Structural damage identification using an iterative two-stage method combining a modal energy based index with the BAS algorithm

Shuqing Wang,Yufeng Jiang,Mingqiang Xu,Yingchao Li,Zhixiong Li 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.36 No.1

The purpose of this study is to develop an effective iterative two-stage method (ITSM) for structural damage identification of offshore platform structures. In each iteration, a new damage index, Modal Energy-Based Damage Index (MEBI), is proposed to help effectively locate the potential damage elements in the first stage. Then, in the second stage, the beetle antenna search (BAS) algorithm is used to estimate the damage severity of these elements. Compared with the well-known particle swarm optimization (PSO) algorithm and genetic algorithm (GA), this algorithm has lower computational cost. A modal energy based objective function for the optimization process is proposed. Using numerical and experimental data, the efficiency and accuracy of the ITSM are studied. The effects of measurement noise and spatial incompleteness of mode shape are both considered. All the obtained results show that under these influences, the ITSM can accurately identify the true location and severity of damage. The results also show that the objective function based on modal energy is most suitable for the ITSM compared with that based on flexibility and weighted natural frequency-mode shape.

Integrated fault location method for distribution networks based on IACO‑PS

Shuqing Zhang,Xiaowen Zhang,Anqi Jiang,Liguo Zhang,Mingliang Li 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.1

This paper develops a new hybrid method based on an improved ant colony optimization algorithm that incorporates pattern search (IACO-PS) for determining the location of faults in a distribution network. The performance of the conventional ant colony optimization (ACO) algorithm is improved using the opposite-based learning strategy to generate the initial population and adding a weight coefficient into the pheromone update mechanism to dynamically adjust the pheromone volatilization factor. The hybrid IACO-PS algorithm combines the individual strengths of ACO and PS. In addition, the fitness function is constructed by counting the false and missing fault information into the fault variable. In optimizing benchmark function experiments, the proposed hybrid IACO-PS presents a superior performance when compared to other improved versions of ACO. The effectiveness of the proposed approach is corroborated by tests performed on an IEEE 134-bus network. Simulation results show that the proposed hybrid IACO-PS method can determine the location of a fault even in the presence of fault distortion. In addition, it is immune to noise and data loss errors. Finally, the method proposed in this paper significantly outperforms other published fault location methods, and it can accurately locate faults and identify the type of distortion.

Dynamic analysis of three adjacent bodies in twin-barge floatover installation

Wang, Shuqing,Li, Xiliang Techno-Press 2014 Ocean systems engineering Vol.4 No.1

Floatover technology has been widely used in offshore installation, which has many substantial advantages compared with the traditional derrick barge. During the topside offloading of a twin-barge floatover installation, the transport barge is side by side moored between two floatover barges. In this paper, the twin-barge model with the connecting hawsers and pneumatic fenders is established. Coupled dynamic analysis is carried out to investigate the motions of the barges under wind, wave and current environments. Particular attention is paid to the effects on system responses with different frictional performance of fender, axial stiffness of the hawsers and environmental conditions. The research results can be used for optimizing the parameters of the system and reducing the risk of topside offloading.

Application of Neural Network Based on Real-Time Recursive Learning and Kalman Filter in Flight Data Identification

Yao Li,Haiqing Si,Yitong Zong,Xiaojun Wu,Peihong Zhang,Hongyin Jia,Shuqing Xu,Dayong Tang 한국항공우주학회 2021 International Journal of Aeronautical and Space Sc Vol.22 No.6

The process of obtaining flight data from flight test is complex and costly, which makes it difficult to identify aerodynamic parameters. Therefore, Cessna172 flight simulator was used for flight data extraction, which ensures the convenience, efficiency and economy of the test. To obtain aerodynamic model, based on the idea of machine learning, a recurrent neural network was used to process multi-dimensional nonlinear flight test data, and a real-time recursive learning algorithm was proved to be suitable for dynamic training. Due to the large amount of state parameter data generated by aircraft, which will cause the real-time recursive learning algorithm to train slowly. So, Kalman filter algorithm was introduced for system identification. Considering validity analysis, the comparative verification method was used to verify system identification model. Results show that the aircraft aerodynamic and aerodynamic moment models have good applicability and can be popularized and applied.

Behavior of three-tube buckling-restrained brace with circumference pre-stress in core tube

Yang Li,Haiyan Qu,Shaowen Xiao,Peijun Wang,Yang You,Shuqing Hu 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.30 No.2

The behavior of a new Three-Tube Buckling-Restrained Brace (TTBRB) with circumference pre-stress (σθ,pre) in core tube are investigated through a verified finite element model. The TTBRB is composed of one core tube and two restraining tubes. The core tube is in the middle to provide the axial stiffness, to carry the axial load and to dissipate the earthquake energy. The two restraining tubes are at inside and outside of the core tube, respectively, to restrain the global and local buckling of the core tube. Based on the yield criteria of fringe fiber, a design method for restraining tubes is proposed. The applicability of the proposed design equations are verified by TTBRBs with different radius-thickness ratios, with different gap widths between core tube and restraining tubs, and with different levels of σθ,pre. The outer and inner tubes will restrain the deformation of the core tube in radius direction, which causes circumference stress (σθ) in the core tube. Together with the σθ,pre in the core tube that is applied through interference fit of the three tubes, the yield strength of the core tube in the axial direction is improved from 160 MPa to 235 MPa. Effects of gap width between the core tube and restraining tubes, and σθ,pre on hysteretic behavior of TTBRBs are presented. Analysis results showed that the gap width and the σθ,pre can significantly affect the hysteretic behavior of a TTBRB.

A numerical study on the transient impulsive pressure of a water jet impacting nonplanar solid surfaces

Fei Huang,Shuqing Li,Yanlin Zhao,Yong Liu 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.9

This paper presents an in-depth investigation into the transient impulsive pressure of an arc-curved water jet impacting a solid surface. The emphasis of this study is on the variations of the surface shape, which are classified into four types: The flat surface, the concave surface, the convex surface and the inclined surface. The numerical tool of arbitrary Lagrangian-Eulerian formulations is used to model the arc-curved jet impacting these different solid surface types. Elaborately designed experiments were conducted to test the impulsive pressure profile; the experimental results are found to be in approximate agreement with the numerical results. The impulsive pressure profiles of water jet impacting the flat and inclined solid surface are observed to exhibit two quintessential stages, in line with the traditional pressure profile; however, a double/multiple-peaked pressure structure is observed for the cases of the water jet impacting the concave and convex solid surfaces. Additionally, the value of the peak pressure is found to be a quadratic representation with the jet velocity, and the duration of the peak pressure is found to be an exponential representation with the jet velocity. The compression degrees of the liquid jet impacting the different surfaces are validated to be the root cause for the discrepancy of the impulsive pressure.

A novel multistage approach for structural model updating based on sensitivity ranking

Yufeng Jiang,Yingchao Li,Shuqing Wang,Mingqiang Xu 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.25 No.6

A novel multistage approach is developed for structural model updating based on sensitivity ranking of the selected updating parameters. Modal energy-based sensitivities are formulated, and maximum-normalized indices are designed for sensitivity ranking. Based on the ranking strategy, a multistage approach is proposed, where these parameters to be corrected with similar sensitivity levels are updated simultaneously at the same stage, and the complete procedure continues sequentially at several stages, from large to small, according to the predefined levels of the updating parameters. At every single stage, a previously developed cross model cross mode (CMCM) method is used for structural model updating. The effectiveness and robustness of the multistage approach are investigated by implementing it on an offshore structure, and the performances are compared with nonmultistage approach using numerical and experimental vibration information. These results demonstrate that the multistage approach is more effective for structural model updating of offshore platform structures even with limited information and measured noise. These findings serve as a preliminary strategy for structural model updating of an offshore platform in service.

CCM.G-K2 key comparison

Francis, Olivier,Baumann, Henri,Ullrich, Christian,Castelein, Stefaan,Van Camp, Michel,Andrade de Sousa, Mauro,Lima Melhorato, Rodrigo,Li, Chunjian,Xu, Jinyi,Su, Duowu,Wu, Shuqing,Hu, Hua,Wu, Kang,Li, BUREAU INTERNATIONAL DES POIDS ET MESURES 2015 METROLOGIA -BERLIN- Vol.52 No.1