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Experimental verification of the interface wave method to detect interlaminar damage of a metal multilayer

Bing LI,Xu GENG,Tong LU,Lei QIANG,Minghang LI

《机械工程前沿（英文）》 2015年 第10卷 第4期   页码 380-391 doi: 10.1007/s11465-015-0365-7

摘要：

The interface wave traveling along the boundary of two materials has been studied for nearly a century. However, experiments, engineering applications, and interface wave applications to the non-destructive inspection of interlaminar composite have developed slowly. In this research, an experiment that applies Stoneley waves (a type of interfacial wave between two solid half-spaces) is implemented to detect the damage in a multilayer structure. The feasibility of this method is also verified. First, the wave velocity and wave structure of Stoneley waves at a perfectly bonded aluminum-steel interface are obtained by solving the Stoneley wave dispersion equation of two elastic half-spaces. Thereafter, an experiment is conducted to measure the Stoneley wave velocity of an aluminum-steel laminated beam and to locate interlaminar cracks by referring to the Stoneley wave velocity and echo wave time. Results indicate that the location error is less than 2%. Therefore, Stoneley waves show great potential as a non-destructive inspection method of a multilayer structure.

关键词： crack localization     interface waves     Stoneley waves     interlaminar damage     multilayer structure    

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大尺寸检查中航天器损伤定量评估 Research Article

张阔1,霍建亮2,王升哲2,张枭2,冯怡婷1

《信息与电子工程前沿（英文）》 2022年 第23卷 第4期   页码 542-554 doi: 10.1631/FITEE.2000733

摘要： 为保证航天器在多次航天任务中的安全性和可靠性，需要对航天器进行原位无损检测，判断微流星体和轨道碎片超高速撞击造成的损伤。本文提出一种创新的基于损伤重建图像拼接技术的定量损伤评估方法。首先，应用高斯混合模型聚类算法提取损伤特征突出的图像。然后，提出基于ORB特征提取算法和改进的具有自适应阈值选择的估计样本一致性（MSAC）算法的图像拼接方法，可创建用于损伤检测的大规模拼接图像。最后，对损伤特征区域进行分割和提取，生成拼接图像。通过计算质心位置和周长定量参数确定损伤区域的位置并判断损伤程度。实验结果验证了所提方法的有效性和适用性。

关键词： 超高速撞击；损伤信息提取；图像拼接；损伤定位；定量评估    

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dynamic stiffness-based framework for harmonic input estimation and response reconstruction considering damage

Yixian LI; Limin SUN; Wang ZHU; Wei ZHANG

《结构与土木工程前沿（英文）》 2022年 第16卷 第4期   页码 448-460 doi: 10.1007/s11709-022-0805-5

摘要： In structural health monitoring (SHM), the measurement is point-wise but structures are continuous. Thus, input estimation has become a hot research subject with which the full-field structural response can be calculated with a finite element model (FEM). This paper proposes a framework based on the dynamic stiffness theory, to estimate harmonic input, reconstruct responses, and to localize damages from seriously deficient measurements. To begin, Fourier transform converts the dynamic equilibrium equation to an equivalent static one in the frequency domain, which is under-determined since the dimension of measurement vector is far less than the FEM-node number. The principal component analysis has been adopted to “compress” the under-determined equation, and formed an over-determined equation to estimate the unknown input. Then, inverse Fourier transform converts the estimated input in the frequency domain to the time domain. Applying this to the FEM can reconstruct the target responses. If a structure is damaged, the estimated nodal force can localize the damage. To improve the damage-detection accuracy, a multi-measurement-based indicator has been proposed. Numerical simulations have validated that the proposed framework can capably estimate input and reconstruct multi-types of full-field responses, and the damage indicator can localize minor damages even with the existence of noise.

关键词： dynamic stiffness     principal component analysis     response reconstruction     damage localization     under-determined equation    

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Robotized machining of big work pieces: Localization of supporting heads

Wojciech SZYNKIEWICZ, Teresa ZIELIŃSKA, Włodzimierz KASPRZAK

《机械工程前沿（英文）》 2010年 第5卷 第4期   页码 357-369 doi: 10.1007/s11465-010-0103-0

摘要： A planner for a self adaptable and reconfigurable fixture system is proposed. The system is composed of mobile support agents that support thin sheet metal parts to minimize part dimensional deformation during drilling and milling operations. Compliant sheet metal parts are widely used in various manufacturing processes including automotive and aerospace industries. The main role of the planner is to generate an admissible plan of relocation of the mobile agents. It has to find the admissible locations for the supporting heads that provide continuous support in close proximity to the tool and trajectories of the mobile bases characterized by very high speeds during the relocation phases.

关键词： fixture     robot     milling     drilling    

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Optimal localization of complex surfaces in CAD-based inspection

XU Jinting, LIU Weijun, SUN Yuwen

《机械工程前沿（英文）》 2008年 第3卷 第4期   页码 426-433 doi: 10.1007/s11465-008-0068-4

摘要： Complex surface inspection requires the optimal localization of the measured surface related to the design surface so that the two surfaces can be compared in a common coordinate frame. This paper presents a new technique for solving the localization problem. The basic approach consists of two steps: 1) rough localization of the measured points to the design surface based on curvature features, which can produce a good initial estimate for the optimal localization; 2) fine localization based on the least-square principle so that the deviation between the measured surface and the design surface is minimized. To efficiently compute the closest points on the design surface of the measured points, a novel method is proposed. Since this approach does not involve an iterative process of solving non-linear equations for the closest points, it is more convenient and robust. The typical complex surface is used to test the developed algorithm. Analysis and comparison of experimental results demonstrate the validity and applicability of the algorithm.

关键词： deviation     comparison     non-linear     localization     inspection    

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Strain localization analyses of idealized sands in biaxial tests by distinct element method

Mingjing JIANG, Hehua ZHU, Xiumei LI,

《结构与土木工程前沿（英文）》 2010年 第4卷 第2期   页码 208-222 doi: 10.1007/s11709-010-0025-2

摘要： This paper presents a numerical investigation on the strain localization of an idealized sand in biaxial compression tests using the distinct element method (DEM). In addition to the dilatancy and material frictional angle, the principal stress field, and distributions of void ratio, particle velocity, and the averaged pure rotation rate (APR) in the DEM specimen are examined to illustrate the link between microscopic and macroscopic variables in the case of strain localization. The study shows that strain localization of the granular material in the tests proceeds with localizations of void ratio, strain and APR, and distortions of stress field and force chains. In addition, both thickness and inclination of the shear band change with the increasing of axial strain, with the former valued around 10–14 times of mean grain diameter and the later overall described by the Mohr-Coulomb theory.

关键词： idealized sand     strain localization     numerical analyses     distinct element method (DEM)    

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Lipin3 leads to hypertriglyceridemia and obesity by disrupting the expression and nucleocytoplasmic localization

《医学前沿（英文）》 doi: 10.1007/s11684-023-1003-0

摘要： Lipin proteins including Lipin 1–3 act as transcriptional co-activators and phosphatidic acid phosphohydrolase enzymes, which play crucial roles in lipid metabolism. However, little is known about the function of Lipin3 in triglyceride (TG) metabolism. Here, we identified a novel mutation (NM_001301860: p.1835A>T/p.D612V) of Lipin3 in a large family with hypertriglyceridemia (HTG) and obesity through whole-exome sequencing and Sanger sequencing. Functional studies revealed that the novel variant altered the half-life and stability of the Lipin3 protein. Hence, we generated Lipin3 heterozygous knockout (Lipin3-heKO) mice and cultured primary hepatocytes to explore the pathophysiological roles of Lipin3 in TG metabolism. We found that Lipin3-heKO mice exhibited obvious obesity, HTG, and non-alcoholic fatty liver disorder. Mechanistic study demonstrated that the haploinsufficiency of Lipin3 in primary hepatocytes may induce the overexpression and abnormal distribution of Lipin1 in cytosol and nucleoplasm. The increased expression of Lipin1 in cytosol may contribute to TG anabolism, and the decreased Lipin1 in nucleoplasm can reduce PGC1α, further leading to mitochondrial dysfunction and reduced TG catabolism. Our study suggested that Lipin3 was a novel disease-causing gene inducing obesity and HTG. We also established a relationship between Lipin3 and mitochondrial dysfunction.

关键词： Lipin3     Lipin1     hypertriglyceridemia     obesity     mitochondrial dysfunction    

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Windborne debris damage prediction analysis

Fangfang SONG, Jinping OU,

《结构与土木工程前沿（英文）》 2010年 第4卷 第3期   页码 326-330 doi: 10.1007/s11709-010-0067-5

摘要： Windborne debris is one of the most important causes of the envelop destruction according to the post-damage investigations. The problem of windborne debris damage could be summarized as three parts, including windborne debris risk analysis, debris flying trajectories, and impact resistance of envelope analysis. The method of debris distribution is developed. The flying trajectories of compact and plate-like debris are solved by using a numerical method according to the different aerodynamic characteristics. The impact resistance of the envelopes is also analyzed. Besides, the process of windborne debris damage analysis is described in detail. An example of industrial building is given to demonstrate the whole method by using the observed data of typhoon Chanchu (2006). The method developed in this paper could be applied to risk assessment of windborne debris for structures in wind hazard.

关键词： typhoon     windborne debris     structural envelopes     damage estimation    

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Corrosion damage assessment and monitoring of large steel space structures

Bo CHEN, You-Lin XU, Weilian QU,

《结构与土木工程前沿（英文）》 2010年 第4卷 第3期   页码 354-369 doi: 10.1007/s11709-010-0088-0

摘要： Large steel space structures, when exposed to a harsh corrosive environment, are inevitably subjected to atmospheric corrosion and stress corrosion cracking. This paper proposes a framework for assessing the corrosion damage of large steel space structures subjected to both stress corrosion cracking and atmospheric corrosion. The empirical model for estimating atmospheric corrosion based on measured information is briefly introduced. The proposed framework is applied to a real large steel space structure built in the southern coastal area in China to assess its corrosion damage and investigate the effects of atmospheric corrosion on stress corrosion cracking. Based on the results, the conceptual design of the corrosion monitoring system of large steel space structures is finally conducted as the first step for a real corrosion monitoring system.

关键词： large steel space structure     atmospheric corrosion     stress corrosion cracking     corrosion damage     damage assessment     monitoring system    

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Detection of damage locations and damage steps in pile foundations using acoustic emissions with deep

Alipujiang JIERULA, Tae-Min OH, Shuhong WANG, Joon-Hyun LEE, Hyunwoo KIM, Jong-Won LEE

《结构与土木工程前沿（英文）》 2021年 第15卷 第2期   页码 318-332 doi: 10.1007/s11709-021-0715-y

摘要： The aim of this study is to propose a new detection method for determining the damage locations in pile foundations based on deep learning using acoustic emission data. First, the damage location is simulated using a back propagation neural network deep learning model with an acoustic emission data set acquired from pile hit experiments. In particular, the damage location is identified using two parameters: the pile location ( ) and the distance from the pile cap ( ). This study investigates the influences of various acoustic emission parameters, numbers of sensors, sensor installation locations, and the time difference on the prediction accuracy of and . In addition, correlations between the damage location and acoustic emission parameters are investigated. Second, the damage step condition is determined using a classification model with an acoustic emission data set acquired from uniaxial compressive strength experiments. Finally, a new damage detection and evaluation method for pile foundations is proposed. This new method is capable of continuously detecting and evaluating the damage of pile foundations in service.

关键词： pile foundations     damage location     acoustic emission     deep learning     damage step    

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Creep life assessment of aero-engine recuperator based on continuum damage mechanics approach

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0702-6

摘要： The creep life of an aeroengine recuperator is investigated in terms of continuum damage mechanics by using finite element simulations. The effects of the manifold wall thickness and creep properties of brazing filler metal on the operating life of the recuperator are analyzed. Results show that the crack initiates from the brazing filler metal located on the outer surface of the manifold with the wall thickness of 2 mm and propagates throughout the whole region of the brazing filler metal when the creep time reaches 34900 h. The creep life of the recuperator meets the requirement of 40000 h continuous operation when the wall thickness increases to 3.5 mm, but its total weight increases by 15%. Decreasing the minimum creep strain rate with the enhancement of the creep strength of the brazing filler metal presents an obvious effect on the creep life of the recuperator. At the same stress level, the creep rupture time of the recuperator is enhanced by 13 times if the mismatch between the minimum creep rate of the filler and base metal is reduced by 20%.

关键词： creep     life assessment     brazed joint     continuum damage mechanics     aeroengine recuperator    

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Bacterial inactivation, DNA damage, and faster ATP degradation induced by ultraviolet disinfection

Chao Yang, Wenjun Sun, Xiuwei Ao

《环境科学与工程前沿（英文）》 2020年 第14卷 第1期 doi: 10.1007/s11783-019-1192-6

摘要： • Long amplicon is more effective to test DNA damage induced by UV. • ATP in bacteria does not degrade instantly but does eventually after UV exposure. • After medium pressure UV exposure, ATP degraded faster. The efficacy of ultraviolet (UV) disinfection has been validated in numerous studies by using culture-based methods. However, the discovery of viable but non-culturable bacteria has necessitated the investigation of UV disinfection based on bacterial viability parameters. We used quantitative polymerase chain reaction (qPCR) to investigate DNA damage and evaluated adenosine triphosphate (ATP) to indicate bacterial viability. The results of qPCR effectively showed the DNA damage induced by UV when using longer gene amplicons, in that sufficiently long amplicons of both 16S and gadA indicated that the UV induced DNA damages. The copy concentrations of the long amplicons of 16S and gadA decreased by 2.38 log/mL and 1.88 log/mL, respectively, after exposure to 40 mJ/cm2 low-pressure UV. After UV exposure, the ATP level in the bacteria did not decrease instantly. Instead it decreased gradually at a rate that was positively related to the UV fluence. For low-pressure UV, this rate of decrease was slow, but for medium pressure UV, this rate of decrease was relatively high when the UV fluence reached 40 mJ/cm2. At the same UV fluence, the ATP level in the bacteria decreased at a faster rate after exposure to medium-pressure UV.

关键词： UV disinfection     DNA damage     qPCR     ATP    

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Yield-height correlation and QTL localization for plant height in two lowland switchgrass populations

Shiva O. MAKAJU, Yanqi WU, Michael P. ANDERSON, Vijaya G. KAKANI, Michael W. SMITH, Linglong LIU, Hongxu DONG, Dan CHANG

《农业科学与工程前沿（英文）》 2018年 第5卷 第1期   页码 118-128 doi: 10.15302/J-FASE-2018201

摘要： Switchgrass ( L.), as a model herbaceous crop species for bioenergy production, is targeted to improve biomass yield and feedstock quality. Plant height is a major component contributing to biomass yield. Accordingly, the objectives of this research were to analyze phenotypic variation for biomass and plant height and the association between them and to localize associated plant height QTLs. Two lowland switchgrass mapping populations, one selfed and another hybrid population established in the field at Perkins and Stillwater, Oklahoma, were deployed in the experiment for two years post establishment. Large genetic variation existed for plant biomass and height within the two populations. Plant height was positively correlated with biomass yield in the selfed population ( = 0.39, <0.0001) and the hybrid population ( = 0.41, <0.0001). In the selfed population, a joint analysis across all environments revealed 10 QTLs and separate analysis for each environment, collectively revealed 39 QTLs related to plant height. In the hybrid population, the joint analysis across overall environments revealed 35 QTLs and the separate analysis for each environment revealed 38 QTLs. The findings of this research contribute new information about the genetic control for plant height and will be useful for future plant breeding and genetic improvement programs in lowland switchgrass.

关键词： yield-height     QTL localization     lowland switchgrass    

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The damage evolution behavior of polypropylene fiber reinforced concrete subjected to sulfate attack

Ninghui LIANG; Jinwang MAO; Ru YAN; Xinrong LIU; Xiaohan ZHOU

《结构与土木工程前沿（英文）》 2022年 第16卷 第3期   页码 316-328 doi: 10.1007/s11709-022-0810-8

摘要： To study the damage evolution behavior of polypropylene fiber reinforced concrete (PFRC) subjected to sulfate attack, a uniaxial compression test was carried out based on acoustic emission (AE). The effect of sulfate attack relative to time and fiber hybridization were analyzed and the compression damage factor was calculated using a mathematical model. The changes to AE ringing counts during the compression could be divided into compaction, elastic, and AE signal hyperactivity stages. In the initial stage of sulfate attack, the concrete micropores and microcracks were compacted gradually under external load and a corrosion products filling effect, and this corresponded with detection of few AE signals and with concrete compression strength enhancement. With increasing sulfate attack time, AE activity decreased. The cumulative AE ringing counts of PFRC at all corrosion ages were much higher than those for plain concrete. PFRC could still produce AE signals after peak load due to drawing effect of polypropylene fiber. After 150 d of sulfate attack, the cumulative AE ringing counts of plain concrete went down by about an order of magnitude, while that for PFRC remained at a high level. The initial damage factor of hybrid PFRC was −0.042 and −0.056 respectively after 150 d of corrosion, indicating that the advantage of hybrid polypropylene fiber was more obvious than plain concrete and single-doped PFRC. Based on a deterioration equation, the corrosion resistance coefficient of hybrid PFRC would be less than 0.75 after 42 drying−wetting sulfate attack cycles, which was 40% longer than that of plain concrete.

关键词： polypropylene fiber reinforced concrete     sulfate attack     damage evolution behavior     acoustic emission     damage factor    

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Spectral element modeling based structure piezoelectric impedance computation and damage identification

Zhigang GUO, Zhi SUN

《结构与土木工程前沿（英文）》 2011年 第5卷 第4期   页码 458-464 doi: 10.1007/s11709-011-0133-7

摘要： This paper presents a numerical simulation study on electromechanical impedance technique for structural damage identification. The basic principle of impedance based damage detection is structural impedance will vary with the occurrence and development of structural damage, which can be measured from electromechanical admittance curves acquired from PZT patches. Therefore, structure damage can be identified from the electromechanical admittance measurements. In this study, a model based method that can identify both location and severity of structural damage through the minimization of the deviations between structural impedance curves and numerically computed response is developed. The numerical model is set up using the spectral element method, which is promised to be of high numerical efficiency and computational accuracy in the high frequency range. An optimization procedure is then formulated to estimate the property change of structural elements from the electric admittance measurement of PZT patches. A case study on a pin-pin bar is conducted to investigate the feasibility of the proposed method. The results show that the presented method can accurately identify bar damage location and severity even when the measurements are polluted by 5% noise.

关键词： PZT     piezoelectric impedance     optimization     spectral element     damage identification    

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标题 作者 时间 类型 操作

Experimental verification of the interface wave method to detect interlaminar damage of a metal multilayer

Bing LI,Xu GENG,Tong LU,Lei QIANG,Minghang LI

期刊论文

大尺寸检查中航天器损伤定量评估

张阔1,霍建亮2,王升哲2,张枭2,冯怡婷1

期刊论文

dynamic stiffness-based framework for harmonic input estimation and response reconstruction considering damage

Yixian LI; Limin SUN; Wang ZHU; Wei ZHANG

期刊论文

Robotized machining of big work pieces: Localization of supporting heads

Wojciech SZYNKIEWICZ, Teresa ZIELIŃSKA, Włodzimierz KASPRZAK

期刊论文

Optimal localization of complex surfaces in CAD-based inspection

XU Jinting, LIU Weijun, SUN Yuwen

期刊论文

Strain localization analyses of idealized sands in biaxial tests by distinct element method

Mingjing JIANG, Hehua ZHU, Xiumei LI,

期刊论文

Lipin3 leads to hypertriglyceridemia and obesity by disrupting the expression and nucleocytoplasmic localization

期刊论文

Windborne debris damage prediction analysis

Fangfang SONG, Jinping OU,

期刊论文

Corrosion damage assessment and monitoring of large steel space structures

Bo CHEN, You-Lin XU, Weilian QU,

期刊论文

Detection of damage locations and damage steps in pile foundations using acoustic emissions with deep

Alipujiang JIERULA, Tae-Min OH, Shuhong WANG, Joon-Hyun LEE, Hyunwoo KIM, Jong-Won LEE

期刊论文

Creep life assessment of aero-engine recuperator based on continuum damage mechanics approach

期刊论文

Bacterial inactivation, DNA damage, and faster ATP degradation induced by ultraviolet disinfection

Chao Yang, Wenjun Sun, Xiuwei Ao

期刊论文

Yield-height correlation and QTL localization for plant height in two lowland switchgrass populations

Shiva O. MAKAJU, Yanqi WU, Michael P. ANDERSON, Vijaya G. KAKANI, Michael W. SMITH, Linglong LIU, Hongxu DONG, Dan CHANG

期刊论文

The damage evolution behavior of polypropylene fiber reinforced concrete subjected to sulfate attack

Ninghui LIANG; Jinwang MAO; Ru YAN; Xinrong LIU; Xiaohan ZHOU

期刊论文

Spectral element modeling based structure piezoelectric impedance computation and damage identification

Zhigang GUO, Zhi SUN

期刊论文