Pub Date : 2024-09-07DOI: 10.1177/13694332241281533
Xiaohong Long, Zonglin Li, Xiaopeng Gu, Xingwang Chen, Yongtao Ma
When calculating the seismic response of structures, conventional methods often neglect uncertainty and suffer from excessive computation. Although robustness metrics have been effective in evaluating structural safety, they are not suitable for isolated continuous girder bridges (ICGB). To address this issue, this paper introduces an uncertain seismic response and robustness assessment method tailored to ICGB: Firstly, the method considers uncertainty in material parameters and ground motion by constructing a data set using Monte Carlo simulation. Secondly, a genetic algorithm for parallel optimisation of radial basis function neural network (GAPO-RBFNN) is trained to predict the seismic responses of the bridges. Thirdly, a robustness metric specifically designed for bridges is derived and applied to bridge. Finally, the proposed robustness metric is validated on lead rubber bearing (LRB) and shape memory alloy-lead rubber bearing (SMA-LRB) bridges. Results indicate that the GAPO-RBFNN model accurately approximates the mapping relationship between structural parameters and seismic response, with an average error of only 0.32% and a 70% reduction in computation time compared with traditional methods. Moreover, the new robustness metric overcomes the limitations of the dismantled member method and is applicable to bridge. The robustness of the SMA-LRB-ICGB, strengthened by SMA, is improved, providing evidence of the effectiveness of the proposed robustness metric.
在计算结构的地震响应时，传统方法通常会忽略不确定性，并存在计算量过大的问题。尽管稳健性指标在评估结构安全方面非常有效，但它们并不适用于孤立连续梁桥（ICGB）。针对这一问题，本文介绍了一种针对 ICGB 的不确定地震响应和鲁棒性评估方法：首先，该方法通过蒙特卡罗模拟构建数据集，考虑了材料参数和地面运动的不确定性。其次，对径向基函数神经网络并行优化遗传算法（GAPO-RBFNN）进行训练，以预测桥梁的地震响应。第三，得出专为桥梁设计的鲁棒性指标，并将其应用于桥梁。最后，在铅橡胶支座（LRB）和形状记忆合金-铅橡胶支座（SMA-LRB）桥梁上验证了所提出的鲁棒性指标。结果表明，GAPO-RBFNN 模型准确地近似了结构参数与地震响应之间的映射关系，与传统方法相比，平均误差仅为 0.32%，计算时间减少了 70%。此外，新的鲁棒性指标克服了拆卸构件法的局限性，适用于桥梁。通过 SMA 加固的 SMA-LRB-ICGB 的鲁棒性得到了改善，证明了所提鲁棒性指标的有效性。
{"title":"Uncertain seismic response and robustness analysis of isolated continuous girder bridges","authors":"Xiaohong Long, Zonglin Li, Xiaopeng Gu, Xingwang Chen, Yongtao Ma","doi":"10.1177/13694332241281533","DOIUrl":"https://doi.org/10.1177/13694332241281533","url":null,"abstract":"When calculating the seismic response of structures, conventional methods often neglect uncertainty and suffer from excessive computation. Although robustness metrics have been effective in evaluating structural safety, they are not suitable for isolated continuous girder bridges (ICGB). To address this issue, this paper introduces an uncertain seismic response and robustness assessment method tailored to ICGB: Firstly, the method considers uncertainty in material parameters and ground motion by constructing a data set using Monte Carlo simulation. Secondly, a genetic algorithm for parallel optimisation of radial basis function neural network (GAPO-RBFNN) is trained to predict the seismic responses of the bridges. Thirdly, a robustness metric specifically designed for bridges is derived and applied to bridge. Finally, the proposed robustness metric is validated on lead rubber bearing (LRB) and shape memory alloy-lead rubber bearing (SMA-LRB) bridges. Results indicate that the GAPO-RBFNN model accurately approximates the mapping relationship between structural parameters and seismic response, with an average error of only 0.32% and a 70% reduction in computation time compared with traditional methods. Moreover, the new robustness metric overcomes the limitations of the dismantled member method and is applicable to bridge. The robustness of the SMA-LRB-ICGB, strengthened by SMA, is improved, providing evidence of the effectiveness of the proposed robustness metric.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194989","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 : 2024-09-07DOI: 10.1177/13694332241281535
Yang Ye, You-Lin Xu, Wulve Lao, Chuang Cui, Qinghua Zhang, Yinlong Zhou
The identification of crystal plasticity (CP) material parameters is indispensable for using CP models to simulate and understand the microcrack initiation and propagation of orthotropic steel decks (OSD). This study proposes a digital twin (DT)-based framework for identifying CP material parameters of weld joints of OSD by fusing multiscale CP finite element model (CPFEM) with macroscale stress–strain material tests. The material tests of the specimen (physical entity) cut from the weld joints of OSD and sliced to the centimeter scale are carried out using the standard dynamic test system. The CPFEM simulation is used to develop a multiscale virtual entity to map the physical entity. The particle swarm optimization algorithm is used to fuse the CPFEM simulation with the material test data to identify CP material parameters and produce a DT. The results demonstrate that the CP material parameters identified by the proposed framework are more accurate than those identified by a single representative volume element method. The results also show that the DT-based identification of CP material parameters has high applicability.
{"title":"Digital twin-based identification of crystal plastic material parameters for weld joints of orthotropic steel decks","authors":"Yang Ye, You-Lin Xu, Wulve Lao, Chuang Cui, Qinghua Zhang, Yinlong Zhou","doi":"10.1177/13694332241281535","DOIUrl":"https://doi.org/10.1177/13694332241281535","url":null,"abstract":"The identification of crystal plasticity (CP) material parameters is indispensable for using CP models to simulate and understand the microcrack initiation and propagation of orthotropic steel decks (OSD). This study proposes a digital twin (DT)-based framework for identifying CP material parameters of weld joints of OSD by fusing multiscale CP finite element model (CPFEM) with macroscale stress–strain material tests. The material tests of the specimen (physical entity) cut from the weld joints of OSD and sliced to the centimeter scale are carried out using the standard dynamic test system. The CPFEM simulation is used to develop a multiscale virtual entity to map the physical entity. The particle swarm optimization algorithm is used to fuse the CPFEM simulation with the material test data to identify CP material parameters and produce a DT. The results demonstrate that the CP material parameters identified by the proposed framework are more accurate than those identified by a single representative volume element method. The results also show that the DT-based identification of CP material parameters has high applicability.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194981","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 : 2024-09-07DOI: 10.1177/13694332241281548
Chenzhi Cai, Ming Xu, Xuhui He, Yunfeng Zou, Shiji Huang
Owing to the direct exposure to complex atmospheric environments, the temperature field of composite box girder bridge with corrugated steel webs (CBGB-CSW) is likely non-uniformly distributed. Whereas, the current researches regarding the thermal responses of CBGB-CSW are insufficient, and the thermal responses of CBGB-CSW under solar radiation are still unknown. Therefore, this paper conducted a long-term temperature experiment on a scaled model to explore the temperature distribution characteristics in CBGB-CSW. Meanwhile, a three-dimensional thermal–mechanical coupling Finite Element (FE) model is established to simulate the temperature field in the experiment girder. The accuracy and effectiveness of the developed FE model has been verified by the measured temperature data. Therewith, the thermal responses (i.e., stress and displacement) of a full-scale continuous CBGB-CSW with a span of 150 m are numerically investigated. The results indicate that the maximum stresses always occur at the midspan section (with a depth of 5 m) of the continuous CBGB-CSW, and considerable concentrations of stress are observed in the steel-concrete junction. The maximum longitudinal tensile and compressive normal stresses within 0.4 m of the upper junction can reach 5.55 MPa and −8.46 MPa respectively, and those of the lower junction can reach 6.96 MPa and −7.05 MPa respectively. Besides, owing to the impacts of vertical and horizontal temperature gradients, significant displacements of the whole bridge can also be observed. The maximum vertical displacement (5.33 mm) of the CBGB-CSW is estimated at the top plate in the midspan, while the maximum horizontal displacement (0.74 mm) is estimated at the trough of the southern corrugated steel web in the midspan. Notably, the outcomes of this paper can provide some useful references for engineers and scholars to understand the thermal responses of the CBGB-CSW.
{"title":"The thermal responses of composite box girder bridges with corrugated steel webs under solar radiation","authors":"Chenzhi Cai, Ming Xu, Xuhui He, Yunfeng Zou, Shiji Huang","doi":"10.1177/13694332241281548","DOIUrl":"https://doi.org/10.1177/13694332241281548","url":null,"abstract":"Owing to the direct exposure to complex atmospheric environments, the temperature field of composite box girder bridge with corrugated steel webs (CBGB-CSW) is likely non-uniformly distributed. Whereas, the current researches regarding the thermal responses of CBGB-CSW are insufficient, and the thermal responses of CBGB-CSW under solar radiation are still unknown. Therefore, this paper conducted a long-term temperature experiment on a scaled model to explore the temperature distribution characteristics in CBGB-CSW. Meanwhile, a three-dimensional thermal–mechanical coupling Finite Element (FE) model is established to simulate the temperature field in the experiment girder. The accuracy and effectiveness of the developed FE model has been verified by the measured temperature data. Therewith, the thermal responses (i.e., stress and displacement) of a full-scale continuous CBGB-CSW with a span of 150 m are numerically investigated. The results indicate that the maximum stresses always occur at the midspan section (with a depth of 5 m) of the continuous CBGB-CSW, and considerable concentrations of stress are observed in the steel-concrete junction. The maximum longitudinal tensile and compressive normal stresses within 0.4 m of the upper junction can reach 5.55 MPa and −8.46 MPa respectively, and those of the lower junction can reach 6.96 MPa and −7.05 MPa respectively. Besides, owing to the impacts of vertical and horizontal temperature gradients, significant displacements of the whole bridge can also be observed. The maximum vertical displacement (5.33 mm) of the CBGB-CSW is estimated at the top plate in the midspan, while the maximum horizontal displacement (0.74 mm) is estimated at the trough of the southern corrugated steel web in the midspan. Notably, the outcomes of this paper can provide some useful references for engineers and scholars to understand the thermal responses of the CBGB-CSW.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194982","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 study investigated the effectiveness of carbon fibre-reinforced polymer (CFRP) materials in strengthening the diagonal tension members of steel-truss bridges. Monotonic tensile and cyclic loading tests were performed on CFRP-strengthened specimens with variations in the CFRP-bonding range on the flanges. This study focused on the strengthening methods A and B, which were proposed to address insufficient CFRP anchoring near gusset plates by bonding CFRP sheets to both sides of the flanges of the diagonal tension members. The results of the monotonic tensile loading tests indicated a significant increase in tensile stiffness and substantial improvements in yield strength (27%) and ultimate load-bearing capacity (51%) when the strengthening methods A and B were employed. Delamination of the bonded CFRP sheets was effectively delayed, occurring only after the steel yielded, owing to the use of a ductile adhesive (polyurea putty). On the other hand, the cyclic loading tests demonstrated a significant enhancement in the load-bearing capacities (33% for tensile, 32% for compressive) of the strengthened specimens. Moreover, the energy dissipation capacities of the specimens strengthened by methods A and B exhibited linear increases, with 12% and 14% higher values respectively than those of the non-strengthened specimen. Although the stiffnesses (tensile and compressive) of the strengthened specimens decreased in each loading loop, the strengthening methods A and B maintained the stiffness values at approximately 35% higher than those of the non-strengthened specimen.
本研究探讨了碳纤维增强聚合物（CFRP）材料在加固钢桁梁桥梁斜拉构件方面的有效性。对 CFRP 加固试样进行了单调拉伸和循环加载试验，试样翼缘上的 CFRP 粘结范围有所变化。本研究重点关注了 A 和 B 两种加固方法，这两种方法是通过在斜拉构件翼缘两侧粘结 CFRP 片材来解决桁架板附近 CFRP 锚固不足的问题。单调拉伸加载试验结果表明，采用 A 和 B 加固方法后，拉伸刚度显著增加，屈服强度（27%）和极限承载能力（51%）大幅提高。由于使用了韧性粘合剂（聚脲腻子），粘合 CFRP 片材的分层被有效延迟，仅在钢材屈服后才发生。另一方面，循环加载试验表明，加固试样的承载能力显著提高（拉伸能力提高 33%，压缩能力提高 32%）。此外，采用 A 和 B 方法加固的试样的能量耗散能力呈线性增长，分别比未加固试样高出 12% 和 14%。虽然加固试样的刚度（拉伸和压缩）在每个加载循环中都有所下降，但加固方法 A 和 B 保持了比未加固试样高出约 35% 的刚度值。
{"title":"Experimental study on strengthening steel-truss bridge diagonal members using carbon-fibre-reinforced polymer bonding methods","authors":"Ngoc Vinh Pham, Kazuo Ohgaki, Takeshi Miyashita, Ngoc Quang Pham","doi":"10.1177/13694332241281545","DOIUrl":"https://doi.org/10.1177/13694332241281545","url":null,"abstract":"This study investigated the effectiveness of carbon fibre-reinforced polymer (CFRP) materials in strengthening the diagonal tension members of steel-truss bridges. Monotonic tensile and cyclic loading tests were performed on CFRP-strengthened specimens with variations in the CFRP-bonding range on the flanges. This study focused on the strengthening methods A and B, which were proposed to address insufficient CFRP anchoring near gusset plates by bonding CFRP sheets to both sides of the flanges of the diagonal tension members. The results of the monotonic tensile loading tests indicated a significant increase in tensile stiffness and substantial improvements in yield strength (27%) and ultimate load-bearing capacity (51%) when the strengthening methods A and B were employed. Delamination of the bonded CFRP sheets was effectively delayed, occurring only after the steel yielded, owing to the use of a ductile adhesive (polyurea putty). On the other hand, the cyclic loading tests demonstrated a significant enhancement in the load-bearing capacities (33% for tensile, 32% for compressive) of the strengthened specimens. Moreover, the energy dissipation capacities of the specimens strengthened by methods A and B exhibited linear increases, with 12% and 14% higher values respectively than those of the non-strengthened specimen. Although the stiffnesses (tensile and compressive) of the strengthened specimens decreased in each loading loop, the strengthening methods A and B maintained the stiffness values at approximately 35% higher than those of the non-strengthened specimen.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194990","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}
Steel-bolt connection joint with embedded steel is increasingly utilized for prefabricated concrete (PC) shear walls and plays an indispensable role in the shear force transmission process. To enhance the mechanical performance of the connection joint in PC walls, a new pre-embedded steel bolt connection is proposed in this paper. The new connection can quickly connect prefabricated shear walls, with a simple construction process and short construction period. The present study respectively designed and fabricated four specimens with different connection configurations to conduct shear performance tests on the steel connectors and hysteresis performance tests on the connection joint. A numerical model for the joint was then established based on the shear test data of the steel connectors, to further analyze the mechanical performance of the proposed connection joint. The results indicate that depending on the different steel connection configurations, shear failure modes can be categorized into bolt shear failure and embedded steel pullout failure. The shear studs have minimal impact on the shear performance of the steel connectors. The flanges on both sides of the joint effectively enhance the hysteresis performance of the connection joint. Among the tested specimens, the one with a steel configuration at the connection joint featuring ribbed channel steel exhibits superior hysteresis performance, with higher load-bearing capacity, gradual stiffness degradation, and excellent energy dissipation capability. It is recommended to use these connection details for embedded steel connections at the joint during the design.
预埋钢筋的钢螺栓连接接头越来越多地用于预制混凝土（PC）剪力墙，在剪力传递过程中发挥着不可或缺的作用。为了提高 PC 墙连接接头的机械性能，本文提出了一种新型预埋钢螺栓连接。这种新型连接方式可快速连接预制剪力墙，施工工艺简单，施工周期短。本研究分别设计并制作了四个不同连接构造的试件，对钢连接件进行了剪切性能测试，并对连接接头进行了滞后性能测试。然后，根据钢连接件的剪切试验数据建立了连接接头的数值模型，进一步分析了拟建连接接头的力学性能。结果表明，根据不同的钢连接结构，剪切失效模式可分为螺栓剪切失效和嵌入钢拉拔失效。剪切螺栓对钢连接件的剪切性能影响很小。连接件两侧的法兰可有效提高连接件的滞后性能。在测试的试样中，连接接头处钢结构为带肋槽钢的试样具有更优越的滞后性能、更高的承载能力、渐进的刚度衰减和出色的消能能力。建议在设计中使用这些连接细节来处理连接处的嵌入式钢连接。
{"title":"Experimental and numerical study on mechanical properties of PC shear wall bolted connection joints","authors":"Yindong Gong, Yunpeng Chu, Yanhui Liu, Zhipeng Zhai","doi":"10.1177/13694332241281542","DOIUrl":"https://doi.org/10.1177/13694332241281542","url":null,"abstract":"Steel-bolt connection joint with embedded steel is increasingly utilized for prefabricated concrete (PC) shear walls and plays an indispensable role in the shear force transmission process. To enhance the mechanical performance of the connection joint in PC walls, a new pre-embedded steel bolt connection is proposed in this paper. The new connection can quickly connect prefabricated shear walls, with a simple construction process and short construction period. The present study respectively designed and fabricated four specimens with different connection configurations to conduct shear performance tests on the steel connectors and hysteresis performance tests on the connection joint. A numerical model for the joint was then established based on the shear test data of the steel connectors, to further analyze the mechanical performance of the proposed connection joint. The results indicate that depending on the different steel connection configurations, shear failure modes can be categorized into bolt shear failure and embedded steel pullout failure. The shear studs have minimal impact on the shear performance of the steel connectors. The flanges on both sides of the joint effectively enhance the hysteresis performance of the connection joint. Among the tested specimens, the one with a steel configuration at the connection joint featuring ribbed channel steel exhibits superior hysteresis performance, with higher load-bearing capacity, gradual stiffness degradation, and excellent energy dissipation capability. It is recommended to use these connection details for embedded steel connections at the joint during the design.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194986","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 : 2024-09-04DOI: 10.1177/13694332241281524
Abbas Rezaeian, Mohammad Sajjad Salehi, Venkatesh Kodur
This paper presents results from an experimental study on the fire behavior of endplate joints and the connected steel beams in a moment resisting frame (MRF). Utilizing the subframe assemblage, full-scale steel beams with various endplate connections were tested according to the ISO834 standard fire exposure. The thermal and structural responses of the beam and its endplate joints to the column, together with failure modes were monitored throughout the fire test. The effect of key factors such as endplate dimensions, bolt size and grade, and the presence of stiffeners were investigated. The results of the fire tests show that the specimen experiences flexural failure in 746–773°C temperature range, through mid-span deflection exceeding the deflection limit as per British standard 476. When the beam experienced a deflection greater than span/20, the endplate joints got fractured at about 40 min in to fire at temperatures higher than 815°C. The results also indicated that the endplate bending and the tensile fracture of the bolts control the failure of the endplate joint under fire exposure. The endplate connection details have a notable influence on the beam’s behavior under fire conditions, and the use of grade 10.9 bolts and wider endplates in the connection can improve the fire resistance of MRFs.
{"title":"Performance of steel beams with endplate connections exposed to fire","authors":"Abbas Rezaeian, Mohammad Sajjad Salehi, Venkatesh Kodur","doi":"10.1177/13694332241281524","DOIUrl":"https://doi.org/10.1177/13694332241281524","url":null,"abstract":"This paper presents results from an experimental study on the fire behavior of endplate joints and the connected steel beams in a moment resisting frame (MRF). Utilizing the subframe assemblage, full-scale steel beams with various endplate connections were tested according to the ISO834 standard fire exposure. The thermal and structural responses of the beam and its endplate joints to the column, together with failure modes were monitored throughout the fire test. The effect of key factors such as endplate dimensions, bolt size and grade, and the presence of stiffeners were investigated. The results of the fire tests show that the specimen experiences flexural failure in 746–773°C temperature range, through mid-span deflection exceeding the deflection limit as per British standard 476. When the beam experienced a deflection greater than span/20, the endplate joints got fractured at about 40 min in to fire at temperatures higher than 815°C. The results also indicated that the endplate bending and the tensile fracture of the bolts control the failure of the endplate joint under fire exposure. The endplate connection details have a notable influence on the beam’s behavior under fire conditions, and the use of grade 10.9 bolts and wider endplates in the connection can improve the fire resistance of MRFs.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194988","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 : 2024-09-02DOI: 10.1177/13694332241276051
Shoufei Shao, Maozu Guo, Ailin Zhang, Yanxia Zhang, Yang Li, ZhuoXuan Li
Tensegrity structures, characterized by enhanced stiffness, slender struts, and superior buckling resistance, have found wide-ranging applications in fields such as engineering, architecture, art, biology, and robotics, attracting extensive attention from researchers. The form-finding process, a critical step in the design of tensegrity structures, aims to discover the self-equilibrated configuration that satisfies specific design requirements. Traditional form-finding methods based on force density often require repeated steps of eigenvalue decomposition and singular value decomposition, making the process complex. In contrast, this paper introduces a new intelligent form-finding algorithm that uses the force density method and combines the Coati optimization algorithm with Graph Neural Networks. This algorithm avoids the complex steps of eigenvalue and singular value decomposition and integrates the physical knowledge of the structure, making the form-finding process faster and more accurate. In this algorithm, various force densities are initially randomized and input into a trained Graph Neural Networks to predict a fitness function’s value. Through optimizing the constrained fitness function, the algorithm determines the appropriate structural force density and coordinates, thereby completing the form-finding process of the structure. The paper presents seven typical tensegrity structure examples and compares various form-finding methods. The results of numerical examples show that the method proposed in this paper can find solutions that align with the super-stable line more quickly and accurately, demonstrating its potential value in practical applications.
{"title":"Form-finding of tensegrity structures based on graph neural networks","authors":"Shoufei Shao, Maozu Guo, Ailin Zhang, Yanxia Zhang, Yang Li, ZhuoXuan Li","doi":"10.1177/13694332241276051","DOIUrl":"https://doi.org/10.1177/13694332241276051","url":null,"abstract":"Tensegrity structures, characterized by enhanced stiffness, slender struts, and superior buckling resistance, have found wide-ranging applications in fields such as engineering, architecture, art, biology, and robotics, attracting extensive attention from researchers. The form-finding process, a critical step in the design of tensegrity structures, aims to discover the self-equilibrated configuration that satisfies specific design requirements. Traditional form-finding methods based on force density often require repeated steps of eigenvalue decomposition and singular value decomposition, making the process complex. In contrast, this paper introduces a new intelligent form-finding algorithm that uses the force density method and combines the Coati optimization algorithm with Graph Neural Networks. This algorithm avoids the complex steps of eigenvalue and singular value decomposition and integrates the physical knowledge of the structure, making the form-finding process faster and more accurate. In this algorithm, various force densities are initially randomized and input into a trained Graph Neural Networks to predict a fitness function’s value. Through optimizing the constrained fitness function, the algorithm determines the appropriate structural force density and coordinates, thereby completing the form-finding process of the structure. The paper presents seven typical tensegrity structure examples and compares various form-finding methods. The results of numerical examples show that the method proposed in this paper can find solutions that align with the super-stable line more quickly and accurately, demonstrating its potential value in practical applications.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194994","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 performance of high-strength steel (HSS) welding joints is crucial for tubular structure design. This paper investigates the hysteretic performance of HSS square hollow section (SHS) T joints considering fracture behaviors. The hysteresis and tensile tests of the HSS SHS T joints and a comparative analysis of failure modes and bearing capacity are conducted. Parameter analysis is conducted based on the validated FE model considering fracture and elastoplastic constitutive relationship with a wide range of parameters covered, including the cross-sectional width ratio and the wall thickness ratio between brace and chord, and the width-thickness ratio of the chord, and the seam weld size of the joint connection. The results show that fracture behavior can affect the failure mode and bearing capacity of the joints, and it cannot be ignored in the hysteresis analysis process. The energy consumption capacity and the ductility coefficients increase when β increases from 0.2 to 1.0, τ increases from 0.3 to 1.0 and 2 γ decreases from 40 to 20. Meanwhile, joints’ failure modes and residual strength vary with the above parameters. It is necessary to use the damage fracture constitutive model of steel in numerical simulation.
{"title":"Hysteretic performance of high-strength steel square hollow section T joints considering fracture behavior","authors":"Shubang Liu, Shicai Chen, Liqun Hou, Zhengming Zhou","doi":"10.1177/13694332241276056","DOIUrl":"https://doi.org/10.1177/13694332241276056","url":null,"abstract":"The performance of high-strength steel (HSS) welding joints is crucial for tubular structure design. This paper investigates the hysteretic performance of HSS square hollow section (SHS) T joints considering fracture behaviors. The hysteresis and tensile tests of the HSS SHS T joints and a comparative analysis of failure modes and bearing capacity are conducted. Parameter analysis is conducted based on the validated FE model considering fracture and elastoplastic constitutive relationship with a wide range of parameters covered, including the cross-sectional width ratio and the wall thickness ratio between brace and chord, and the width-thickness ratio of the chord, and the seam weld size of the joint connection. The results show that fracture behavior can affect the failure mode and bearing capacity of the joints, and it cannot be ignored in the hysteresis analysis process. The energy consumption capacity and the ductility coefficients increase when β increases from 0.2 to 1.0, τ increases from 0.3 to 1.0 and 2 γ decreases from 40 to 20. Meanwhile, joints’ failure modes and residual strength vary with the above parameters. It is necessary to use the damage fracture constitutive model of steel in numerical simulation.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194991","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 : 2024-08-28DOI: 10.1177/13694332241276055
Weiping Zhao, Xinxin Li, Guangjie Li
Composite concrete structures are designed to integrate various concrete types at different levels, thereby improving their shear properties. In this paper, the effects of the interfacial keyway, reinforcement ratio, and pouring sequence on the shear strength of concrete-coal gangue concrete interface are studied by experiments and analyses. A total of 10 specimens were made, and the push-off test was carried out. Nonlinear finite element simulation was carried out using ABAQUS, and the influence of keyway angle on crack development was studied based on the extended finite element method (XFEM). It is found that the remarkable tensile and crack stability of engineered cementitious composites (ECC) has a positive effect on the shear strength of the ECC-coal gangue concrete interface. The ultimate shear strength of the interface and the ductility of the interface under shear load are significantly improved by interfacial shear reinforcement. The introduction of an interfacial keyway improves the shear strength of the concrete interface, and the number of keyways has the most significant effect on the interfacial shear strength. The angle between the crack propagation direction and interface will increase with the increase of keyway angle, the simulation results are in good agreement with the experiments.
{"title":"The experimental and numerical simulation of interface shear behavior between ECC and coal gangue concrete","authors":"Weiping Zhao, Xinxin Li, Guangjie Li","doi":"10.1177/13694332241276055","DOIUrl":"https://doi.org/10.1177/13694332241276055","url":null,"abstract":"Composite concrete structures are designed to integrate various concrete types at different levels, thereby improving their shear properties. In this paper, the effects of the interfacial keyway, reinforcement ratio, and pouring sequence on the shear strength of concrete-coal gangue concrete interface are studied by experiments and analyses. A total of 10 specimens were made, and the push-off test was carried out. Nonlinear finite element simulation was carried out using ABAQUS, and the influence of keyway angle on crack development was studied based on the extended finite element method (XFEM). It is found that the remarkable tensile and crack stability of engineered cementitious composites (ECC) has a positive effect on the shear strength of the ECC-coal gangue concrete interface. The ultimate shear strength of the interface and the ductility of the interface under shear load are significantly improved by interfacial shear reinforcement. The introduction of an interfacial keyway improves the shear strength of the concrete interface, and the number of keyways has the most significant effect on the interfacial shear strength. The angle between the crack propagation direction and interface will increase with the increase of keyway angle, the simulation results are in good agreement with the experiments.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194992","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 : 2024-08-24DOI: 10.1177/13694332241276059
Maha RI Mahmoud, Xin Wang, Bai Xingyu, Mohamedelmujtaba Altayeb, Shui Liu, Amr MA Moussa
This study investigates the flexural behaviour of eight full-scale semi-precast slabs, where the precast bottom layer comprises fibre-reinforced concrete (FRC) with varying fibre types such as steel, chopped basalt, and basalt minibar fibres. The upper layer of these semi-precast slabs is cast-in-situ normal-strength concrete, with the interface bonding between the layers enhanced by two steel truss members. The semi-precast FRC slabs are longitudinally reinforced with prestressed basalt fibre-reinforced polymer (BFRP) and steel bars. Within the eight semi-precast slabs, two reference specimens are prepared for comparative analysis. These reference specimens have a precast bottom panel cast with normal-strength concrete, with one reinforced using longitudinal steel bars and the other reinforced with prestressed BFRP bars. The study focuses on assessing cracking patterns, ultimate moment capacity, stress distribution, stiffness, and ductility of these semi-precast slabs. The experimental test results demonstrate that the use of FRC and prestressed BFRP bars has a significant effect on improving the flexural behaviour of the semi-precast slabs, enhancing their strength, curbing deflection, cracking behaviour, and ultimate load capacity. Furthermore, the research includes an evaluation comparing three distinct code specifications for ultimate moment capacity against the experimental outcomes. This comparative analysis reveals a notable discrepancy, emphasizing the need to revise current code equations to better address the complexities associated with combining FRC and prestressed FRP materials in structural applications.
{"title":"Flexural behaviour of semi-precast slabs of fibre-reinforced concrete reinforced with prestressed basalt fibre-reinforced polymer and steel bars","authors":"Maha RI Mahmoud, Xin Wang, Bai Xingyu, Mohamedelmujtaba Altayeb, Shui Liu, Amr MA Moussa","doi":"10.1177/13694332241276059","DOIUrl":"https://doi.org/10.1177/13694332241276059","url":null,"abstract":"This study investigates the flexural behaviour of eight full-scale semi-precast slabs, where the precast bottom layer comprises fibre-reinforced concrete (FRC) with varying fibre types such as steel, chopped basalt, and basalt minibar fibres. The upper layer of these semi-precast slabs is cast-in-situ normal-strength concrete, with the interface bonding between the layers enhanced by two steel truss members. The semi-precast FRC slabs are longitudinally reinforced with prestressed basalt fibre-reinforced polymer (BFRP) and steel bars. Within the eight semi-precast slabs, two reference specimens are prepared for comparative analysis. These reference specimens have a precast bottom panel cast with normal-strength concrete, with one reinforced using longitudinal steel bars and the other reinforced with prestressed BFRP bars. The study focuses on assessing cracking patterns, ultimate moment capacity, stress distribution, stiffness, and ductility of these semi-precast slabs. The experimental test results demonstrate that the use of FRC and prestressed BFRP bars has a significant effect on improving the flexural behaviour of the semi-precast slabs, enhancing their strength, curbing deflection, cracking behaviour, and ultimate load capacity. Furthermore, the research includes an evaluation comparing three distinct code specifications for ultimate moment capacity against the experimental outcomes. This comparative analysis reveals a notable discrepancy, emphasizing the need to revise current code equations to better address the complexities associated with combining FRC and prestressed FRP materials in structural applications.","PeriodicalId":50849,"journal":{"name":"Advances in Structural Engineering","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142194993","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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