检索结果-内蒙古大学图书馆

arXiv 2020年

作者： Zheng, Zhibao Dai, Hongzhe Wang, Yuyin Wang, Wei Key Lab of Structures Dynamic Behavior and Control Harbin Institute of Technology Ministry of Education Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China

This paper presents a new numerical scheme for simulating stochastic processes specified by their marginal distribution functions and covariance functions. Stochastic samples are firstly generated to automatically satisfy target marginal distribution functions. An iterative algorithm is proposed to match the simulated covariance function of stochastic samples to the target covariance function, and only a few times iterations can converge to a required accuracy. Several explicit representations, based on Karhunen-Loève expansion and Polynomial Chaos expansion, are further developed to represent the obtained stochastic samples in series forms. Proposed methods can be applied to non-gaussian and non-stationary stochastic processes, and three examples illustrate their accuracies and efficiencies. Copyright © 2020, The Authors. All rights reserved.

关键词： Stochastic systems

来源：评论

学校读者我要写书评

暂无评论

A sample-based stochastic finite element method for structural reliability analysis

arXiv

引用

arXiv 2020年

This paper presents a new methodology for structural reliability analysis via stochastic finite element method (SFEM). A novel sample-based SFEM is firstly used to compute structural stochastic responses of all spatial points at the same time, which decouples the stochastic response into a combination of a series of deterministic responses with random variable coefficients, and solves corresponding stochastic finite element equation through an iterative algorithm. Based on the stochastic response obtained by the SFEM, the limit state function described by the stochastic response and the multidimensional integral encountered in reliability analysis can be computed without any difficulties, and failure probabilities of all spatial points are calculated once time. The proposed method can be applied to high-dimensional stochastic problems, and one of the most challenging issues encountered in high-dimensional reliability analysis, known as Curse of Dimensionality, can be circumvented without expensive computational costs. Three practical ex- Copyright © 2020, The Authors. All rights reserved.

关键词： Reliability analysis

来源：评论

学校读者我要写书评

暂无评论

Corrigendum to “Experimental evaluation of mechanical properties and microstructure for recycled aggregate concrete collaboratively modified with nano-silica and mixed fibers” [Constr. Build. Mater. 403 (2023) 133125]

引用

Construction and Building Materials 2023年 404卷

作者： Hang Sun Liang Luo Huan Yuan Xi Li School of Transportation and Science 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 School of Civil Engineering Harbin Institute of Technology Harbin 150090 China

来源：评论

学校读者我要写书评

暂无评论

Machine-learning-based methods for output-only structural modal identification

arXiv

引用

arXiv 2020年

作者： Bao, Yuequan Liu, Dawei Tang, Zhiyi Li, Hui Key Lab of Structures Dynamic Behavior Control of the Ministry of Education Harbin Institute of Technology Harbin150090 China Key Lab of Intelligent Disaster Mitigation Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China

In this study, we propose a machine-learning-based approach to identify the modal parameters of the output-only data for structural health monitoring (SHM) that makes full use of the characteristic of independence of modal responses and the principle of machine learning. By taking advantage of the independence feature of each mode, we use the principle of unsupervised learning, making the training process of the deep neural network become the process of modal separation. A self-coding deep neural network is designed to identify the structural modal parameters from the vibration data of structures. The mixture signals, that is, the structural response data, are used as the input of the neural network. Then we use a complex cost function to restrict the training process of the neural network, making the output of the third layer the modal responses we want, and the weights of the last two layers are mode shapes. The deep neural network is essentially a nonlinear objective function optimization problem. A novel loss function is proposed to constrain the independent feature with consideration of uncorrelation and non-Gaussianity to restrict the designed neural network to obtain the structural modal parameters. A numerical example of a simple structure and an example of actual SHM data from a cable-stayed bridge are presented to illustrate the modal parameter identification ability of the proposed approach. The results show the approach's good capability in blindly extracting modal information from system responses. Copyright © 2020, The Authors. All rights reserved.

关键词： Deep neural networks

来源：评论

学校读者我要写书评

暂无评论

Uniaxial Stress-Strain Relationship and Thermal Properties of Concrete with Fine Recycled Aggregate Under Elevated Temperatures

SSRN

引用

SSRN 2022年

作者： Zhang, Huan Zhao, Hui Liu, Faqi Yang, Hua Pan, Kainan Key Lab of Structures Dynamic Behaviour 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 Department of Civil Engineering Tianjin University Tianjin30072 China College of Civil Engineering Taiyuan University of Technology Taiyuan030024 China School of Engineering Harbin Institute of Technology Harbin150090 China

The models for the stress-strain relationship under elevated temperatures and thermal properties of recycled aggregate concrete (RAC) are essential in the fire resistance design of RAC structures, while no such models are available for RAC made with fine recycled aggregate (FRA). To establish the above models, 33 RAC prisms with three FRA replacement levels (0%, 50%, and 100%) under five temperatures (20 °C, 200 °C, 400 °C, 600 °C, and 800 °C) were tested for the uniaxial compressive stress-strain relationship;Meanwhile, thermal properties (including the specific heat, thermal conductivity, and thermal expansion) of these concrete mixes under a temperature range of 20-800 °C were also tested. A prediction model for the stress-strain relationship under elevated temperatures was proposed by extending the model for RAC under normal temperatures. Based on the test data, models for the thermal properties of RAC with FRA were also established. Results showed that the FRA does not change the shear failure mode of concrete, and its influence on the stress-strain relationship is independent of temperature;the specific heat increases while the thermal conductivity decreases with the FRA replacement ratio;the thermal expansion of concrete under temperature higher than 500 °C decreases with FRA;the proposed models have a good prediction for the stress-strain relationship and thermal properties of RAC. © 2022, The Authors. All rights reserved.

关键词： Stress-strain curves

来源：评论

学校读者我要写书评

暂无评论

Optimisation route of embodied carbon emissions and cost of prefabricated buildings: A case study of prefabricated shear wall residential structures

引用

Energy and Buildings 2025年 343卷

作者： Yifan Dong Qingpeng Man Yadi Zhang Yuan Chang School of Civil Engineering Harbin Institute of Technology Harbin 150001 China Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin 150009 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 150009 China School of Management Science and Engineering Central University of Finance and Economics Beijing 100081 China

Prefabricated buildings are increasingly replacing traditional cast-in-place concrete structures to reduce construction time and environmental impacts. However, prefabricated components frequently struggle to simultaneously achieve economic cost-effectiveness and carbon emissions reduction. Thus, the construction industry urgently requires component-level technical guidance on prefabricated construction to ensure economic feasibility while also supporting carbon neutrality goals. This study used a typical prefabricated shear wall residential building as a case study to improve the economic and environmental performance of prefabricated building construction. Seven types of structural components are examined, including interior shear walls (ISW) and exterior shear walls (ESW), composite floor slabs (CFS), air-conditioning panels/canopies (A/C), stair landings (SL), beams (BM), and stair flights (SF). By systematically replacing cast-in-place components with their prefabricated counterparts using Revit and Glodon soft tools, the study quantifies and analyses the differences in carbon emissions and costs. The key results are: (i) The optimal replacements for minimising carbon emissions are “BM → SL → SF → CFS → ESW → ISW → A/C,” whereas the most economical cost-effective sequence is “BM → SL → SF → A/C → ISW → ESW → CFS.” (ii) Prefabrication does not universally result in lower carbon emissions. Among the seven types of components, four exhibit higher carbon emissions per unit volume of concrete than their cast-in-place counterparts, with the highest value of CFS (86.2 kg/m 3 ). (iii) To achieve carbon emissions reduction through prefabrication, an optimal prefabrication rate of 3.8–10.6 % is recommended. Within this range, increasing the prefabrication rate results in cost increases while enabling carbon reduction. However, exceeding the 10.6 % cap rate results in both higher costs and carbon emissions compared to traditional cast-in-place methods.

关键词： Carbon emissions Cost-effectiveness Design simulation method Prefabricated buildings

来源：评论

学校读者我要写书评

暂无评论

Study on load distribution characteristics and wind-resistant performance of standstill wind turbines considering the effect of wind veer

引用

Renewable Energy 2025年

作者： Tao Wu YiEr Cheng Ying Sun Jian Zhang School of Mechanical Engineering University of Shanghai for Science and Technology Shanghai 200093 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 School of Materials Science and Engineering Harbin Institute of Technology Harbin 150090 China

The increasing size of wind turbines has amplified the effects of wind veer, leading to significant differences in the response of wind turbines under varying wind fields. This study, based on Ekman theory, uses CFD simulations to investigate the effect of wind veer on wind load distribution of DTU 10MW wind turbine under shutdown state. The effectiveness of the numerical method is verified by comparing the node pressure of tower, blade and rotor thrust with results from OpenFAST. A numerical model of the wind turbine is developed in ANSYS to assess its wind-resistance performance. The results indicate that wind veer significantly alters the responses of wind turbine. Specifically, compared with the wind field without veering, the lateral thrust of the wind turbine at 30° veering angle increases by nearly 6 times, while the torque around the z-axis increases by nearly 8 times, resulting in more pronounced torsional deformation of the wind turbine. Moreover, the wind veer changes the locations of maximum displacement and stress on wind turbine.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Prediction of uneven distribution of snow load based on generalized regression neural network 10

Prediction of uneven distribution of snow load based on gene...

引用

10th International Structural Engineering and Construction Conference, ISEC 2019

作者： Ren, Zhicheng Zhang, Qingwen Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters Ministry of Industry and Information Technology Harbin Institute of Technology Harbin China

ISBN: (纸本)9780996043762

At present, there are mainly three research ways on the distribution of snow load: field measurement, experimental simulation, and numerical simulation. They all need expensive equipment, specimen model used only once, and slight defective simulation software. Artificial Neural Networks (ANNs) rely on a large number of input functions to estimate unknown or known occurrences. This paper applies ANNs to predict the uneven distribution of snow loads. First, the snow load database is collected and set up, including all the data from field measurement and experimental simulation. Second, part of the data from the 1m3 model is used as a training set to train Backpropagation Neural Networks (BPNN) and Generalized Regression Neural Networks (GRNN). The parameters of the two neural networks are determined (such as the smoothing factor in the GRNN), and the rest of the data is used to examine the model;the prediction and measurement results of the two models are compared. Finally, based on different wind direction angles and wind speed, a GRNN model is established to predict the uneven snow load distribution. Through comparative analysis, GRNN is more suitable for predicting the uneven distribution of snow loads, especially in predicting snow thickness. In particular, the prediction effect of the model on the snow load distribution trend is good, and the prediction ability of the neural network model is displayed. Copyright © 2019 ISEC Press.

关键词： Neural network models

来源：评论

学校读者我要写书评

暂无评论

Crack pattern prediction of laterally loaded panels with openings based on ANN method 10

Crack pattern prediction of laterally loaded panels with ope...

引用

10th International Structural Engineering and Construction Conference, ISEC 2019

作者： Wang, Yongfei Zhang, Yu Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters Ministry of Industry and Information Technology Harbin Institute of Technology Harbin China

ISBN: (纸本)9780996043762

In this paper, a Back Propagation Neural Network (BPNN) is used to predict crack pattern for masonry panels with opening subjected to lateral loading. The cellular automata method is used to digitalize the panels, including two steps - dividing a panel into a certain number of cells and calculating cell state values by use of a Von Neumann neighborhood model. These digitalized values are used as input data of NN model, respectively. All the experimental data is collected, including panel configuration, material property, opening ratio and location, state values, and crack pattern. The NN model is trained repeatedly, taking part of the data as a training set, to determine parameters, and the rest of the data is taken to check the model. Well-trained NN models can predict the crack pattern of any other panel. The results show that NN method is suitable for prediction of crack pattern. Comparing the two ways of prediction, the Fragility Coefficient Method gets a more precise pattern. The predicted cracks are distributed successively in some specific areas, especially in high similarity, compared with experimental crack pattern. Copyright © 2019 ISEC Press.

关键词： Forecasting

来源：评论

学校读者我要写书评

暂无评论

High-temperature electric induction constructing conductive UHPC: Effect of curing regime on stability of conductive network and mechanical properties

引用

Construction and Building Materials 2025年 489卷

作者： Minjie Jia Kunyang Yu Xiangyi Chen Zhichao Xu Yingzi Yang School of Civil Engineering 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 Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin 150090 China School of Water Conservancy and Civil Engineering Northeast Agricultural University Harbin 150030 China

The resistivity of ultra-high-performance concrete (UHPC) can be effectively reduced by the dielectric breakdown phenomenon arising from the high-temperature electric induction, endowing UHPC with potential multifunctional applications. However, the instability in the resistivity of conductive UHPC is presented owing to the short duration of the electric field. In this study, the influence of electrical field duration on the stable formation of conductive networks in UHPC was explored. It turned out that the resistivity of UHPC with 2-h electric field duration after dielectric breakdown can be maintained at a steady low level (decreased from 66 kΩ·cm to 403.56 Ω·cm compared to that of steam-cured UHPC), and it also exhibited a superior compressive strength (137.9 MPa) comparable to that with 3-day steam curing (135.1 MPa), while its energy consumption was accounted for only 11 % required for steam curing. XRD and TG analysis proved the enhanced effect of the electric field on the hydration degree of UHPC, accompanied by the emergence of tobermorite and aragonite products. Moreover, the MIP experiment indicated that the pore structures of UHPC were gradually refined with the electric field duration. This work had opened up a new path for constructing an effective conductive network and rapidly enhancing the electrical and mechanical properties of UHPC.

关键词：

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：