Abstract:
A method for probabilistic fatigue life prediction using nondestructive testing data considering uncertainties from nondestructive examination (NDE) data and fatigue model parameters. The method utilizes uncertainty quantification models for detection, sizing, fatigue model parameters and inputs. A probability of detection model is developed based on a log-linear model coupling an actual flaw size with a nondestructive examination (NDE) reported size. A distribution of the actual flaw size is derived for both NDE data without flaw indications and NDE data with flaw indications by using probabilistic modeling and Bayes theorem. A turbine rotor example with real world NDE inspection data is presented to demonstrate the overall methodology.
Abstract:
A method dynamically reconstructing a stress and strain field of a turbine blade includes providing a set of response measurements from at least one location on a turbine blade, band-pass filtering (32) the set of response measurements based on an upper frequency limit and a lower frequency limit, determining (33) an upper envelope and a lower envelope of the set of response measurements from local minima and local maxima of the set of response measurements, calculating (34) a candidate intrinsic mode function (IMF) from the upper envelope and the lower envelope of the set of response measurements, providing (37) an N x N mode shape matrix for the turbine blade, where N is the number of degrees of freedom of the turbine blade, when the candidate IMF is an actual IMF, and calculating (38) a response for another location on the turbine blade from the actual IMF and mode shapes in the mode shape matrix.
Abstract:
A method and system for automatically detecting liver lesions in medical image data, such as 3D CT images, is disclosed. A liver region is segmented in a 3D image. Liver lesion center candidates are detected in the segmented liver region. Lesion candidates are segmented corresponding to the liver lesion center candidates, and lesions are detected from the segmented lesion candidates using learning based verification.
Abstract:
A method for predicting fatigue crack growth in materials includes providing a prior distribution obtained using response measures from one or more target components using a fatigue crack growth model as a constraint function, receiving new crack length measurements, providing a posterior distribution obtained using the new crack length measurements, and sampling the posterior distribution to obtain crack length measurement predictions.
Abstract:
A method and system for automatically detecting liver lesions in medical image data, such as 3D CT images, is disclosed. A liver region is segmented in a 3D image. Liver lesion center candidates are detected in the segmented liver region. Lesion candidates are segmented corresponding to the liver lesion center candidates, and lesions are detected from the segmented lesion candidates using learning based verification.
Abstract:
A method and system for automatically detecting liver lesions in medical image data, such as 3D CT images, is disclosed. A liver region is segmented in a 3D image. Liver lesion center candidates are detected in the segmented liver region. Lesion candidates are segmented corresponding to the liver lesion center candidates, and lesions are detected from the segmented lesion candidates using learning based verification.
Abstract:
A method for multiple bone segmentation for three-dimensional computed tomography comprises the acts: - receiving (20) computed tomography (CT) data representing first and second bones of a patient; - separately segmenting (22) the first and second bones; - refining (30) the segmenting of the first bone as a function of a first confidence map of the segmenting; - refining (30) the segmenting of the second bone as a function of a second confidence map of the segmenting; - adjusting (34) results of the segmenting of the first and second bones jointly as a function the first and second confidence maps; and - outputting (30) an image showing the first and second bones with the adjusted results of the segmenting.
Abstract:
A method for probabilistically predicting fatigue life in materials includes sampling (41) a random variable for an actual equivalent initial flaw size (EIFS), generating (42) random variables for parameters (InC, m) of a fatigue crack growth equation [Formula should be inserted here] from a multivariate distribution, and solving (43) the fatigue crack growth equation using these random variables. The reported EIFS data is obtained by ultrasonically scanning a target object, recording echo signals from the target object, and converting echo signal amplitudes to equivalent reflector sizes using previously recorded values from a scanned calibration block. The equivalent reflector sizes comprise the reported EIFS data.
Abstract:
A method of fatigue life prediction including: calculating a critical crack size of an object of interest; identifying a first flaw in ultrasound data of the object of interest; determining that the first flaw interacts with a second flaw, the first flaw is to be merged with the second flaw, or the first flaw is isolated; calculating an initial crack size based on the determination; and calculating an increase in the initial crack size due to fatigue and creep to determine a number of load cycles until the initial crack size reaches the critical crack size.
Abstract:
In a general methodology for insulation defect identification in a generator core, a Chattock coil is used to measure magnetic potential difference between teeth. Physical knowledge and empirical knowledge is combined in a model to predict insulation damage location and severity. Measurements are taken at multiple excitation frequencies to solve for multiple characteristics of the defect.