Disclosed are methods of determining enamel micro-crack and/or microscratch resistance and also methods of identifying compositions that are effective in increasing enamel micro-crack and/or microscratch resistance or evaluating the efficacy of compositions in increasing enamel micro-crack and/or microscratch resistance.

A state quantity acquisition unit acquires a state quantity of a target apparatus including a temperature of the target apparatus. A load specification unit specifies a load history of the target apparatus, based on the state quantity. A remaining life calculation unit calculates a parameter related to a remaining life of the target apparatus for each of a plurality of degradation types, based on the load history specified by the load specification unit.

The present invention discloses a landslide experimental device for remotely controlling and simulating a constant seepage flow and weight load and an experimental method thereof in centrifuge test. The landslide experimental device includes a model box, a landslide device, a near-constant water flow control box, remote control devices and a water outlet pipe. The landslide device comprises a landslide model, a load balancing device, a weight storage device, an angle control panel and a tension bar. The remote control devices are arranged at the control box water outlet, at the control box water inlet, on the tension bar, on telescoping control sensors and on the weight storage device, respectively. With the present invention, the influences on the stability of landslide model with different landslide angles under the condition of the seepage flow and weight load can be simulated.

A method includes forming, by a laser beam supplied by a laser cutting system, a laser-cut line in each of a plurality of glass samples. Each different laser-cut line in each different glass sample of the plurality of glass samples is formed when the laser cutting system is at a different process setting. The method also includes subjecting each of the plurality of glass samples with the laser-cut lines to a break test, and obtaining a plurality of break strength values. Each different break strength value of the plurality of break strength values is indicative of a laser-cut line quality of the respective glass sample of the plurality of glass samples.

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.

To prevent a crack from occurring on a sheared end face due to press forming, a technology is provided for evaluating and predicting a crack limit of the sheared end face of a metal sheet and determining press forming conditions. In a deformation limit evaluation method for, when deforming by press forming a metal sheet subjected to shearing, evaluating a deformation limit of the sheared end face of the metal sheet, the deformation limit is evaluated by an index value obtained from two stress gradients at an evaluation position among stress distributions occurring in the vicinity of the sheared end face of the metal sheet due to the press forming, which gradients are a stress gradient in a sheet thickness direction and a stress gradient in a direction away from the sheared end face.

The multiple rig stress corrosion cracking testing device is a stress corrosion cracking and sulfide stress cracking testing device for engineering material specimens. The device includes a pressure and temperature autoclave chamber and also includes four testing rigs for simultaneous stress corrosion cracking testing of a circumferential notched tensile specimen, a compact tension or a double cantilever beam specimen, a cantilever bend specimen, and a center cracked plate specimen under varying experimental conditions. The specimens may be of similar or different materials.

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.

The present invention discloses a thermal fatigue crack generator for a large pipe. According to the present invention, the thermal fatigue crack generator for a large pipe precisely manages and controls the heating and cooling conditions for the large size test pipes having a diameter of 250 to 610 mm to significantly improve the reliability of the accuracy and a reproducibility of the thermal fatigue cycle so that a useful advantage is expected to ensure the reliability and the effectiveness of the skill verification of the non-destructive testing.

There are provided an evaluation method and a prediction method for a technology to be reflected in a press die designing method. A deformation limit evaluation method includes evaluating the deformation limit on a sheared surface of a metal sheet in press-forming the sheared metal sheet. The deformation limit is evaluated and a crack in the sheared surface is predicted based on the relationship between an index value determined from two surface strain distribution gradients of a surface strain distribution gradient in a sheet thickness direction in the sheared surface and a surface strain distribution gradient in a bending ridge line direction by bending in a direction away from the sheared surface at an evaluation position among distributions of strains generated near the boundary between a bending outside surface and the sheared surface of the metal sheet to be bent and a tension generated in the sheared surface.