An electronics system may include a substrate, an electronic device bonded to the substrate, a plurality of photoluminescent particles disposed on the electronic device, an illuminator, a sensor, and a control module. The illuminator can illuminate the electronic device. The sensor can capture a first set of positions of the photoluminescent particles on the electronic device when the electronic device is not operating under a load and a second set of positions of the photoluminescent particles when the electronic device is operating under a load. The control module can determine thermomechanical stress on the electronic device based at least in part on a difference between the first set of positions and the second set of positions.

In an embodiment, an optical ice detection method is provided. The method includes contacting a multilayer structure with water under conditions effective to form ice, the multilayer structure comprising an optically transparent or semi-transparent material disposed over at least a portion of a material probe. The method further includes performing Raman spectroscopy on one or more of the material probe, water, or ice to obtain Raman spectra, detecting a shift in the Raman spectra, and calculating ice-induced strain in the material probe. Apparatus for optically detecting ice are also provided.

A method for measuring a residual stress, including irradiating a cast and forged steel product with X-rays; two-dimensionally detecting intensities of diffracted X-rays originating from the X-rays; and calculating a residual stress based on a diffraction ring formed by an intensity distribution of the diffracted X-rays, wherein the irradiating includes changing a condition for irradiation of the cast and forged steel product with the X-rays, the irradiating is a step of performing the changing each time the cast and forged steel product is irradiated with the X-rays, the calculating is a step of calculating the residual stress each time the cast and forged steel product is irradiated with the X-rays, and the method further includes averaging a plurality of residual stresses calculated in the calculating after the irradiating, the detecting, and the calculating are performed in this order a plurality of times.

A method for measuring a residual stress, including irradiating a cast and forged steel product with X-rays; two-dimensionally detecting intensities of diffracted X-rays originating from the X-rays; and calculating a residual stress based on a diffraction ring formed by an intensity distribution of the diffracted X-rays, wherein the irradiating includes changing a condition for irradiation of the cast and forged steel product with the X-rays, the irradiating is a step of performing the changing each time the cast and forged steel product is irradiated with the X-rays, the calculating is a step of calculating the residual stress each time the cast and forged steel product is irradiated with the X-rays, and the method further includes averaging a plurality of residual stresses calculated in the calculating after the irradiating, the detecting, and the calculating are performed in this order a plurality of times.

A method that measures stress of a test subject including a metal includes: detecting, using a two-dimensional detector, a diffraction ring of diffracted X-rays which is formed by causing X-rays from an irradiation unit to be incident on the test subject and to be diffracted by the test subject; and calculating the stress of the test subject based on detection results during the detection step. Therein, the detection step involves causing X-rays from the irradiation unit to be incident on each of a plurality of sites on the test subject with the irradiation unit angled relative to the test subject in a manner such that the angle of incidence on the test subject is within the range of 5-20, inclusive, and detecting, using a two-dimensional detector, the diffraction ring formed by the diffraction of the X-rays by the test subject.

A method for determining residual stress in a selectively hardened parts including an unhardened region adjacent to a hardened region is provided. The method includes obtaining a Barkhausen Noise (BN) value for the unhardened region and selecting a corresponding absolute residual stress value from a correlation between BN values and absolute residual stress values. The selected absolute residual stress value accurately estimates the absolute residual stress in the hardened region of the selectively hardened part. In variations of the method the unhardened region is surrounded by the hardened region, the hardened region is a laser hardened region and the unhardened region is not laser hardened.

A magnetostrictive-type sensor temperature-detecting circuit configured to be used in a magnetostrictive-type sensor including an applied stress-detecting coil, and a driving section to output an alternating voltage, excite the coil with a resulting alternating electric current, and switch flow directions of the electric current flowing in the coil in response to switching voltage polarities of the output alternating voltage, to detect a temperature of the coil in the sensor. This temperature-detecting circuit includes an alternating electric current direction switching time-detecting section to detect an amount of time from when the voltage polarities of the output alternating voltage are switched until when the flow directions of the electric current flowing in the coil are switched, and a temperature-computing section to compute the temperature of the coil on the basis of the amount of time detected by the alternating electric current direction switching time-detecting section.

A disclosed leaky coaxial resonant sensor system and methods. In use, the system includes at least one split-ring resonator (SRR) embedded within a material of the component. The at least one SRR is formed from a composite material. Additionally, the at least one SRR is configured to resonate at a first frequency in response to an interrogation signal from a leaky coaxial cable antenna. In some aspects, each SRR may resonate at a first frequency in response to an electromagnetic ping when the composite material is in a first state, and may resonate at a second frequency in response to the electromagnetic ping when the composite material is in a second state. A resonant frequency of the composite material may be based on physical characteristics of the composite material.

A disclosed leaky coaxial resonant sensor system and methods. In use, the system includes at least one split-ring resonator (SRR) embedded within a material of the component. The at least one SRR is formed from a composite material. Additionally, the at least one SRR is configured to resonate at a first frequency in response to an interrogation signal from a leaky coaxial cable antenna. In some aspects, each SRR may resonate at a first frequency in response to an electromagnetic ping when the composite material is in a first state, and may resonate at a second frequency in response to the electromagnetic ping when the composite material is in a second state. A resonant frequency of the composite material may be based on physical characteristics of the composite material.

The present disclosure relates to the technical field of non-destructive detecting of residual stress, and in particular to a non-destructive detecting device for component residual stress gradient. the non-destructive detecting device comprises: groups of transmitting transducers and receiving transducers arranged symmetrically to each other, the transmitting transducers closer to the symmetry axis have greater excitation frequencies; an acoustic wedge coupled to the groups of transmitting transducers and receiving transducers, wherein groups of cylindrical transmitting tunnels and receiving tunnels are provided obliquely within the transmitting connection area and the receiving connection area through their top surfaces and toward their bottom surfaces, the transmitting transducers are coupled to the transmitting tunnels in a one-to-one correspondence, the receiving transducers are coupled to the receiving tunnels in a one-to-one correspondence, and the bottom surfaces of the transmitting connection area and the receiving connection area are pressed against the surface of the detected component; and a calculation processing module electrically connected to the transmitting transducers and the receiving transducers. The non-destructive detecting device solves the problem that the residual stress values of components at different penetration depths cannot be detected at the same time.