A method for evaluating the delayed fracture characteristics of a metal material. The method including placing a solution-retaining material impregnated with a solution containing a chloride and having a pH of 3.5 or more on a stress loading part of the metal material, and maintaining a state in which the solution-retaining material is held at a deliquescence humidity of the chloride to thereby corrode the stress loading part.

A method for evaluating the delayed fracture characteristics of a metal material. The method including placing a solution-retaining material impregnated with a solution containing a chloride and having a pH of 3.5 or more on an edge face of the metal material, and maintaining a state in which the solution-retaining material is held at a deliquescence humidity of the chloride to thereby corrode the edge face.

A method of performing an automated non-destructive examination of a composite structure includes identifying surface damage on the composite structure, coupling an automated tap tester device to a surface of the composite structure at a location of the surface damage, and performing, with the automated tap tester device, a plurality of tapping impacts on the surface within a testing area that encapsulates the surface damage. The method also includes receiving a plurality of acoustic signals associated with the plurality of tapping impacts, modeling sub-surface damage associated with the surface damage based on an analysis of the plurality of acoustic signals.

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.

A new vibration test-cell that allows a static load to be applied simultaneously with lateral vibration coupled with in-situ microscopy that allows for the ability to open a fatigue crack up to a desired gap, as well as generate acoustic emission (AE) from vibration excitation, micro-fracture events are captured by the AE measurement while the physical observation of the crack faying surfaces is performed in-situ with an optical microscope embedded in the test cell.

A method that improves stretch flange formability of a steel sheet by individual treatment matching a material of the steel sheet without performing heat treatment in a die. This method is a method for manufacturing a steel sheet for cold press, and the steel sheet is manufactured by heating an edge of the steel sheet to a temperature within a heating temperature range preset according to a microstructure of the steel sheet and cooling the steel sheet. A region, within an edge of the steel sheet subjected to shearing in a shearing step, where it is estimated that a stretch flange crack is likely to occur when a press component is formed by cold pressing is determined, and a site to be heated and cooled is set within the region. By press-forming the manufactured steel sheet, a target press component is manufactured.

A notch treatment method for flaw simulation including providing the specimen with the notch, the notch having a re-melt material layer; isolating the notch; and selectively etching the notch to provide an etched surface of the notch; wherein at least a portion of the re-melt material layer has been removed from the notch. In one aspect, there is provided a notch treatment method for flaw simulation including providing the specimen with the notch, the notch having a re-melt material layer, the specimen includes steel or an alloy thereof; isolating the notch; and selectively etching the notch with a first etching solution and a second etching solution to provide an etched surface on the notch; wherein at least a portion of the re-melt material layer has been removed from the notch.

A rotating electric machine includes a stator and a rotor. An imaging device images a test target portion which is a part of the rotor, to generate image data of the test target portion, and transmits the generated image data to an image processing device. The image processing device generates strain change information representing change in the strain distribution in the test target portion by digital image correlation on the basis of the test image data generated by the imaging device. The state of the rotor is tested using the generated strain change information.

A method for testing a ceramic component for a fracture toughness includes changing the temperature of the component to a first temperature, for example, by heating the component, and changing the temperature of the component to a second temperature, for example, by cooling the component and testing the component for cracks. The temperature difference between the first temperature and the second temperature is determined based on a minimum fracture toughness.

A process for analyzing a fracture or crack surface of a TiAl turbomachine part is provided. The process includes: marking on the surface the position and the orientation of cleavage facets, so as to identify a region of fracture or crack initiation and to determine the direction of propagation of this fracture or crack; examining the surface and detecting the regions with the presence of equiaxed grains and/or lamellar grains, so as to evaluate the temperature at which the fracture or crack has taken place, and comparing the heat tintings of the surface with those of samples from a heat tinting color chart so as to evaluate the speed of propagation of the fracture or crack.