摘要:
A device for detecting different conditions of a component, such as distorted conditions, movements and loaded conditions. Said device comprises a transmitter and a receiver which are located independently on at least one component at a distance from one another and an evaluation unit. The transmitter emits an electromagnetic wave (such as e.g. a laser beam), or a focused particle beam to the receiver. The spatial resolution can be increased by multiple reflections from a mirror and a semi-transparent mirror.
摘要:
Output-only modal testing of an object. Vibrations are excited in said object and measured by a number of vibration sensitive detectors. From the data of the measurements, a spectral density matrix function is determined. From this density matrix, auto spectral densities for the individual modes are identified performing a decomposition based on the Singular Value Decomposition technique. From the auto spectral densities of the individual modes, natural frequencies and damping ratios for the modes can be estimated, and from the singular vectors of the Singular Value Decomposition, the modes shapes can be estimated.
摘要:
A method of ultrasonically testing the disk bore and keyway area of a shrunk-on steam turbine rotor disk or hub is provided. The method employs a one or more scanning ultrasonic phased linear array probes mounted on the disk to inspect the disk bore and keyway area on the opposite side of the disk.
摘要:
A method and system for monitoring the condition of a bearing mounted on a rotating shaft, particularly one present in an aircraft gas turbine engine, where the vibration sensor that monitors the bearing is remote therefrom but proximate to the rotating shaft. The vibration sensor obtains a broadband signal having frequencies that include the bearing defect peak of the monitored bearing. The broadband signal is analyzed to identify the presence of the bearing defect peak. If the bearing defect peak is present, the amplitude of this peak is quantified to determine whether degradation of the monitored bearing has at least reached a threshold criteria previously established.
摘要:
A process is provided for determining the degree of damage to keratinous fibers. The process includes providing a container containing a liquid preparation, introducing keratinous fibers into the container, and applying at least one impulse to the container to determine the degree of damage. The liquid preparation contains at least two immiscible continuous liquid phases, where the phases differ in densities at 20° C. by at least 0.04 g/ml.
摘要:
Tissue-mimicking material suitable for phantoms for use with at least ultrasound and MRI have sections of material in contact with each other which mimic ultrasound and magnetic resonance imaging properties of human tissues, and preferably also computed tomography properties, so that the phantom can be used for the testing of imaging by various types of medical imagers. A suitable tissue-mimicking material for use in phantoms of this type includes an aqueous mixture of large organic water soluble molecules, a copper salt, a chelating agent for binding the copper ions in the salt, and a gel-forming material. Small glass beads may be intermixed therewith to provide a selected ultrasound attenuation coefficient without substantially affecting the MRI properties of the material. Larger glass beads may be used in a section to control primarily the ultrasound backscatter coefficient without significant effect on the ultrasound attenuation coefficient. Tissue-mimicking material that simulates muscle may have smaller glass beads and a higher concentration of gel-forming material than an adjacent section. Such similar materials in contact with one another show relative stability over extended periods of time.
摘要:
A method and system for determining meat quality in cattle is provided. In preferred embodiments the method comprises obtaining an ultrasound measurement of a cattle specimen between the 12th rib and 13th rib at weaning age. The ultrasound measurement is utilized to extrapolate a harvest quality parameter. Based on the harvest quality parameter, and preferably a yield grade, the specimen is categorized. Particularly preferred harvest quality parameters are ribeye area, fat thickness, intramuscular fat and ribeye shape. Methods for determining tenderness, stress and intramuscular fat are described and claimed.
摘要:
A method and apparatus is proposed for judging the friction behavior between two counter-running partners, each of which has a contact surface, with the one contact surface moving along the other contact surface in the operating state. One of the contact surfaces is charged with ultrasonic signals (UI; UW), ultrasonic signals which are reflected by the contact surface are received as echo signals (ES), the echo signals (ES) are supplied to an evaluation unit as received signals, the Doppler shift of the received signals is determined by means of the evaluation unit, and the friction behavior between the counter-running partners is judged by means of the Doppler shift.
摘要:
A method is provided for measuring the residual stress in metals. The method includes the steps of drilling one or more holes in a metal workpiece to a preselected depth and mounting one or more acoustic sensors on the metal workpiece and connecting the sensors to an electronic detecting and recording device. A liquid metal capable of penetrating into the metal workpiece placed at the bottom of the hole or holes. A recording is made over a period of time (typically within about two hours) of the magnitude and number of noise events which occur as the liquid metal penetrates into the metal workpiece. The magnitude and number of noise events are then correlated to the internal stress in the region of the workpiece at the bottom of the hole.
摘要:
A method and system are provided for detecting a void in backfill material such as soil surrounding a buried conduit such as a pipeline. The void is detected by monitoring an acoustic response from the conduit in response to acoustic excitation of the interior of the conduit. An analysis of changes in the acoustic response is then related to the presence or absence of a void in the backfill material.