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Environmental impact assessment of aircraft elevator made with new lightning protection material

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2022年第9期23卷 669-682页

作者： Shao-ce DONG Cheng-gao LI Gui-jun XIAN Zhong-jie ZHAO Xu-feng ZHANG Qing-wen YUN MOE Key Laboratory of Structures Dynamic Behavior and Control Harbin Institute of TechnologyHarbin 150090China MIIT Key Laboratory of Smart Prevention and Mitigation of Civil Engineering Disasters Harbin Institute of TechnologyHarbin 150090China Shool of Civil Engineering Harbin Institute of TechnologyHarbin 150090China Aviation Industry Corporation of China Ltd.(AVIC)Composite Technology CenterBeijing 101300China Aviation Industry Corporation of China Ltd.(AVIC)Harbin Aircraft Industry Group Co.Ltd.Harbin 150066China

The non-metallic lightning strike protection film covering carbon fiber reinforced polymers(NM-LSP covering CFRP)can reduce the weight and thus the fuel consumption of aircraft by replacing the traditional lightning strike protection(LSP)*** the present study,in order to study the environmental influence of utilizing NM-LSP covering CFRP in an aircraft elevator,a new elevator was designed and manufactured,replacing the aluminium net and glass fiber reinforced polymers(GFRP)with NM-LSP covering CFRP,with the same mechanical and LSP abilities.A comparative life cycle assessment was conducted between the two kinds of aircraft elevators,including material extraction,transportation,elevator manufacturing phase,service phase,and end-of-life ***,the environmental impacts of producing two LSP materials were compared by considering the environmental effects of different buy-to-fly ratios and recycling strategies on the production of aluminium *** analysis indicates that the new elevator achieved reduction for all the environmental impact categories used,such as human toxicity potential and marine aquatic ecotoxicity potential(3.83%and 3.20%reduction).Furthermore,it is found that the service phase makes the greatest contribution to the environmental impact of the elevators under *** recycling is excluded,NM-LSP covering CFRP is more environmentally friendly than the traditional *** the same time,CFRP prepreg and electricity from the production of NM-LSP covering CFRP contribute to a higher environmental impact compared to the NM-LSP *** the sensitivity analysis,it is believed that NM-LSP covering CFRP can reduce environmental impact compared with traditional LSP materials.

关键词： Environmental impact assessment Lightning strike protection(LSP)material Aircraft elevator Life cycle assessment(LCA) Non-metallic lightning strike protection(NM-LSP)material

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Cathode Potential Regulates the Microbiome Assembly and Function in Electrostimulated Bio- Dechlorination System

SSRN

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SSRN 2022年

作者： Li, Zhi-Ling Cao, Di Shi, Ke Liang, Bin Zhu, Zhongli Liu, Wenzong Nan, Jun Sun, Kai Wang, Ai-Jie State Key Laboratory of Urban Water Resources and Environment School of Environment Harbin Institute of Technology Harbin150090 China Shenzhen518055 China Key Lab of Structures Dynamic Behavior and Control of China Ministry of Education School of Civil Engineering Harbin Institute of Technology Harbin150090 China

Mechanism of microbiome assembly and function driven by cathode potential in electro-stimulated microbial reductive dechlorination system remain poorly understood. Here, core microbiome structure, interaction, function and assembly regulating by cathode potential were investigated in a 2,4,6-trichlorophenol bio-dechlorination system. The highest dechlorination rate(24.30μM/d)was observed under-0.36Vwith phenol as a major end metabolite, while, lower (-0.56V) or higher (0.04Vor-0.16V)potentials resulted in 1.3~3.8 times decreased of dechlorination kinetic constant. The lower the cathode potential, the higher the generated CH4 , revealing cathode participated in hydrogenotrophic methanogenesis. Taxonomic and functional structure of core microbiome significantly shifted within groups of -0.36V and -0.56V, with dechlorinators ( Desulfitobacteriu , Dehalobacter ), fermenters ( norank_f_Propionibacteriaceae , Dysgonomonas )and cathode-utilizing methanogen ( Methanosarcina ) highly enriched, and the more positive interactions between functional genera were found. The lowest number of nodes and links and the highest positive correlations were observed among constructed sub-networks classified by function, revealing simplified and strengthened cooperation of functional genera driven by group of -0.36 V. Cathode potential plays one important driver controlling core microbiome assembly, and the low potentials drove the assembly of major dechlorinating, methanogenic and electro-active genera to be more deterministic, while, the major fermenting genera were mostly governed by stochastic processes. © 2022, The Authors. All rights reserved.

关键词： Dechlorination

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dynamic Characteristics and Force Analysis of Box Girder Under Tsunami Action Based On Level-Set Method

SSRN

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SSRN 2024年

作者： Niu, Shilei Liu, Zhongxiang Guo, Tong Guo, Anxin Liu, Aimin School of Transportation Southeast University Nanjing210096 China Key Laboratory of Concrete and Prestressed Concrete Structures School of Civil Engineering Southeast University Nanjing210096 China Ministry-of-Education Key Laboratory of Structural Dynamic Behavior and Control School of Civil Engineering Harbin Institute of Technology Harbin150090 China China Energy Engineering Group Jiangsu No.1 Electric Power Construction Co. Ltd. Nanjing210001 China

Tsunamis pose significant threats to the safety of sea-crossing bridges. Understanding the dynamics of wave forces and girder responses during tsunami events is crucial for ensuring their safe maintenance. In this research, a 2D numerical flume with solitary waves was utilized to simulate tsunamis. The level-set method was used for the treatment of fluid-solid interface and free surface. The interaction between the tsunami and the bridge girder was replicated through real-time data exchange between the fluid and a spring-mass-damper system. Subsequently, the hydrodynamic behaviors of the fluid surrounding the box girder and the structural responses of the girder under tsunami conditions were examined through parametric analysis. Findings suggest that tsunami with larger wave height interacts with box girder for longer duration. The maximum resistance and moment occur at the instant when the fluid acts on the top plate. Considering fluid-structure interaction and bearing constraints, increasing bearing stiffness results in substantial reductions (79.28%~85.32%) in girder displacement. Additionally, the maximum horizontal displacement of the unsubmerged box girder exceeds that of the submerged state by 2.04mm. Moreover, horizontal forces on the box girder decrease by 19.25%~45.30%, while maximum horizontal compression and tension on the wave-facing side bearing decrease by 10.7%~14.8% and 25.7%~29.9%, respectively. The maximum compression is approximately 2.68~3.34 times the maximum tension. © 2024, The Authors. All rights reserved.

关键词： Numerical methods

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Recovering compressed images for automatic crack segmentation using generative models

arXiv

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arXiv 2020年

作者： Huang, Yong Zhang, Haoyu Li, Hui Wu, Stephen Key Laboratory of Intelligent Disaster Prevention and Mitigation for Civil Infrastructures Ministry of Industry and Information Technology Harbin Heilongjiang150090 China Ministry of Education Key Laboratory of Structural Dynamic Behavior and Control School of Civil Engineering Harbin Institute of Technology Harbin China Institute of Statistical Mathematics Research Organization of Information and Systems 10-3 Midori-cho Tachikawa Tokyo190-8562 Japan Graduate University for Advanced Studies SOKENDAI 10-3 Midori-cho Tachikawa Tokyo190-8562 Japan

In a structural health monitoring (SHM) system that uses digital cameras to monitor cracks of structural surfaces, techniques for reliable and effective data compression are essential to ensure a stable and energy-efficient crack images transmission in wireless devices, e.g., drones and robots with high definition cameras installed. Compressive sensing (CS) is a signal processing technique that allows accurate recovery of a signal from a sampling rate much smaller than the limitation of the Nyquist sampling theorem. The conventional CS method is based on the principle that, through a regularized optimization, the sparsity property of the original signals in some domain can be exploited to get the exact reconstruction with a high probability. However, the strong assumption of the signals being highly sparse in an invertible space is relatively hard for real crack images. In this paper, we present a new approach of CS that replaces the sparsity regularization with a generative model that is able to effectively capture a low dimension representation of targeted images. We develop a recovery framework for automatic crack segmentation of compressed crack images based on this new CS method and demonstrate the remarkable performance of the method taking advantage of the strong capability of generative models to capture the necessary features required in the crack segmentation task even the backgrounds of the generated images are not well reconstructed. The superior performance of our recovery framework is illustrated by comparing with three existing CS algorithms. Furthermore, we show that our framework is extensible to other common problems in automatic crack segmentation, such as defect recovery from motion blurring and *** Codes 62P30, 97M50 Copyright © 2020, The Authors. All rights reserved.

关键词： Compressed sensing

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Seismic fragility analysis of steel-concrete composite bridges excited by near-fault ground motions

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Tumu Gongcheng Xuebao/China Civil Engineering Journal 2016年 49卷 56-60and77页

作者： Liu, Yang Lu, Dagang Yu, Xiaohui Key Lab of Structural Dynamic Behavior and Control of China Ministry of Education Harbin Institute of Technology Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China State Key Laboratory for Disaster Reduction in Civil Engineering Tongji University Shanghai200092 China

The seismic fragility analysis was conducted for a steel-concrete composite bridge (SCCB) including the effects of the near-fault pulse-like ground motions. A total of 60 real ground motions were selected from the PEER strong earthquake database as the inputs. The global fragility curves and local fragility curves of the bridge were obtained through the fragility analysis. Compared to the fragility results of the far-field earthquake records, it is found that the demands due to the near-fault ground motions are significantly larger than that due to the far-field ground motions. Under the near-fault pulse-like ground motions, the pier is the most fragile component, while the concrete crossbeam and the studs are less fragile. © 2016, Editorial Office of China Civil Engineering Journal. All right reserved.

关键词： Concretes

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Experimental study on the lateral impact of fully clamped circular steel tubes

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Tianjin Daxue Xuebao (Ziran Kexue yu Gongcheng Jishu Ban)/Journal of Tianjin University Science and Technology 2016年 49卷 28-33页

作者： Zhang, Rong Zhi, Xudong Fan, Feng Wu, Qijian Key Laboratory of Structures Dynamic Behavior and Control of Ministry of Education Harbin Institute of Technology Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China

The performance of longitudinal welded steel tubes under drop hammer impact was experimentally *** order to simulate fixed conditions of specimen,loading mechanism platform and clamping device were *** influencing factors included:drop height of hammer,ratio of length to diameter of steel tube,and shape of *** results show that the failure mode of fully clamped tubes is shear failure,and with the increase of the impact energy,the deformation of circular steel tube goes through three stages:elastic small deformation stage,plastic large deformation stage,and shear failure stage. Drop height of hammer and ratio of length to diameter of steel tube have significant effects on strain growth rate,duration of impact and peak impact force. The shape of the plastic hinge is determined by the shape of the impact indenter. © 2016, Editorial Board of Journal of Tianjin University(Science and Technology). All right reserved.

关键词： Hammers

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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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Early-Age Hydration Heat Evolution and Kinetics of Portland Cement Containing Nano-Silica at Different Temperatures

SSRN

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SSRN 2022年

作者： Bai, Shuai Guan, Xinchun Li, Guoyu 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 Harbin Institute of Technology Harbin150090 China State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou730000 China

This study investigated the influence of nano-silica dosages and hydration temperatures on the early-age hydration heat of cement using isothermal calorimetry, and a hydration kinetics model was used to analyze the nucleation and growth rates of hydrates. The calorimetry results show that the addition of nano-silica and the increase of hydration temperature can accelerate the process of hydration reaction. As the dosage of nano-silica increases, the induction period decreases, the acceleration period and exothermic rate peak value increase. The fast pozzolanic effect of nano-silica is responsible for accelerating the hydration reaction. However, the excessive addition (5%) of nano-silica may form many agglomerations, thereby inhibiting the modification effect of nano-silica on the cement hydration. The simulating results of kinetic parameters show that, at three hydration temperatures, the nucleation rate of hydrates increase with the increasing of nano-silica dosages, which indirectly confirms the nucleation effect of nano-silica in the early-age hydration. At 20 °C and 30 °C, the growth rate of hydrates also increases with the increasing of nano-silica dosages. At 40 °C, the growth rate of hydrates is decreased gradually, possibly due to the lack of sufficient Ca2+ and H2SiO42-. In addition, the nucleation rate is more sensitive and the growth rate is less sensitive to the hydration temperature. © 2022, The Authors. All rights reserved.

关键词： Hydration

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Temperature and electric-field induced phase transitions, and full tensor properties of C-poled domain-engineered tetragonal 0.63Pb(Mg1/3Nb2/3)−0.37PbTiO3 single crystals

引用

Physical Review B 2016年第9期93卷 094104-094104页

作者： Limei Zheng Yujia Jing Xiaoyan Lu Ruixue Wang Gang Liu Weiming Lü Rui Zhang Wenwu Cao Condensed Matter Science and Technology Institute Harbin Institute of Technology Harbin 150080 China Key Laboratory of Structures Dynamic Behavior and Control of the Ministry of Education School of Civil Engineering Harbin Institute of Technology Harbin 150001 China Center for High Pressure Science and Technology Advanced Research Shanghai 201203 China Department of Mathematics Materials Research Institute The Pennsylvania State University University Park Pennsylvania 16802 USA

The phase-transition sequence of 0.67Pb(Mg1/3Nb2/3)−0.37PbTiO3 (PMN-0.37PT) single crystals driven by the electric (E) field and temperature is comprehensively studied. Based on the strain-E field loop, polarization-E field loop, and the evolution of domain configurations, the E field along the [011]C induced phase transitions have been confirmed to be as follows: tetragonal (T) → monoclinic (MC)→ single domain orthorhombic (O) phase. As the E field decreases, the induced O phase cannot be maintained and transformed to the MC phase, then to the coexistence state of MC and T phases. In addition, the complete sets of dielectric, piezoelectric, and elastic constants for the [011]C-poled domain-engineered PMN-0.37PT single crystal were measured at room temperature, which show high longitudinal dielectric, piezoelectric, and electromechanical properties (ɛ33T=10661,d33=1052pC/N, and k33=0.766). Our results revealed that the MC phase plays an important role in the high electromechanical properties of this domain-engineered single crystal. The temperature dependence of the domain configuration revealed that the volume fraction of the MC phase decreases with temperature accompanied by the reduction of ɛ33T,d31, and k31 due to the substantially smaller intrinsic properties of the T phase.

关键词： Electric polarization Ferroelectricity Phase transitions Piezoelectricity Ferroelectrics Piezoelectrics Relaxor ferroelectrics Polarization

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Spatial Correlation of Intensity Measures of Mainshock-Aftershock Ground Motion Sequence Pairs

SSRN

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SSRN 2024年

作者： Ding, Jiawei Lu, Dagang Cao, Zheng-Gang School of Civil Engineering Harbin Institute of Technology Harbin China Key Lab of Structural Dynamic Behaviors 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 Key Laboratory of Earthquake Disaster Mitigation The Ministry of Emergency Management Harbin Institute of Technology Harbin150090 China

This manuscript examines spatial correlations among ground motion intensity measures (IMs) for mainshock and aftershock, including spectral acceleration (Sa), peak ground acceleration (PGA), peak ground velocity (PGV), cumulative absolute velocity (CAV), Arias intensity (Ia), significant duration parameters (Ds5-75, Ds5-95), using a suite of 662 mainshock-aftershock ground motion sequence pairs from 13 earthquake sequences in the NGA-West2 ground motion database based on geostatistical tools. Univariate and multivariate normality of intraevent residuals of IMs for the mainshock and aftershock are verified. We proposed Adaptive Weighted Particle Swarm Optimization Algorithm—Inverse Distance Weighting (AWPSO-IDW) fitting method and use the exponential semivariogram model to fit the empirical semivariogram. An improved Monte Carlo random simulation procedure is used to evaluate the stability of the estimation and several fitting methods used in past research. The results show AWPSO-IDW fitting method is more stable and reliable than other methods, and the results show that the spatial correlation range between the mainshock-aftershock ground motions sequence pairs at different periods of spectral acceleration has a similar trend, only have differences in individual spectral acceleration periods, and the model proposed by Jayaram and Baker (2009) has been improved. Finally, this manuscript employs the spatial correlation range between the mainshock and the aftershock to generate an independent regional spatial correlation influence field. It further constructs the conditional generation of the aftershock spatial correlation influence field, considering the known mainshock spatial correlation influence field. This is achieved by adopting multivariate conditional normal characteristics between intensity measures (IMs) for both mainshocks and aftershocks. © 2024, The Authors. All rights reserved.

关键词： Monte Carlo methods

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