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Detecting Multiple Change Points in Distributional Sequences Derived from Structural Health Monitoring Data: An Application to Bridge Damage Detection

arXiv

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arXiv 2023年

作者： Lei, Xinyi Chen, Zhicheng Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China

Detecting damage in critical structures using monitored data is a fundamental task of structural health monitoring, which is extremely important for maintaining structures' safety and life-cycle management. Based on statistical pattern recognition paradigm, damage detection can be conducted by assessing changes in the distribution of properly extracted damage-sensitive features (DSFs). This can be naturally formulated as a distributional change-point detection problem. A good change-point detector for damage detection should be scalable to large DSF datasets, applicable to different types of changes, and capable of controlling for false-positive indications. This study proposes a new distributional change-point detection method for damage detection to address these challenges. We embed the elements of a DSF distributional sequence into the Wasserstein space and construct a moving sum (MOSUM) multiple changepoint detector based on Fréchet statistics and establish theoretical properties. Extensive simulation studies demonstrate the superiority of our proposed approach against other competitors to address the aforementioned practical requirements. We apply our method to the cable-tension measurements monitored from a long-span cable-stayed bridge for cable damage detection. We conduct a comprehensive change-point analysis for the extracted DSF data, and reveal interesting patterns from the detected changes, which provides valuable insights into cable system damage. Copyright © 2023, The Authors. All rights reserved.

关键词： Damage detection

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A robust deep learning-based damage identification approach for SHM considering missing data

arXiv

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arXiv 2023年

作者： Deng, Fan Tao, Xiaoming Wei, Pengxiang Wei, Shiyin Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China

Data-driven method for Structural Health Monitoring (SHM), that mine the hidden structural performance from the correlations among monitored time series data, has received widely concerns recently. However, missing data significantly impacts the conduction of this method. Missing data is a frequently encountered issue in time series data in SHM and many other real-world applications, that harms to the standardized data mining and downstream tasks, such as condition assessment. Imputation approaches based on spatiotemporal relations among monitoring data are developed to handle this issue, however, no additional information is added during imputation. This paper thus develops a robust method for damage identification that considers the missing data occasions, based on long-short term memory (LSTM) model and dropout mechanism in the autoencoder (AE) framework. Inputs channels are randomly dropped to simulate the missing data in training, and reconstruction errors are used as the loss function and the damage indicator. Quasi-static response (cable tension) of a cable-stayed bridge released in 1st IPC-SHM is employed to verify this proposed method, and results show that the missing data imputation and damage identification can be implemented together in a unified way. © 2023, CC BY.

关键词： Structural health monitoring

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A Silicon Monoxide Lithium-Ion Battery Anode with Ultrahigh Areal Capacity

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Nano-Micro Letters 2022年第3期14卷 229-243页

作者： Jiang Zhong Tao Wang Lei Wang Lele Peng Shubin Fu Meng Zhang Jinhui Cao Xiang Xu Junfei Liang Huilong Fei Xidong Duan Bingan Lu Yiliu Wang Jian Zhu Xiangfeng Duan State Key Laboratory for Chemo/Biosensing and Chemometrics College of Chemistry and Chemical EngineeringSchool of Physics and ElectronicsHunan Key Laboratory of Two‑Dimensional MaterialsEngineering Research Center of Advanced Catalysis of the Ministry of EducationHunan UniversityChangsha 410082People’s Republic of China International Graduate School at Shenzhen Tsinghua UniversityShenzhen 518057People’s Republic of China Key Laboratory of Structures Dynamic Behavior and Control of the Ministry of Education Key Laboratory of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information TechnologyHarbin Institute of TechnologyHarbin 150090People’s Republic of China School of Energy and Power Engineering North University of ChinaTaiyuan 030051People’s Republic of China Department of Chemistry and Biochemistry University of CaliforniaLos AngelesCA 90095USA

Silicon monoxide(SiO)is an attractive anode material for next-generation lithium-ion batteries for its ultra-high theoretical capacity of 2680 mAh g−*** studies to date have been limited to electrodes with a rela-tively low mass loading(<3.5 mg cm^(−2)),which has seriously restricted the areal capacity and its potential in practical *** areal capacity with such high-capacity materials is critical for capitalizing their potential in practi-cal ***,we report a monolithic three-dimensional(3D)large-sheet holey gra-phene framework/SiO(LHGF/SiO)composite for high-mass-loading *** specifically using large-sheet holey graphene building blocks,we construct LHGF with super-elasticity and exceptional mechanical robustness,which is essential for accommodating the large volume change of SiO and ensuring the structure integrity even at ultrahigh mass ***,the 3D porous graphene network structure in LHGF ensures excellent electron and ion *** systematically tailoring microstructure design,we show the LHGF/SiO anode with a mass loading of 44 mg cm^(−2)delivers a high areal capacity of 35.4 mAh cm^(−2)at a current of 8.8 mA cm^(−2)and retains a capacity of 10.6 mAh cm^(−2)at 17.6 mA cm^(−2),greatly exceeding those of the state-of-the-art commercial or research ***,we show an LHGF/SiO anode with an ultra-high mass loading of 94 mg cm^(−2)delivers an unprecedented areal capacity up to 140.8 mAh cm^(−2).The achievement of such high areal capacities marks a critical step toward realizing the full potential of high-capacity alloy-type electrode materials in practical lithium-ion batteries.

关键词： Silicon monoxide Large-sheet holey graphene Lithium-ion batteries High mass loading Ultra-high areal capacity

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The Micro–Mechanical Mechanism of Multiple Cracking behavior Induced by Interface Strengthening for Ultra–High–Performance Concrete

SSRN

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SSRN 2023年

作者： Du, Junjie Xiao, Huigang Zhang, Fengling Liu, Min Key Lab of Structures Dynamic Behavior and Control The Ministry of Education Harbin Institute of Technology Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China School of Civil Engineering Shandong University 17923 Jingshi Road Jinan250061 China

The multiple cracking behavior of ultra–high–performance concrete （UHPC） is strongly dependent on the bridging of cracks by fibers and the spatial strength distribution of matrix. A good match between fiber bridging properties and matrix tensile strength can significantly improve the utilization of fibers and matrix. In this study, a micromechanics based theoretical model is proposed, which can match the matrix tensile strength with the fiber–matrix interface bonding strength. The spatial strength distribution of the matrix and the stress transfer between the fiber and the matrix is considered in the model. Bridge stresses, additional stresses, stress transfer distances, and pulley forces at the crack face for various crack openings are derived. Dense multiple cracks were observed in the UHPC tensile samples at a common condition ( ) designing based on the calculation results. The applicability of the model is validated by comparing the simulation results and the experimental results in previous investigations at the same paraments ( ). With the proposed model, the mechanism of fiber–matrix interface enhancement contributing to the multiple cracking behavior can be understood. The results of this study could provide fundamental insights for the design of UHPC for various ductility and strength requirements. © 2023, The Authors. All rights reserved.

关键词： Fibers

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An experimental study on early age compression and shear strength properties of mixed clay soil

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Arabian Journal of Geosciences 2024年第2期17卷 1-14页

作者： Abbas, Azhar Akbar, Muhammad Huali, Pan Zar, Ali Ramzan, Samar Hussain, Zahoor Department of Geotechnical Engineering Tongji University Shanghai China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu China Sir Syed University of Engineering & Technology Karachi Pakistan Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin China Department of Civil Engineering University of Engineering and Technology Lahore Lahore Pakistan Zhengzhou University Zhengzhou China

Clay mixed soil is a combination of clay and soil components that may be used as the core of earth dams and the foundation for building and road construction. Up until now, significant research work has been carried out to design cement-based clay materials; however, only a couple of studies have been reported in the literature on earth-based materials. The methodology portion provides an overview of the different materials, tools, and protocols used during work to develop ways to earth-based materials and study their early age compression strength along with their shear strength. Finally, it summarizes all the results and the outcome of the experimental work done. The probability of producing an object using earth-based material was examined. Improvement in the compressive strength in the early age of strength by adding additives like bentonite and rice husk was assessed in this study. Three clayey soil samples were investigated. The undrained shear strength based on an unconfined compression test (UCT) over those samples was measured by varying the moisture content (MC). After performing all these tests, a relationship was developed between the UCT and vane shear test (VST) undrained shear strengths of the selected soil samples. Clay samples with different mix designs were investigated, and building components were printed out to check the early age shear strength development and printable properties of different mix designs. This study will lay the foundation for further research on different aspects relating to the emerging technology of 3D clay printing in Pakistan.

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Engineering Interfacial Transition Zone with Polymer Nanocomposites: Break the Dilemma between Strength and Damping

SSRN

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SSRN 2023年

作者： Li, Cheng Tang, Zhuo Zhong, Jing School of Civil Engineering Harbin Institute of Technology Harbin150090 China Key Lab of Structures Dynamic Behavior and Control Ministry of Education Harbin Institute of Technology Harbin150090 China Key Lab of Smart Prevention and Mitigating of Industry and Information Technology Harbin Institute of Technology Harbin150090 China

The damping performance of mortar/concrete is typically promoted by randomly hybridizing with an excessive mass of soft polymers at the cost of strength. We propose a strategy to break the typically observed dilemma between strength and damping by coating aggregates with a thin layer of polyacrylic ester/carbon nanotube (PAE/CNT) nanocomposite, which was readily achieved by dip coating. The coated nanocomposite with high modulus is subjected to high stress at ITZ upon external load due to stress concentration, greatly enhancing its energy dissipation capability. The friction at the nano-interface between CNT and polymer matrix further contributes to the much-improved damping, while the coating layer can densify the ITZ thus increases the strength of the concrete. With an optimal coating mass of 5 mg/g, the compressive strength and loss factor at 28 days are increased by 21.7% and 33.3%, respectively. © 2023, The Authors. All rights reserved.

关键词： Carbon nanotubes

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Optimized Repairment Properties Of Wer-Cement Composite Material: An Experimental and Simulation Study

SSRN

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SSRN 2023年

作者： Li, Cong Xiao, Huigang Min, Liu Wang, Wei Xu, Fan School of Civil Engineering Harbin Institute of Technology Heilongjiang China Key Lab of Structures Dynamic Behavior and Control The Ministry of Education Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters The Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China Heilongjiang Construction Group Co. Ltd Heilongjiang China

The demand for high-performance repair materials has significantly increased in modern society after the completion of infrastructure construction. However, current research on epoxy resin cement mortar composite lacks theoretical investigation of the proportion of epoxy resin and hardener to prepare a composite material with optimal performance, as it often relies on empirical and previous studies. To address this issue, this study employed E44 and D230 raw materials and determined through theoretical calculations that the optimal ratio for the composite material is 4:1. The best ratio and content were validated by various testing techniques, such as workability, mechanical properties, self-developed shear bond strength test, and impermeability performance. These analyses showed that the composite material's epoxy resin and hardener ratio should be 4:1, with a content of 30%. Additionally, the microstructure of the composite material was analyzed using various testing techniques, including SEM, SEM-EDS, XRD, FTIR, and MIP, to investigate its influence on the ITZ, composition, and pore structure. Furthermore, molecular dynamics simulation was conducted to analyze the mechanical properties, adsorption energy, MSD, and RDF of C-S-H and epoxy resin molecules (cross-linked structures) composite, explaining the effect of water molecules on the composite material from an atomic scale perspective. By combining experimentation and simulation, this study proposed a computationally based ratio design method, which could provide new ideas for research and development of WER-cement composite while created a simple shear bond strength testing method for repair materials. © 2023, The Authors. All rights reserved.

关键词： Epoxy resins

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Real-Time Seismic Damage Simulation for Urban Building Portfolio Based on Basic Building Information and Machine Learning

SSRN

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SSRN 2023年

作者： Li, Shuang Li, Changqing Huang, Yuwen Zhai, Changhai Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China Beijing Glory PKPM Technology Co. Ltd Beijing100013 China

Timely and accurate simulation of seismic damage of the urban building portfolio is important for pre-earthquake planning and post-earthquake rescue. This study proposes a real-time seismic damage simulation method for the urban building portfolio based on the multiple degree-of-freedom (MDOF) shear model and flexural-shear model established by basic building information and the machine learning. The formulas for predicting periods of six types of structures are proposed and the surrogate model-Ⅰ for predicting the key inter-story hysteretic parameters are established to optimize the MDOF models. The surrogate model-Ⅱ is established to rapidly predict the engineering demand parameters and damage states of structures under earthquakes. In terms of the generalization capability, an incremental learning strategy is advised to guarantee the accuracy of the surrogate model-Ⅱ in predicting the seismic damage of other urban building portfolios. The results in two city-scale cases show that the proposed method can achieve real-time seismic damage simulation of urban building portfolio with acceptable accuracy, and it’s not necessary to retrain or only needs minor additional training on the existing surrogate model when applied to other urban building portfolios. © 2023, The Authors. All rights reserved.

关键词： Machine learning

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考虑非线性相关性影响的结构整体可靠度评估——增强型高阶矩方法

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Acta Mechanica Sinica 2023年第4期39卷 3-13页

作者：宋鹏彦王涛吕大刚 College of Civil Engineering and Architecture Hebei UniversityBaoding071002China School of Transportation Science and Engineering Harbin Institute of TechnologyHarbin150040China Chongqing Research Institute of Harbin Institute of Technology Harbin Institute of TechnologyChongqing401151China Key Lab of Structure Dynamic Behavior and Control of China Ministry of Education Harbin Institute of TechnologyHarbin150090China

考虑随机变量间相关性的复杂工程结构整体可靠性分析仍然是一个挑战,特别是对于非线性相关问题.该文考虑到随机变量之间非线性相关的影响,提出了一种用于结构整体可靠性分析的增强型高阶矩方法.该文首先回顾了传统的Nataf变换,进而通过... 详细信息

考虑随机变量间相关性的复杂工程结构整体可靠性分析仍然是一个挑战,特别是对于非线性相关问题.该文考虑到随机变量之间非线性相关的影响,提出了一种用于结构整体可靠性分析的增强型高阶矩方法.该文首先回顾了传统的Nataf变换,进而通过引入Copula理论提出了广义Nataf变换;其次,采用状态变量描述法统一描述整体可靠性问题对应的功能函数,并发展了基于GL_(2)-偏差点集的状态变量高阶矩估计和灵敏度分析方法;再次,通过改进的最大熵法准确估计了结构整体可靠度;最后,通过两个算例验证了所提方法的准确性和有效性以及考虑随机变量间的非线性相关性对结构整体可靠度影响的必要性.算例结果与蒙特卡洛模拟方法比较表明,随机变量间的非线性相关性对结构的整体可靠度有显著影响,所提方法对结构高阶矩估计和全局可靠度分析具有较高的精度和效率.

关键词：最大熵法非线性相关整体可靠性随机变量状态变量可靠度评估蒙特卡洛模拟方法功能函数

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Influence of Mix Proportioning Parameters and Curing Regimes on the Properties of Ultra-High Strength Alkali-Activated Concrete

SSRN

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SSRN 2023年

作者： He, Haiyu Zhang, Rong Song, Yuhuan Zhi, Xudong Fan, Feng Key Lab of Structures Dynamic Behaviour and Control The Ministry of Education Harbin Institute of Technology Harbin150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters The Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China

This study investigates the influence of mix proportioning parameters and curing regimes on the material properties of alkali-activated binder-based ultra-high strength concrete (AAB-UHSC). The effects of five groups of mix proportioning parameters (i.e., fly ash replacement ratio, silica fume replacement ratio, alkali to binder ratio, water glass modulus, and steel fiber content) and three curing regimes(i.e., ambient curing, standard curing, and hybrid curing) on the workability, compressive strength, flexural strength and microstructure development of AAB-UHSC were systematically evaluated. The results indicated that increasing the steel fiber and silica fume dosage negatively affected the flowability of freshly mixed AAB-UHSC. There existed an optimal alkali-to-binder ratio and water glass modulus in terms of flowability, compressive strength, and flexural strength, but the fly ash replacement ratio had a complex effect on the material performance of the AAB-UHSC. The microstructures of the specimens cured in hybrid curing regimes were denser, and fewer cracks were observed, which resulted in higher strength compared to specimens cured under ambient curing and standard curing conditions. The three types of curing regimes adopted barely alter the phases and molecular bonds of hydration products based on the XRD and FTIR results. In addition, the correlations between the compressive strength of the AAB-UHSC obtained under ambient curing conditions, standard curing conditions, and obtained under hybrid curing and standard curing conditions were analyzed, and the fitted results had higher correlation coefficients (R2). © 2023, The Authors. All rights reserved.

关键词： Compressive strength

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