Panasonic Intellectual Property Management Co., Ltd.

Takuya Niioka

Yousuke N Irie

Hirotsugu Inoue

Yu Kurokawa

Shogo Tokunaga

In a stress measurement method, an object to be measured is vibrated at a plurality of oscillation frequencies, and a temperature amplitude of the object to be measured is measured by using a temperature sensor. Parameters of a one-dimensional heat conduction equation described below are identified by performing curve-fitting, on the basis of the one-dimensional heat conduction equation, on a measurement value of the temperature amplitude with respect to frequency characteristics of a temperature change component and a phase component based on a thermoelastic effect. The frequency characteristics are obtained at the plurality of oscillation frequencies. The one-dimensional heat conduction equation indicates a theoretical solution of a temperature amplitude on a surface of a coating film based on heat conduction and the thermoelastic effect of each of a substrate and the coating film. Then, a stress of the object to be measured is obtained based on the identified parameters.

Stress measurement method, stress measurement device, and stress measurement system

Method for measuring a depth of a defect inside an inspection object is provided. The method comprises steps of: generating thermal image data corresponding to a temperature of a surface of the inspection object by photographing a heated surface of the inspection object at a predetermined time interval by a photographing device; obtaining a temperature curve showing a temporal change in temperature of the surface of the inspection object based on the thermal image data; fitting a theoretical equation obtained from a heat conduction equation including a parameter related to the depth of the defect of the inspection object to the temperature curve to obtain a theoretical curve showing a temporal change in temperature of the surface of the inspection object; and obtaining the depth of the defect of the inspection object based on a value of the parameter in the theoretical equation corresponding to the theoretical curve.

Growing community of inventors

Tokyo, Japan

Takuya Niioka