Fiber Bragg grating curvature sensing test device and test method thereof

A fiber Bragg grating (FBG) curvature sensing test device, comprising:

• a test platform, wherein the test platform comprises an optical plate and two constraint components arranged at two relative positions on the optical plate along a Y-axis direction, test pieces are connected between the two constraint components, wherein each of the two constraint component comprises an X-axis displacement stage, a Z-axis rotation stage and a fixture, wherein the X-axis displacement stage is connected to the optical plate and is allowed to move along an X-axis direction, a first end of the Z-axis rotation stage is connected to the X-axis displacement stage, and a second end of the Z-axis rotation stage is connected to the fixture, and is configured to drive the fixture to rotate around a Z-axis direction, the fixture is configured as a fixed connection to the test piece;
• the test piece is an elastic material piece;
• wherein an angle index is formed in a circumferential direction of the fixture, when the test piece is fixedly mounted between two fixtures, both ends of the test piece are allowed to be fixed at a specified torsion angle and/or rotation angle;
• an FBG demodulator, wherein the FBG demodulator is connected to a surface of the test piece through an FBG test line, and is configured to convert an optical signal of a wavelength change monitored by the FBG test line based on a deformation of the test piece into an electrical signal;
• and
• a computer, wherein the computer is coupled to the FBG demodulator, and is configured to receive the electrical signal converted by the FBG demodulator, and performs reconstruction and data acquisition of a bending shape of the test piece;
• wherein the X-axis direction, the Y-axis direction and the Z-axis direction are perpendicular to each other.