Pub Date : 2024-03-04DOI: 10.1177/13694332241237580
Jinlong Liu, Chen Chen, Junqi Lin, Zhile Yang
The existing constitutive models of shape memory alloy (SMA) cannot accurately describe the mechanical behavior in martensitic strengthening segment since their loading and unloading paths in strengthening segment completely overlap. This study proposes a multi-segment linear mathematical model for SMA, which realizes the separation of loading path and unloading path in strengthening segment. A four-story steel frame structure and corresponding braced structures with various SMA constitutive models are designed, and seismic control effects of SMA braces with these models are analyzed and compared through time history analysis. The results show that the sub-cycle unloading mode of SMA constitutive model affects the seismic mitigation capacity of SMA brace in a certain extent. The position of the inflection point of unloading path has very little influence on the structural control ability of SMA braces. The SMA brace using the SMA constitutive model with a single linear sub-cyclic unloading path has the minimal seismic response and the highest seismic reduction ratio. For most evaluation indexes, the seismic mitigation ability calculated by the proposed path separation constitutive model is in the middle of the results calculated by the existing models. SMA models without considering the mechanical behavior of strengthening segment may lead to an erroneous estimation of the energy consumption of SMA brace and the structural damage. The difference of simulation results among various SMA constitutive models is almost independent with ground motion.
现有的形状记忆合金（SMA）构成模型无法准确描述马氏体强化段的力学行为，因为强化段的加载和卸载路径完全重叠。本研究提出了一种 SMA 多段线性数学模型，实现了强化段加载路径和卸载路径的分离。设计了一个四层钢框架结构和相应的具有不同 SMA 构成模型的支撑结构，并通过时间历程分析比较了这些模型下 SMA 支撑的抗震控制效果。结果表明，SMA 构造模型的次周期卸载模式在一定程度上影响了 SMA 支撑的抗震减灾能力。卸载路径拐点的位置对 SMA 支撑的结构控制能力影响很小。采用单一线性亚周期卸载路径的 SMA 构 造模型的 SMA 支撑具有最小的地震响应和最高的减震率。在大多数评价指标上，所提出的路径分离构成模型计算出的减震能力处于现有模型计算结果的中间位置。不考虑加强段力学行为的 SMA 模型可能会导致对 SMA 支撑能耗和结构损伤的错误估计。各种 SMA 构成模型之间的模拟结果差异几乎与地面运动无关。
{"title":"A new constitutive model of shape memory alloy and its seismic mitigation capacity compared with existing models","authors":"Jinlong Liu, Chen Chen, Junqi Lin, Zhile Yang","doi":"10.1177/13694332241237580","DOIUrl":"https://doi.org/10.1177/13694332241237580","url":null,"abstract":"The existing constitutive models of shape memory alloy (SMA) cannot accurately describe the mechanical behavior in martensitic strengthening segment since their loading and unloading paths in strengthening segment completely overlap. This study proposes a multi-segment linear mathematical model for SMA, which realizes the separation of loading path and unloading path in strengthening segment. A four-story steel frame structure and corresponding braced structures with various SMA constitutive models are designed, and seismic control effects of SMA braces with these models are analyzed and compared through time history analysis. The results show that the sub-cycle unloading mode of SMA constitutive model affects the seismic mitigation capacity of SMA brace in a certain extent. The position of the inflection point of unloading path has very little influence on the structural control ability of SMA braces. The SMA brace using the SMA constitutive model with a single linear sub-cyclic unloading path has the minimal seismic response and the highest seismic reduction ratio. For most evaluation indexes, the seismic mitigation ability calculated by the proposed path separation constitutive model is in the middle of the results calculated by the existing models. SMA models without considering the mechanical behavior of strengthening segment may lead to an erroneous estimation of the energy consumption of SMA brace and the structural damage. The difference of simulation results among various SMA constitutive models is almost independent with ground motion.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"38 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140036322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-03-04DOI: 10.1177/13694332241237573
Yan Liang, Shun-En Ren, Ming-Na Tong, Jiang-Nan Zhu, Li Yan
In recent years, assembled bridges have become widely utilized in bridge construction, raising concerns about durability-related bridge diseases over time. These issues significantly impact the fatigue life of assembled bridges, necessitating an in-depth exploration of their fatigue performance. While existing research primarily concentrates on the transverse connection of multiple longitudinal beams, there is a notable dearth of studies on longitudinal precast segmental assembled bridges. This paper addresses this gap by establishing a fatigue benchmark finite element model for segmental assembled concrete beams, building upon existing experiments. The study employs numerical simulation to analyze the entire fatigue process, examining stress distribution, damage development, and considering the influence of reinforcement corrosion. Furthermore, a fatigue life prediction method, based on fatigue residual strength (R), is proposed for predicting the fatigue life (N) of concrete in precast segmental assembled beams. Results reveal that prestressed and ordinary reinforcements experience increasing stress with loading cycles, peaking around 100,000 cycles. Throughout fatigue loading, compressive stress in concrete remains low, preventing fatigue compression failure. However, tensile stress near joints gradually rises, initiating cracks at the mid-span beam’s bottom. With continued cyclic loading, these cracks propagate towards the loading point. The upper and lower limits of fatigue life predicted by the fatigue life prediction method closely align with the compressive fatigue test values of concrete, proposed fatigue life prediction method is efficient and accurate.
{"title":"Fatigue performance analysis of precast segmental assembled concrete beams","authors":"Yan Liang, Shun-En Ren, Ming-Na Tong, Jiang-Nan Zhu, Li Yan","doi":"10.1177/13694332241237573","DOIUrl":"https://doi.org/10.1177/13694332241237573","url":null,"abstract":"In recent years, assembled bridges have become widely utilized in bridge construction, raising concerns about durability-related bridge diseases over time. These issues significantly impact the fatigue life of assembled bridges, necessitating an in-depth exploration of their fatigue performance. While existing research primarily concentrates on the transverse connection of multiple longitudinal beams, there is a notable dearth of studies on longitudinal precast segmental assembled bridges. This paper addresses this gap by establishing a fatigue benchmark finite element model for segmental assembled concrete beams, building upon existing experiments. The study employs numerical simulation to analyze the entire fatigue process, examining stress distribution, damage development, and considering the influence of reinforcement corrosion. Furthermore, a fatigue life prediction method, based on fatigue residual strength (R), is proposed for predicting the fatigue life (N) of concrete in precast segmental assembled beams. Results reveal that prestressed and ordinary reinforcements experience increasing stress with loading cycles, peaking around 100,000 cycles. Throughout fatigue loading, compressive stress in concrete remains low, preventing fatigue compression failure. However, tensile stress near joints gradually rises, initiating cracks at the mid-span beam’s bottom. With continued cyclic loading, these cracks propagate towards the loading point. The upper and lower limits of fatigue life predicted by the fatigue life prediction method closely align with the compressive fatigue test values of concrete, proposed fatigue life prediction method is efficient and accurate.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"48 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140035793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-03-02DOI: 10.1177/13694332241237576
Saif Khudhair Ali Al-Tameemi, Ehab G Al-hasany, Hussein Kareem Mohammad, Hussain A Jabir, Teghreed H Ibrahim, Abbas A Allawi, Ayman El-Zohairy
Lacing reinforcement plays a critical role in the design and performance of reinforced concrete (RC) slabs by distributing the applied loads more evenly across the slab, ensuring that no specific area of the slab is overloaded. In this study, nine slabs, divided into three groups according to the investigated parameters, were meticulously designed and evaluated to study the interplay between the lacing reinforcement and other key parameters. Each slab was crafted for simple support and was subjected to both static and repeated two-point load tests. The lacing reinforcement had an angle of 45° with various tension and lacing steel. The repeated-tested specimens with lacing reinforcement experienced smaller ductility than those of similar static-tested specimens, where the reduction in ductility factor ranged between 8.4% and 22.3% for all specimens. Additionally, the tested slabs were analyzed numerically using the ABAQUS software package. The validated FE test program was used to study the effect of varying the lacing reinforcement ratio, the compressive strength of concrete, and the material types of the tension and lacing reinforcements. The lacing reinforcement becomes more effective in increasing the slab capacity when using the higher compressive strength of concrete.
绑扎钢筋在钢筋混凝土（RC）楼板的设计和性能中起着至关重要的作用，它能将施加的荷载更均匀地分布在楼板上，确保楼板的任何特定区域都不会超载。在这项研究中，根据所研究的参数将九个楼板分为三组，对其进行了精心设计和评估，以研究绑扎钢筋与其他关键参数之间的相互作用。每块板都是为简单支撑而设计的，并接受了静态和重复两点荷载试验。绑扎钢筋的角度为 45°，张力和绑扎钢筋各不相同。与类似的静力测试试样相比，带有系带钢筋的重复测试试样的延性较小，所有试样的延性系数降低幅度在 8.4% 到 22.3% 之间。此外，还使用 ABAQUS 软件包对测试板进行了数值分析。经过验证的 FE 测试程序用于研究不同绑扎钢筋比例、混凝土抗压强度以及拉筋和绑扎钢筋材料类型的影响。当使用抗压强度较高的混凝土时，绑扎钢筋在提高板承载能力方面更加有效。
{"title":"Simulation and design model for reinforced concrete slabs with lacing systems","authors":"Saif Khudhair Ali Al-Tameemi, Ehab G Al-hasany, Hussein Kareem Mohammad, Hussain A Jabir, Teghreed H Ibrahim, Abbas A Allawi, Ayman El-Zohairy","doi":"10.1177/13694332241237576","DOIUrl":"https://doi.org/10.1177/13694332241237576","url":null,"abstract":"Lacing reinforcement plays a critical role in the design and performance of reinforced concrete (RC) slabs by distributing the applied loads more evenly across the slab, ensuring that no specific area of the slab is overloaded. In this study, nine slabs, divided into three groups according to the investigated parameters, were meticulously designed and evaluated to study the interplay between the lacing reinforcement and other key parameters. Each slab was crafted for simple support and was subjected to both static and repeated two-point load tests. The lacing reinforcement had an angle of 45° with various tension and lacing steel. The repeated-tested specimens with lacing reinforcement experienced smaller ductility than those of similar static-tested specimens, where the reduction in ductility factor ranged between 8.4% and 22.3% for all specimens. Additionally, the tested slabs were analyzed numerically using the ABAQUS software package. The validated FE test program was used to study the effect of varying the lacing reinforcement ratio, the compressive strength of concrete, and the material types of the tension and lacing reinforcements. The lacing reinforcement becomes more effective in increasing the slab capacity when using the higher compressive strength of concrete.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"260 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140017987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-03-02DOI: 10.1177/13694332241237587
Ali Ghanim Abbas AL-Khafaji, Sabah Hashim Muhammed, Awad Jadooe, Muhammad Abdulredha
This study investigates the effect of strengthening self-compacted concrete (SCC) beams using CFRP sheets on flexural behaviour subjected to repeated loads. During the experiment, six rectangular reinforced SCC beams were evaluated; two were reference beams without strengthening, while the remaining four were strengthened with CFRP sheets. The beam’s length, depth, and width are 2100 mm, 300 mm, and 200 mm, respectively. A monotonic load was applied to one of the reference beams, while repeated loads were applied to the remaining (compression cyclic loads). The main parameters studied in this experimental work were the type of loading (monotonic and repeated), the positions of strengthening and the dimensions of CFRP sheets. The flexural behaviour of these beams was investigated through experimental examination by recording the ultimate load and maximum deflection. Meanwhile, the cracks’ pattern and failure modes were observed. The findings of the present study demonstrated that the limited cycles of repeated loads have marginal effect on the flexural behaviour of the beams. This results in an ultimate load reduction of no more than 11%. It was also noted that SCC beams strengthened using CFRP sheets subjected to repeated loads significantly affected the flexural behaviour of these beams. Consequently, the ultimate load of the strengthened beams was improved by up to 18%. Besides, the maximum deflection of the strengthened SCC beams was reduced by 45% compared to those without strengthening. Using strengthening throughout the beams’ entire width and length that are subjected to repeated loads improved their ultimate load to surpass that of non-strengthened beams under monotonic loads by as much as 7%.
{"title":"Effect of strengthening by carbon fiber reinforced polymer sheets on the flexural behavior of reinforced self-compacting concrete beams under repeated loads","authors":"Ali Ghanim Abbas AL-Khafaji, Sabah Hashim Muhammed, Awad Jadooe, Muhammad Abdulredha","doi":"10.1177/13694332241237587","DOIUrl":"https://doi.org/10.1177/13694332241237587","url":null,"abstract":"This study investigates the effect of strengthening self-compacted concrete (SCC) beams using CFRP sheets on flexural behaviour subjected to repeated loads. During the experiment, six rectangular reinforced SCC beams were evaluated; two were reference beams without strengthening, while the remaining four were strengthened with CFRP sheets. The beam’s length, depth, and width are 2100 mm, 300 mm, and 200 mm, respectively. A monotonic load was applied to one of the reference beams, while repeated loads were applied to the remaining (compression cyclic loads). The main parameters studied in this experimental work were the type of loading (monotonic and repeated), the positions of strengthening and the dimensions of CFRP sheets. The flexural behaviour of these beams was investigated through experimental examination by recording the ultimate load and maximum deflection. Meanwhile, the cracks’ pattern and failure modes were observed. The findings of the present study demonstrated that the limited cycles of repeated loads have marginal effect on the flexural behaviour of the beams. This results in an ultimate load reduction of no more than 11%. It was also noted that SCC beams strengthened using CFRP sheets subjected to repeated loads significantly affected the flexural behaviour of these beams. Consequently, the ultimate load of the strengthened beams was improved by up to 18%. Besides, the maximum deflection of the strengthened SCC beams was reduced by 45% compared to those without strengthening. Using strengthening throughout the beams’ entire width and length that are subjected to repeated loads improved their ultimate load to surpass that of non-strengthened beams under monotonic loads by as much as 7%.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"261 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140018357","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-03-01DOI: 10.1177/13694332241237362
Hao Zhang, Qiu Zhao, Feng Xiao, Yiyan Chen, Xiaoqiang Yang
Prestressed concrete (PC) box girder is an innovative structure that is widely used in large-span bridges. Under eccentric loads such as vehicles, PC girders are inevitably under combined bending and torsion. To study its bending-torsional behavior, a refined full-range analysis model based on the combined action softening truss model (CA-STM) was proposed, where a simple and effective solution procedure and failure criteria were provided. The equilibrium equation, initial estimation equation for torque, and material constitutive model were modified by considering the prestressing effect to improve the CA-STM. An optimized algorithm was also employed to simplify the solution procedure instead of the traditional trial-and-error method, thus increasing the solution rate and stability. The theoretical curves predicted from the improved CA-STM exhibited great agreement with the available experimental results, and the predicted cracking and ultimate loads were also close to the experimental values. Hence, the improved CA-STM can reasonably predict the full-range mechanical response and failure modes of PC box girders subjected to combined bending and torsion, which provides great support to the design evaluation of such bridges.
预应力混凝土（PC）箱梁是一种创新结构，广泛应用于大跨度桥梁。在车辆等偏心荷载作用下，PC 梁不可避免地会受到弯曲和扭转的共同作用。为研究其弯曲扭转行为，提出了基于联合作用软化桁架模型（CA-STM）的精细全范围分析模型，并提供了简单有效的求解程序和失效准则。考虑到预应力效应，对平衡方程、扭矩初始估计方程和材料构成模型进行了修改，以改进 CA-STM。此外，还采用了优化算法来简化求解过程，而不是传统的试错法，从而提高了求解速度和稳定性。改进后的 CA-STM 预测的理论曲线与现有的实验结果非常吻合，预测的开裂荷载和极限荷载也接近实验值。因此，改进的 CA-STM 可以合理预测 PC 箱梁在弯曲和扭转联合作用下的全范围力学响应和破坏模式，为此类桥梁的设计评估提供了有力支持。
{"title":"Improved softened truss model of prestressed concrete box girders subjected to combined bending and torsion","authors":"Hao Zhang, Qiu Zhao, Feng Xiao, Yiyan Chen, Xiaoqiang Yang","doi":"10.1177/13694332241237362","DOIUrl":"https://doi.org/10.1177/13694332241237362","url":null,"abstract":"Prestressed concrete (PC) box girder is an innovative structure that is widely used in large-span bridges. Under eccentric loads such as vehicles, PC girders are inevitably under combined bending and torsion. To study its bending-torsional behavior, a refined full-range analysis model based on the combined action softening truss model (CA-STM) was proposed, where a simple and effective solution procedure and failure criteria were provided. The equilibrium equation, initial estimation equation for torque, and material constitutive model were modified by considering the prestressing effect to improve the CA-STM. An optimized algorithm was also employed to simplify the solution procedure instead of the traditional trial-and-error method, thus increasing the solution rate and stability. The theoretical curves predicted from the improved CA-STM exhibited great agreement with the available experimental results, and the predicted cracking and ultimate loads were also close to the experimental values. Hence, the improved CA-STM can reasonably predict the full-range mechanical response and failure modes of PC box girders subjected to combined bending and torsion, which provides great support to the design evaluation of such bridges.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"5 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140018194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-02-28DOI: 10.1177/13694332241237585
Ronaldas Jakubovskis, Aleksandr Sokolov
Developments in concrete technologies have allowed engineers to design lightweight, slender, and aesthetically attractive structures. The application of new concrete types in real projects, however, is uncommon. The lack of regulation, uncertainty in material performance, and the absence of successfully implemented projects hinders the use of modern concretes in everyday design projects. The present paper examines the application of two specific concrete types in a prototype footbridge: ultra-high-performance concrete (UHPC), and biological self-healing concrete (BSHC). The material properties of UHPC were selected and tailored specifically for the prototype structure, applying the principles of performance-based design. To evaluate the efficiency of self-healing under real environmental conditions, BSHC beams were designed as a structural part of the bridge. The step-by step presentation of the bridge development demonstrates the specifics in material design and a structural analysis of the prototype structure. The prototype structure serves as demonstrative example of the use of BSH and UHP concretes, encouraging engineers towards the wider application of advanced materials in construction projects.
{"title":"The development of a prototype footbridge composed of biological self-healing and ultra-high-performance concretes","authors":"Ronaldas Jakubovskis, Aleksandr Sokolov","doi":"10.1177/13694332241237585","DOIUrl":"https://doi.org/10.1177/13694332241237585","url":null,"abstract":"Developments in concrete technologies have allowed engineers to design lightweight, slender, and aesthetically attractive structures. The application of new concrete types in real projects, however, is uncommon. The lack of regulation, uncertainty in material performance, and the absence of successfully implemented projects hinders the use of modern concretes in everyday design projects. The present paper examines the application of two specific concrete types in a prototype footbridge: ultra-high-performance concrete (UHPC), and biological self-healing concrete (BSHC). The material properties of UHPC were selected and tailored specifically for the prototype structure, applying the principles of performance-based design. To evaluate the efficiency of self-healing under real environmental conditions, BSHC beams were designed as a structural part of the bridge. The step-by step presentation of the bridge development demonstrates the specifics in material design and a structural analysis of the prototype structure. The prototype structure serves as demonstrative example of the use of BSH and UHP concretes, encouraging engineers towards the wider application of advanced materials in construction projects.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"80 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140008722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The mechanical properties of bridge bearings gradually deteriorate over time, resulting from daily traffic loading and harsh environmental conditions. However, efficient detection of in-service bridge bearings is still challenging, especially in quantifying support stiffness. This study presents a bridge bearing condition assessment framework of a simply elastic supported beam based on impact vibration testing and structural flexibility identification. Firstly, the dynamic response equation of a simply supported beam with elastic boundary constraints is established. The modal orthogonality of Euler-Bernoulli beams and the corresponding overall matrix of undetermined coefficients are derived using the separate variable method. Subsequently, the flexibility matrix of the simply elastic supported beam is derived and verified in the cases of forward and inverse analysis, respectively. Furthermore, the vertical and rotational stiffness of the bearings are established based on the structural flexibility matrix. Finally, experimental verification is performed to identify the flexibility and the vertical support stiffness of the simply elastic supported beam based on impact vibration tests. The results indicate that the proposed the bearing condition assessment framework can straightforwardly quantify support stiffness.
{"title":"Bearing condition assessment of a simply elastic supported beam based on impact vibration testing","authors":"Qi Xia, Jiang-wei Zhou, Ya-ru Yang, Lin-qing Wang, Jian Zhang","doi":"10.1177/13694332241237572","DOIUrl":"https://doi.org/10.1177/13694332241237572","url":null,"abstract":"The mechanical properties of bridge bearings gradually deteriorate over time, resulting from daily traffic loading and harsh environmental conditions. However, efficient detection of in-service bridge bearings is still challenging, especially in quantifying support stiffness. This study presents a bridge bearing condition assessment framework of a simply elastic supported beam based on impact vibration testing and structural flexibility identification. Firstly, the dynamic response equation of a simply supported beam with elastic boundary constraints is established. The modal orthogonality of Euler-Bernoulli beams and the corresponding overall matrix of undetermined coefficients are derived using the separate variable method. Subsequently, the flexibility matrix of the simply elastic supported beam is derived and verified in the cases of forward and inverse analysis, respectively. Furthermore, the vertical and rotational stiffness of the bearings are established based on the structural flexibility matrix. Finally, experimental verification is performed to identify the flexibility and the vertical support stiffness of the simply elastic supported beam based on impact vibration tests. The results indicate that the proposed the bearing condition assessment framework can straightforwardly quantify support stiffness.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"40 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140008466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper investigates the effectiveness of ultra-high performance concrete (UHPC) collars in strengthening reinforced concrete (RC) bridge piers against heavy tractor-trailer collisions through finite element (FE) analysis. First, validated FE models of UHPC and a heavy tractor-trailer were provided. Then, FE analyses were conducted to evaluate the strengthening performance of the UHPC collar. The effectiveness of UHPC collar was compared with conventional RC collar, and the effects of varying UHPC collar thickness, height, and collar reinforcement were investigated. The results showed that the most severe damage observed on bridge piers due to heavy vehicle collisions primarily occurred below a height of approximately 2000 mm, manifested as diagonal shear cracks and plastic hinges. Therefore, the recommended minimum collar height is 2000 mm. The comparison between UHPC collar and RC collar strengthening demonstrated the superior effectiveness of UHPC collars. A 130-mm UHPC collar exhibited a similar strengthening effect as an 180-mm RC collar. Among the three investigated parameters of UHPC collar thickness, height, and collar reinforcement, the study found that collar thickness had the most significant influence on the effectiveness of the UHPC collar in terms of damage pattern, energy absorption, and maximum deflection. While collar height primarily influenced deflection, a larger collar height was beneficial in reducing pier deflection at the end of the strengthened segment. Adding a small amount of collar reinforcement improved the performance of piers; however, this improvement was limited. The findings of this study address the lack of research on using UHPC for strengthening full-scale bridge piers against heavy tractor-trailer collisions and provide valuable references for future designs with similar applications.
{"title":"Strengthening reinforced concrete bridge piers against heavy vehicle collisions with ultra-high performance concrete collars: A finite element analysis study","authors":"Chunpeng Qu, Farhad Farzaneh, Sungmoon Jung, Qian Zhang","doi":"10.1177/13694332241237575","DOIUrl":"https://doi.org/10.1177/13694332241237575","url":null,"abstract":"This paper investigates the effectiveness of ultra-high performance concrete (UHPC) collars in strengthening reinforced concrete (RC) bridge piers against heavy tractor-trailer collisions through finite element (FE) analysis. First, validated FE models of UHPC and a heavy tractor-trailer were provided. Then, FE analyses were conducted to evaluate the strengthening performance of the UHPC collar. The effectiveness of UHPC collar was compared with conventional RC collar, and the effects of varying UHPC collar thickness, height, and collar reinforcement were investigated. The results showed that the most severe damage observed on bridge piers due to heavy vehicle collisions primarily occurred below a height of approximately 2000 mm, manifested as diagonal shear cracks and plastic hinges. Therefore, the recommended minimum collar height is 2000 mm. The comparison between UHPC collar and RC collar strengthening demonstrated the superior effectiveness of UHPC collars. A 130-mm UHPC collar exhibited a similar strengthening effect as an 180-mm RC collar. Among the three investigated parameters of UHPC collar thickness, height, and collar reinforcement, the study found that collar thickness had the most significant influence on the effectiveness of the UHPC collar in terms of damage pattern, energy absorption, and maximum deflection. While collar height primarily influenced deflection, a larger collar height was beneficial in reducing pier deflection at the end of the strengthened segment. Adding a small amount of collar reinforcement improved the performance of piers; however, this improvement was limited. The findings of this study address the lack of research on using UHPC for strengthening full-scale bridge piers against heavy tractor-trailer collisions and provide valuable references for future designs with similar applications.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"123 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140008678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-02-19DOI: 10.1177/13694332241232047
Song Hu, Li Zhou, Yong Huang
In order to improve the shear capacity and seismic performance of cold–formed thin–walled steel (CFS) walls, in this research, a novel CFS wall filled with phosphogypsum (PG) was developed. Taking PG filling area and covering the wall with sheathing as design parameters, four full–scale test specimens were designed and constructed. Failure mode and seismic performance indexes of each specimen were investigated by performing cyclic loading tests and the effect of PG filler on CFS wall seismic performance was evaluated. Research results showed that PG filler significantly improved the seismic performance and shear capacity of CFS walls. Importantly, the proposed wall presented a remarkable dual–mechanism of lateral force resistance, which was provided by PG filler and wall sheathings, respectively. In addition, analytical models were developed for the calculation of the shear capacity and lateral stiffness of the proposed walls, which presented high prediction accuracy.
{"title":"Cold–formed thin–walled steel walls filled with phosphogypsum subjected to lateral cyclic loading: testing and analysis","authors":"Song Hu, Li Zhou, Yong Huang","doi":"10.1177/13694332241232047","DOIUrl":"https://doi.org/10.1177/13694332241232047","url":null,"abstract":"In order to improve the shear capacity and seismic performance of cold–formed thin–walled steel (CFS) walls, in this research, a novel CFS wall filled with phosphogypsum (PG) was developed. Taking PG filling area and covering the wall with sheathing as design parameters, four full–scale test specimens were designed and constructed. Failure mode and seismic performance indexes of each specimen were investigated by performing cyclic loading tests and the effect of PG filler on CFS wall seismic performance was evaluated. Research results showed that PG filler significantly improved the seismic performance and shear capacity of CFS walls. Importantly, the proposed wall presented a remarkable dual–mechanism of lateral force resistance, which was provided by PG filler and wall sheathings, respectively. In addition, analytical models were developed for the calculation of the shear capacity and lateral stiffness of the proposed walls, which presented high prediction accuracy.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"49 1","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139955579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-01-10DOI: 10.1177/13694332241226921
Yong Yu, Jinjun Xu, Weisen Chen, Bo Wu
This paper presents a computational study on the flexural fracture behaviors of steel fiber reinforced concrete (SFRC). The focus is on investigating the impacts of various factors on SFRC, utilizing a discrete-continuum coupled finite element method. This method explicitly models each material phase, including coarse aggregates, mortar paste, steel fibers and interfacial transition zones (ITZs), allowing precise tracking of mesoscale cracking during bending. The simulation method is developed, calibrated and validated before conducting a parametric investigation. Critical factors considered include the spatial positioning of coarse aggregates and steel fibers, fiber content, length and diameter, and the bonding property of fiber-mortar ITZs. Results indicate that steel fibers modify crack development in notched beams, causing greater distortion in the primary crack. Increasing fiber content from 0 to 2% enhances flexural tensile strength but introduces more variability. Longer fibers initially increase strength, then decrease, while thicker fibers consistently reduce strength. Improving the bond between fibers and mortar does not substantially increase the load-bearing capacity of the beam. In conclusion, this study shows how the established approach enhances understanding of the mechanical responses of SFRC under flexural-fracture loading.
{"title":"Mesoscale modeling of flexural fracture behavior in steel fiber reinforced concrete","authors":"Yong Yu, Jinjun Xu, Weisen Chen, Bo Wu","doi":"10.1177/13694332241226921","DOIUrl":"https://doi.org/10.1177/13694332241226921","url":null,"abstract":"This paper presents a computational study on the flexural fracture behaviors of steel fiber reinforced concrete (SFRC). The focus is on investigating the impacts of various factors on SFRC, utilizing a discrete-continuum coupled finite element method. This method explicitly models each material phase, including coarse aggregates, mortar paste, steel fibers and interfacial transition zones (ITZs), allowing precise tracking of mesoscale cracking during bending. The simulation method is developed, calibrated and validated before conducting a parametric investigation. Critical factors considered include the spatial positioning of coarse aggregates and steel fibers, fiber content, length and diameter, and the bonding property of fiber-mortar ITZs. Results indicate that steel fibers modify crack development in notched beams, causing greater distortion in the primary crack. Increasing fiber content from 0 to 2% enhances flexural tensile strength but introduces more variability. Longer fibers initially increase strength, then decrease, while thicker fibers consistently reduce strength. Improving the bond between fibers and mortar does not substantially increase the load-bearing capacity of the beam. In conclusion, this study shows how the established approach enhances understanding of the mechanical responses of SFRC under flexural-fracture loading.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":"66 19","pages":""},"PeriodicalIF":2.6,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139441030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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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