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A change-point detection method for detecting and locating the abrupt changes in distributions of damage-sensitive features of SHM data, with application to structural condition assessment

arXiv

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arXiv 2021年

作者： Lei, Xinyi Chen, Zhichng Li, Hui Wei, Shiyin Key Lab of Intelligent Disaster Mitigation The Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China 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

Diagnosing the changes of structural behaviors using monitoring data is an important objective of structural health monitoring (SHM). The changes in structural behaviors are usually manifested as the feature changes in monitored structural responses;thus, developing effective methods for automatically detecting such changes is of considerable significance. Existing methods for change detection in SHM are mainly used for scalar or vector data, thus incapable of detecting the changes of the features represented by complex data, e.g., the probability density functions (PDFs). Detecting the abrupt changes occurred in the distributions (represented by PDFs) associated with the damage-sensitive features extracted from SHM data are usually of crucial interest for structural condition assessment;however, the SHM community still lacks effective diagnostic tools for detecting such changes. In this study, a change-point detection method is developed in the functional data-analytic framework for PDF-valued sequence, and it is leveraged to diagnose the distributional information break encountered in structural condition assessment. A major challenge in PDF-valued data modeling or analysis is that the PDFs are special functional data subjecting to nonlinear constraints. To tackle this issue, the PDFs are embedded into the Bayes space, and the associated change-point model is constructed by using the linear structure of the Bayes space;then, a hypothesis testing procedure is presented for distributional change-point detection based on the isomorphic mapping between the Bayes space and a functional linear space. Comprehensive simulation studies are conducted to validate the effectiveness of the proposed method as well as demonstrate its superiority over the competing method. Finally, an application to real SHM data illustrates its practical utility in structural condition assessment. Copyright © 2021, The Authors. All rights reserved.

关键词： Probability density function

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Functional outlier detection for density-valued data with application to robustify distribution to distribution regression

arXiv

引用

arXiv 2021年

作者： Lei, Xinyi Chen, Zhicheng Li, Hui Key Lab of Intelligent Disaster Mitigation 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

Distributional data analysis, concerned with statistical analysis and modeling for data objects consisting of random probability density functions (PDFs) in the framework of functional data analysis (FDA), has received considerable interest in recent years. However, many important aspects remain unexplored, such as outlier detection and robustness. Existing functional outlier detection methods are mainly used for ordinary functional data and usually perform poorly when applied to PDFs. To fill this gap, this study focuses on PDF-valued outlier detection, as well as its application in robust distributional regression. Similar to ordinary functional data, detecting the shape outlier masked by the "curve net’’ formed by the bulk of the PDFs is the major challenge in PDF-outlier detection. To this end, we propose a tree-structured transformation system for feature extraction as well as converting the shape outliers to easily detectable magnitude outliers, relevant outlier detectors are designed for the specific transformed data. A multiple detection strategy is also proposed to account for detection uncertainties and to combine different detectors to form a more reliable detection tool. Moreover, we propose a distributional-regression-based approach for detecting the abnormal associations of PDF-valued two-tuples. As a specific application, the proposed outlier detection methods are applied to robustify a distribution-to-distribution regression method, and we develop a robust estimator for the regression operator by downweighting the detected outliers. The proposed methods are validated and evaluated by extensive simulation studies or real data applications. Relevant comparative studies demonstrate the superiority of the developed outlier detection method with other competitors in distributional outlier detection. © 2021, CC BY.

关键词： Statistics

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CFD investigations into snow loads on tandem-arranged gabled-roofed buildings under mutual interferences

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Cold Regions Science and Technology 2025年 238卷

作者： Zhang, Guolong Zhang, Qingwen Mo, Huamei Guo, Dong Zhi, Xudong Wu, Jinzhi Fan, Feng Key Laboratory of Structures Dynamic Behavior and Control of China Ministry of Education Harbin Institute of Technology Harbin150090 China Key Laboratory of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China Company Limited Macau999078 China Faculty of Architecture Civil and Transportation Engineering Beijing University of Technology Beijing100124 China Key Laboratory of Urban Security and Disaster Engineering Ministry of Education Beijing University of Technology Beijing100124 China

Gable-roofed buildings arranged in tandem layouts are prevalent in various industrial factories and warehouses. However, during extreme blizzards, these snow-sensitive roof structures frequently sustain significant damages due to mutual interferences between adjacent buildings. Regrettably, the snow load calculation methods provided by various national load codes primarily depend on the studies of snowdrifts on multiple flat roofs in built-up environments, overlooking the impact of other roof shapes on the interference effects. Therefore, this study delves into the snow loads on tandem-arranged gable-roofed buildings with diverse layouts under mutual interferences. Initially, a wind tunnel test of snowdrifts on a gable roof was carried out to validate the numerical method adopted in this study. Subsequently, a series of pre-simulations were performed to identify the key parameters essential for analyzing the interference effects. On the basis, an extensive study was carried out to investigate the interference mechanisms and snowdrift characteristics on two tandem-arranged gable roofs with different layouts. Overall, the interference effect manifests solely as the redistribution of snow on downstream gable roofs, categorizable into the sheltering effect in the downwind direction and the disturbance effect in the crosswind direction. The disturbed snow load on the downstream gable roof exhibits an overall uniform distribution pattern controlled by the sheltering effect, but locally shows erosion due to the disturbance effect. Across various building layouts, the snow loads on disturbed gable roofs display a strong linear trend with the spacing. Consequently, a calculation method for snow loads on disturbed gable roofs was finally proposed, comprehensively considering the interference effects of height differences and spacings. © 2025

关键词： Tall buildings

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Sustainable synthesis of hydrophobic waste glass powder for enhanced water and frost resistance in mortar

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Construction and Building Materials 2025年 487卷

作者： Juncheng Wen Yan Wan Yingzi Yang School of Civil Engineering Harbin Institute of Technology Harbin 150090 China Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin 150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin 150090 China

Most durability issues in cement-based materials stem from water intrusion, which can be mitigated by hydrophobic materials with excellent waterproofing properties. This study proposes a green wet chemical method using stearic acid (SA) and waste glass powder (WGP) to synthesize hydrophobic WGP (HWGP). The effect of SA dosage on the water contact angle of HWGP was investigated, and the optimal SA dosage for preparing HWGP was determined through TG analysis. XRD, FTIR, XPS, and TEM tests revealed the synthesis mechanism of HWGP. The effects of HWGP on mortar's mechanical properties, water and frost resistance were also studied, and the optimal dosage of HWGP for preparing hydrophobic mortar was determined. The results show that 8 % SA is optimal for preparing HWGP, and its water contact angle is 132.2°. The synthesis occurs through reactions between SA and Na + , Ca 2+ , and Si-OH groups, with the long carbon chains of SA grafted onto WGP, forming a hydrophobic layer about 4 nm thick. As HWGP content increases, compressive strength initially increases and then decreases, while water and frost resistance improve significantly. The optimal dosage for preparing hydrophobic mortar is 15 % HWGP, where compressive strength decreases by only 6.9 %, flexural strength increases by 12.5 %, and water contact angle increases by 91.2°. Additionally, initial and secondary water absorption rates decrease by 79.4 % and 92.2 %, respectively, total water absorption amount over 8d decreases by 64.9 %, and frost resistance improves by 70.9 %.

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Essential Stressing State Features of Laterally Loaded Masonry Wall Panels Revealed from Experimental Displacements

Research Square

引用

Research Square 2021年

作者： Liu, Bai Li, Rui Zhang, Yu Zhou, Guangchun Key Lab of Structures Dynamic Behavior and Control of China Ministry of Education Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology School of Civil Engineering Harbin Institute of Technology Harbin150090 China Urban and Engineering Disaster Prevention Laboratory Institute of Engineering Mechanics China Earthquake Administration Harbin150086 China

This study reveals the essential and general working features of laterally loaded masonry (LLM) wall panels from their experimental displacements by applying structural stressing state theory. Firstly, the generalized work of force is proposed to express the stressing state mode and its characteristic parameter. Then, the Mann-Kendall criterion is applied to detect the mutation point in the curve of the characteristic parameter with the load increase. Correspondingly, it is verified that the evolution of the stressing state mode also embodies the mutation feature. The stressing state mutation feature is inherent and common as the embodiment of the natural law from quantitative change to qualitative change of a system. The stressing state mutation feature reveals the starting point of structural failure process, which could update the existing definition of structural failure load. Further, the elastoplastic branch (EPB) point is revealed referring to the updated failure load, which might be directly taken as the design load with the rational margin of safety. In a sense, this paper presents a new way to address the classic issue of structural load-bearing capacity uncertainty and to update the existing design codes of LLM wall panels. © 2021, CC BY.

关键词： Fracture mechanics

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Mechanical properties of an innovative variable stiffness bonded-type anchorage for CFRP cables

Transactions of Materials Research

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Transactions of Materials Research 2025年第2期1卷

作者： Yanzhao Niu Makeev Aleksander Chen Wang Rui Guo Guijun Xian Key Lab of Structures Dynamic Behavior and Control (Ministry of Education) Harbin Institute of Technology Harbin 150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin 150090 China School of Civil Engineering Harbin Institute of Technology Harbin 150090 China

To address the challenges of anchoring Carbon Fiber Reinforced Polymer (CFRP) cables, this paper presents an innovative variable stiffness bonded-type anchorage, which builds upon traditional anchorage designs and incorporates high-temperature resistant bonding media with variable stiffness, along with bent CFRP cables. To evaluate the anchoring performance of this anchorage, mechanical tests were conducted and compared with traditional bond-type anchorage systems. The results show that when the bending angle of CFRP bars exceeds 4°, the tensile strength will be less than 95 % of ultimate strength. As the amount of additive increases, both the tensile strength and elastic modulus of the high-temperature resistant bonding medium gradually improve. The mechanical properties of the high-temperature resistant bonding medium are similar to those of traditional bonding media, but its glass transition temperature ( T g ) is significantly higher than that of traditional bonding media. Additionally, when the bonding layer thickness exceeds 2 mm, it has no effect on the bonding performance. The average bonding stress gradually decreases as the anchorage length increases and the internal cone angle decreases. Furthermore, the Ф4-7 and Ф4-19 CFRP cables anchored by VB anchorage demonstrate ideal brittle failure modes, with anchorage efficiencies exceeding 95 %, and the average slip amounts are 2.78 mm and 5.44 mm, respectively, and the anchorage demonstrates good stability. In contrast, EP anchorage shows less desirable failure modes, with most anchorage efficiencies falling below 95 %. The average slip amounts are 3.22 mm and 7.62 mm, but the results display greater variability.

关键词： CFRP cable Variable stiffness bonding-type anchorage Tensile test High-temperature resin Anchoring performance

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An engineering-oriented multi-fidelity surrogate modeling approach using multisource data aggregation in data-scarce environments

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Journal of Building Engineering 2025年 108卷

作者： Wang, Zhaoyong Cao, Zhengfeng Mulyanto, Joshua Adriel Wu, Yue Zheng, Chaorong School of Civil Engineering Harbin Institute of Technology Harbin150090 China China Construction Machinery Co. LTD Hebei Langfang065000 China Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin150090 China

The multi-fidelity surrogate (MFS) model has become an emerging hotspot in engineering prediction and optimization. However, this model typically relies on abundant low-fidelity data (LF data) and a limited amount of high-fidelity data (HF data). In practical engineering, data-scarce environments make it difficult to obtain sufficient LF data, leading to a significant decline in MFS model performance. To address this issue, we propose a multi-fidelity surrogate model based on multi-source data aggregation (MDA-MFS), which effectively balances predictive accuracy and modeling cost. Firstly, we utilize a combination of LF data and HF data to construct a data augmentation strategy, generating medium-fidelity data (CF data), which increases the data diversity and fidelity categories without increasing the sample size. Secondly, we build the MDA-MFS model that integrates LF, CF, and HF data, achieving a balance between modeling efficiency and cost through innovative MFS modeling strategies. We validate the practicality of the MDA-MFS model in the engineering application of wind pressure prediction. Finally, through testing on high-dimensional functions (dimensions of 10, 30, and 100), we demonstrate that the MDA-MFS model has good generalizability and scalability. Our findings are encouraging in that the MDA-MFS model demonstrates excellent prediction accuracy and robust generalization performance. Compared with the MFS model, the MDA-MFS model significantly reduces modeling costs while markedly improving modeling efficiency. More importantly, in light of the growing desire for efficient solutions to prediction or optimization problems in data-scarce environments, our results hold broader significance. © 2025 Elsevier Ltd

关键词： Work simplification

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A mechanism-data dual-driven approach for predicting profile changes in rails

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Wear 2025年 578-579卷

作者： Yadi Yang Jianxi Wang Yang Li Wenjie An Jiasheng Cai Key Laboratory of Roads and Railway Engineering Safety Control Ministry of Education Shijiazhuang Tiedao University Shijiazhuang 050043 PR China State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang 050043 PR China

Accurate prediction of rail profile changes is crucial for scientifically formulating rail wear mitigation strategies, maintaining track reliability, and ensuring economic benefit. However, traditional models based on rail wear mechanisms are limited in prediction accuracy due to their idealized assumptions. While possessing strong nonlinear fitting capabilities, data-driven models often lack interpretability and rely on large amounts of high-quality training data. To address these challenges, this paper proposes a novel method that integrates the advantages of both approaches to predict rail profile changes. Utilizing a prototype network, a rail profile change model is pre-trained with simulation data and then fine-tuned using measurement rail profile data through transfer learning. K-fold cross-validation and noise augmentation are employed to enhance the model's prediction accuracy and robustness. The study results indicate that for tracks with curve radii between 400 and 600 m, the precision of 10 random prediction trials exceeds 90 %, with standard deviations of Mean Squared Error ( MSE ), Root Mean Squared Error ( RMSE ), Mean Absolute Error ( MAE ), and Mean Absolute Percentage Error ( MAPE ) being 0.03397 mm 2 , 0.04261 mm, 0.0204 mm, and 0.175 %, respectively, demonstrating excellent predictive accuracy and stability. Compared to models using only measurement data, this method achieves reductions in average MSE , RMSE , MAE , and MAPE by 30.60 %, 11.76 %, 12.94 %, and 10.45 %, respectively.

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Experimental Study on Shear Strength Characteristics of Frozen Soil - Cast-in-Situ Concrete Interface

SSRN

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SSRN 2022年

作者： Sun, Tiecheng Dong, Chuangqi Zhang, Jiao Zong, Zihang Wu, Kai State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures Shijiazhuang Tiedao University Shijiazhuang050043 China Key Laboratory of Roads and Railway Engineering Safety Control Ministry of Education Shijiazhuang050043 China Hebei Province Technology and Innovation Center on Intelligent Construction of Infrastructure Shijiazhuang050043 China School of Civil Engineering Shijiazhuang Tiedao University Shijiazhuang050043 China

The roughness of contact surface is closely related to the friction coefficient and shear strength characteristics of pile-soil interface. At present, there is no recognized and unified quantitative characterization method of contact surface roughness. In this paper, the roughness formula is corrected in combination with the proposed form factor, and the low temperature direct shear test of the frozen soil-cast-in-situ concrete interface is carried out. The influence of several test factors, such as contact surface roughness, normal pressure and moisture content of soil sample, on frozen shear strength of frozen soil-cast-in-situ concrete contact surface is analyzed. The test results show that: (a) The frozen shear strength at the contact surface is mainly determined by the cementation of ice cementation force, cohesion and the bite force between frozen soil and concrete. The roughness corrected by the form coefficient can accurately characterize the contribution of bite force to the frozen shear strength of the contact surface. (b) The primary and secondary order of the influence of test control factors on the frozen shear strength of contact surface is normal pressure > moisture content of soil sample > test temperature > roughness > dry density. The normal pressure and moisture content have a strong and significant influence on the test results, the influence of dry density is not significant, and the influence of test temperature and roughness is in the middle. (c) The frozen shear strength of the contact surface increases with the increase of roughness, but the increase of normal pressure can weaken the effect of roughness on the enhancement of shear strength. © 2022, The Authors. All rights reserved.

关键词： Temperature

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Numerical analysis and design on the embedded column base for circular CFST under seismic loads

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Engineering structures 2025年 340卷

作者： Shasha Tan Lanhui Guo Ou Zhao Chen Jia Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin 150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin 150090 China School of Civil and Environmental Engineering Nanyang Technological University Singapore

The type and configuration of column base significantly affects the seismic behavior and design of concrete-filled steel tube (CFST) structures. This paper presents a numerical investigation into the seismic performance of embedded column bases for CFST structures. Finite element (FE) models for seismic analyses of embedded column bases were developed, with the modeling techniques and parameters detailed, and validated against available test results. On the basis of the obtained numerical results, the working mechanisms of embedded column bases under seismic loads, including failure modes, load transfer mechanisms, and interaction stress distributions among different components, were discussed in detail. Parametric studies were subsequently conducted to investigate the influence of a series of identified key parameters. The results revealed that the embedded depth ratio, steel ratio, and cross-section diameter of CFST significantly affected the failure mode, ultimate strength, and energy dissipation capacity of embedded column bases, whereas the endplate dimensions and shear studs influenced only the energy dissipation capacity. Additionally, the anchor bolt ratio and foundation concrete strength showed minimal effects for the investigated parameter ranges. Finally, calculation methods for the ultimate strengths of both deeply and shallowly embedded column bases were established, and the seismic design method and process for embedded column bases were also proposed and validated.

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