A test result evaluating method and a material tester are provided. A test result evaluating part includes a representative value calculating part that acquires a representative value of section data corresponding to one period of a natural vibration frequency from data of a time period representing a force applied to a test piece also including a natural vibration and a ratio calculating part that calculates a ratio between the representative value acquired by the representative value calculating part and a value based on an amplitude of the natural vibration. The representative value calculating part and the ratio calculating part are arranged in a test result evaluating part as programs realizing functions by operating an arithmetic operation device.

A test result evaluating method and a material tester are provided. A test result evaluating part includes a representative value calculating part that acquires a representative value of section data corresponding to one period of a natural vibration frequency from data of a time period representing a force applied to a test piece also including a natural vibration and a ratio calculating part that calculates a ratio between the representative value acquired by the representative value calculating part and a value based on an amplitude of the natural vibration. The representative value calculating part and the ratio calculating part are arranged in a test result evaluating part as programs realizing functions by operating an arithmetic operation device.

To provide a characteristic evaluation device that can properly evaluate a characteristic of a shaft coupling while considering a delay in a response of a motor, a characteristic evaluation device of a shaft coupling includes: a motor system including a drive motor, a rotation angle sensor configured to acquire a rotation angle of a drive shaft, and a motor control unit configured to control the drive motor based on a torque command; a rotational load connected to a driven shaft; and a processor configured to output the torque command and calculate a frequency response of a gain of an amplitude of an angular velocity ? of the rotation angle, wherein the processor is configured to calculate a characteristic of the shaft coupling based on a response characteristic of the motor system and the frequency response.

To provide a characteristic evaluation device that can properly evaluate a characteristic of a shaft coupling while considering a delay in a response of a motor, a characteristic evaluation device of a shaft coupling includes: a motor system including a drive motor, a rotation angle sensor configured to acquire a rotation angle of a drive shaft, and a motor control unit configured to control the drive motor based on a torque command; a rotational load connected to a driven shaft; and a processor configured to output the torque command and calculate a frequency response of a gain of an amplitude of an angular velocity ? of the rotation angle, wherein the processor is configured to calculate a characteristic of the shaft coupling based on a response characteristic of the motor system and the frequency response.

A method of identifying a fault in a system of gears in a wind turbine is provided. The method determines a first centre harmonic frequency amplitude according to vibrations of the system of gears and determines a plurality of sideband amplitudes of the first centre harmonic frequency amplitude. Further, the method calculates an average sideband amplitude from the plurality of sideband amplitudes and determines a value indicative of damage incurred by the system of gears based upon the first centre harmonic frequency amplitude and the average sideband amplitude. The centre harmonic frequencies may be harmonic tooth mesh frequencies and the value indicative of damage may be a ratio of the centre harmonic frequency amplitude and a difference between the centre harmonic frequency amplitude and the associated average sideband amplitude or vice versa. The method may analyse the value of any ratio obtained and use the ratio values to identify, and monitor the progress of, a fault.

A method of identifying a fault in a system of gears in a wind turbine is provided. The method determines a first centre harmonic frequency amplitude according to vibrations of the system of gears and determines a plurality of sideband amplitudes of the first centre harmonic frequency amplitude. Further, the method calculates an average sideband amplitude from the plurality of sideband amplitudes and determines a value indicative of damage incurred by the system of gears based upon the first centre harmonic frequency amplitude and the average sideband amplitude. The centre harmonic frequencies may be harmonic tooth mesh frequencies and the value indicative of damage may be a ratio of the centre harmonic frequency amplitude and a difference between the centre harmonic frequency amplitude and the associated average sideband amplitude or vice versa. The method may analyse the value of any ratio obtained and use the ratio values to identify, and monitor the progress of, a fault.

Noise and vibration sensing includes generating with an acceleration sensor a sense signal representative of the acceleration that acts on the acceleration sensor, and processing the sense signal to provide a processed sense signal having an adjustable signal bandwidth and an adjustable signal dynamic. The signal bandwidth extends between a lowest frequency and a highest frequency of the sense signal, and the signal dynamic is the ratio between a maximum amplitude of the sense signal and an output noise floor generated by the acceleration sensor. Noise and vibration sensing further includes adjusting the signal bandwidth and the signal dynamic in accordance with a control signal so that the signal bandwidth increases when the signal dynamic decreases and vice versa.

Noise and vibration sensing includes generating with an acceleration sensor a sense signal representative of the acceleration that acts on the acceleration sensor, and processing the sense signal to provide a processed sense signal having an adjustable signal bandwidth and an adjustable signal dynamic. The signal bandwidth extends between a lowest frequency and a highest frequency of the sense signal, and the signal dynamic is the ratio between a maximum amplitude of the sense signal and an output noise floor generated by the acceleration sensor. Noise and vibration sensing further includes adjusting the signal bandwidth and the signal dynamic in accordance with a control signal so that the signal bandwidth increases when the signal dynamic decreases and vice versa.

A rotating electrical machine of the present invention evaluates a relative displacement of members and improves reliability further even when two or more members operate or move. A rotating electrical machine of the present invention comprises a stator and a rotor disposed on an inner side of the stator with a predetermined gap. The stator includes vibration measuring devices, each of the vibration measuring devices placed on each of at least two members included in the stator, the members having different displacements or phases with each other. The rotating electrical machine includes a device that acquires a relative displacement of one of the members included in the stator by evaluating a difference between displacements or phases measured by the vibration measuring devices and that evaluates a lifetime of the one of the members included in the stator based on the relative displacement.

A method for monitoring the operation of a gas turbine is provided, in which component vibrations are detected during the operation of the gas turbine by an acceleration sensor arranged on the component, a plurality of signal sections being determined by a plurality of frequency bands fb from the signal forwarded and processed by the acceleration sensor. To avoid an unnecessary shutdown of the gas turbine to perform an inspection which subsequently proves unnecessary, thereby increasing the availability of the gas turbine, a total vibration period is determined by adding together the vibration periods of signal sections during which the amplitudes of the signal sections concerned are greater than a frequency band-specific threshold.