检索结果-内蒙古大学图书馆

Enhancing ventilation in street canyons using adjustable roof-level wind flow deflectors

Energy and Built Environment 2025年第2期6卷 201-218页

作者： Vasudevan, Madhavan Pilla, Francesco McNabola, Aonghus Department of Civil Structural and Environmental Engineering Trinity College Dublin Ireland School of Architecture Planning and Environmental Policy University College Dublin Ireland

Traffic emission impacts the air quality at both the road surface and in near road buildings. Previous research has examined the benefit of using roof-level wind catchers to reduce concentration along building facades in urban environments. Although roof-level interventions are more effective in improving the street canyon air quality in its entirety, localized re-distributions that detrimentally affect specific regions in and around the street canyons are unavoidable. In the current work, a deflector system that can adjust its position and orientation to changing ambient conditions is introduced to ensure that no particular region perpetually experiences compromised air quality. At optimal roof-level positions, the wind deflectors resulted in a local maximum and minimum of pollution removal through mean flow-induced fluxes and overall canyon concentrations respectively. In this study, the potential of the wind deflectors was first demonstrated using 2D Computational Fluid Dynamics (CFD) investigations. A maximum reduction in overall canyon concentration of 2.84 fold was predicted when the deflector was placed 2 m from the leeward walls. Subsequently, the benefit of the dynamic nature of the intervention and the efficacy of the same in a more realistic 3D city-type environment was demonstrated by considering two different pollution source conditions. The wind deflectors performed modestly for the Cross Road Pollution (CRP) source model by reducing 7%, 11% and 13% of CO exposure on the leeward wall, upwind side wall and downwind side wall without affecting the windward wall of the target street canyon. Whereas for the Side Road Pollution (SRP) source model, it reduced 91%, 32% and 34% on the same with a 17% reduction on the windward wall of the target street canyon. Finally, the concept of an adjustable deflector system was demonstrated to mitigate prolonged high exposure for building occupants exposed to changing traffic emission sources via all the surrounding buil

关键词： Roofs

来源：评论

学校读者我要写书评

暂无评论

Refined span-to-depth ratio expressions for one-way slabs aligned with ACI-318 deflection limits

引用

Journal of Umm Al-Qura University for engineering and architecture 2025年 1-9页

作者： Elgohary, Hamdy A. El Zareef, Mohamed A. Civil Engineering Department College of Engineering and Architecture Umm Al-Qura University Makkah Saudi Arabia Structural Engineering Department Faculty of Engineering Mansoura University Mansoura 35516 Egypt

The ACI-318 code presents span-to-depth ratio expressions for solid, non-prestressed one-way slabs to control deflection when the impact on nonstructural items is not significant. These expressions relate slab thickness to span length, incorporating adjustments for steel yield strength and concrete density. However, they do not account for key design factors such as live load and concrete compressive strength, often resulting in conservative slab thickness estimates where the minimum reinforcement ratio is used. The adoption of the Bischoff formula for the effective moment of inertia in ACI-318-19 has further increased predicted deflections compared to the previous Branson formula, necessitating a review of span-to-depth ratio accuracy for deflection control. This study evaluates the compatibility of existing span-to-depth limits with deflections predicted using the Bischoff formula and proposes a new, efficient span-to-depth ratio formula for one-way slab design. The proposed expression incorporates key design factors, including concrete compressive strength, live load, and span length. A parametric analysis was performed to assess the influence of these parameters, and the new formula was derived based on deflection calculations and ACI-318 deflection limits. The suggested span-to-depth ratio is advised for slabs that do not support or connect to elements vulnerable to damage due to excessive deflections. Verification through case studies demonstrates that the predicted deflections using the proposed formula remain within ACI-318 limits while achieving more efficient designs with reduced slab thickness. © The Author(s) 2025.

关键词： Deflection control Deflection limits One-way slab Span-to-depth ratio

来源：评论

学校读者我要写书评

暂无评论

A simplified trilinear concrete stress–strain curve: energy-based modeling of experimental data compliant with various codes

引用

Journal of Umm Al-Qura University for engineering and architecture 2025年 1-11页

作者： Elgohary, Hamdy A. Civil Engineering Department College of Engineering and Architecture Umm Al-Qura University Mecca Saudi Arabia Structural Engineering Department Faculty of Engineering Mansoura University Mansoura 35516 Egypt

The stress–strain relationship of concrete is a key factor in structural engineering, helping to determine how concrete elements respond to loads in terms of strength and deformation. The accuracy of these evaluations depends on the shape of the stress–strain curve, the mathematical model used to represent it, the precise identification of the peak stress point, and the behavior of the material after reaching its peak strength. Energy-based modeling has gained recognition as a powerful and adaptable approach for analyzing concrete mechanical properties. By integrating the stress–strain curve, this method effectively captures energy dissipation and material behavior, providing valuable insights into performance. This study utilizes energy-based modeling to analyze experimental data and develop a more simple and precise stress–strain relationship for concrete. The proposed model is rigorously evaluated by comparing its predictions with experimental results and the idealized response curves from various structural design codes. The findings reveal that the new model aligns more closely with experimental data. This improved accuracy highlights its potential to enhance the reliability of concrete behavior predictions in structural applications. © The Author(s) 2025.

关键词： Concrete Energy modeling Stress–strain diagram

来源：评论

学校读者我要写书评

暂无评论

A STUDY ON STRUCTURE OF WIND VELOCITY DISTRIBUTION AND CORRESPONDING PRESSURE DEFICIT CHARACTERISTICS UNDER THE TORNADO-LIKE WIND FLOW AFFECTED BY SURFACE ROUGHNESS

Journal of Structural and Construction Engineering

引用

Journal of structural and Construction engineering 2025年第827期90卷 15-26页

作者： Kikitsu, Hitomitsu Okuda, Yasuo Takadate, Yuki Building Department National Institute for Land and Infrastructure Management Japan Dept. of Architecture Faculty of Science and Engineering Setsunan University Japan Dept. of Structural Engineering Building Research Institute Japan

In this study, PIV and wind pressure experiments were carried out under tornado-like wind flow affected by surface roughness. The authors discussed the effects of swirl ratio and roughness density on the velocity field and the pressure deficit characteristics near the surface. It was confirmed that the velocity field structure gradually transitioned by changing swirl ratio and roughness density. Next, the pressure deficit characteristics showed that the measured pressure was the lowest when the roughness density was 0.014 at any swirl ratio. In the above discussion, the models on the radial velocity distribution and the pressure deficit distribution were proposed. © 2025 Architectural Institute of Japan. All rights reserved.

关键词： Wind stress

来源：评论

学校读者我要写书评

暂无评论

Use of the Fine Fraction from High-Quality Concrete Recycling as an Alternative Cement Substitute 1st

Use of the Fine Fraction from High-Quality Concrete Recyclin...

引用

1st International Conference on Net-Zero Built Environment: Innovations in Materials, Structures, and Management Practices, NTZR 2024

作者： De Brabandere, Laurena Grigorjev, Vadim Van den Heede, Philip Nachtergaele, Hannah Degezelle, Krist De Belie, Nele Magnel-Vandepitte Laboratory Department of Structural Engineering and Building Materials Faculty of Engineering and Architecture Ghent University Ghent Belgium Devagro Waregem Belgium

ISBN: (纸本)9783031696251

In order to meet the new demand for sustainability and lower carbon emissions for concrete, the production and recycling process has to be adapted. Regarding concrete recycling, the main focus in literature and industry is on the reuse of coarse aggregates. However, the recycling of concrete also generates a fine fraction. In this research, the fine fraction with size 0/2 is ground and studied as a partial cement replacement. First of all, the fines were characterized and their physical, chemical and mineralogical properties were determined. Preliminary tests on pastes and mortars with 0%, 5%, 10%, 15%, 20%, 25% and 30% cement replacement, such as isothermal calorimetry and strength tests, were performed. Based on these results, two concrete mixes were made: one reference mix with CEM I as a binder and natural aggregates and a concrete mix with 10% of CEM I replaced by concrete fines and a combination of natural and recycled aggregates. In this second mix, 27.8% of the sand and 100% of the coarse aggregates were replaced by recycled sand and recycled coarse aggregates. The concrete samples were tested on compressive strength, shrinkage and freeze–thaw resistance. The compressive strength of the green concrete was comparable to the strength of the reference concrete after 28, 56 and 90 days of curing. Concrete specimens containing the recycled fines and recycled aggregates had a higher drying shrinkage;however, a lower autogenous shrinkage was measured in comparison to the reference. Regarding durability, the green concrete had a lower freeze–thaw resistance compared to the reference. © The Author(s) 2025.

关键词： Concrete aggregates

来源：评论

学校读者我要写书评

暂无评论

Distributed Parameter Model for Quantifying Higher Mode Effects in SDRC Systems 30th

Distributed Parameter Model for Quantifying Higher Mode Effe...

引用

30th International Conference on Computational and Experimental engineering and Sciences, ICCES 2024

作者： Dai, Chunxue Wang, Wei Hu, Shuling State Key Laboratory of Disaster Reduction in Civil Engineering and Department of Structural Engineering Tongji University Shanghai200092 China Department of Architecture and Architectural Engineering Kyoto University Kyoto615-8246 Japan

ISBN: (纸本)9783031829062

Self-centering dual rocking core (SDRC) system was developed to improve the seismic relicense of the buildings. However, analysis of the multi-story and high-rise rocking SDRC systems revealed that the higher mode effects led to amplified force demands in the structural members, hence worsening the seismic performance of the structures. To elucidate the working mechanism of the higher mode, analyze the dynamic characteristics of the SDRC systems, and provide design suggestions for the SDRC systems accounting for the higher mode effects, this paper proposed a novel simplified distributed parameter model. Based on the developed simplified model, the modal shape and the characteristic equation of the SDRC system were solved to study the effects of the structural design parameters on the eigenvalues, modal shapes, and internal force distribution of the rocking cores. Based on the analysis results, some structural design recommendations were proposed. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.

关键词： structural members

来源：评论

学校读者我要写书评

暂无评论

A DFE2-SPCE Method for Multiscale Parametric Analysis of Heterogenous Piezoelectric Materials and Structures

引用

Computers, Materials & Continua 2025年第4期83卷 79-96页

作者： Qingxiang Pei Fan Li Ziheng Fei Haojie Lian Xiaohui Yuan College of Architecture and Civil Engineering Xinyang Normal UniversityXinyang464000China Henan International Joint Laboratory of Structural Mechanics and Computational Simulation College of Architecture and Civil EngineeringHuanghuai UniversityZhumadian463000China Key Laboratory ofIn-Situ Property-Improving Mining of Ministry of Education Taiyuan University of TechnologyTaiyuan030024China Department of Architectural Engineering Hanyang UniversitySeoul04763Republic of Korea

This paper employs the Direct Finite Element Squared(DFE2)method to develop Sparse Polynomial Chaos Expansions(SPCE)models for analyzing the electromechanical properties of multiscale piezoelectric *** incorporating variations in piezoelectric and elastic constants,the DFE2 method is utilized to simulate the statistical characteristics—such as expected values and standard deviations—of electromechanical properties,including Mises stress,maximum in-plane principal strain,electric potential gradient,and electric potential,under varying *** approach achieves a balance between computational efficiency and *** SPCE models are used to investigate the influence of piezoelectric and elastic constants on multiscale piezoelectric ***,the multiscale parameterization study investigates how microscale material properties affect the macroscopic response of these structures and materials.

关键词： DFE2 SPCE piezoelectric structures parameter analyses

来源：评论

学校读者我要写书评

暂无评论

Fast-Running Analysis of the Safety of Masonry Constructions 18th

Fast-Running Analysis of the Safety of Masonry Constructions

引用

18th International Brick and Block Masonry Conference, IB2MaC 2024

作者： Gilbert, Matthew Grillanda, Nicola He, Linwei Smith, Colin Valentino, John Department of Civil and Structural Engineering University of Sheffield Sheffield United Kingdom Department of Architecture University of Ferrara Ferrara Italy Faculty for the Built Environment University of Malta Msida Malta

ISBN: (纸本)9783031733130

Limit analysis provides a simple yet effective means of verifying the safety of masonry constructions. Of the numerical rigid block-based approaches that have been developed for this purpose, it has been common to model rocking, sliding and/or crushing of the masonry by use of suitable joint interface failure envelopes. However, in this case failure can only occur at joints (or at a limited number of other pre-defined failure planes). Also, as it will seldom be feasible to model every masonry unit in a real physical construction with a rigid block, engineering judgement must usually be exercised on the number of rigid blocks to be employed;if too few blocks are used there is a danger of over-estimating the safety of a given construction. In this contribution discontinuity layout optimization (DLO) is used as a powerful alternative to the traditional rigid block limit analysis method. DLO involves discretizing a solid body using nodes, and then interconnecting node pairs with potential discontinuities. Parametric surfaces are used to describe the geometry, allowing discontinuities to be identified even within curved structures. A homogenized masonry failure envelope is used to enable a masonry construction comprising numerous physical units to be modelled in a computationally efficient manner. Solutions are obtained using optimization, with the critical subset of discontinuities at failure that define the geometry of the critical failure mechanism sought. In the contribution the proposed approach is applied to simple 3D example problems, demonstrating the efficacy and computational efficiency of the proposed DLO-based analysis approach. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.

关键词： Failure (mechanical)

来源：评论

学校读者我要写书评

暂无评论

Interaction Effect Between RC Frames and Infilled Walls 18th

Interaction Effect Between RC Frames and Infilled Walls

引用

18th International Brick and Block Masonry Conference, IB2MaC 2024

作者： Zhou, Tian Yu, Qian-Qian Gu, Xiang-Lin Zhang, Hong Jin, Xian-Yu State Key Laboratory of Disaster Reduction in Civil Engineering Tongji University Shanghai200092 China Department of Structural Engineering Tongji University Shanghai200092 China Department of Civil Engineering and Architecture Zhejiang University Hangzhou310058 China

ISBN: (纸本)9783031733130

The masonry-infilled reinforced concrete (RC) frame is a common architectural form in many countries around the world. Extensive studies have been conducted to investigate the differences between RC sole frames and masonry-infilled RC frames. Various models, such as equivalent strut models and finite element method-based models, have been proposed to simplify and analyze the seismic performance of a masonry-infilled RC frame. However, the frame-infill interaction effect has not been fully understood. In this paper, a three-dimensional rigid body spring model based on the discrete element method (DEM) was developed to simulate the seismic performance of a masonry-infilled RC frame, such as the lateral bearing capacity, initial stiffness, failure modes and load-displacement curves. Four models with different infilled walls, i.e., hollow clay bricks, concrete hollow blocks, ceramsite concrete blocks, and aerated concrete blocks, were verified by experimental findings from the literature. Stress of the springs between the concrete and masonry elements versus the lateral load was extracted to analyze the frame-infill interaction effect. Based on the analysis of the stress of different specimens, the strength of masonry mortars and the thickness of infilled walls might influence the frame-infill interaction. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.

关键词： Reinforced concrete

来源：评论

学校读者我要写书评

暂无评论

Dynamic anaerobic digestion-based biorefineries for on-demand renewable energy and bioproducts in a circular bioeconomy

引用

Trends in Biotechnology 2025年第5期43卷 1140-1165页

作者： Shinde, Rajas Hackula, Anga Marycz, Milena Bose, Archishman O'Shea, Richard Barth, Susanne Murphy, Jerry D. Wall, David M. SFI MaREI Centre for Energy Climate and Marine Environmental Research Institute University College Cork Cork Ireland Civil Structural and Environmental Engineering School of Engineering and Architecture University College Cork Cork Ireland Crops Environment and Land Use Programme Crop Science Department Teagasc Oak Park Ireland Faculty of Electronics Telecommunications and Informatics and Advanced Materials Centre Gdansk University of Technology Gdańsk Poland Process and Chemical Engineering School of Engineering and Architecture University College Cork Cork Ireland

Anaerobic digestion (AD) is an important biotechnology for treating biodegradable residues and producing bioenergy, yet its full potential remains untapped. We investigate a two-phase AD system for biorefinery applications, producing valuable bioproducts, such as volatile fatty acids (VFAs) and biogas, from grass feedstock. We introduce a demand-driven operational approach to match market conditions, while minimising water use by reusing the process effluent. The proposed biorefinery model yields ~23 kg of VFAs and 75 kWh of biogas, with a potential gross revenue of €84 per tonne of grass. However, a preliminary economic analysis indicates that this biorefinery model is currently unprofitable. A sensitivity analysis suggests that reducing operating costs through technology advancements and policy support are vital to ensure economic viability. Such biorefineries offer opportunities for the diversification of farmers' incomes and the transition away from fossil resources. Our work exemplifies the role of AD as a key biotechnology in the circular bioeconomy. © 2025 The Author(s)

关键词： Sensitivity analysis

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：