Deformable sensors and methods for modifying membrane stiffness are provided. A deformable sensor may include a membrane coupled to a housing to form a sensor cavity. The deformable sensor may further include a rotational element having an adjustable vertical position and a modifiable rotation. The rotational element may be supported at a base of the sensor cavity. The rotational element may be configured to establish and withdraw contact with respect to the membrane to modify stiffness of the membrane. The rotational element may further be configured to modify stiffness of the membrane by withdrawing the rotational element from the membrane.

A method includes the steps of arranging mark points for image recognition on a plane of a test piece to be measured; recognizing and recording positions of two-dimensional Cartesian coordinates of each mark point of the test piece to be measured before and after each stretching; and determining a deformation gradient of each mark point and deformation measurement parameters of each mark point through a numerical method, where the deformation measurement parameters include a deformation gradient matrix, an elongation tensor matrix, a finite strain tensor matrix, an orthogonal tensor matrix, an angular tensor matrix, a rotation angle, and a curvature. According to the method, objective measurement of super-large deformation of the plane relating to rotation deformation is achieved.

Disclosed example video extensometers include: a load string configured to secure a test specimen; an imaging device configured to capture images of a surface of the test specimen when secured in the load string; a storage device configured to store a plurality of first calibration parameters corresponding to intrinsic properties of the imaging device; and control circuitry configured to: perform a verification process using the first calibration parameters to verify that a plurality of second calibration parameters correspond to an arrangement of the test specimen with respect to the imaging device; and perform an optical strain measurement process to measure displacement of the test specimen based on the first calibration parameters and the second calibration parameters.

Disclosed example video extensometers include: a load string configured to secure a test specimen; an imaging device configured to capture images of a surface of the test specimen when secured in the load string; a storage device configured to store a plurality of first calibration parameters corresponding to intrinsic properties of the imaging device; and control circuitry configured to: perform a verification process using the first calibration parameters to verify that a plurality of second calibration parameters correspond to an arrangement of the test specimen with respect to the imaging device; and perform an optical strain measurement process to measure displacement of the test specimen based on the first calibration parameters and the second calibration parameters.

An estimating device estimates a target physical amount by a learned model that is learned by using as learning data a plurality of at least three physical amounts, which are of vary in accordance with deformation at a member deforming linearly or non-linearly. The learned model is a model that has been subjected to learning so as to output the target physical amount from inputs two physical amounts of an object of estimation that correspond to at least two physical amounts other than the target physical amount.

A high backscattering optical fiber comprising a perturbed segment in which the perturbed segment reflects a relative power such that the optical fiber has an effective index of n.sub.eff, a numerical aperture of NA, a scatter of R.sub.p.fwdarw.r.sup.(fiber) that varies axially along the optical fiber, a total transmission loss of α.sub.fiber, an in-band range greater than one nanometer (1 nm), and a figure of merit (FOM) in the in-band range. The FOM being defined as: $\mathrm{FOM}=\frac{R_{p.fwdarw.r}^{\left(\mathrm{fiber}\right)}}{{{\alpha }_{\mathrm{fiber}}\left(\frac{\mathrm{NA}}{2n_{\mathrm{eff}}}\right)}^2}.$

A fiber includes M primary cores and N redundant cores, where M an integer is greater than two and N is an integer greater than one. Interferometric circuitry detects interferometric pattern data associated with the M primary cores and the N redundant cores when the optical fiber is placed into a sensing position. Data processing circuitry calculates a primary core fiber bend value for the M primary cores and a redundant core fiber bend value for the N redundant cores based on a predetermined geometry of the M primary cores and the N redundant cores in the fiber and detected interferometric pattern data associated with the M primary cores and the N redundant cores. The primary core fiber bend value and the redundant core fiber bend value are compared in a comparison. The detected data for the M primary cores is determined reliable or unreliable based on the comparison. A signal is generated in response to an unreliable determination.

The present application relates to tunnel monitoring and measuring, more particularly, to a quick fixing device for measuring a tunnel peripheral convergence and an application method thereof. A right-angle steel sheet includes a first steel sheet and a second steel sheet which are vertically fixed with each other. The fastener vertically penetrates the first steel sheet, and an explosive powder loading portion on a rear end of the fastener is arranged at a side of the second steel sheet. The reinforcing steel sheet is respectively connected to the first steel sheet and the second steel sheet as a reinforcing bar. A through hole is provided on the reinforcing spacer, through which the reinforcing spacer is sleeved on the fastener. The reinforcing spacer is arranged between the explosive powder loading portion on the rear end of the fastener and the first steel sheet.

The present application relates to tunnel monitoring and measuring, more particularly, to a quick fixing device for measuring a tunnel peripheral convergence and an application method thereof. A right-angle steel sheet includes a first steel sheet and a second steel sheet which are vertically fixed with each other. The fastener vertically penetrates the first steel sheet, and an explosive powder loading portion on a rear end of the fastener is arranged at a side of the second steel sheet. The reinforcing steel sheet is respectively connected to the first steel sheet and the second steel sheet as a reinforcing bar. A through hole is provided on the reinforcing spacer, through which the reinforcing spacer is sleeved on the fastener. The reinforcing spacer is arranged between the explosive powder loading portion on the rear end of the fastener and the first steel sheet.

A method for calibrating an elongated metallurgical tool based on a laser distance sensor (6). A temperature measurement/sampling tool (3) is driven by an industrial robot (1) so that a standard temperature measurement/sampling gun (4) enters a calibration area, the standard temperature measurement/sampling gun (4) reciprocates at the vicinity of a laser distance sensor (6), the standard axis is obtained by using a vector on a generatrix of the standard temperature measurement/sampling gun (4) based on the laser distance sensor (6), the position and orientation of the temperature measurement/sampling tool (3) is adjusted so that the axis of the standard temperature measurement/sampling gun (4) is parallel to the set standard axis, and moreover, positioning and identification is performed on an end TCP point of the temperature measurement/sampling tool (3) to obtain a tool coordinate system corresponding to the temperature measurement/sampling tool (3), and deformation of the standard temperature measurement/sampling gun (4) can be detected in the calibration process, to ensure the accuracy and stability of system operation of the industrial robot (1). In addition, also provided is a device for calibrating an elongated metallurgical tool based on a laser distance sensor (6).