Modal Identification from Non-Stationary Responses of High-Rise Buildings by Variational Mode Decomposition and Direct Interpolation Techniques

2020 ◽  
Vol 20 (11) ◽  
pp. 2050115
Author(s):  
Meng-Meng Sun ◽  
Qiu-Sheng Li ◽  
Kang Zhou ◽  
Ying-Hou He ◽  
Lun-Hai Zhi
Keyword(s):  
Field Measurements ◽  
Modal Identification ◽  
Frame Structure ◽  
The Novel ◽  
Variational Mode Decomposition ◽  
High Rise ◽  
Mode Decomposition ◽  
Structural Responses ◽  
Novel Method ◽  
High Level

For high-rise buildings subjected to ambient excitations such as typhoons and earthquake actions, their structural responses may include non-stationary features. Under such conditions, traditional modal identification methods may not be applicable due to the violation of the stationary assumption of the response signals. To deal with this issue, a novel modal identification method is presented in this paper based on combination of the variational mode decomposition (VMD) and direct interpolation (DI) techniques. Through numerical simulation study of a three-story frame structure, the effectiveness and accuracy of the combined VMD-DI method for modal identification of the structure are validated for the case of the structural responses containing non-stationary properties and high-level noise. Moreover, the novel method is further applied to the field measurements of acceleration responses of a 600[Formula: see text]m high skyscraper during a typhoon. The identified results verify the applicability and accuracy of the combined VMD-DI method in field measurements. This paper aims to provide an effective tool for modal identification from non-stationary structural responses of high-rise buildings.

Identification of modal parameters from non-stationary responses of high-rise buildings

2021 ◽  
pp. 136943322110339
Author(s):  
Lunhai Zhi ◽  
Feng Hu ◽  
Qiusheng Li ◽  
Zhixiang Hu
Keyword(s):  
Damping Ratio ◽  
Modal Identification ◽  
Frame Structure ◽  
Modal Parameters ◽  
Strong Wind ◽  
Modal Parameter ◽  
Civil Structures ◽  
High Rise ◽  
Random Decrement Technique ◽  
Structural Responses

A key issue in the control, health monitoring, and condition assessment of civil structures is the estimation of structural modal parameters based on measured structural responses. However, field measurements of structural responses from civil structures under strong wind or earthquake excitations usually exhibit non-stationary feature and therefore cannot be adequately deal with by traditional modal identification methods. In this study, a novel procedure is integrated for modal parameter identification of civil structures from non-stationary structural responses on the basis of the variational mode decomposition (VMD) technique. First, the VMD algorithm is applied to decompose measured vibration signals into individual mode components. Then, the random decrement technique (RDT) is employed to obtain free vibration response of each mono component. Next, normalized Hilbert transform (NHT) is used to estimate modal natural frequency and damping ratio. The performance of the developed approach is evaluated using simulated non-stationary responses of a frame structure, and the identified results are validated. The effects of crucial factors such as levels of noise involved in structural response and data length on the modal parameter estimations are examined through detailed parametric study. Furthermore, the approach is applied to modal identification based on field measured non-stationary responses of a high-rise building during Typhoon Nida. The case study illustrates that the integrated method is an efficient tool for estimating the modal parameters of civil structures from non-stationary structural responses.

scholarly journals EFFICIENT THREE-DIMENSIONAL MODELLING OF HIGH-RISE BUILDING STRUCTURES

2013 ◽  
Vol 19 (6) ◽  
pp. 811-822 ◽  
Author(s):  
Mohammed Jameel ◽  
A. B. M. Saiful Islam ◽  
Mohammed Khaleel ◽  
Aslam Amirahmad
Keyword(s):  
Three Dimensional ◽  
Shear Walls ◽  
Shear Wall ◽  
Frame Structure ◽  
Building Structures ◽  
Structural Behaviour ◽  
High Rise ◽  
Structural Responses ◽  
Wall Openings ◽  
Storey Building

A multi-storey building is habitually modelled as a frame structure which neglects the shear wall/slab openings along with the inclusion of staircases. Furthermore, the structural strength provided by shear walls and slabs is not precisely incorporated. With increasing building height, the effect of lateral loads on a high-rise structure increases substantially. Inclusion of shear walls and slabs with the frame leads to improved lateral stiffness. Besides, their openings may play imperative role in the structural behaviour of such buildings. In this study, 61 multi-storey building configurations have been modelled. Corresponding analyses are performed to cope with the influence of shear walls, slabs, wall openings, masonry walls and staircases in addition to frame modelling. The finite element approach is used in modelling and analysis. Structural responses in each elemental combination are evaluated through equivalent static and free vibration analyses. The assessment reveals that inclusion of only slab components with frame modelling contributes trivial improvement on structural performance. Conversely, the presence of shear wall slabs with frame improves the performance noticeably. Increasing wall openings decreases the structural responses. Furthermore, it is not recommended to model staircases in addition to frame–slab–shear wall modelling, unless the effect of wall openings and slab openings is adequately considered.

Research on Seismic Strengthening with the Performance of the Dynamic Measurement Method

2014 ◽  
Vol 1021 ◽  
pp. 152-155 ◽  
Author(s):  
Jian Jian Zhang ◽  
Yong Sheng Zhang
Keyword(s):  
Seismic Performance ◽  
Dynamic Characteristics ◽  
Residential Building ◽  
High Sensitivity ◽  
Modal Identification ◽  
Frame Structure ◽  
Test Results ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
High Rise

The structure of the dynamic characteristics can comprehensively reflect the seismic performance of the structure. By high sensitivity under external excitation vibration pickup pick structure dynamic response to obtain the dynamic characteristics of buildings, this paper introduces the principle of vibration test and modal identification method of information. To high-rise shear wall of reinforced concrete frame structure of a residential building as an example, has carried on the test, through the test results of the seismic performance of this structure after reinforcement.

Research on Related Technology of Content-Based Image Retrieval

2013 ◽  
Vol 448-453 ◽  
pp. 3616-3620
Author(s):  
Yu Bing Dong ◽  
Ming Jing Li ◽  
Bai Chuan Li
Keyword(s):  
Image Retrieval ◽  
Relevance Feedback ◽  
Image Feature ◽  
Content Based Image Retrieval ◽  
The Novel ◽  
Effective Solution ◽  
Retrieval Accuracy ◽  
Novel Method ◽  
Feedback Method ◽  
High Level

Content-Based Image Retrieval (CBIR) system existed a gap between high-level concepts and low-level features. As an effective solution, the Relevance Feedback (RF) technique has been used on many CBIR systems to improve the retrieval precision. In order to further improve convergence speed and retrieval accuracy, a novel relevance feedback method was proposed. According to feedback from user, image feature was weighted and adjusted in the novel method.

scholarly journals Impulse Signal Detection for Bearing Fault Diagnosis via Residual-Variational Mode Decomposition

2021 ◽  
Vol 11 (7) ◽  
pp. 3053
Author(s):  
Yuhu Liu ◽  
Yi Chai ◽  
Bowen Liu ◽  
Yiming Wang
Keyword(s):  
Iteration Process ◽  
Variational Mode Decomposition ◽  
Optimal Parameters ◽  
Bearing Fault ◽  
Bearing Fault Diagnosis ◽  
Mode Decomposition ◽  
Fault Features ◽  
Novel Method ◽  
Simulation Signal ◽  
Two Stages

A novel method named residual-variational mode decomposition (RVMD) is proposed in this study to extract bearing fault features accurately. RVMD can determine the number of modes and the balance parameter adaptively, and it has two stages. In the first stage, the signal is decomposed into a series of modes until the correlation coefficient between the raw signal and the decomposition results reaches the threshold. A redefined kurtosis, which can resist the interferences from aperiodic impulse efficiency, is applied to rebuild the ensemble kurtosis index. The mode that has the largest rebuild-ensemble kurtosis, and its neighbors, are kept. By putting the residual signal into the second stage, an iteration process is applied to determine the optimal parameters for variational mode decomposition (VMD). VMD is re-run with the optimal parameters, and the sub-mode filtered with the larger rebuild-ensemble kurtosis is examined by the envelope analysis technology to observe the fault feature. The effectiveness of RVMD is verified by the simulation signal and three experiment signals. Its superiority is shown by comparing it with some existing methods.

scholarly journals Time Domain Strain/Stress Reconstruction Based on Empirical Mode Decomposition: Numerical Study and Experimental Validation

2016 ◽  
Author(s):  
Jingjing He ◽  
Yibin Zhou ◽  
Xuefei Guan ◽  
Wei Zhang ◽  
Wei Fang Zhang ◽  
...  
Keyword(s):  
Empirical Mode Decomposition ◽  
Stress Responses ◽  
Numerical Study ◽  
Reconstruction Method ◽  
Fiber Sensors ◽  
Mode Decomposition ◽  
Structural Responses ◽  
Novel Method ◽  
Strain Stress ◽  
Increasing Demand

Structural health monitoring has been studied by a number of researchers as well as various industries to keep up with the increasing demand for preventive maintenance routines. This work presents a novel method for reconstruct prompt, informed strain/stress responses at the hot spots of the structures based on strain measurements at remote locations. The structural responses measured from usage monitoring system at available locations are decomposed into modal responses using empirical mode decomposition. Transformation equations based on finite element modeling are derived to extrapolate the modal responses from the measured locations to critical locations where direct sensor measurements are not available. Then, two numerical examples (a two-span beam and a 19956-degree of freedom simplified airfoil) are used to demonstrate the overall reconstruction method. Finally, the present work investigates the effectiveness and accuracy of the method through a set of experiments conducted on an aluminium alloy cantilever beam commonly used in air vehicle and spacecraft. The experiments collect the vibration strain signals of the beam via optical fiber sensors. Reconstruction results are compared with theoretical solutions and a detailed error analysis is also provided.

EEMD-ApEn Applied in Power Quality Detection and Classification

2013 ◽  
Vol 423-426 ◽  
pp. 2443-2447 ◽  
Author(s):  
Yu Xiang Su ◽  
Guo Ping Liu ◽  
Xiao Qun Shen
Keyword(s):  
Power Quality ◽  
Approximate Entropy ◽  
Svm Classifier ◽  
The Novel ◽  
Intrinsic Mode Functions ◽  
Feature Vectors ◽  
Quality Detection ◽  
Transient Oscillation ◽  
Mode Decomposition ◽  
Novel Method

Ensemble Empirical Mode DecompositionApproximate Entropy (EEMD-ApEn) is proposed in this paper, which is mainly analyzed the transient pulse and transient oscillation. In order to overcome the modal mixing problems by empirical mode decomposition (EMD), ensemble EMD (EEMD) is used to obtain intrinsic mode functions (IMFs). Then effective IMFs with physical meaning are reconstructed. Finally, the approximate entropy of IMFs and original signal are calculated which are used to be the input feature vectors of the SVM classifier. The stimulant results show that EEMD-ApEn has better performance in detection and classification of transient pulse, transient oscillation, their noisy signal and the composite disturbance signals. The novel method has many advantages, such as simple, strong anti-noise, required fewer features and so on. Therefore the EEMD-ApEn is an effective method for power quality detection and feature vectors extraction.

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