Abstract: An embodiment may provide a sensing device comprising: a stator comprising stator teeth; and a rotor comprising magnets, wherein: the stator teeth comprise a first stator tooth and a second stator tooth arranged to overlap the first stator tooth in the radial direction from the center of the stator; the first stator tooth comprises multiple first teeth and multiple third teeth, and the second stator tooth comprises multiple second teeth; one of the multiple first teeth is arranged to overlap one of the multiple second teeth in the radial direction; and the magnets are disposed between the multiple first teeth and the multiple third teeth, respectively.

Abstract: In a stress corrosion cracking evaluation method for a steam turbine, a sample having a high sensitivity is housed in a sample box of the steam turbine, and a sample breakage time is acquired. Then, based on the sample breakage time, a breakage time of the steam turbine is estimated.

Abstract: A device and method for checking an integrity of a glue joint that connects one portion of a body box and a body skin are provided. The body box and body skin connected by the glue joint define an inner volume therebetween. The method includes arranging at least one ultrasound sensing device in the inner volume; emitting a pressurized directional air jet opposite a predetermined area of the glue joint; recording a noise level detected by the ultrasound sensing device in the inner volume; and determining an integrity defect in the glue joint according to the recorded noise level.

Abstract: Provided is a reusability determination method for a gear that makes it possible to determine reusability of a gear during or after use to increase the reuse ratio. The reusability determination method for a gear of the present invention includes a step of measuring a content of retained ? phases in the gear, a step of calculating a change rate of the content of the retained ? phases, a step of measuring residual stress applied to the gear, a residual stress ratio calculation step of calculating a residual stress ratio to residual stress in an initial state of the gear, and a reusability determination step of determining whether or not the gear is reusable on the basis of results of the calculation in the retained ? phase change rate calculation step and the residual stress ratio calculation step.

Abstract: An apparatus and a method for measuring a creep crack growth property using a small specimen with a micro groove are provided. The apparatus for measuring a creep crack growth property includes a lower die on which an edge of the specimen is mounted and which includes a lower die hole formed in the center thereof, an upper die coupled to an upper portion of the lower die so as to fix the specimen, and a punching unit inserted into an upper die hole formed in the center of the upper die so as to press an upper surface of the specimen, wherein a semielliptical micro groove is formed in a lower surface of the specimen to measure a creep crack growth property.

Abstract: A sensor for measuring the fatigue life of a structure subjected to repetitive loads is disclosed. The sensor includes a backing material arranged for securement to the structure, and a foil arranged for securement to the backing material. The foil includes a conductive path along which electrical current flows at an initial resistance measured prior to the structure being subjected to repetitive loads. A crack initiation feature in the form of a notch is located on the conductive path. In response to repetitive loads applied to the structure, one or more cracks propagate from the crack initiation feature across the conductive path to cause electrical resistance to increase whereby the progression of fatiguing of the structure may be determined.

Abstract: A method for determining characteristics of a crack detected in a material, comprising: determining initial mechanical loads applied to the material, applying a plurality of crack-opening mechanical loads to the material, each opening mechanical load being a linear combination of the initial mechanical loads, and measuring the relative displacement of the first point with respect to the second point induced by each opening mechanical load, applying a plurality of crack-closing mechanical loads to the material, each closing mechanical load being a linear combination of the initial mechanical loads, and measuring the relative displacement of the first point with respect to the second point induced by each closing mechanical load, and estimating the direction of the crack as a function of the amplitude of each opening and closing mechanical load applied to the material and of the measured relative displacements.

Abstract: A testing system for causing a physical change in a crack tip region of a crack within a specimen. The testing system includes a load application system for applying a load to the specimen having the crack formed therein, an electrothermal system for applying an electrical current through the specimen and comprising a power supply and a controller operably coupled to the load application system and the electrothermal system. The load application system configured to perform a crack growth test on the specimen. A method of thermally influencing a crack tip region of a crack within a specimen includes applying at least one pulse of current to the specimen to generate flux tangentially around the crack within the specimen and at the crack tip region and causing the crack tip region of the crack within the specimen to reach a predetermined activation temperature.

Abstract: A system and method for determining the strength of a bond joining a composite structure is provided. The system includes a gas gun produces a short gas pulse directed normal to a surface of the composite structure and that creates a compression wave through the composite structure; a monochromatic x-ray system produces a monochromatic x-ray that is incident at an angle to the surface and that passes through the composite structure; a scintillator screen receives transmitted x-rays that pass through the composite structure; a mirror receives and magnifies radiation emitted from the scintillator screen; a detector receives the radiation from the scintillator screen; an electronic processor configured to process the radiation detected by the detector; and a synchronization controller configured to synchronize operation of the gas gun, the monochromatic x-ray system, and the detector.

Abstract: Tubular elasticity is applied to determine tubular wear volume. In general, a torque and drag model is applied to calculate the dynamic stretch of the inner tubular string (e.g., drill string). The dynamic stretch is then integrated into a casing wear model to improve the accuracy of the calculated wear and its corresponding position along the outer tubular string (e.g., casing string).

Abstract: An airborne platform includes a body and a sensor device. The body includes a first material having a first flexibility. The sensor device is positioned inside the body, and includes an electric conductor. The electric conductor includes a second material that has a second flexibility that is less than the first flexibility. The sensor device is configured to output an output signal indicating whether the sensor device has undergone mechanical failure in response to a load applied to the sensor device that is greater than a load threshold.

Abstract: The invention provides a method and device for measuring the elasticity of hardened cement for cementing of oil-gas wells. The measurement method comprises: determining the loading and unloading rates of the hardened cement; determining the maximum loading on the hardened cement; determining the experimental temperature and the experimental pressure of the hardened cement; establishing a stress-strain curve for the hardened cement; and describing the elasticity of the hardened cement with the degree of strain recovery of the hardened cement in different cycles, and describing the mechanic integrity of the hardened cement with the degree of damage to the hardened cement in different cycles. The invention further provides a device for measuring the elasticity of hardened cement for cementing of oil-gas wells.

Abstract: A method for analyzing material wear in a hydrocarbon production environment is disclosed. The method includes the steps of preparing a sample of material to be disposed proximate the hydrocarbon production environment; selecting a placement location for the sample of material, wherein the placement location is in fluid communication with a fluid flow for which the impact of the fluid flow on the sample of material is to be tested; disposing the sample of material in the placement location for a pre-determined amount of time; allowing the sample of material to be exposed to the fluid flow; retrieving the sample of material from the placement location after the pre-determined amount of time has passed; and analyzing the sample of material for wear caused by the hydrocarbon production environment.

Abstract: A transmission structure of an ozone testing machine has: a transmission frame, a rotation unit, a connecting unit, and a lifting unit. The transmission structure is connected to the lifting shaft and the lifting device via the connecting unit, the bottom of the sleeve of the connecting unit is provided with threaded member screwed to the threaded rod of the lifting device, and the sleeve is fixed onto the sliding member to achieve the linear displacement along the guiding track. During the clockwise and reverse rotations of the servo motor of the lifting device, the lifting shaft can achieve the synchronous operation of the rotation and lifting due to the limited connection with the connecting unit, thereby greatly improving the smoothness of the test process, while maintaining the static and dynamic tests.

Abstract: A method of testing a material sample of a type used in a wall of a structure in a standard test for in-plane fracture toughness evaluation. The method comprises obtaining a sample having a lateral length no larger than a thickness of the wall of the structure, shaping the sample to have (a) a bottom surface, (b) a profiled top surface having a central notch, (c) a first coupling feature on a first side of the central notch, and (d) a second coupling feature on a second side of the central notch, assembling a test specimen which increases the width of the sample beyond the lateral width by coupling a first lateral extension to the first coupling feature and a second lateral extension to the second coupling feature, and applying a standard fracture toughness test to the so-assembled test specimen and sample to evaluate the fracture toughness of the sample.

Abstract: Disclosed herein is an apparatus for inspecting structural integrity of a part. The apparatus includes a body and at least one sensor. The body is movable relative to the part. The at least one sensor is coupled to the body and includes a plurality of nanotubes configured to generate electrical signals when acted upon by an acoustic shockwave propagating through the part. The electrical signals are proportional to an intensity of the acoustic shockwave.

Abstract: An apparatus 300 for simulating a pulsed pressure induced cavitation technique (PPCT) from a pressurized working fluid (F) provides laboratory research and development for enhanced geothermal systems (EGS), oil, and gas wells. A pump 304 is configured to deliver a pressurized working fluid (F) to a control valve 306, which produces a pulsed pressure wave in a test chamber 308. The pulsed pressure wave parameters are defined by the pump 304 pressure and control valve 306 cycle rate. When a working fluid (F) and a rock specimen 312 are included in the apparatus, the pulsed pressure wave causes cavitation to occur at the surface of the specimen 312, thus initiating an extensive network of fracturing surfaces and micro fissures, which are examined by researchers.

Abstract: An aspect of the invention is a testing system for applying loads to a test specimen. The testing system includes the actuator and the first support portion supporting the actuator. The actuator is configured to support a first end of the test specimen, while a second support portion configured to support a second end of the test specimen. In various embodiments, combination of sensors that can include displacement sensor and/or accelerometer(s) provide associated output signals that are received by a displacement compensator that is configured to provide a displacement output signal indicative of differential displacement between first end and the second end of the test specimen.

Abstract: A method of testing a material sample of a type used in a wall of a structure in a standard test for in-plane fracture toughness evaluation. The method comprises obtaining a sample having a lateral length no larger than a thickness of the wall of the structure, shaping the sample to have (a) a bottom surface, (b) a profiled top surface having a central notch, (c) a first coupling feature on a first side of the central notch, and (d) a second coupling feature on a second side of the central notch, assembling a test specimen which increases the width of the sample beyond the lateral width by coupling a first lateral extension to the first coupling feature and a second lateral extension to the second coupling feature, and applying a standard fracture toughness test to the so-assembled test specimen and sample to evaluate the fracture toughness of the sample.

Abstract: A device for stress-freezing experiments during fracturing process according to the present application, in which heating and cooling treatment on a specimen under corresponding temperature control according to a preset temperature gradient and a photosensitive curve is performed by a temperature control system, to realize stress-freezing of the specimen; a pressure is applied to a specimen by a true triaxial servo loading system; and corresponding fracturing experiments are performed to the specimen by a fracturing liquid pumping system having an output end arranged in a thermo-controlled oven.

Abstract: The present disclosure relates to a flexible strain sensor. The flexible strain sensor includes a composite structure, a first electrode, a second electrode and a detector. The composite structure includes a carbon nanotube film and a substrate combined with each other. The carbon nanotube film defines a desired deformation direction and includes a plurality of first carbon nanotubes oriented substantially perpendicular with the desired deformation direction. The plurality of first carbon nanotubes are joined end to end with each other along their orientation direction. The first electrode and the second electrode are separately located at two opposite ends of the carbon nanotube film and electrically coupled with the carbon nanotube film. The detector is electrically connected with the first electrode and the second electrode.

Abstract: A method and system monitor coupler fatigue by determining an upcoming fatigue metric representative of fatigue that is to be experienced by a coupler configured to connect plural vehicles in a vehicle system, determining whether a failure metric of the coupler during the upcoming trip exceeds a designated failure threshold (where the failure metric is based on the upcoming fatigue metric), and, responsive to determining that the failure metric exceeds the designated failure threshold, one or more of notifying an operator of the upcoming fatigue metric, displaying one or more of the upcoming fatigue metric or the failure metric, changing a driving plan for controlling movement of the vehicle system during the upcoming trip, and/or changing a characteristic of the vehicle system.

Abstract: The remaining serviceable life of a critical rotating component of a gas turbine engine can be predicted using a remote detection component. The remote detection component is inspected to determine whether a crack has formed at a dedicated crack-initiation feature. If a crack has formed, a known correlation between the remote detection component and the critical rotating component is used to estimate the remaining serviceable life of the critical rotating component. Because the detection component is remote from the critical component, there is no risk of failure of the critical component.

Abstract: A device for testing mixed-mode fatigue crack growth rate includes a plate-like specimen, and a first fixture mechanism for exerting stretch, shear and torsion actions on the specimen via a second fixture mechanism. The second fixture mechanism is used for clamping the specimen and enabling the specimen to generate a mixed-mode fatigue crack in cooperation with the first fixture mechanism. The device further comprises a fatigue crack measurement instrument for measuring and recording the length of mixed-mode fatigue crack generated on the specimen.

Abstract: A strain inspection device of a printed circuit board (PCB) which is easily cracked or damaged by external pressure (force) applied to the PCB while the PCB is being assembled, and an attaching method thereof. The strain inspection device of a printed circuit board (PCB) includes a fixing member; and a damage indicator fixed to the PCB by the fixing member, having a crack guide through hole, and cracked or damaged along a corner of the crack guide through hole due to deformation of the PCB.

Abstract: A portable electronic device for assessing an affected area of an aircraft is disclosed. A reference marker having a known size is located on the aircraft. The portable electronic device includes a processor in communication with a structural database, where the structural database includes a template that defines a maximum allowable size of damage to the aircraft. The processor executes instructions for determining an actual size of the affected area based on the known size of the reference marker. The processor also executes instructions for comparing the actual size of the affected area with the maximum allowable size of damage to the aircraft. The processor further executes instructions for determining that the actual size of the affected area exceeds the maximum allowable size of damage to the aircraft.

Abstract: A system for assessing an affected area of an aircraft is disclosed. A reference marker having a known size is placed along an exterior of the aircraft. The system includes a portable electronic device including a processor in communication with a structural database. The structural database includes a template that defines a maximum allowable size of damage to the aircraft. The processor executes an instruction for determining an actual size of the affected area based on the known size of the reference marker. The processor executes an instruction for comparing the actual size of the affected area of the aircraft with the maximum allowable size of damage to the aircraft. The processor executes an instruction for determining if the actual size of the affected area exceeds the maximum allowable size of damage to the aircraft. The processor executes an instruction for determining a further action.

Abstract: A method for determining a threshold crack length in a machine component including a fatigue crack defining a fatigue crack length and a fatigue crack angle. The method includes determining a component threshold stress intensity factor for the fatigue crack angle, determined from a dataset that includes threshold stress intensity factors for mixed-mode phase angles formed by conducting an asymmetric four point bend test on a test specimen having an initial notch. The method includes determining a threshold crack length based on the component fatigue crack length and fatigue crack angle using a formula disclosed herein.

Abstract: Provided herein is a test equipment for evaluating safety of a piping for use in nuclear power plants, the test equipment having a test specimen made of a same material as the piping, and having a notch cut from a first surface which is an end portion of the test specimen, with a crack formed at an end portion of the notch; and a load applier connected to the test specimen to apply a load in a direction perpendicular to a direction in which the notch is cut, wherein a pair of pin holes are connected to the load applier such that they are arranged to be distanced from each other along the direction of the load applied to the test specimen, and a central point is provided in a space between a second surface opposing the first surface and an end portion of the crack.

Abstract: A method of fatigue testing a component comprising the steps of machining a channel of predetermined depth and predetermined width in a surface of a component, applying a salt solution into the channel in the surface of the component and heating the component to a suitable temperature to evaporate the solvent from the salt solution to deposit the salt in the channel in the surface of the component, placing the component in an atmosphere containing air and sulphur dioxide at a predetermined temperature for a predetermined period of time to precondition the grain boundaries, and fatigue testing the component. The method is useful for determining the fatigue life of gas turbine engine discs or gas turbine engine rotor blades particularly the firtree shaped disc posts or the firtree shaped rotor blade roots.

Abstract: A method for evaluating the corrosion-fatigue life of a steel material includes: bringing a corrosive medium into contact with a predetermined portion of the steel material; measuring strain on the steel material while applying cyclic loads to the steel material; measuring an N-th strain index from strain amplitude at the number of initial load applications and strain amplitude at the N-th load application (N is a natural number larger than the number of initial load applications); and estimating the corrosion-fatigue life of the steel material by comparing the N-th strain index with a previously certified life strain index.

Abstract: A method of determining a crack depth of a crack in a metallic material including the steps: feeding a current with a first magnitude to a transmitter coil for generating a magnetic field in the metallic material; controlling the current such that it obtains a second magnitude when the magnetic field is estimated to have penetrated deeper than a deepest crack depth desired to be measured in the metallic material; detecting the magnetic field by means of a receiver coil; determining a first characteristic value of the signal in a first time range; determining a second characteristic value of the signal in a second time range after the first time range; and determining a possible presence of a crack and its crack depth based on the first characteristic value and the second characteristic value.

Abstract: A method and system for determining creep capability of turbine components is provided. A plurality of turbine components are manufactured from a material having known creep characteristics. Each of the plurality of turbine components is subjected to at least one of tensile stress, centrifugal stress and thermal stress, until a measurable amount of creep is acquired. The turbine components so tested are compared against known creep characteristics for the material used in the components. Components exhibiting an amount of creep greater than a predefined amount of creep will be separated from the plurality of turbine components and not placed into service.

Abstract: A device for testing the adhesive strength of a coating on a substrate, containing a unit for generating mechanical stress in a predefinable surface area of the coating and an evaluation system, which contains a unit for image acquisition and a unit for evaluating the cracks that occur, wherein the device further contains a transport unit, by which the substrate can be moved at least from the unit for generating mechanical stress to the evaluation system, and a heating unit, by which the substrate can be heated to a predefinable temperature.

Abstract: A device is provided for the early detection of crack formations in work pieces or in components that are subjected to mechanical loading. Wherein in the region of at least one surface at risk of cracking there is arranged at least one testing chamber that is formed by a generative process of manufacturing the work piece or a portion of a work piece and to which a testing medium under pressure is admitted. Either a pressure sensor for determining a drop in pressure resulting from a crack formation of the work piece is connected to the testing chamber or a gas sensor that can also react to a testing medium escaping from the testing chamber in the event of crack formation is arranged in the vicinity of the testing chamber.

Abstract: A method of preparing a forming limit diagram in press forming includes obtaining a forming limit curve by subjecting a surface of a metal plate to be press-formed to marking at a distance between reference points of 0.5-1.0 mm, bulging the metal plate with a punch having a top minimum curvature radius of 3-10 mm and measuring a maximum principal strain and minimum principal strain at a time of generating cracks on the surface of the metal plate at a top portion of the punch from a change of the marking.

Abstract: In a method of arresting fatigue crack growth in a metal member, a hole is formed beside a tip portion of a fatigue crack with respect to a crack extension direction, in a metal member body, in which the fatigue crack occurs due to an action of applied cyclic tensile stress. Then, a press-fit object being higher in stiffness than the metal member body and larger in external size than the hole is press-fitted into the hole. Compressive stress is made to act on the tip portion of the fatigue crack from directions lateral to the crack extension direction.

Abstract: A device, a system and a method for detecting an irregularity in a structure of an aircraft are proposed. The device includes a resonant circuit with a resonance frequency and a probe for tuning the resonance frequency of the resonant circuit. The resonant circuit and the probe are operatively connected in such a way that the probe changes the resonance frequency of the resonant circuit if the structure changes due to a formation of an irregularity.

Abstract: A method for evaluating the corrosion-fatigue life of a steel material includes: bringing a corrosive medium into contact with a predetermined portion of the steel material; measuring strain on the steel material while applying cyclic loads to the steel material; measuring an N-th strain index from strain amplitude at the number of initial load applications and strain amplitude at the N-th load application (N is a natural number larger than the number of initial load applications); and estimating the corrosion-fatigue life of the steel material by comparing the N-th strain index with a previously certified life strain index.

Abstract: A fusion bead testing device is provided for testing the strength of a fusion bead removed from a pipe joint. The testing device comprises a first pressing means for exerting a force against the fusion bead. If the fusion bead splits as a result of the applied force then the fusion bead fails a quality control test and the fusion bead and consequently the pipe joint from which the bead was removed are deemed too weak. The fusion bead testing apparatus comprises an automatic split detection device for detecting a split in the bead.

Abstract: In a method of arresting fatigue crack growth in a metal member, a hole is formed beside a tip portion of a fatigue crack with respect to a crack extension direction, in a metal member body, in which the fatigue crack occurs due to an action of applied cyclic tensile stress. Then, a press-fit object being higher in stiffness than the metal member body and larger in external size than the hole is press-fitted into the hole. Compressive stress is made to act on the tip portion of the fatigue crack from directions lateral to the crack extension direction.

Abstract: Test structures for semiconductor devices, methods of forming test structures, semiconductor devices, methods of manufacturing thereof, and testing methods for semiconductor devices are disclosed. In one embodiment, a test structure for a semiconductor device includes at least one first contact pad disposed in a first material layer in a scribe line region of the semiconductor device. The at least one first contact pad has a first width. The test structure also includes at least one second contact pad disposed in a second material layer proximate the at least one first contact pad in the first material layer. The at least one second contact pad has a second width that is greater than the first width.

Abstract: Systems and methods are described for concurrently applying loads to multiple test specimens. The systems and methods are useful for cyclical tensile loading of specimens such as in fatigue strength evaluations. The systems and methods are also useful for low frequency cyclical loading evaluations.

Abstract: In a method of determining a fatigue crack lifetime of a low-alloy steel material coming in contact with high-pressure hydrogen in a high-pressure hydrogen environment, estimate a fatigue crack acceleration starting point KmaxT of the low-alloy steel material using a crack-growth threshold stress intensity factor KIH-R obtained through a rising load test on the low-alloy steel material in a high-pressure hydrogen environment. The high-pressure hydrogen environment of the rising load test is a high-pressure hydrogen environment which has the same pressure and atmosphere as in the high-pressure hydrogen environment in which KmaxT is estimated and in which the test temperature tolerance between both environments is ±5° C.

Abstract: A system for sulfide stress cracking testing comprises an enclosed testing chamber including a fluid bath comprising a liquid saturated with hydrogen sulfide gas. In addition, the system comprises a test fixture disposed in the testing chamber and at least partially submerged in the fluid bath. The test fixture includes a housing having an internal chamber in fluid communication with the fluid bath and a test assembly disposed in the internal chamber. The test assembly comprises a first upper support and a second upper support, a first lower support and a second lower support, and a first platen engaging each of the upper supports and adapted to transfer an applied vertical load to the upper supports. Further, the system comprises a test specimen mounted in the test assembly between the upper supports and the lower supports.

Abstract: A method for three-dimensional crack propagation, morphology, and initiation suited to directed surfaces, or stacks of directed surfaces. An external damage measure and failure criteria can be incorporated, as well as a rule-based crack direction and morphology capability. This method is ideal for laminated composites. Further, the use of external damage and failure, and rule-based crack propagation, this method is ideal for multi-scale modeling and use in applications where knowledge and rules are necessary or desirable for guiding, driving, or influencing failure modes, directions, or other situations that are not directly incorporated into the governing mechanical equations.

Abstract: A method for indicating fatigue damage rate of a hardened metal object in relation to load cycles, N, exerted on the hardened metal object, wherein the hardened metal object presents a temperature essentially corresponding to the operating conditions of the hardened metal object is disclosed. It comprises calculating the fatigue rate based on an effective activation energy parameter for the dislocation climb process, Q, shear stress amplitude, T, the absolute local temperature of the hardened metal object, T, and load frequency, f. Methods for indicating fatigue and predicting life of a metal object are disclosed.

Abstract: A method of predicting sheet formability at a microscale level includes the steps of providing a grid pattern on a test sheet, bulging the test sheet to a hemispherical shape until a crack is initiated on the surface of the test sheet, detecting the initiation of the crack, acquiring two images of the surface adjacent to the crack and calculating surface strains on the test sheet.

Abstract: The stress corrosion cracking (SCC) testing device includes a corrosion cell for placing a specimen to be tested therein. The corrosion cell is configured to simulate the extreme high temperature and pressure, as well as the corrosive environments experienced by engineered, industrial components. A heating element and a pressurizing assembly are operatively attached to the corrosive cell to simulate the high temperature and pressure environs. A circulation assembly is also attached to the corrosion cell to simulate both flowing and stagnant conditions of the corrosion solution that the industrial component can be subjected to. A loading assembly with a specimen holding shaft is operatively attached to the specimen to place a predetermined and constant tensile load on the specimen until fracture in order to determine KI and KIsec of the engineered component. PTFE seals are used to seal the specimen holding shaft during testing.

Abstract: A sample for fatigue and/or crack growth testing, including an axisymmetric or cylindrical gage section with a concentric hole running from a first end, and terminating within the gage section, with one mode of loading introduced at the terminus of the hole, and reacted at the end where the hole originates. A second mode of loading is optionally introduced at a second end of the specimen. Use of the specimen is described in both in the context of an apparatus for fatigue/crack growth testing described in the referenced parent application, as well as with conventional test machines.