This application relates to an apparatus and method for detecting a microcrack using orthogonality analysis of a mode shape vector and a principal plane in a resonance point. The apparatus may include a measurement unit comprising multiple sensors and configured to measure whether a crack exists at a measurement target, and an analysis unit configured to determine whether a crack exists, on the basis of measurement values of the respective sensors. The measurement unit includes a fixing jig configured to fix the measurement target, an excitation means configured to apply a predetermined impact to the measurement target, and multiple acceleration sensors attached at predetermined locations on the measurement target. The analysis unit may further calculate frequency responses of the measurement target to the impact applied by the excitation means, and determine whether a crack exists by analyzing the number of resonance points and independence of the resonance points.

This application relates to an apparatus and method for detecting a microcrack using orthogonality analysis of a mode shape vector and a principal plane in a resonance point. The apparatus may include a measurement unit comprising multiple sensors and configured to measure whether a crack exists at a measurement target, and an analysis unit configured to determine whether a crack exists, on the basis of measurement values of the respective sensors. The measurement unit includes a fixing jig configured to fix the measurement target, an excitation means configured to apply a predetermined impact to the measurement target, and multiple acceleration sensors attached at predetermined locations on the measurement target. The analysis unit may further calculate frequency responses of the measurement target to the impact applied by the excitation means, and determine whether a crack exists by analyzing the number of resonance points and independence of the resonance points.

An example hinged device flexible substrate testing system includes: a first plate comprising a first surface configured to hold stationary a first portion of a hinged device under test; a second plate comprising a second surface configured to hold a second portion of the hinged device under test, the second portion of the hinged device coupled to the first portion via a first hinge having a first folding radius; a third plate comprising a third surface configured to hold a third portion of the hinged device under test, the third portion of the hinged device coupled to the first portion via a second hinge having a second folding radius; a first cam follower coupled to the second plate; a first drive arm configured to move the first cam follower to cause the second plate to rotate about a first hinge pivot axis of the first hinge; a first actuator configured to rotate the first drive arm; a second cam follower coupled to the third plate; a second drive arm configured to move the second cam follower to cause the third plate to rotate about a second hinge pivot axis of the second hinge; a second actuator configured to rotate the second drive arm; and a load cell configured to measure first loads on the first plate while the first actuator moves the second plate and to measure second loads on the first plate while the second actuator moves the third plate.

An example hinged device flexible substrate testing system includes: a first plate comprising a first surface configured to hold stationary a first portion of a hinged device under test; a second plate comprising a second surface configured to hold a second portion of the hinged device under test, the second portion of the hinged device coupled to the first portion via a first hinge having a first folding radius; a third plate comprising a third surface configured to hold a third portion of the hinged device under test, the third portion of the hinged device coupled to the first portion via a second hinge having a second folding radius; a first cam follower coupled to the second plate; a first drive arm configured to move the first cam follower to cause the second plate to rotate about a first hinge pivot axis of the first hinge; a first actuator configured to rotate the first drive arm; a second cam follower coupled to the third plate; a second drive arm configured to move the second cam follower to cause the third plate to rotate about a second hinge pivot axis of the second hinge; a second actuator configured to rotate the second drive arm; and a load cell configured to measure first loads on the first plate while the first actuator moves the second plate and to measure second loads on the first plate while the second actuator moves the third plate.

Characterizing the decay of the microstructure of a drilling fluid gel using a model based on two exponential functions. Based on the model, identify at least two components of the decay model comprising a fast decay component and a slow decay component, wherein the fast decay component decays more quickly than the slow decay component. The decay of the microstructure of the gel over a time period can be determined using a rheometer or viscometer. Wellbore processes, including start up and tripping operations can be optimized based on the determination of the fast decay component and/or a slow decay component of the drilling fluid gel.

Characterizing the decay of the microstructure of a drilling fluid gel using a model based on two exponential functions. Based on the model, identify at least two components of the decay model comprising a fast decay component and a slow decay component, wherein the fast decay component decays more quickly than the slow decay component. The decay of the microstructure of the gel over a time period can be determined using a rheometer or viscometer. Wellbore processes, including start up and tripping operations can be optimized based on the determination of the fast decay component and/or a slow decay component of the drilling fluid gel.

A method for evaluating a crack in a metal member comprises a first removal step (S10) and a second removal step (S20). In the first removal step (S10), a step for electrolyzing a metal member having an oxide scale formed on a surface thereof, a step for acquiring an image of the oxide scale as a first image, and a step for determining whether or not a scale crack has occurred are repeated until occurrence of a scale crack is determined. In the second removal step (S20), a step for electrolyzing the metal member having the scale crack, a second image acquisition step for acquiring an image of the oxide scale as a second image, and a second determination step for determining whether or not the scale crack has disappeared are repeated until disappearance of the oxide scale is determined.

A method for evaluating a crack in a metal member comprises a first removal step (S10) and a second removal step (S20). In the first removal step (S10), a step for electrolyzing a metal member having an oxide scale formed on a surface thereof, a step for acquiring an image of the oxide scale as a first image, and a step for determining whether or not a scale crack has occurred are repeated until occurrence of a scale crack is determined. In the second removal step (S20), a step for electrolyzing the metal member having the scale crack, a second image acquisition step for acquiring an image of the oxide scale as a second image, and a second determination step for determining whether or not the scale crack has disappeared are repeated until disappearance of the oxide scale is determined.

According to one embodiment, a diagnostic method includes changing a position of a mechanical structure to be diagnosed with a drive unit based on an acceleration command, the acceleration command being generated based on a log swept sine (LOGSS) signal, calculating an impulse response based on the acceleration command and measured acceleration of the mechanical structure, the measured acceleration being measured by an accelerometer, analyzing at least one of a linear characteristic and a nonlinear characteristic relating to the mechanical structure based on the impulse response, and diagnosing the mechanical structure based on the at least one of the linear characteristic and the nonlinear characteristic relating to the mechanical structure.

According to one embodiment, a diagnostic method includes changing a position of a mechanical structure to be diagnosed with a drive unit based on an acceleration command, the acceleration command being generated based on a log swept sine (LOGSS) signal, calculating an impulse response based on the acceleration command and measured acceleration of the mechanical structure, the measured acceleration being measured by an accelerometer, analyzing at least one of a linear characteristic and a nonlinear characteristic relating to the mechanical structure based on the impulse response, and diagnosing the mechanical structure based on the at least one of the linear characteristic and the nonlinear characteristic relating to the mechanical structure.