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

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arXiv

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

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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General Effect of Internal Span of U-shaped Stud on UHPC-NC Interfacial Failure Load 9th

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General Effect of Internal Span of U-shaped Stud on UHPC-NC ...

9th International Conference on Civil Engineering and Materials Science, ICCEMS 2024

作者： Wu, Zhongchong Liu, Dayong Wu, Xiangguo Zhang, Yun Wu, Chengen Lin, Lanri Zhong, Jing Zhu, Hongbing Zhou, Ruiquan You, Xianhui CGN New Energy Holdings Co. Ltd. Beijing China Fujian Provincial Key Laboratory of Multi-Disasters Prevention and Mitigation in Civil Engineering College of Civil Engineering Fuzhou University Fuzhou350108 China 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 the Industry and Information Technology Harbin Institute of Technology Harbin150090 China College of Civil Engineering Fuzhou University Fuzhou350108 China Sinovel Wind Group Co. Ltd Beijing100086 China Shanghai Electric Wind Power Group Co. Ltd Shanghai200233 China Wind Power Hybrid Tower Co. Ltd Fulaerji161042 China China Power Engineering Consulting Group CO. LTD Beijing100120 China

ISBN: (纸本)9789819615735

To improve the durability design level of the foundation bearing platform for offshore fixed wind power, Ultra-high performance concrete (UHPC) is used as a non-demolding membrane shell system, and a high-performance composite concrete bearing platform structure is formed with on-site pouring of core concrete. The interface performance between the prefabricated UHPC membrane shell and the post cast core concrete has become an important aspect of the overall integrity of the high-performance composite concrete bearing platform. The use of interface shear key design to improve interface integrity is necessary for improving the overall stress of the bearing platform structure. The objective of this study is to assess the effect of the internal span on the shear behavior at the junction of UHPC and normal concrete (NC). © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.

关键词： Ultra-high performance concrete

Simulation of thermal radiation effects on the thermal properties of parietodynamic walls using an innovative model

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Low-carbon Materials and Green Construction 2024年第1期2卷 279-296页

作者： Xianzhang Dong Baochen Lin Huigang Xiao Min Liu School of Civil Engineering Harbin Institute of Technology73 Huanghe RoadHarbinHeilongjiang 150090People’s Republic of China Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of TechnologyHarbin 150090People’s Republic of China Heilongjiang Heijianyi Construction Engineering Co. Ltd.Harbin 150040People’s Republic of China

The parietodynamic wall, a type of dynamic insulation, has been recognized as an effective technology to reduce energy loss in buildings by recovering heat energy through forced convection. However, current research on the thermal performance of parietodynamic walls has overlooked the influence of thermal radiation, a crucial factor in energy transfer within the air layers of these walls. To bridge this gap, an innovative simulation model was developed and experimentally validated. Employing simulation methods, we investigated the impact of thermal radiation on the thermal behavior of parietodynamic walls under various influencing factors. Our findings reveal that thermal radiation markedly increases heat loss. Specifically, at an emissivity of 1, thermal radiation contributes up to 80.7% to the heat transfer coefficient (HTC) of the parietodynamic wall. Moreover, for a parietodynamic wall without insulation, the HTC of this wall will increase by more than 268% when thermal radiation is taken into account, compared to when it is not considered. These revelations deepen our comprehension of the role of thermal radiation in parietodynamic walls and offer valuable guidance for the development of more energy-efficient buildings.

关键词： Parietodynamic wall Thermal performance Thermal radiation Air layer Heat recovery Simulation

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

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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

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

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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

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

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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

Effect of Thermal Radiation on the Thermal Properties of Parietodynamic Walls

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SSRN 2023年

作者： Dong, Xianzhang Lin, Baochen Xiao, Huigang Liu, Min 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 Heilongjiang Heijianyi Construction Engineering Co. Ltd 150040 China

The parietodynamic wall, a type of dynamic insulation, has been identified as an effective technology to reduce energy loss in buildings by recovering heat and cold energy through forced convection. However, current research on the thermal performance of parietodynamic walls has neglected the influence of thermal radiation, a crucial factor in energy transfer within the air layer of the wall. To address this gap, a numerical model that couples thermal radiation, heat transfer in solids and fluids, and turbulence is established to evaluate the effect of thermal radiation. Our results indicate that emissivity, the thermal resistance of the insulation layer, and air layer thickness significantly affect the proportion of thermal radiation in heat transfer. Specifically, when the emissivity is 1, the contribution ratio of thermal radiation to the heat transfer coefficient (HTC) of the parietodynamic wall is by up to 80.7%. Moreover, low thermal resistance of the insulation layer can increase the HTC by 268%-630% through thermal radiation gain. These findings improve our understanding of the effect of thermal radiation in parietodynamic walls, which would aid in the development of more energy-efficient buildings. © 2023, The Authors. All rights reserved.

关键词： Heat radiation

A Study On Properties of Pu-Cement Composites Repairing Material for Seepage control and Plugging

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SSRN 2023年

作者： Li, Cong Bai, Jinrong Jiang, Ying Xiao, Huigang Wang, Wei Xu, Fan School of Civil Engineering Harbin Institution 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

Composite grouting materials are increasingly becoming the focus of seepage control and plugging research, and in order to improve its mechanical properties and delayed hydration repairment effect without compromising its workability, PU-cement composites grouting materials, in which cement are not the main component, still, requiring a finer particle size and good shape. In this study, the ball-milled cement are prepared to combine with WPU and OPU, creating a new PU-cement composites grouting *** particle size distribution, early strength, and micro-structure of ball-milled cement were analyzed, then the best preparation process was determined as 120min ball-milling time and 0.03% grinding aid doping. The viscosity, swelling rate, bond strength, FTIR, XRD and micro-structure of the composites with different ratios of polymer/cement and OPU/WPU were then examined, especially, based on moisture distribution, a new method to evaluate the impermeability of repair materials is proposed, and the function of ball-milled cement in composites and the interaction mechanism between ball-milled cement and PU were discussed. The results showed that the best performance was achieved with the P/C ratio of 3:1 and 4:1, and the OPU/WPU ratio of 2:1 or 3:1, indicating that PU-cement grouting material can be an ideal choice for underground structure seepage control and plugging. © 2023, The Authors. All rights reserved.

关键词： Cements