Pub Date : 2023-12-29DOI: 10.3390/buildings14010094
Weihao Hao, Abel Tablada, Xuepeng Shi, Lijun Wang, Xi Meng
Productive facades, consisting of photovoltaic shading and vertical farming systems, have been proposed as a means to improve the thermal and visual status of residential buildings while also maintaining energy performance and providing vegetables. However, how to quickly and accurately predict electricity and vegetable output during the numerous influencing architectural and environmental factors is one of the key issues in the early stages of design, and few studies have investigated the impact of such structures on both indoor environmental qualities and production performance. In this paper, we present a novel prediction method that uses experimental data to train and test an artificial neural network (ANN). The results indicated that using the Bipolar Sigmoid activation function to process the experimental data input to the artificial neuron network gives more accurate predicted results both in the yield of photovoltaic shading and vertical farming systems. In addition, this prediction method was applied to a typical high-rise residential building in Singapore to assess the self-sufficiency potential of high-rise residential buildings integrated with productive facades. The results indicated that the upper part of the building can meet 20.0–23.1% of the annual household electricity demand of a family of four in a four-room residential unit in Singapore and almost the entire year’s vegetable demand, while the middle part can meet 18.4–21.2% and 89.1%, respectively. The results demonstrated the importance of a productive facade in reducing energy demand, enhancing food security, and improving indoor visual and thermal comfort.
{"title":"Efficiency Analysis of the Photovoltaic Shading and Vertical Farming System by Employing the Artificial Neural Network (ANN) Method","authors":"Weihao Hao, Abel Tablada, Xuepeng Shi, Lijun Wang, Xi Meng","doi":"10.3390/buildings14010094","DOIUrl":"https://doi.org/10.3390/buildings14010094","url":null,"abstract":"Productive facades, consisting of photovoltaic shading and vertical farming systems, have been proposed as a means to improve the thermal and visual status of residential buildings while also maintaining energy performance and providing vegetables. However, how to quickly and accurately predict electricity and vegetable output during the numerous influencing architectural and environmental factors is one of the key issues in the early stages of design, and few studies have investigated the impact of such structures on both indoor environmental qualities and production performance. In this paper, we present a novel prediction method that uses experimental data to train and test an artificial neural network (ANN). The results indicated that using the Bipolar Sigmoid activation function to process the experimental data input to the artificial neuron network gives more accurate predicted results both in the yield of photovoltaic shading and vertical farming systems. In addition, this prediction method was applied to a typical high-rise residential building in Singapore to assess the self-sufficiency potential of high-rise residential buildings integrated with productive facades. The results indicated that the upper part of the building can meet 20.0–23.1% of the annual household electricity demand of a family of four in a four-room residential unit in Singapore and almost the entire year’s vegetable demand, while the middle part can meet 18.4–21.2% and 89.1%, respectively. The results demonstrated the importance of a productive facade in reducing energy demand, enhancing food security, and improving indoor visual and thermal comfort.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"91 3","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139147382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-29DOI: 10.3390/buildings14010095
Usman Masood, M. Haggag, Ahmed Hassan, Mohammad Laghari
This research investigates the use of phase change materials (PCMs) in thermal energy storage (TES) unit-based cooling systems to increase the efficiency of air conditioners (ACs) by reducing the air inlet temperature. This study aims to evaluate different configurations of PCM enclosures, and different PCMs (paraffin and salt hydrate), by changing the speed of inlet air to achieve heat reduction of inlet air. The study includes experimental and simulation investigations. Every configuration simulates the hot-season atmospheric conditions of the UAE. A duct containing enclosures of paraffin RT-31 and salt hydrate (calcium chloride hexahydrate) was used for the simulation study using ANSYS/Fluent. A conjugate heat transfer model employing an enthalpy-based formulation is developed to predict the optimized PCM number of series and optimum airflow rate. Four designs of the AC duct were modelled and evaluated that contained one to four series of PCM containers subjected to different levels of supplied air velocities ranging from 1 m/s–4 m/s. The simulation study revealed that employing four series (Design 4) of PCM enclosures at a low air velocity of 1 m/s enhanced the pre-cooling performance and reduced the outlet air temperature to 33 °C, yielding a temperature drop up to 13 °C. The performance of salt hydrate (calcium chloride hexahydrate) was observed to be better than paraffin (RT-31) in terms of the cooling effect. Characterization of paraffin wax (RT-31) and salt hydrate was performed to establish the thermophysical properties. The experimental setup based on a duct with integrated PCM enclosures was studied. The experiment was repeated for three days as the repeatability test incorporating RT-31 as the PCM and a 3 °C maximum temperature drop was observed. The drop in the outlet air temperature of the duct system quantifies the cooling effect. Net heat reduction was around 16%.
{"title":"Evaluation of Phase Change Materials for Pre-Cooling of Supply Air into Air Conditioning Systems in Extremely Hot Climates","authors":"Usman Masood, M. Haggag, Ahmed Hassan, Mohammad Laghari","doi":"10.3390/buildings14010095","DOIUrl":"https://doi.org/10.3390/buildings14010095","url":null,"abstract":"This research investigates the use of phase change materials (PCMs) in thermal energy storage (TES) unit-based cooling systems to increase the efficiency of air conditioners (ACs) by reducing the air inlet temperature. This study aims to evaluate different configurations of PCM enclosures, and different PCMs (paraffin and salt hydrate), by changing the speed of inlet air to achieve heat reduction of inlet air. The study includes experimental and simulation investigations. Every configuration simulates the hot-season atmospheric conditions of the UAE. A duct containing enclosures of paraffin RT-31 and salt hydrate (calcium chloride hexahydrate) was used for the simulation study using ANSYS/Fluent. A conjugate heat transfer model employing an enthalpy-based formulation is developed to predict the optimized PCM number of series and optimum airflow rate. Four designs of the AC duct were modelled and evaluated that contained one to four series of PCM containers subjected to different levels of supplied air velocities ranging from 1 m/s–4 m/s. The simulation study revealed that employing four series (Design 4) of PCM enclosures at a low air velocity of 1 m/s enhanced the pre-cooling performance and reduced the outlet air temperature to 33 °C, yielding a temperature drop up to 13 °C. The performance of salt hydrate (calcium chloride hexahydrate) was observed to be better than paraffin (RT-31) in terms of the cooling effect. Characterization of paraffin wax (RT-31) and salt hydrate was performed to establish the thermophysical properties. The experimental setup based on a duct with integrated PCM enclosures was studied. The experiment was repeated for three days as the repeatability test incorporating RT-31 as the PCM and a 3 °C maximum temperature drop was observed. The drop in the outlet air temperature of the duct system quantifies the cooling effect. Net heat reduction was around 16%.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":" 45","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139144176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-29DOI: 10.3390/buildings14010098
Xue Ding, Long Feng, Yao Huang, Wei Li
A PBO is a temporary organization formed by assembling members with diverse experiences and backgrounds, aimed at achieving specific innovation goals. Constructing a reasonable communication network structure and enhancing organizational synergy are effective ways to promote the sustainable development of the system. This study, based on the Input–Process–Output (IPO) model and social network analysis, utilized a group collaboration platform to conduct a three-stage communication experiment on 685 construction project managers. Under two organizational sizes, the internal mechanism of how communication networks with two levels of centralization influence task performance were tested. The results indicate that in the case of a smaller organizational size, PBOs using a decentralized communication network tend to achieve higher task performance. However, as the organizational size expands, PBOs employing a centralized communication network may surpass in task performance. Additionally, we found that with the expansion of organizational size, bootleg innovation behaviors of organizational members are continually stimulated, further enhancing collective task performance. This study, based on the evolution of communication network parameters, explores the structural characteristics of organizational communication networks and the mechanisms underlying the emergence of bootleg innovation behaviors. It delineates the key pathways for improving collective task performance. The findings can provide a scientific reference for the organizational evolution and development of engineering project management.
{"title":"The Interactive Effects of Communication Network Structure and Organizational Size on Task Performance in Project-Based Organizations: The Mediating Role of Bootleg Innovation Behavior","authors":"Xue Ding, Long Feng, Yao Huang, Wei Li","doi":"10.3390/buildings14010098","DOIUrl":"https://doi.org/10.3390/buildings14010098","url":null,"abstract":"A PBO is a temporary organization formed by assembling members with diverse experiences and backgrounds, aimed at achieving specific innovation goals. Constructing a reasonable communication network structure and enhancing organizational synergy are effective ways to promote the sustainable development of the system. This study, based on the Input–Process–Output (IPO) model and social network analysis, utilized a group collaboration platform to conduct a three-stage communication experiment on 685 construction project managers. Under two organizational sizes, the internal mechanism of how communication networks with two levels of centralization influence task performance were tested. The results indicate that in the case of a smaller organizational size, PBOs using a decentralized communication network tend to achieve higher task performance. However, as the organizational size expands, PBOs employing a centralized communication network may surpass in task performance. Additionally, we found that with the expansion of organizational size, bootleg innovation behaviors of organizational members are continually stimulated, further enhancing collective task performance. This study, based on the evolution of communication network parameters, explores the structural characteristics of organizational communication networks and the mechanisms underlying the emergence of bootleg innovation behaviors. It delineates the key pathways for improving collective task performance. The findings can provide a scientific reference for the organizational evolution and development of engineering project management.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":" 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139142879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-29DOI: 10.3390/buildings14010097
Kai Ren, Tiehong Wu
The rural construction community embodies a confluence of social dynamics within rural areas, constituting an organic self-organization with hierarchical relationships. Over a specific period, the amalgamation of various roles and relationships within the rural construction community shapes the prevalent culture, distinctive image, and production techniques within villages. This study examines the structural composition of village communities and endeavors to establish a linkage mechanism among different elements within the construction framework. Focusing on villages and their inhabitants, this research traces the temporal evolution along the following axes: (1) Traditional Agricultural Civilization Age; (2) Collective Economy Age; (3) Rural Industrialization Age; (4) Rural Differentiation Age; and (5) Rural Revitalization Age. This paper primarily observes the evolution through the cultural foundation and manifestation of rural communities, emphasizing that the communities represent cooperative, autonomous, and transformative constructs. From the perspective of cultural landscapes, this article elucidates the interconnected trajectory of ecology–institution–livelihood in the creation of rural communities. It interprets the interplay among the resource patterns, social structure, and economic forms of villages across five distinct periods, fostering a comprehensive understanding of rural community development amidst changing circumstances. Recent years have seen a concerning decline in rural areas, where rural community culture faces a significant impact from modern industrial civilization, resulting in the disintegration of the social fabric within community construction. Nevertheless, the resilient common sense and self-organization capabilities of villagers persist. This study seeks to offer theoretical guidance and decision-making support to advance innovative social governance in rural locales. Moving forward, China’s rural revitalization demands a more adaptive sustainable assessment within rural construction communities.
{"title":"Analyzing the Evolution of a Rural Construction Community in China from the Perspective of Cultural Landscape","authors":"Kai Ren, Tiehong Wu","doi":"10.3390/buildings14010097","DOIUrl":"https://doi.org/10.3390/buildings14010097","url":null,"abstract":"The rural construction community embodies a confluence of social dynamics within rural areas, constituting an organic self-organization with hierarchical relationships. Over a specific period, the amalgamation of various roles and relationships within the rural construction community shapes the prevalent culture, distinctive image, and production techniques within villages. This study examines the structural composition of village communities and endeavors to establish a linkage mechanism among different elements within the construction framework. Focusing on villages and their inhabitants, this research traces the temporal evolution along the following axes: (1) Traditional Agricultural Civilization Age; (2) Collective Economy Age; (3) Rural Industrialization Age; (4) Rural Differentiation Age; and (5) Rural Revitalization Age. This paper primarily observes the evolution through the cultural foundation and manifestation of rural communities, emphasizing that the communities represent cooperative, autonomous, and transformative constructs. From the perspective of cultural landscapes, this article elucidates the interconnected trajectory of ecology–institution–livelihood in the creation of rural communities. It interprets the interplay among the resource patterns, social structure, and economic forms of villages across five distinct periods, fostering a comprehensive understanding of rural community development amidst changing circumstances. Recent years have seen a concerning decline in rural areas, where rural community culture faces a significant impact from modern industrial civilization, resulting in the disintegration of the social fabric within community construction. Nevertheless, the resilient common sense and self-organization capabilities of villagers persist. This study seeks to offer theoretical guidance and decision-making support to advance innovative social governance in rural locales. Moving forward, China’s rural revitalization demands a more adaptive sustainable assessment within rural construction communities.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"180 1","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139145639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-29DOI: 10.3390/buildings14010091
Hongwei Zhu, Liang Wang, Chao Li, Simon P. Philbin, Hujun Li, Hui Li, Martin Skitmore
With digital transformation underway in various Chinese construction enterprises, each enterprise has progressed differently, and a clear direction for future digital transformation and upgrading is lacking. As such, the importance of measuring the level of digitization among Chinese construction enterprises is increasing. This paper presents a model for evaluating digital transformation maturity within construction enterprises. The model considers six aspects: digital strategy, digital business applications, digital technology capabilities, and so on. The digital maturity of enterprises is determined using the Analysis of Hierarchy (AHP)-Decision Making Experiment and Evaluation Laboratory (DEMATEL) method. Technical abbreviations are explained when first used. This study demonstrates that digital business applications are the most significant primary indicator, with a weight of 29.53%. The success of digital transformation in the construction industry is strongly influenced by the interconnection between digital technology and construction sites, as well as other factors such as new technical personnel, digital infrastructure, digital innovation, and innovation iteration ability. It is crucial to understand how digital technology and the construction industry can effectively connect in order to achieve success in this realm. This paper aims to enhance the digital transformation capabilities and efficiency of construction companies and boost their core competitiveness through targeted measures.
{"title":"Building a Digital Transformation Maturity Evaluation Model for Construction Enterprises Based on the Analytic Hierarchy Process and Decision-Making Trial and Evaluation Laboratory Method","authors":"Hongwei Zhu, Liang Wang, Chao Li, Simon P. Philbin, Hujun Li, Hui Li, Martin Skitmore","doi":"10.3390/buildings14010091","DOIUrl":"https://doi.org/10.3390/buildings14010091","url":null,"abstract":"With digital transformation underway in various Chinese construction enterprises, each enterprise has progressed differently, and a clear direction for future digital transformation and upgrading is lacking. As such, the importance of measuring the level of digitization among Chinese construction enterprises is increasing. This paper presents a model for evaluating digital transformation maturity within construction enterprises. The model considers six aspects: digital strategy, digital business applications, digital technology capabilities, and so on. The digital maturity of enterprises is determined using the Analysis of Hierarchy (AHP)-Decision Making Experiment and Evaluation Laboratory (DEMATEL) method. Technical abbreviations are explained when first used. This study demonstrates that digital business applications are the most significant primary indicator, with a weight of 29.53%. The success of digital transformation in the construction industry is strongly influenced by the interconnection between digital technology and construction sites, as well as other factors such as new technical personnel, digital infrastructure, digital innovation, and innovation iteration ability. It is crucial to understand how digital technology and the construction industry can effectively connect in order to achieve success in this realm. This paper aims to enhance the digital transformation capabilities and efficiency of construction companies and boost their core competitiveness through targeted measures.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":" 46","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139143199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, a data-driven modeling method for precast concrete (PC) balcony components was proposed to solve the problems of low informatization and the difficult modeling of components at the design stage. Through the analysis of the characteristics of PC balcony components and the combination of modular design methods, the paper designed a data structure for the components and developed a data-driven modeling tool for PC balcony components that can realize the input of structural design data, automatically generating component models. First, this paper introduced the data-driven modeling concept and the modeling process. Second, the PC balcony components in common prefabricated residential projects were analyzed to identify their characteristics. By using a modular design approach, these components were divided and a module dataset was created based on the split modules. Consequently, a data structure for the prefabricated balcony component model was established, wherein both conventional parameters and adaptive parameters between modules were interrelated. Finally, the function of data-driven modeling was achieved by developing a modular design tool on the Revit platform using the C# programming language. The application conducted on a prefabricated building project demonstrated that the software tool and modeling method in this paper effectively improve the level of informatization and modeling efficiency of PC balcony components. The modular design approach was satisfied with the standardization and diversification requirements of balcony components, thereby offering insights for modeling other complex components.
本文提出了一种数据驱动的预制混凝土（PC）阳台构件建模方法，以解决设计阶段构件信息化程度低、建模困难的问题。通过分析 PC 阳台构件的特点，结合模块化设计方法，本文设计了构件数据结构，开发了数据驱动的 PC 阳台构件建模工具，可实现结构设计数据的输入，自动生成构件模型。首先，本文介绍了数据驱动建模的概念和建模过程。其次，分析了常见预制住宅项目中的 PC 阳台构件，找出了它们的特点。通过模块化设计方法，对这些组件进行了划分，并根据划分后的模块创建了模块数据集。因此，建立了预制阳台组件模型的数据结构，其中模块之间的常规参数和自适应参数相互关联。最后，通过使用 C# 编程语言在 Revit 平台上开发模块化设计工具，实现了数据驱动建模的功能。在一个预制建筑项目中的应用表明，本文的软件工具和建模方法有效提高了 PC 阳台组件的信息化水平和建模效率。模块化设计方法满足了阳台构件标准化和多样化的要求，从而为其他复杂构件的建模提供了启示。
{"title":"Research on a Data-Driven Modeling Method for Precast Concrete Balcony Components","authors":"Jie Cai, Xin Wang, Junfeng Shi, Xingxing Xie, Yu Feng, Yingjun Wu","doi":"10.3390/buildings14010096","DOIUrl":"https://doi.org/10.3390/buildings14010096","url":null,"abstract":"In this paper, a data-driven modeling method for precast concrete (PC) balcony components was proposed to solve the problems of low informatization and the difficult modeling of components at the design stage. Through the analysis of the characteristics of PC balcony components and the combination of modular design methods, the paper designed a data structure for the components and developed a data-driven modeling tool for PC balcony components that can realize the input of structural design data, automatically generating component models. First, this paper introduced the data-driven modeling concept and the modeling process. Second, the PC balcony components in common prefabricated residential projects were analyzed to identify their characteristics. By using a modular design approach, these components were divided and a module dataset was created based on the split modules. Consequently, a data structure for the prefabricated balcony component model was established, wherein both conventional parameters and adaptive parameters between modules were interrelated. Finally, the function of data-driven modeling was achieved by developing a modular design tool on the Revit platform using the C# programming language. The application conducted on a prefabricated building project demonstrated that the software tool and modeling method in this paper effectively improve the level of informatization and modeling efficiency of PC balcony components. The modular design approach was satisfied with the standardization and diversification requirements of balcony components, thereby offering insights for modeling other complex components.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":" 2","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139143140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-29DOI: 10.3390/buildings14010099
Y. Shin, J. Ko, Dong-An Cha, J. Hong
An inappropriate thermal environment negatively impacts workers, causing mental stress and safety accidents. Unskilled workers are more vulnerable to industrial accidents and thermal stress compared with skilled workers due to suboptimal and unfamiliar work. Previous studies have focused on individual characteristics (such as gender, age, and race), with limited emphasis on the thermal comfort sensation. This study identified the preferred thermal environment according to work experience and how mental stress differed between unskilled and skilled workers by examining their thermal comfort sensation. Predicted mean vote (PMV) was used as an indicator of the thermal environment, and five environments were constructed for PMV: -2, -1, 0, 1, and 2. Participants were recruited among current workers and the public. Mental stress and thermal comfort sensation were assessed using heart rate variability and thermal comfort vote, respectively. This study demonstrated that the skilled group experienced higher mental stress and a lower thermal comfort sensation. Contrastingly, in the sensitivity analysis, the unskilled group exhibited greater sensitivity to changes in the thermal environment. Through a comprehensive analysis, this study derived an optimal PMV range for each group. The findings can provide a reference for configuring the optimal thermal environment of the workplace.
{"title":"The Effect of Length of Service in a Thermal Environment on Thermal Comfort and Mental Stress","authors":"Y. Shin, J. Ko, Dong-An Cha, J. Hong","doi":"10.3390/buildings14010099","DOIUrl":"https://doi.org/10.3390/buildings14010099","url":null,"abstract":"An inappropriate thermal environment negatively impacts workers, causing mental stress and safety accidents. Unskilled workers are more vulnerable to industrial accidents and thermal stress compared with skilled workers due to suboptimal and unfamiliar work. Previous studies have focused on individual characteristics (such as gender, age, and race), with limited emphasis on the thermal comfort sensation. This study identified the preferred thermal environment according to work experience and how mental stress differed between unskilled and skilled workers by examining their thermal comfort sensation. Predicted mean vote (PMV) was used as an indicator of the thermal environment, and five environments were constructed for PMV: -2, -1, 0, 1, and 2. Participants were recruited among current workers and the public. Mental stress and thermal comfort sensation were assessed using heart rate variability and thermal comfort vote, respectively. This study demonstrated that the skilled group experienced higher mental stress and a lower thermal comfort sensation. Contrastingly, in the sensitivity analysis, the unskilled group exhibited greater sensitivity to changes in the thermal environment. Through a comprehensive analysis, this study derived an optimal PMV range for each group. The findings can provide a reference for configuring the optimal thermal environment of the workplace.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":" 7","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139144566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-29DOI: 10.3390/buildings14010092
Abdullah Cengiz, Tuba Gurbuz, A. Ilki, Metin Aydogan
Columns can suffer heavy damage due to dynamic impact effects, which are ignored during their design. The impact effect could be a vehicle crash to columns of streetside buildings, parking garages or bridges. However, the effect of impact loading on the behavior of reinforced concrete columns has not been sufficiently studied. In this study, an experimental and numerical investigation is carried out on the impact behavior of axially loaded reinforced concrete columns. Dynamic experiments were carried out by dropping a mass from different heights to apply low-elevation impact on axially loaded, full-scale (30 × 30 × 320 cm) columns. After evaluating the performance of the columns under varied impact loadings, the residual load carrying capacities of the columns were also obtained by static loading. Additionally, a three-dimensional finite element model was developed and validated by using drop weight experimental results. The effect of increasing the impact energy on the behavior of RC columns was also examined numerically. As a result of the research, it has been observed that, as the applied impact energy increases, the dynamic damage/failure mode changes from flexure to shear. When a column was impacted by 75.8% of its total impact energy capacity, a decrease of 38.1% in its stiffness and a decrease of 49.7% in its load carrying capacity were determined compared to its previous unimpacted state. Additionally, the static energy dissipation capacity loss of the column was reached, up to 81.7% of its preloading state. The developed finite element model can also be utilized to determine the dynamic performance and the damage modes of columns under vehicle collision-type low-elevation impacts, which can be a guide for structural engineers in the design of such vulnerable columns and will contribute to safer structural designs.
{"title":"Dynamic and Residual Static Behavior of Axially Loaded RC Columns Subjected to Low-Elevation Impact Loading","authors":"Abdullah Cengiz, Tuba Gurbuz, A. Ilki, Metin Aydogan","doi":"10.3390/buildings14010092","DOIUrl":"https://doi.org/10.3390/buildings14010092","url":null,"abstract":"Columns can suffer heavy damage due to dynamic impact effects, which are ignored during their design. The impact effect could be a vehicle crash to columns of streetside buildings, parking garages or bridges. However, the effect of impact loading on the behavior of reinforced concrete columns has not been sufficiently studied. In this study, an experimental and numerical investigation is carried out on the impact behavior of axially loaded reinforced concrete columns. Dynamic experiments were carried out by dropping a mass from different heights to apply low-elevation impact on axially loaded, full-scale (30 × 30 × 320 cm) columns. After evaluating the performance of the columns under varied impact loadings, the residual load carrying capacities of the columns were also obtained by static loading. Additionally, a three-dimensional finite element model was developed and validated by using drop weight experimental results. The effect of increasing the impact energy on the behavior of RC columns was also examined numerically. As a result of the research, it has been observed that, as the applied impact energy increases, the dynamic damage/failure mode changes from flexure to shear. When a column was impacted by 75.8% of its total impact energy capacity, a decrease of 38.1% in its stiffness and a decrease of 49.7% in its load carrying capacity were determined compared to its previous unimpacted state. Additionally, the static energy dissipation capacity loss of the column was reached, up to 81.7% of its preloading state. The developed finite element model can also be utilized to determine the dynamic performance and the damage modes of columns under vehicle collision-type low-elevation impacts, which can be a guide for structural engineers in the design of such vulnerable columns and will contribute to safer structural designs.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"10 35","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139147405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-12-28DOI: 10.3390/buildings14010085
Kai Ma, Changyong Zhang, Xinzhi Dang, Guoquan Zhang
To investigate the vortex-induced vibration (VIV) characteristics of two rectangular cylinders with a width-to-depth ratio of 5:1 in a tandem arrangement, sectional model wind tunnel tests that measure vibration responses and pressure distributions simultaneously were adopted. The ratio of the spacing between the cylinders to its width is 1.2. The analyses were performed considering VIV responses as well as the distribution characteristics of mean and rms pressure coefficients. Additionally, the time-frequency domain statistical parameters like correlation and contribution coefficients, phase lags between distributed and general vortex excited forces (VEFs), and amplitudes of VEF coefficients at predominant frequencies were calculated to analyze the physical VIV mechanism of two 5:1 rectangular cylinders in tandem. This study indicates that the influence of incidence angles on the dynamic responses is notable; the contribution of the distributed VEFs acting on the trailing surface of the upstream cylinder and the leading surface of the downstream one is significant to VIVs of the cylinders from wind pressure distribution characteristics and correlation analyses.
{"title":"Study on VIV Behavior of Two 5:1 Rectangular Cylinders in Tandem Based on Correlation Analysis","authors":"Kai Ma, Changyong Zhang, Xinzhi Dang, Guoquan Zhang","doi":"10.3390/buildings14010085","DOIUrl":"https://doi.org/10.3390/buildings14010085","url":null,"abstract":"To investigate the vortex-induced vibration (VIV) characteristics of two rectangular cylinders with a width-to-depth ratio of 5:1 in a tandem arrangement, sectional model wind tunnel tests that measure vibration responses and pressure distributions simultaneously were adopted. The ratio of the spacing between the cylinders to its width is 1.2. The analyses were performed considering VIV responses as well as the distribution characteristics of mean and rms pressure coefficients. Additionally, the time-frequency domain statistical parameters like correlation and contribution coefficients, phase lags between distributed and general vortex excited forces (VEFs), and amplitudes of VEF coefficients at predominant frequencies were calculated to analyze the physical VIV mechanism of two 5:1 rectangular cylinders in tandem. This study indicates that the influence of incidence angles on the dynamic responses is notable; the contribution of the distributed VEFs acting on the trailing surface of the upstream cylinder and the leading surface of the downstream one is significant to VIVs of the cylinders from wind pressure distribution characteristics and correlation analyses.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"30 2","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139149728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Under the influence of material defects, structural grooving, environmental corrosion, and other factors in engineering, concrete-filled steel tubes incur local defects on their external surfaces that affect their structural integrity and service life. This work conducts axial compression tests on 10 grooving-damaged square hollow concrete-filled steel tube (SHCFST) columns to investigate the effect of grooving damage on their axial compressive ultimate bearing capacity and the effect of steel tubes on concrete confinement. It explores the effects of three parameters, namely, the length of grooves, presence of slots in internal and external steel tubes, and orientation of grooves, on structural static performance. This study analyzes the loading, failure mechanisms, and axial compressive ultimate bearing capacity of grooving-damaged SHCFST columns. Results indicate that grooving weakens the steel tube’s confinement effect on the concrete core, reducing the axial compressive ultimate bearing capacity of specimens. On the basis of this experimental research, a method for calculating the axial compressive ultimate bearing capacity and axial compressive stiffness of grooving-damaged SHCFST columns is proposed. The calculation results closely align with experimental outcomes, providing valuable insights for related scientific research and engineering applications.
{"title":"Experimental Investigation on the Axial Loading Performance of Grooving-Damaged Square Hollow Concrete-Filled Steel Tube Columns","authors":"Jing Liu, Zimao Pan, Zhicheng Pan, Shaohua He, Wenzhuo Yu","doi":"10.3390/buildings14010087","DOIUrl":"https://doi.org/10.3390/buildings14010087","url":null,"abstract":"Under the influence of material defects, structural grooving, environmental corrosion, and other factors in engineering, concrete-filled steel tubes incur local defects on their external surfaces that affect their structural integrity and service life. This work conducts axial compression tests on 10 grooving-damaged square hollow concrete-filled steel tube (SHCFST) columns to investigate the effect of grooving damage on their axial compressive ultimate bearing capacity and the effect of steel tubes on concrete confinement. It explores the effects of three parameters, namely, the length of grooves, presence of slots in internal and external steel tubes, and orientation of grooves, on structural static performance. This study analyzes the loading, failure mechanisms, and axial compressive ultimate bearing capacity of grooving-damaged SHCFST columns. Results indicate that grooving weakens the steel tube’s confinement effect on the concrete core, reducing the axial compressive ultimate bearing capacity of specimens. On the basis of this experimental research, a method for calculating the axial compressive ultimate bearing capacity and axial compressive stiffness of grooving-damaged SHCFST columns is proposed. The calculation results closely align with experimental outcomes, providing valuable insights for related scientific research and engineering applications.","PeriodicalId":48546,"journal":{"name":"Buildings","volume":"3 11","pages":""},"PeriodicalIF":3.8,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139148710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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