检索结果-内蒙古大学图书馆

Wave action by arrays of vertical cylinders with arbitrary smooth cross-section

Journal of Hydrodynamics 2020年第1期32卷 70-81页

作者： Jia-bin Liu An-xin Guo Qing-he Fang Hui Li Hui Hu Peng-fei Liu Key Lab of Structures Dynamic Behavior and Conrol of the Ministry of Education Harbin Institute of Techno-logyHarbin 150090China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of TechnologyHarbin 150090China Depariment of Aerospace Engineering lowa State UniversityAmeslowa 50011USA China Railway Bridge Science Research Institute LtdWuhan 430034China

This paper presents an analytical model to solve the linear wave diffraction problem by arrays of bottom-mounted cylinders with arbitrary smooth *** on the assumption of ideal fluid and potential theory,the unknown coefficients of total velocity potential can be solved by system of linear equations,which are obtained from the boundary *** accuracy of the present method is verified by comparing it with the numerical tool in terms of the wave force and wave *** cylinders with different configurations are tested,the cross-section of which is circular with cosine *** results show that the proposed method could obtain an accurate prediction of the wave action with multiple cylinder ***,the diffraction wave is investigated on arrays of bottom-mounted cylinders with different cross-section and *** near-trapping problem with effects of the multi-body interaction are also investigated.

关键词： Wave diffraction cylinder array arbitrary smooth cross-section analytical solution

来源：评论

学校读者我要写书评

暂无评论

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

SSRN

引用

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

来源：评论

学校读者我要写书评

暂无评论

Efficient structural seismic performance evaluation method using improved endurance time analysis

引用

Earthquake Engineering and Engineering Vibration 2019年第4期18卷 795-809页

作者： Li Shuang Liu Kun Liu Xiangyang Zhai Changhai Xie Fengwei 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

Evaluation of structural performance under seismic excitations from low intensity to high intensity is essential to verify the seismic resistant capacity of a structure, and usually carried out by the incremental dynamic analysis (IDA) method or pushover method. The recently developed endurance time (ET) method is another method that uses dynamic pushover excitations, i.e., endurance time acceleration function, to obtain results similar to those obtained by IDA or pushover methods with low computational cost and acceptable accuracy. This study proposes an improvement on the ET method by considering more restrictions for both the elastic and inelastic response spectra in the generation procedure, and by specifying a target duration. Four reinforced concrete frame structures with 4, 8, 12, and 16 stories are adopted to verify the accuracy of the improved method. Comparison of the results obtained by the proposed method, the ET method and the IDA method shows that the improved method has a higher accuracy than the ET method. For evaluation of structural responses under specifi c ground motion intensity, which is typically required in seismic design codes, the results obtained by the proposed method are compared with fi ve commonly used ground motion selection methods, and shows the proposed method provides acceptable accuracy for engineering applications.

关键词： seismic performance evaluation endurance time method inelastic response spectra target duration

来源：评论

学校读者我要写书评

暂无评论

Development of dimensionless P-I diagram for curved SCS sandwich shell subjected to uniformly distributed blast pressure

引用

Frontiers of Structural and Civil Engineering 2019年第6期13卷 1432-1445页

作者： Yonghui WANG Ximei ZHAI Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of TechnologyHarbin 150090China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of TechnologyHarbin 150090China

The curved steel-concrete-steel(SCS)sandwich shell was recently proposed to resist blast loading and it showed better blast resistant performance as compared to flat SCS sandwich shell via developing compressive force along the *** this paper,a dimensionless Pressure-Impulse(P-I)diagram was constructed as a convenient tool to predict the damage level of curved SCS sandwich shell subjected to uniformly distributed blast *** curved SCS sandwich shell was equivalent to a single-degree-oMreedom(SDOF)system and the equation of motion was established by employing the Lagrange's *** construct the dimensionless P-I diagram,the energy balance method was utilized to yield the pressure and impulse asymptotes and the responses in the dynamic response regime were obtained via employing the SDOF ***,the finite element method was employed to validate the developed dimensionless P-I ***,the procedures of using the constructed dimensionless P-I diagram to quickly conduct the blast resistant design of curved SCS sandwich shell were presented.

关键词： blast loading curved steel-concrete-steel sandwich shell Pressure-Impulse diagram single-degree-of-freedom method finite element analysis

来源：评论

学校读者我要写书评

暂无评论

Aerodynamic design and analysis for offshore wind turbine blade model

引用

Energy 2025年 330卷

作者： Zhang, Ziyang Chen, Wen-Li Liu, Jiabin 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

Model experiments are essential for designing and analysing offshore wind turbines. During the scaling process of the model, the rotor thrust significantly decreases due to the Reynolds number effect. As wind turbines increase in size, blade length also gradually increases. The scaling ratio of the model decreases due to laboratory size constraints, affecting the structural loading characteristics. Therefore, this study performs an aerodynamic design for model blades, considering the Reynolds number effects and geometric dimensions. The optimised blade satisfies the scaled model's thrust requirements when its length is shorter than the scaled prototype blade. We employed the low Reynolds number airfoil SG 6043 to optimise the model blade. The geometric parameters of the optimised blades were calculated using the blade element momentum theory and pattern search method. Wind tunnel experiments were conducted on the optimised blade to analyse the variation characteristics of rotor thrust. The research results show that the numerical calculation results of rotor thrust generally align with the experimental results. The rotor thrust of the optimised blades was significantly enhanced, meeting the scaled model's thrust requirements. The error between the optimised blade's rotor thrust and the scaled target value is less than 2 %. © 2025 Elsevier Ltd

关键词： Wind turbine blades

来源：评论

学校读者我要写书评

暂无评论

Genetic algorithm-based shape optimization of plates for reducing wave loads on cylindrical structure

引用

Ocean Engineering 2025年 337卷

作者： Jingbo Qing Peimian Du Pengwei Bei Jiabin Liu Anxin Guo 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

Theoretical studies have shown that incorporating protective plates into cylindrical structures reduces wave-induced loads. This study applies the Boundary Element Method (BEM) to analyze linear wave-structure interactions and employs the Genetic Algorithm (GA) for global optimization to determine the optimal plate shape. Experimental analyses were conducted under various wave conditions to further evaluate the performance of the protective plates. The evaluation included three distinct types of protective plates: the GA-optimized curved plate, the flat plate, and the porous plate. The results show that all three protective plate types effectively reduce wave-induced loads but also increase wave run-up. Compared to flat and porous plates, the optimized curved plate performs better in reducing bending moments. The effectiveness of the protective plates is not significant near k 0 R = 0.5 , and may even increase wave loads. The influence of protective plates resembles wave shoaling, altering wave forms and dissipating energy. Wave impact and breaking can occur during this process, highlighting the limitations of linear potential flow theory in modeling interactions between waves and protective plates.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Experimental Study of High-Temperature Resistance of Alkali-Activated Slag Crushed Aggregate Mortar

SSRN

引用

SSRN 2022年

作者： Huang, Wenxuan Wang, Ying Zhang, Yaming Zheng, Wenzhong School of Civil Engineering Harbin Institute of Technology Haihe Road #202 Nangang District Harbin150090 China Key Lab of Structures Dynamic Behavior and Control Ministry of Education Key Lab Smart Prevention and Mitigation of Civil Engineering Disasters Ministry of Industry and Information Technology School of Civil Engineering Harbin Institute of Technology Haihe Road #202 Nangang District Harbin150090 China

In this research, a special type of mortar with alkali-activated slag as cementitious material was examined, which had the characteristics of high strength, high temperature resistance and environmental protection. Its aggregates consisted of crushed and sieved particles of alkali-activated slag paste. The compressive strengths of 126 cubic and 126 prismatic specimens during and after high-temperature treatment were investigated. The test results showed that both the compressive and flexural strengths of the mortar during and after high-temperature treatment decreased with increasing temperature. Moreover, the compressive strength of the mortar after high-temperature treatment was higher than that during the treatment in which strength grade and temperature were constant. The high-temperature strength loss of the mortar was also found to be lower than that of concrete. The formulated equations for calculating the compressive and flexural strengths during and after high-temperature treatment provided a basis for evaluating the fire resistance of this new type of masonry material. The microstructure and composition of the mortar were analyzed using scanning electron microscopy with energy-dispersive spectrometry and X-ray diffraction. At 600 ℃, the mortar gradually produced new melilite products. © 2022, 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

Preparation and Properties of a Cement-Based Permeable Crystalline Repair Material

SSRN

引用

SSRN 2021年

作者： Lu, Rongwei Guan, Xinchun Zhang, Chenchen Kou, Yufeng Li, Jinglu Li, Yazhao Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China Harbin Institute of Technology Harbin150090 China

According to the performance requirements of concrete repair materials, a new cement-based permeable crystalline repair material（CCRM） was prepared, and its repair performance and repair mechanism were studied by means of macro mechanical property test, micro ESEM and XRD. The experimental results show that the prepared repair material not only has good flow performance and strength, but also enhances the strength of the repair interface, so that the repair interface is no longer the weak point of the repaired specimen. Through the observation of the microstructure of the repaired specimen, it is found that CCRM can penetrate into the interface of the repaired specimen to form a cross transition zone, and then form a better integration with the repaired specimen, with very good compatibility. Through the test of CCRM repair products by XRD and TG, it is found that there is an active component in CCRM, which can consume calcium hydroxide to form a complex, promote the transformation of calcium carbonate and C-S-H, and then enhance the repair effect. © 2021, The Authors. All rights reserved.

关键词： Repair

来源：评论

学校读者我要写书评

暂无评论

Deep-Learning-Based Bridge Condition Assessment by Probability Density Distribution Reconstruction of Girder Vertical Deflection and Cable Tension Using Unsupervised Image Transformation Model 10th

Deep-Learning-Based Bridge Condition Assessment by Probabili...

引用

10th European Workshop on Structural Health Monitoring, EWSHM 2020

作者： Xu, Yang Tian, Yadi Zhang, Yufeng Li, Hui 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 Dynamics Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China State Key Laboratory of Safety and Health for Inservice Long Span Bridges Nanjing211112 China

ISBN: (纸本)9783030649074

This study proposes a deep-learning-based condition assessment approach by reconstructing marginal probability density distributions of girder vertical deflection (GVD) and cable tension (CT) using unsupervised image transformation (UNIT) model for a real cable-stayed bridge. 27 and 139 sensors of GVD and CT are distributed along the full bridge, and both the sampling frequencies are 2 Hz. First, vehicle-induced components of GVD and CT are extracted by data pre-processing while the temperature-induced components are removed, a time window of 3 h with a sliding length of 10 min is used to obtain original GVD and CT segments, and the corresponding margin probability density distributions (PDFs) are calculated by kernel density estimation. The training and test sets consist of 2986 and 6236 PDFs, respectively. The proposed UNIT model consists of a series of variational autoencoders (VAEs) and generative adversarial networks (GANs). Both the PDFs of GVD and CT are used as inputs. Then, the proposed UNIT model is updated by solving the mini-max problem of training GANs, in which VAEs act as generative models. Finally, the Wasserstein distance between the predicted and ground-truth PDFs of CT acts as the indicator of bridge condition change. Results show that specific modes of PDF variations induced by SHM system upgrade, cable damage, data anomaly, and traffic jam can be recognized to assess bridge condition. © 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Deep learning

来源：评论

学校读者我要写书评

暂无评论

Discovering Governing Equations by Machine Learning implemented with Invariance

arXiv

引用

arXiv 2022年

作者： Chen, Chao Jin, Xiaowei Li, Hui 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 Dynamics Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China

The partial differential equation (PDE) plays a significantly important role in many fields of science and engineering. The conventional case of the derivation of PDE mainly relies on first principles and empirical observation. However, the development of machine learning technology allows us to mine potential control equations from the massive amounts of stored data in a fresh way. Although there has been considerable progress in the data-driven discovery of PDE, the extant literature mostly focuses on the improvements of discovery methods, without substantial breakthroughs in the discovery process itself, including the principles for the construction of candidates and how to incorporate physical priors. In this paper, through rigorous derivation of formulas, novel physically enhanced machining learning discovery methods for control equations: GSNN (Galileo Symbolic Neural Network) and LSNN (Lorentz Symbolic Neural Network) are firstly proposed based on Galileo invariance and Lorentz invariance respectively, setting forth guidelines for building the candidates of discovering equations. The adoption of mandatory embedding of physical constraints is fundamentally different from PINN in the form of the loss function, thus ensuring that the designed Neural Network strictly obeys the physical prior of invariance and enhancing the interpretability of the network. By comparing the results with PDE-NET in numerical experiments of Burgers equation and Sine-Gordon equation, it shows that the method presented in this study has better accuracy, parsimony, and interpretability. © 2022, CC BY.

关键词： Numerical methods

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：