检索结果-内蒙古大学图书馆

SSRN 2023年

作者： Li, Zhihao Zhou, Wei School of Civil Engineering Key Lab of Structures Dynamic Behavior and Control Ministry of Education Key Lab of Smart Prevention and Mitigation of Civil Engineering Disaster Ministry of Industry and Information Technology Harbin Institute of Technology 73 Huanghe Road Nangang District Harbin150090 China

Ultra-High-Performance Fiber Reinforced Concrete (UHPFRC) not only has high compressive and tensile strength, but also exhibits strain-hardening characteristics in tension due to the addition of steel fibers. In this study, a new-style fiber orientation device equipped with a vibration motor of adjustable vibrational frequency was used to prepare UHPFRC. The wall effect and fiber length were considered in the manufacturing process of the device. Uniaxial tensile tests were conducted on fiber-oriented UHPFRC to explore the effects of vibrational frequency and corresponding vibrational force on the tensile behaviors. The test results showed that the elastic ultimate tensile strength, elastic ultimate tensile strain, tensile strength, peak tensile strain, and tensile elastic modulus of UHPFRC specimens cast by fiber orientation process at various vibrational frequencies were different. The fiber orientation parameters were quantitatively evaluated by the image analysis technique to explain the differences in tensile properties of the specimens. The effect of different vibrational frequencies on the tensile strength of UHPFRC matrix and its porosity was also considered. Therefore, this study provides a reference for how to adjust the vibrational frequency of the vibrating platform under the directional channel when pouring relevant components. © 2023, The Authors. All rights reserved.

关键词： Steel fibers

来源：评论

学校读者我要写书评

暂无评论

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

引用

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.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Mussel-Inspired Modified Tannic Acid Additive To Strengthen Interfacial Bonds Of Epoxy Resin With Steel Substrates

Mussel-Inspired Modified Tannic Acid Additive To Strengthen ...

引用

第八届中国国际粘接技术大会

作者： Noel Babu Guijun Xian Key Lab of Structures Dynamic Behavior and Control Ministry of EducationHarbin Institute of Technology Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology School of Civil Engineering Harbin Institute of Technology

Epoxies are widely used as coatings and adhesives in many structural ***,the loss of interfacial adhesion between the resin and substrate is a concern,especially in moist *** recent years,much attention has been directed toward mimicking the adhesion mechanism utilised by mussels to holdfast themselves onto underwater *** an inexpensive solution that can be quickly adopted for large-scale industrial applications is yet to be *** acid(TA) is a readily available polyphenol from plants with abundant phenolic hydroxyl *** was found that chemical modification of TA was necessary to use its phenolic –OH groups to mimic mussel *** was grafted with hydrophobic chains of allyl glycidyl ether(AGE) in the presence of a base *** 1wt.% additive in the resin(TA-AGE1),a 37% increase in shear strength was obtained with steel *** Boeing wedge test was performed in a harsh environment(water bath at 60 ℃) to confirm the interfacial bond *** is proposed that with the incorporation of the additive,more hydrogen and coordination bonds can be formed at the resin-adherend interface contributing to the strengthening of interfacial bonds.

关键词： Epoxy resin Mussel adhesion Tannic acid Interfacial bond durability

来源：评论

学校读者我要写书评

暂无评论

Defect-Mediated Work Function Regulation in Graphene Film for High-Performing Triboelectric Nanogenerators

SSRN

引用

SSRN 2022年

作者： Zhou, Jian Zhang, Jianing Deng, Yuanpeng Zhao, Han Zhang, Pengyu Fu, Shubing Xu, Xiang Li, Hui Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters The Ministry of Industry and Information Technology Key Lab of Structures Dynamic Behavior and Control The Ministry of Education Harbin Institute of Technology Harbin150090 China

Triboelectric nanogenerators (TENGs) demonstrate an attractive pathway to directly convert broadband mechanical energy into electrical energy for a green and clean energy source. Triboelectric material design with tailored work function has played a critical role in enhancing the output performance of TENGs. However, regulating the work function of triboelectric materials still remains challenging due to the limited particle/group/ion doping rate. Here, we reported a simple defect-mediated strategy (DMS) to regulate the work function in graphene film as the positive triboelectric material by different contents of oxygen and carbon defects derived at annealing temperatures from 500 ºC to 3000 ºC. Our DMS features a continuous and wide-range tunable work function from 4.680 eV to 4.479 eV, and the as-assembled TENGs produce output voltages and currents up to 190 V and 14 μA, respectively. The efficient work function regulation of this type establishes a set of fundamental considerations in triboelectric material design, especially the two-dimensional materials, to enhance the energy harvesting and sensing performances of TENGs. © 2022, The Authors. All rights reserved.

关键词： Nanogenerators

来源：评论

学校读者我要写书评

暂无评论

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

SSRN

引用

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

来源：评论

学校读者我要写书评

暂无评论

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

引用

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

来源：评论

学校读者我要写书评

暂无评论

Convective meta-thermal concentration for ultrahigh efficient Stirling engine with waste heat and cold utilization

arXiv

引用

arXiv 2023年

作者： Zhou, Xinchen Xu, Xiang Ouyang, Xiaoping Huang, Jiping Fudan University Shanghai200433 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters the Ministry of Industry and Information Technology Key Lab of Structures Dynamic Behavior and Control the Ministry of Education Harbin Institute of Technology Harbin150090 China School of Materials Science and Engineering Xiangtan University Xiangtan411105 China

The Stirling engine, which possesses external combustion characteristics, a simple structure, and high theoretical thermal efficiency, has excellent potential for utilizing finite waste heat and cold resources. However, practical applications of this technology suffered from thermal inefficiency due to the discontinuity and instability of waste resources. Despite advances in energy storage technology, temperature variations in the heat-exchanging fluids at the hot and cold ends of the Stirling engine remained significant obstacles. In this work, convective meta-thermal concentration (CMTC) was introduced between the heating (cooling) fluids and the hot (cold) end of the Stirling engine, employing alternating isotropic materials with high and low thermal conductivities. It was demonstrated that CMTC effectively enhanced the temperature difference between the hot and cold ends, leading to a remarkable improvement in Stirling engine efficiency. Particularly, when the Stirling engine efficiency tended to zero due to the limited availability of waste heat and cold resources, CMTC overcame this limitation, surpassing existing optimization technology. Further analysis under various operating conditions showed that CMTC achieved a significant thermal efficiency improvement of up to 1460%. This work expanded the application of thermal metamaterials to heat engine systems, offering an exciting avenue for sustainable energy utilization. Copyright © 2023, The Authors. All rights reserved.

关键词： Waste heat

来源：评论

学校读者我要写书评

暂无评论

Experimental and Numerical Studies of Compressive Strength of 3d Printed Concrete Considering Interlayer Bonding Performance

SSRN

引用

SSRN 2023年

作者： Tang, Boyang Yan, Jiachuan Han, Xiaoyu Lin, Yini Fan, Feng 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 the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China

This paper studied the compressive properties of 3D printed concrete and analyzed their influencing factors, including layer thickness and printing time interval. The investigation also explored the impact of inter-layer and inter-bar bonding properties on concrete's compressive strength by examining key factors. The findings revealed that compressive strength decreases as layer thickness decreases and printing time interval increases. Moreover, interlayer tensile and shear strength decrease with longer printing time intervals, while the anisotropic mechanical properties of 3D printed concrete become more pronounced as the number of printed layers increases. The study employed cohesive elements to numerically simulate the compressive strength of concrete specimens with varying number of layers and interlayer intervals. Parametric analysis was conducted to investigate bonding layer failure under different loading directions, and damage modes were analyzed. Finally, an empirical equation for predicting the compressive strength of 3D printed concrete was proposed and validated using experimental data. © 2023, The Authors. All rights reserved.

关键词： Compressive strength

来源：评论

学校读者我要写书评

暂无评论

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

arXiv

引用

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

来源：评论

学校读者我要写书评

暂无评论

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

arXiv

引用

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

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：