Partially encased composite (PEC) members are becoming increasingly popular because of their high strength and suitability for prefabrication and assembly. Corrugated steel plate has higher out-of-plane stiffness than flat steel plate. When it is combined with concrete, the bonding between corrugated steel plate and concrete is more obvious than that between flat steel plate and concrete. For this reason, a new type of corrugated web PEC column (CPEC column) was proposed in this paper, and its eccentric compression performance was studied by experiment and numerical method. Nine specimens were tested, of which two were subjected to axial compression and seven were subjected to eccentric compression. The key factors considered in the experiment were the loading direction, load eccentricity, link spacing, and width-to-thickness ratio of flange. A three-dimensional finite element model of the CPEC columns was established and verified, and the influence of the wave angle of corrugated web on the behavior of CPEC columns under eccentric compression was investigated using a parametric study. Finally, the current design codes for estimating the interaction curve and bearing capacity of CPEC columns were assessed.
{"title":"Experimental and numerical study on eccentric compression performance of partially encased composite columns with corrugated web","authors":"Wei Wang, Hengli Cai, Congyou Bai, Haiyang Bao, Boyuan Gao, Zhiwei Yuan, Jianhui Niu","doi":"10.1002/tal.2084","DOIUrl":"https://doi.org/10.1002/tal.2084","url":null,"abstract":"Partially encased composite (PEC) members are becoming increasingly popular because of their high strength and suitability for prefabrication and assembly. Corrugated steel plate has higher out-of-plane stiffness than flat steel plate. When it is combined with concrete, the bonding between corrugated steel plate and concrete is more obvious than that between flat steel plate and concrete. For this reason, a new type of corrugated web PEC column (CPEC column) was proposed in this paper, and its eccentric compression performance was studied by experiment and numerical method. Nine specimens were tested, of which two were subjected to axial compression and seven were subjected to eccentric compression. The key factors considered in the experiment were the loading direction, load eccentricity, link spacing, and width-to-thickness ratio of flange. A three-dimensional finite element model of the CPEC columns was established and verified, and the influence of the wave angle of corrugated web on the behavior of CPEC columns under eccentric compression was investigated using a parametric study. Finally, the current design codes for estimating the interaction curve and bearing capacity of CPEC columns were assessed.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138628087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reinforced concrete (RC) shear wall buildings with unreinforced masonry (URM) infilled moment frames are common in India and neighboring countries. This study assesses the influence of the URM infills on their seismic performance. Fully infilled, open first-storied, and bare frame versions of a 25-story shear wall building are considered. Multiple stripe analysis is conducted at five return periods to estimate their performance. Fragility functions for the collapse prevention limit state, which is based on seven engineering demand parameter exceedance thresholds, are generated and compared. The presence of infills (full or partial) is observed to have an overall positive effect on the performance of the RC frame-shear wall buildings. The performance of the open first-story building was comparable to that of the fully infilled building. The ratio of story shear carried by the moment frames and shear walls is studied at all return periods to understand the variation in frame shear wall interaction with increased damage for each building. In the case of buildings with infills, the frames carry a higher proportion of story shear at lower return periods. For all three buildings, the fraction of story shear carried by moment frames increases along the height of the building.
{"title":"Effect of unreinforced masonry infills on seismic performance of reinforced concrete frame-shear wall buildings","authors":"Mayank Sharma, Yogendra Singh, Henry V. Burton","doi":"10.1002/tal.2069","DOIUrl":"https://doi.org/10.1002/tal.2069","url":null,"abstract":"Reinforced concrete (RC) shear wall buildings with unreinforced masonry (URM) infilled moment frames are common in India and neighboring countries. This study assesses the influence of the URM infills on their seismic performance. Fully infilled, open first-storied, and bare frame versions of a 25-story shear wall building are considered. Multiple stripe analysis is conducted at five return periods to estimate their performance. Fragility functions for the collapse prevention limit state, which is based on seven engineering demand parameter exceedance thresholds, are generated and compared. The presence of infills (full or partial) is observed to have an overall positive effect on the performance of the RC frame-shear wall buildings. The performance of the open first-story building was comparable to that of the fully infilled building. The ratio of story shear carried by the moment frames and shear walls is studied at all return periods to understand the variation in frame shear wall interaction with increased damage for each building. In the case of buildings with infills, the frames carry a higher proportion of story shear at lower return periods. For all three buildings, the fraction of story shear carried by moment frames increases along the height of the building.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138627755","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As a result of the combination of the complex behavior of masonry buildings with insufficient material quality and lack in engineering calculations, a large number of damages has been observed in the earthquakes that occurred in recent years. Therefore, a realistic understanding of the behavior of masonry walls and buildings is necessary to construct seismic-resistant structures. Since masonry walls have many variables, performing experiments in which each variable is present at the same time will make it difficult to understand the behavior. For these reasons, considering the out-of-plane failures that are frequently mentioned in recent earthquakes, in this study, variables in dry-stack brick masonry buildings such as the aspect ratio of the wall (2, 1.33, and 1), the presence of the transverse walls (2, 1, and 0), and the openings in the walls (door and/or window) were taken into account separately. Eighteen different wall configurations were designed, and a total of 48 dry-stack walls having U-shape, L-shape, and I-shape in plan were tested by a specially constructed tilting table setup to determine their out-of-plane behavior. From the test results, it was found that lateral load capacity of the U-shaped walls without openings increased as the aspect ratio (L/H) decreased. No change in capacity was observed in L- and I-shaped walls when the aspect ratio was reduced from 2 to 1. Door and/or window openings were found to affect only the L-shaped walls. In addition, it was determined that failure patterns were affected from the aspect ratio and the presence of the openings.
{"title":"Out-of-plane behavior of dry-stack brick masonry walls","authors":"Barış Erdil, Fırat Kıpçak, Mücip Tapan","doi":"10.1002/tal.2089","DOIUrl":"https://doi.org/10.1002/tal.2089","url":null,"abstract":"As a result of the combination of the complex behavior of masonry buildings with insufficient material quality and lack in engineering calculations, a large number of damages has been observed in the earthquakes that occurred in recent years. Therefore, a realistic understanding of the behavior of masonry walls and buildings is necessary to construct seismic-resistant structures. Since masonry walls have many variables, performing experiments in which each variable is present at the same time will make it difficult to understand the behavior. For these reasons, considering the out-of-plane failures that are frequently mentioned in recent earthquakes, in this study, variables in dry-stack brick masonry buildings such as the aspect ratio of the wall (2, 1.33, and 1), the presence of the transverse walls (2, 1, and 0), and the openings in the walls (door and/or window) were taken into account separately. Eighteen different wall configurations were designed, and a total of 48 dry-stack walls having U-shape, L-shape, and I-shape in plan were tested by a specially constructed tilting table setup to determine their out-of-plane behavior. From the test results, it was found that lateral load capacity of the U-shaped walls without openings increased as the aspect ratio (L/H) decreased. No change in capacity was observed in L- and I-shaped walls when the aspect ratio was reduced from 2 to 1. Door and/or window openings were found to affect only the L-shaped walls. In addition, it was determined that failure patterns were affected from the aspect ratio and the presence of the openings.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138628083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Piezoelectric energy harvester devices have been widely used for collection of the vibration energy. Especially, the cantilever structure has been extensively studied to optimizing its energy harvesting performance. In this paper, a new type of bending torsion coupled piezoelectric energy harvester is proposed with the combination of the elastic connection and the optimized design of the eccentric mass. The energy harvesting performance under indirect impact load is analyzed by the theory of mechanical vibration and Hamiltonian principle. The geometry effect of the tip mass is investigated. The theoretical calculation method is verified by comparison with the finite element method. The results show that reasonable resistance selection and the frequency matching of the main structure and the energy capture structure will significantly change the energy harvesting effect. The frequency matching of the structures can be optimized by improving the eccentric arrangement. It is demonstrated that the proposed structure of the piezoelectric energy harvester has better energy harvesting efficiency as compared with the traditional structures.
{"title":"Electromechanical analysis of a bending-torsion coupling piezoelectric energy harvester","authors":"Taotao Zhang, Linda Wang, Wende Liu","doi":"10.1002/tal.2081","DOIUrl":"https://doi.org/10.1002/tal.2081","url":null,"abstract":"Piezoelectric energy harvester devices have been widely used for collection of the vibration energy. Especially, the cantilever structure has been extensively studied to optimizing its energy harvesting performance. In this paper, a new type of bending torsion coupled piezoelectric energy harvester is proposed with the combination of the elastic connection and the optimized design of the eccentric mass. The energy harvesting performance under indirect impact load is analyzed by the theory of mechanical vibration and Hamiltonian principle. The geometry effect of the tip mass is investigated. The theoretical calculation method is verified by comparison with the finite element method. The results show that reasonable resistance selection and the frequency matching of the main structure and the energy capture structure will significantly change the energy harvesting effect. The frequency matching of the structures can be optimized by improving the eccentric arrangement. It is demonstrated that the proposed structure of the piezoelectric energy harvester has better energy harvesting efficiency as compared with the traditional structures.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138627956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Traditional wooden structures are characterized by the presence of a column base that seems to be floated above the foundation stone. This study used pseudo-static experiments to assess the seismic performance of flat pendulum floating resting columns, focusing on the decay and repair of the wood frame (WF). First, an artificial method was used to simulate fungal decay damage of column-foot joints, and filling reinforcement was applied to the decayed column-foot joints, and second, according to the design method in the Sung dynasty architecture, the Ying-tsaofa-shih (building standards). This study presents the findings of pseudo-static tests that were conducted at Yangzhou University. Three 1:3.52 scaled specimen WFs with flat-pendulum-floating-shelf (FPFS)-typed (Ping-bai-fu-ge) columns, i.e., non-damaged WF (named after NT), considering the damaged WF (named after DF) and strengthening damaged WF (named after DR) with one-way straight mortise-tenon joints (OWSMT) joints were made and subjected to cyclic lateral loads during testing. The properties of the WFs with FPFS columns, such as the failure mode, hysteretic and envelope curves, strength and stiffness deterioration, and energy dissipation, have been studied. Finally, the effects of additional damage and reinforcement measures on the seismic performance of WFs are analyzed and compared with the finite element numerical simulation results. This research shows that damage to the column foot decreases the WF's seismic performance, although filler reinforcement may increase it. The foot and mortise joints are interconnected and interact in the wood frame's seismic stressing mechanism. Foot decay reduces the seismic performance of the foot joint, hence increasing the seismic energy dissipation activity of the mortise joints.
{"title":"Floating column mechanism experimental investigation in historic timber buildings subjected to decay for seismic resilience","authors":"Lingkun Chen, Chencheng Zhai, Qizhi Chen, Xiaolun Hu, Teng Wu, Liming Zhu, Xiaoming Huang","doi":"10.1002/tal.2082","DOIUrl":"https://doi.org/10.1002/tal.2082","url":null,"abstract":"Traditional wooden structures are characterized by the presence of a column base that seems to be floated above the foundation stone. This study used pseudo-static experiments to assess the seismic performance of flat pendulum floating resting columns, focusing on the decay and repair of the wood frame (WF). First, an artificial method was used to simulate fungal decay damage of column-foot joints, and filling reinforcement was applied to the decayed column-foot joints, and second, according to the design method in the Sung dynasty architecture, the Ying-tsaofa-shih (building standards). This study presents the findings of pseudo-static tests that were conducted at Yangzhou University. Three 1:3.52 scaled specimen WFs with flat-pendulum-floating-shelf (FPFS)-typed (Ping-bai-fu-ge) columns, i.e., non-damaged WF (named after NT), considering the damaged WF (named after DF) and strengthening damaged WF (named after DR) with one-way straight mortise-tenon joints (OWSMT) joints were made and subjected to cyclic lateral loads during testing. The properties of the WFs with FPFS columns, such as the failure mode, hysteretic and envelope curves, strength and stiffness deterioration, and energy dissipation, have been studied. Finally, the effects of additional damage and reinforcement measures on the seismic performance of WFs are analyzed and compared with the finite element numerical simulation results. This research shows that damage to the column foot decreases the WF's seismic performance, although filler reinforcement may increase it. The foot and mortise joints are interconnected and interact in the wood frame's seismic stressing mechanism. Foot decay reduces the seismic performance of the foot joint, hence increasing the seismic energy dissipation activity of the mortise joints.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138561784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Folded plate roofs are widely used in building roofs due to their light weight and high stiffness. However, traditional folded plate roofs are often limited in application due to insufficient stiffness under the current trend of pursuing larger-span roofs. Ribbed folded plate roofs can effectively solve this problem because ribs not only increase the stiffness of the roof and reduce stress concentration, but they are also easy to be formed into various shapes to meet different needs for buildings. Therefore, the detailed analysis was carried out on a reinforced concrete ribbed folded plate roof (RCRFR) under the vertical uniform load to investigate its static behavior. The bearing capacity, failure mode, load–displacement relationship, and strain variation were obtained through the test. Additionally, based on the finite element (FE) method, not only a comparison was conducted between RCRFR and reinforced concrete ribless folded plate roof (RCLFR), but the influence of material nonlinearity and geometric nonlinearity on the structure was also investigated. Moreover, the bending characteristics of RCRFR under design load were analyzed based on the reproducing kernel particle method. The experimental results showed that this structure had good mechanical properties within the design load. In the overload stage, the concrete on the underside of the structure was severely damaged. Furthermore, the yielding of the ribbed plate's reinforcing bars caused the increased vertical deformation difference between the ribbed plate and the top chord, and the ribbed plate and the central ridge beam. Eventually, the failure of the anchorage of the ribbed plate's reinforcing bars anchored in the central ridge beam and the top chord led to the loss of structural load-bearing capacity. The FE analysis results demonstrated that ribs enhance the stiffness of the structure, with material nonlinearity having the primary impact and geometric nonlinearity exerting a secondary effect. The meshfree method analysis was in concordance with the experimental results as well as those of the FE analysis.
{"title":"Static behavior of ribbed folded plate roof under vertical uniform load—Experimental study and meshfree method analysis","authors":"Renzhong Sun, Kejian Ma, Huagang Zhang, Fang Yu, Qiang Fang","doi":"10.1002/tal.2079","DOIUrl":"https://doi.org/10.1002/tal.2079","url":null,"abstract":"Folded plate roofs are widely used in building roofs due to their light weight and high stiffness. However, traditional folded plate roofs are often limited in application due to insufficient stiffness under the current trend of pursuing larger-span roofs. Ribbed folded plate roofs can effectively solve this problem because ribs not only increase the stiffness of the roof and reduce stress concentration, but they are also easy to be formed into various shapes to meet different needs for buildings. Therefore, the detailed analysis was carried out on a reinforced concrete ribbed folded plate roof (RCRFR) under the vertical uniform load to investigate its static behavior. The bearing capacity, failure mode, load–displacement relationship, and strain variation were obtained through the test. Additionally, based on the finite element (FE) method, not only a comparison was conducted between RCRFR and reinforced concrete ribless folded plate roof (RCLFR), but the influence of material nonlinearity and geometric nonlinearity on the structure was also investigated. Moreover, the bending characteristics of RCRFR under design load were analyzed based on the reproducing kernel particle method. The experimental results showed that this structure had good mechanical properties within the design load. In the overload stage, the concrete on the underside of the structure was severely damaged. Furthermore, the yielding of the ribbed plate's reinforcing bars caused the increased vertical deformation difference between the ribbed plate and the top chord, and the ribbed plate and the central ridge beam. Eventually, the failure of the anchorage of the ribbed plate's reinforcing bars anchored in the central ridge beam and the top chord led to the loss of structural load-bearing capacity. The FE analysis results demonstrated that ribs enhance the stiffness of the structure, with material nonlinearity having the primary impact and geometric nonlinearity exerting a secondary effect. The meshfree method analysis was in concordance with the experimental results as well as those of the FE analysis.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138561790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During the past decade, the progressive collapse of structures has received growing attention, and the study of member importance is a key step for investigating the progressive collapse resistance. However, traditional methods for evaluating the member importance usually employ a single indicator, and when multiple indicators are involved, different indicators may generate different member rankings. Moreover, the truss string structure is a multiple super-stationary structure with many members, and the current studies mainly focus on cable failure, which does not mean that other members are not important. In this study, the initial selection of important members is first performed based on concept evaluation, and then, the alternate path method is used to analyze the progressive collapse resistance of truss string structures; the slope degradation coefficient γ of incremental dynamic analysis curve, load capacity degradation coefficient β, and nested load capacity degradation coefficient β′ are introduced; and the sensitivity coefficient SIj and fragility coefficient VIi are defined with axial force as the structural response. Based on the above five indicators, two cases are conducted to evaluate the member importance. The analysis results show that the cable and the bottom chord member at the support are evaluated as the first-level important members. Through the analysis of different indicators, it is found that the regularity of the coefficient of each member is inconsistent for different indicators. The results could be one-sided if the important members were evaluated by a single indicator only. In addition, the second-level important members of truss string structures are evaluated by multi-indicator analysis. Finally, the nominal progressive collapse resistance of truss string structures is given based on the importance coefficient of the first- and second-level important members.
{"title":"Multi-indicator evaluation method of important members of truss string structures","authors":"Wenhao Liu, Bin Zeng, Zhen Zhou, Yifan Zheng","doi":"10.1002/tal.2085","DOIUrl":"https://doi.org/10.1002/tal.2085","url":null,"abstract":"During the past decade, the progressive collapse of structures has received growing attention, and the study of member importance is a key step for investigating the progressive collapse resistance. However, traditional methods for evaluating the member importance usually employ a single indicator, and when multiple indicators are involved, different indicators may generate different member rankings. Moreover, the truss string structure is a multiple super-stationary structure with many members, and the current studies mainly focus on cable failure, which does not mean that other members are not important. In this study, the initial selection of important members is first performed based on concept evaluation, and then, the alternate path method is used to analyze the progressive collapse resistance of truss string structures; the slope degradation coefficient <i>γ</i> of incremental dynamic analysis curve, load capacity degradation coefficient <i>β</i>, and nested load capacity degradation coefficient <i>β</i>′ are introduced; and the sensitivity coefficient <i>SI</i><sub><i>j</i></sub> and fragility coefficient <i>VI</i><sub><i>i</i></sub> are defined with axial force as the structural response. Based on the above five indicators, two cases are conducted to evaluate the member importance. The analysis results show that the cable and the bottom chord member at the support are evaluated as the first-level important members. Through the analysis of different indicators, it is found that the regularity of the coefficient of each member is inconsistent for different indicators. The results could be one-sided if the important members were evaluated by a single indicator only. In addition, the second-level important members of truss string structures are evaluated by multi-indicator analysis. Finally, the nominal progressive collapse resistance of truss string structures is given based on the importance coefficient of the first- and second-level important members.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138561567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Saman Saadatfar, Fereshteh Emami, Mohsen Khatibinia, Hussein Eliasi
The active tuned mass damper (ATMD) is a reliable energy-dissipating device to effectively protect structures from serious damages due to earthquake excitations. This study proposes the optimal design of sliding sector control (SSC) for the seismic protection of an 11-story shear building structure equipped with ATMD. First, the SSC controller is optimally designed for the seismic control of the structure subjected to an artificial earthquake. Then, the effectiveness of the optimized SSC (OSSC) is assessed in reducing the seismic responses of the structure subjected to four near- and far-fault earthquake excitations. The efficient performance of the OSSC technique is also validated and compared with that of a number of the control techniques such as linear quadratic regulator (LQR), fuzzy logic control (FLC), proportional-integral-derivative (PID), and optimal sliding mode control (OSMC). Comparative results demonstrate the efficiency and robustness of the proposed OSSC in comparison with those of the other controllers.
{"title":"Optimization-based design of sliding sector control for active seismic protection of structures","authors":"Saman Saadatfar, Fereshteh Emami, Mohsen Khatibinia, Hussein Eliasi","doi":"10.1002/tal.2073","DOIUrl":"https://doi.org/10.1002/tal.2073","url":null,"abstract":"The active tuned mass damper (ATMD) is a reliable energy-dissipating device to effectively protect structures from serious damages due to earthquake excitations. This study proposes the optimal design of sliding sector control (SSC) for the seismic protection of an 11-story shear building structure equipped with ATMD. First, the SSC controller is optimally designed for the seismic control of the structure subjected to an artificial earthquake. Then, the effectiveness of the optimized SSC (OSSC) is assessed in reducing the seismic responses of the structure subjected to four near- and far-fault earthquake excitations. The efficient performance of the OSSC technique is also validated and compared with that of a number of the control techniques such as linear quadratic regulator (LQR), fuzzy logic control (FLC), proportional-integral-derivative (PID), and optimal sliding mode control (OSMC). Comparative results demonstrate the efficiency and robustness of the proposed OSSC in comparison with those of the other controllers.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138511038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mahmoud Ali, Seyed Rasoul Mirghaderi, Amir Reza Ghiami Azad, Iman Karami
The eccentricity between connected steel parts and the anchor rods in base-plate T-stub connections makes base plates the weaker components in tension and compression. Additionally, the oversized holes in base plates lead to irregular placement of anchor rods, resulting in an unsymmetrical shear behavior. Thus, this paper aims to develop a special all-round fillet weld to connect the anchor rods beneath the base plate concentrically to the steel part, removing the base plate from the load-transferring chain. Accordingly, design criteria were first developed based on Eurocode's directional method considering all the potential failure modes. Next, results were validated by conducting experimental work. The digital image correlation technique (DIC) was also used to capture the strain distribution developed over the tested specimen till failure. Consequently, numerical analysis was carried out to investigate the fracture strength and the fracture angle and compare the special fillet weld with its equivalent standard one, which has the same weld volume. The results indicated that the proposed design criteria produced safe strength prediction for the developed special all-round fillet weld. Furthermore, the results revealed that using a special all-round fillet weld instead of the equivalent standard one can increase the strength by about 8% and improve the ductility of the weld. However, it decreases the stiffness of the weld by about 21%. The fracture surface occurred at from the face of the anchor rod, which produced a higher strength than the predicted tensile strength calculated according to the theoretical throat plane.
在t型连接中，连接钢件与锚杆之间的偏心使底板成为受拉、受压较弱的构件。此外，底板上的超大孔导致锚杆位置不规则，从而导致不对称的剪切行为。因此，本文旨在开发一种特殊的全方位角焊缝，将底板下方的锚杆与钢部分同心连接，从而将底板从荷载传递链中移除。因此，首先根据欧洲规范的定向方法制定了考虑所有潜在破坏模式的设计准则。其次，通过实验工作对结果进行验证。数字图像相关技术(DIC)也被用来捕捉应变分布发展到试样破坏。为此，对特殊角焊缝的断裂强度和断裂角度进行了数值分析，并与相同焊缝体积的等效标准角焊缝进行了比较。结果表明，所提出的设计准则对所研制的专用全方位角焊缝进行了安全强度预测。此外，结果表明，采用特殊的全方位角焊缝代替等效标准焊缝，强度可提高约8% and improve the ductility of the weld. However, it decreases the stiffness of the weld by about 21%. The fracture surface occurred at 15°$$ {15}^{{}^{circ}} $$ from the face of the anchor rod, which produced a higher strength than the predicted tensile strength calculated according to the theoretical throat plane.
{"title":"Special all-round fillet weld for anchor rods of base-plate T-stub connections","authors":"Mahmoud Ali, Seyed Rasoul Mirghaderi, Amir Reza Ghiami Azad, Iman Karami","doi":"10.1002/tal.2072","DOIUrl":"https://doi.org/10.1002/tal.2072","url":null,"abstract":"The eccentricity between connected steel parts and the anchor rods in base-plate T-stub connections makes base plates the weaker components in tension and compression. Additionally, the oversized holes in base plates lead to irregular placement of anchor rods, resulting in an unsymmetrical shear behavior. Thus, this paper aims to develop a special all-round fillet weld to connect the anchor rods beneath the base plate concentrically to the steel part, removing the base plate from the load-transferring chain. Accordingly, design criteria were first developed based on Eurocode's directional method considering all the potential failure modes. Next, results were validated by conducting experimental work. The digital image correlation technique (DIC) was also used to capture the strain distribution developed over the tested specimen till failure. Consequently, numerical analysis was carried out to investigate the fracture strength and the fracture angle and compare the special fillet weld with its equivalent standard one, which has the same weld volume. The results indicated that the proposed design criteria produced safe strength prediction for the developed special all-round fillet weld. Furthermore, the results revealed that using a special all-round fillet weld instead of the equivalent standard one can increase the strength by about 8% and improve the ductility of the weld. However, it decreases the stiffness of the weld by about 21%. The fracture surface occurred at <math altimg=\"urn:x-wiley:15417794:media:tal2072:tal2072-math-0001\" display=\"inline\" location=\"graphic/tal2072-math-0001.png\" overflow=\"scroll\">\u0000<semantics>\u0000<mrow>\u0000<mn>15</mn>\u0000<mo>°</mo>\u0000</mrow>\u0000$$ {15}^{{}^{circ}} $$</annotation>\u0000</semantics></math> from the face of the anchor rod, which produced a higher strength than the predicted tensile strength calculated according to the theoretical throat plane.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138511034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohammad Younes Rahnama, Seyed Rasoul Mirghaderi, Mohammad Reza Bahaari
Despite good rigidity, braced frames have weak nonlinear behavior and inadequate distribution of ductility in stories, which cause significant structural damage. In this research, a seismic resistant system called coupled concentrically braced frame (CCBF) is developed to enhance the performance of braced frames by coupling them with a beam. In this case, the coupling beams are the primary source for ductility of the system, and after their yielding in more severe earthquakes, the structure continues to benefit from the ductility of the braces as the secondary source; therefore, the system has two-level behavior caused by different probable seismic excitations. In this case, in addition to maintaining the stiffness of the two concentrically braced frames, the coupling beams resist against the movement of the braced frames, and as a result, the stiffness of the system is increased. Therefore, lighter elements can be used to resist lateral loads. Linear and nonlinear analyses of CCBF, and its comparison with other braced frames, indicate that participation of the coupling beams provides an adequate stiffness and ductility. These frames have more stable nonlinear behavior than conventional ones and continue their nonlinear behavior even after fracture of coupling beams in severe earthquakes.
{"title":"Multi-level enhancement of structural behavior of bracing systems with coupling beams at floor level","authors":"Mohammad Younes Rahnama, Seyed Rasoul Mirghaderi, Mohammad Reza Bahaari","doi":"10.1002/tal.2068","DOIUrl":"https://doi.org/10.1002/tal.2068","url":null,"abstract":"Despite good rigidity, braced frames have weak nonlinear behavior and inadequate distribution of ductility in stories, which cause significant structural damage. In this research, a seismic resistant system called coupled concentrically braced frame (CCBF) is developed to enhance the performance of braced frames by coupling them with a beam. In this case, the coupling beams are the primary source for ductility of the system, and after their yielding in more severe earthquakes, the structure continues to benefit from the ductility of the braces as the secondary source; therefore, the system has two-level behavior caused by different probable seismic excitations. In this case, in addition to maintaining the stiffness of the two concentrically braced frames, the coupling beams resist against the movement of the braced frames, and as a result, the stiffness of the system is increased. Therefore, lighter elements can be used to resist lateral loads. Linear and nonlinear analyses of CCBF, and its comparison with other braced frames, indicate that participation of the coupling beams provides an adequate stiffness and ductility. These frames have more stable nonlinear behavior than conventional ones and continue their nonlinear behavior even after fracture of coupling beams in severe earthquakes.","PeriodicalId":501238,"journal":{"name":"The Structural Design of Tall and Special Buildings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138511130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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