a first housing member that includes a first end plate, a first sidewall extending from an outer edge of the first end plate and a first post extending from a central region of the first end plate and a second housing member that includes a second end plate, a second sidewall extending from an outer edge of the second end plate and a second post extending from the second end plate;
• forming the first and second sidewalls to each have inward facing notches at end edge portions thereof;
• arranging the first and second housing members end-to-end such that the inward facing notches cooperate to define an inward-facing groove;
• mounting a damping member at a central region of the support member;
• mounting an outer edge portion of the flexural disk in the inward-facing groove;
• aligning the first and second posts end-to-end to define a support member extending between oppositely facing portions of the first and second end plates;
• arranging the support member to extend through a central passage in the flexural disk with an inner edge of the central passage being spaced apart from the support member;
• and
• arranging the damping member to exert a radial force on the inner edge of the flexural disk to dampen vibrations of the flexural disk and thereby control the sensor output signal amplitude over a selected frequency range.