公开(公告)号：US20190391037A1

公开(公告)日：2019-12-26

申请号：US16342922

申请日：2018-03-23

Applicant: Dalian University of Technology

Inventor： Tinghua YI ,  Haibin HUANG ,  Hongnan LI

IPC: G01M5/00 ,  G06F17/50

Abstract: Health monitoring for civil structures, and a performance alarming method for long-span bridge girder considering time-varying effects. First, establish accurate relationship model between temperature and strain fields to eliminate the temperature effect in the girder strain; second, build principal component analysis model for the girder strain after eliminating temperature effect to further eliminate the effects of wind and vehicle loads. Then, construct the performance alarming index and determine its reasonable threshold for the strain after eliminating the effects of temperature, wind and vehicle loads. Finally, construct the performance degradation locating index based on the contribution analysis.

公开(公告)号：US20200284687A1

公开(公告)日：2020-09-10

申请号：US16479730

申请日：2019-03-01

Applicant: Dalian University of Technology

Inventor： Tinghua YI ,  Xiaomei YANG ,  Chunxu QU ,  Hongnan LI

IPC: G01M7/02 ,  G01H17/00

Abstract: A method for automatically detecting the free vibration response segment of the high-speed railway bridges after trains passing. First, pre-select the test response sequence to be decomposed based on the maximum of the time instants corresponding to the absolute maximums of the response vectors at various measuring point. Then, Extract the single-frequency modal response from the test response by the iterative variational mode decomposition and fit the envelope amplitude of the modal response by Hilbert transform. Finally, the vibration features at each time instants are marked as decay vibration or non-decay vibration. The longest structural response segment that meets the decay vibration features is determined as the detected free vibration response segment for modal identification. This invention can effectively detect the free vibration data segment without human participation, which is of great significance for the real-time accurate modal analysis of high-speed railway bridges.

公开(公告)号：US20200089733A1

公开(公告)日：2020-03-19

申请号：US16342951

申请日：2018-06-04

Applicant: Dalian University of Technology

Inventor： Tinghua YI ,  Xueyang PEI ,  Chunxu QU ,  Hongnan LI

IPC: G06F17/18 ,  A61B5/00

Abstract: Sensor placement for structural health monitoring and sensor placement method for reducing uncertainty of structural modal identification. Influences of structural model error and measurement noise on measured responses are separated. Structural stiffness variation is used as model error, and Gaussian noise is used as measurement noise. Monte Carlo method simulates a large number of possible cases, and structural mode shape matrices under each model error condition are obtained. Conditional information entropy index quantifies and calculates uncertainty of identified modal parameter results. Conditional information entropy index solves the problem of uncertain Fisher information matrix, which cannot be solved by traditional information entropy method. Optimal sensor placement corresponds to maximum conditional information entropy index value. The sensor placement method considers influences of structural model error and measurement noise on structural modal identification, which is helpful for improving accuracy of structural modal parameter identification.

公开(公告)号：US20200089730A1

公开(公告)日：2020-03-19

申请号：US16342953

申请日：2018-08-27

Applicant: Dalian University of Technology

Inventor： Tinghua YI ,  Xiaojun YAO ,  Chunxu QU ,  Hongnan LI

IPC: G06F17/15 ,  G06F17/14 ,  G06F17/16 ,  G06F17/13

Abstract: Data analysis for structural health monitoring relating to a method of modal identification for structures with non-proportional damping based on extended sparse component analysis. Hilbert transform constructs analytical signal of acceleration response. Analytical signal is transformed into time-frequency domain using short-time-Fourier transform. The criterion is taken as the correlation coefficient of adjacent frequency points is close to 1. Points contributed by only one mode are detected from the time-frequency plane. Phases calculated at single-source-points are used to remove local outliers through local outlier factor method. Amplitudes of complex-valued mode shapes are estimated by Hierarchical clustering of amplitudes for time-frequency coefficients at single-source-points. Averaged phases of grouped single-source-points are estimated phases of complex-valued mode shapes. Finally, complex-valued mode shapes are acquired. Modal responses are estimated by sparse reconstruction method. This method extends application range of sparse component analysis method, and can identify complex modes of non-proportionally damped structures.

公开(公告)号：US20190243935A1

公开(公告)日：2019-08-08

申请号：US16342902

申请日：2018-03-16

Applicant: Dalian University of Technology

Inventor： Tinghua YI ,  Xueyang PEI ,  Hongnan LI

IPC: G06F17/50 ,  G01P15/18 ,  G01P15/08 ,  G01L1/22 ,  G01M5/00

CPC classification number: G06F17/5018 ,  G01L1/2206 ,  G01M5/0008 ,  G01P15/0802 ,  G01P15/18 ,  G06F2217/16

Abstract: A structural modal estimation based sensor placement method of strain gauges and accelerometers, including three steps: selection of initial accelerometer positions, selection of positions to be estimated and selection of strain gauge positions. First, use the modal confidence criterion and modal information redundancy to select the initial accelerometer position. Second, combined with the actual situation, when some positions cannot arrange the accelerometer, define the positions where the displacement modal estimation is needed. Third, use the strain mode shapes estimates the displacement mode shapes of the positions to be estimated, and uses the modal estimation effect to select the positions of the strain gauges. This can fully utilize the monitoring data collected by the strain gauges. The obtained sensor placement conforms to the modal confidence criterion and contains few modal redundancy information, which is an effective joint sensor placement method.

公开(公告)号：US20190228117A1

公开(公告)日：2019-07-25

申请号：US16336807

申请日：2018-03-14

Applicant: DALIAN UNIVERSITY OF TECHNOLOGY

Inventor： Tinghua YI ,  Haibin HUANG ,  Hongnan LI

IPC: G06F17/50 ,  G06F17/15 ,  G06F17/16 ,  E01D19/06

Abstract: The present invention belongs to the technical field of health monitoring for civil structures, and a performance alarming method for bridge expansion joints based on temperature displacement relationship model is proposed. First, the canonically correlated temperature is proposed to maximize the correlation between bridge temperature field and expansion joint displacement; second, a temperature displacement relationship model for bridge expansion joints is established based on canonically correlated temperatures; then, a mean-value control chart is constructed to the error of temperature displacement relationship model; finally, reasonable control limits are determined for the mean-value control chart. A more accurate temperature displacement relationship model can be established based on canonically correlated temperatures, which is of important value to improve the performance alarming ability for expansion joint.