International Journal of Steel Structures最新文献

{"title":"Experimental and Analytical Study on the Seismic Performance of PEC T-Shaped Columns Assembled Frames with ALC Open-Hole Wall","authors":"Bo Wang,&nbsp;Changyao Hu,&nbsp;Jingfeng Wang,&nbsp;Xin Gao,&nbsp;Jia Sun","doi":"10.1007/s13296-024-00872-1","DOIUrl":"10.1007/s13296-024-00872-1","url":null,"abstract":"<div><p>To investigate the seismic performance of a fully assembled framework consisting of prefabricated autoclaved lightweight concrete (ALC) wall panels with partially encased concrete T-shaped columns, a horizontal low-cycle reciprocating load test was conducted on a non-open hole ALC wall panel specimen and an ALC wall panel specimen with a rectangular opening. The influence of the opening on the structure was analyzed, and a comparative discussion is carried out in this article on hysteresis curves and skeleton curves. The experimental results showed that a wall panel opening weakened the overall integrity of the wall, resulting in stress concentration around the door opening and accelerated the damage to the infill wall. In addition, a numerical model was established for analysis, and the finite element results were cross-verified with the experimental results. Based on the experimentally validated numerical model, the influence of different opening parameters on the lateral resistance performance of the framework combination was analyzed, providing theoretical references for engineering construction.</p></div>","PeriodicalId":596,"journal":{"name":"International Journal of Steel Structures","volume":"24 4","pages":"986 - 1004"},"PeriodicalIF":1.1,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141745199","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}

{"title":"RL-based Control of Smart Base Isolation System Using Unity ML-Agents","authors":"Hyun-Su Kim,&nbsp;Joo-Won Kang","doi":"10.1007/s13296-024-00862-3","DOIUrl":"10.1007/s13296-024-00862-3","url":null,"abstract":"<div><p>Reinforcement learning (RL) has been used in the development of various control systems presenting desirable control performances. There have been many studies examining the development of structural control algorithms using conventional methods and soft computing algorithms. However, research investigating RL-based structural control techniques in particular is still in an early stage. In RL algorithms, the agent interacts with the environment by taking the appropriate action under the specific state. In the RL-based structural control problem, the environment usually includes the structure, control system, external loads, etc., and it is generally presented by the finite element model. In the present study, the Unity game engine—which has recently come to be used in various engineering simulations because of its accurate physics calculations—was used to construct a reinforcement learning environment for structural control systems. A smart base isolation system (SBIS) that was composed of a magnetorheological damper and four friction pendulum systems was used as an example structural control system, and it was modeled using the Unity physics engine for RL environment. Among various RL algorithms, a Deep Q-Network (DQN) was used to make the control algorithm for the SBIS. The command voltage for the smart base isolation was mapped into the agent’s action. The reward of the DQN algorithm was designed to be a higher value when the agent takes a better action resulting in reduced seismic responses. Three artificial ground motions were used to train the DQN-based control algorithm, and another artificial earthquake was used to investigate the control efficiency of the trained DQN-based control algorithm. The passive-on case with the maximum damper force was used for comparative study. This study shows that the DQN-based algorithm can successfully control the SBIS. The findings show that the unity game engine can accurately present the dynamic responses of the SBIS, showing that it can be effectively used for the construction of a RL environment for structural dynamic systems.</p></div>","PeriodicalId":596,"journal":{"name":"International Journal of Steel Structures","volume":"24 4","pages":"908 - 917"},"PeriodicalIF":1.1,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141745328","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}

{"title":"Experimental and Numerical Investigation of Cross-Shaped Joints with Adjustable Stiffness for Cold-formed Thick-Walled Steel Column–Column Connections","authors":"Zhanhong Li,&nbsp;Yuanqi Li,&nbsp;Fuwei Wu,&nbsp;Xue Bai,&nbsp;Fudong Ma","doi":"10.1007/s13296-024-00864-1","DOIUrl":"10.1007/s13296-024-00864-1","url":null,"abstract":"<div><p>Cold-formed thick-walled steel members have a higher bearing capacity and wider applicability in the mid-rise buildings in comparison with the widely-used cold-formed thin-walled steel framing walls in low-rise buildings. To avoid the shortcomings of cold-forming effect, a structure with hinged or semi-rigid joint steel frame using cold-formed thick-walled steel and cold-formed thin-walled steel framing shear wall is one reasonable choices, and it will be very helpful to simplify the on-site assembling processes. In this paper, a cross-shaped joint with adjustable stiffness was proposed, and better seismic performance was investigated and confirmed by tests. By increasing the thickness of the web plates of the cross-shaped joint, the bearing capacity, stiffness, and ductility of the joint can be significantly improved, and the buckling deformation of the web plate will be reduced. Moreover, a strengthening stiffener, Type 2 proposed in the paper, has a significantly effect on the cross-shaped joint for seismic damage and intact specimens. Using ANSYS software and the SOLID185 element, a finite element model was established. With the increasing thickness of the end plate of the stiffener Type 2, both the stiffness and bearing capacity of the cross-shaped joint can be significantly increased.</p></div>","PeriodicalId":596,"journal":{"name":"International Journal of Steel Structures","volume":"24 4","pages":"918 - 946"},"PeriodicalIF":1.1,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141745327","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}

{"title":"Experimental Study on the Dynamic Characteristics of Steel Slit Dampers with and Without Out-of-Plane Deformation Restraints","authors":"Jinwoo Kim,&nbsp;U-Jin Kwon,&nbsp;Hae-Yong Park,&nbsp;Young-Ju Kim,&nbsp;Jae-Bong Kim","doi":"10.1007/s13296-024-00869-w","DOIUrl":"10.1007/s13296-024-00869-w","url":null,"abstract":"<div><p>Increasing the strut thickness to prevent or restrain out-of-plane deformation increases in-plane stiffness and strength, leading to excessive stress concentration at the junction of the damper and damper systems. We developed restraining panels to suppress out-of-plane deformation and enhance the deformation performance of steel slit dampers. Additionally, we investigated the impact of applying restraining panels on the plastic deformation capability and strength of the steel slit dampers. The experimental variables included (1) the presence of out-of-plane deformation restraining panels, (2) the ratio of effective height to strut width (aspect ratio), (3) the ratio of strut thickness to width (thickness-width ratio), and (4) loading amplitude. When the restraining panels were not applied, cracks occurred at the end of the strut. In the test specimen where out-of-plane deformation occurred, the cumulative plastic deformation angle improved from 1.97 to 3.29 times owing to the use of restraining panels. However, the strength increase ratio for all test specimens ranged from approximately 1.3–1.7, indicating that minimal strength enhancement was attributable to the restraining panels.</p></div>","PeriodicalId":596,"journal":{"name":"International Journal of Steel Structures","volume":"24 4","pages":"958 - 968"},"PeriodicalIF":1.1,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141644067","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}

{"title":"Effects of Solution Temperature on the Galvanic Corrosion Between Carbon Fiber and Carbon Steel SM490A","authors":"Jian Tang,&nbsp;Muye Yang","doi":"10.1007/s13296-024-00870-3","DOIUrl":"10.1007/s13296-024-00870-3","url":null,"abstract":"<div><p>Temperature significantly affects the galvanic corrosion behavior between carbon fiber reinforced plastic (CFRP) and carbon steel. The corrosion rate of steel components in bridges may increase at high temperatures during summer. To examine the impact of solution temperature on the galvanic corrosion between CFRP and carbon steel, electrochemical tests were conducted at different temperatures. The open circuit potential results and potentiodynamic polarization results indicated that the presence of carbon fiber to carbon steel led to increased potential and accelerated corrosion rates. Subsequently, the temperature-promoting factor was used to predict the corrosion rates of steel with galvanic corrosion based on the Arrhenius equation. Finally, the limitations of the temperature-promotion factor were analyzed theoretically.</p></div>","PeriodicalId":596,"journal":{"name":"International Journal of Steel Structures","volume":"24 6","pages":"1312 - 1321"},"PeriodicalIF":1.1,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613827","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}

{"title":"Utilization of Sodium Polyacrylate Hydrogels in the Sacrificial Anode Cathodic Protection Method for Steel Members at the Atmospheric Environment","authors":"Jie Xu,&nbsp;Shigenobu Kainuma","doi":"10.1007/s13296-024-00865-0","DOIUrl":"10.1007/s13296-024-00865-0","url":null,"abstract":"<div><p>To achieve sacrificial anode cathodic protection (SACP) for steel members in the atmospheric environment, the sodium polyacrylate hydrogels were prepared and acted as electrolyte carriers in the protection system. The hydrogels absorbing varying concentrations of sodium chloride solution were verified by the water swelling and retention test, the electrochemical test, and the constant exposure test. The result shows that the hydrogel shows a remarkable water absorption capacity with the NaCl solution. However, within 48 h, little difference shows in the swelling ratio. And the water retentivity weakens with the concentrations of sodium chloride solution increasing up to 3.5 mass%. The hydrogel absorbing 10.0 mass% sodium chloride solution exhibits the highest retention ratio. Moreover, the steel specimens immersed in the hydrogel show greater resistance to corrosion compared to exposure in NaCl aqueous solution. Besides, the SACP method using the hydrogel can sustain corrosion protection for over 200 h, based on the time-dependent anti-corrosion current density, which ensures the durability of the system. Overall, the findings suggest that sodium polyacrylate hydrogels demonstrate promising attributes as electrolyte carriers, broadening the potential application of the SACP method to atmospheric environments.</p></div>","PeriodicalId":596,"journal":{"name":"International Journal of Steel Structures","volume":"24 6","pages":"1304 - 1311"},"PeriodicalIF":1.1,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141615039","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}

{"title":"Effect of Lip Depth on the Flexural Capacity of Cold-Formed Steel Section","authors":"Nitish Vijayamurugan,&nbsp;Vaishnavi Prabaharan,&nbsp;Punitha kumar Akhas","doi":"10.1007/s13296-024-00867-y","DOIUrl":"10.1007/s13296-024-00867-y","url":null,"abstract":"<div><p>Cold-formed steel section (CFS) is broadly utilised in structural elements such as compression members, flexural members and tension members. Owing to its commendable properties such as light weight, easy handling, faster installation, aesthetic appearance and high strength to weight ratio, this study investigates the impact of lip depth and web depth on the flexural strength of light gauge steel C-sections. Specifically, it examines the flexural strength, including the strength-to-weight ratio, of C-sections with varying lip depths, and comparing these trends across different web depths. A finite element analysis was carried out to determine the optimum dimension of the depth of the lip by using the software ABAQUS. Load–deflection behaviour, failure modes, strength to weight ratio and changes in the load carrying capacity were discussed in this paper. The paper explores the load–deflection behaviour, failure modes, strength-to-weight ratio variations and corresponding differences in bending carrying capacity. The analysis reveals that the strength-to-weight ratio of C-sections increases gradually with lip depth. Moreover, an increase in lip depth positively influences the load carrying capacity of lipped channel sections in CFS structures.</p></div>","PeriodicalId":596,"journal":{"name":"International Journal of Steel Structures","volume":"24 4","pages":"849 - 861"},"PeriodicalIF":1.1,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141573332","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}

{"title":"Topology Optimization and 3D Printing of Steel Joints by SJ-BESO and FDM Method","authors":"Pengshan Tang,&nbsp;Wenfeng Du,&nbsp;Chao Wang,&nbsp;Jinchao Gu,&nbsp;Mijia Yang","doi":"10.1007/s13296-024-00863-2","DOIUrl":"10.1007/s13296-024-00863-2","url":null,"abstract":"<div><p>The problems of low computational efficiency and checkerboard phenomenon in optimizing steel joints with the bi-directional evolutionary structural optimization (BESO) method are intractable, which usually leads to failure to achieve optimized solutions even after spending long calculation time. This paper proposes an improved algorithm based on the BESO theory for steel joints (SJ-BESO) by utilizing a sensitivity filtering radius to weight the sensitivity values of each element. And a sensitivity threshold segment is proposed to determine the deletion or addition of elements. Additionally, a convergence parameter is developed to ensure the stability of the optimization calculation. Several real-word examples of steel joints are provided to illustrate the proposed method. The results show that the improved BESO algorithm not only reduces the number of iterations, but also produces ideal structures with good stiffness. The 3D printing manufacturing of the example model verifies the manufacturability of the obtained designs and enhances its intuitive understanding. The SJ-BESO is applicable and promising for the topology optimization of steel joints.</p></div>","PeriodicalId":596,"journal":{"name":"International Journal of Steel Structures","volume":"24 4","pages":"743 - 757"},"PeriodicalIF":1.1,"publicationDate":"2024-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141573331","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}

{"title":"Behaviour of Braced and Unbraced Multi-storey Steel Framed Buildings on Flat and Sloping Terrain","authors":"Palash Dey,&nbsp;Sylvia Wahengbam,&nbsp;Ainal Hoque Gazi","doi":"10.1007/s13296-024-00866-z","DOIUrl":"10.1007/s13296-024-00866-z","url":null,"abstract":"<div><p>In recent days, emerging nations have needed new and enhanced infrastructure projects to support their growing populations. There is a daily rise in the demand for residential land as the population expands. In addition to flat land, sloping land in hilly areas must be considered to satisfy the demand for housing land. Moreover, vertical development in the form of multi-storey buildings is the only solution to the problem. In this context the effects of various forms of bracing on the seismic performance of two hill building configurations, such as stepback and stepback-setback, were investigated and compared to a building standing on level ground. A time history dynamic analysis was performed to assess structural responses in terms of seismic parameters such as fundamental time period, top storey lateral displacement, storey drift, base shear, and torsion. The building standing on leveled and sloping ground have been modelled with bracings placed at three different locations, namely at the corners, the mid-edge, and the centre of the building. Buildings standing on sloping land are found to be extremely vulnerable to earthquakes due to irregularities in elevation. X-braced frames, V braced frames, and inverted V braced frames have all been examined in order to identify the best bracing system that significantly improved the seismic resilience of building frames. The Stepback-setback X-braced frame, positioned at the center of the building model, demonstrated the highest percentage decrease in lateral displacement compared to the control model during the El Centro earthquake: 16.27% along and 15.55% across the slope line, respectively. Similar trends were observed for the Northridge and Loma Prieta earthquakes. This highlights the effectiveness of the setback-stepback model with a centrally placed X-bracing system as the preferred choice for buildings on sloping ground due to its superior seismic resilience.</p></div>","PeriodicalId":596,"journal":{"name":"International Journal of Steel Structures","volume":"24 4","pages":"758 - 776"},"PeriodicalIF":1.1,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141549214","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}

{"title":"Residual Mechanical Properties of Q345FR Steel Exposed to High Temperatures","authors":"Suhang Yang,&nbsp;Chen Hu,&nbsp;Zhifeng Xu","doi":"10.1007/s13296-024-00859-y","DOIUrl":"10.1007/s13296-024-00859-y","url":null,"abstract":"<div><p>Steel structures used in engineering projects and infrastructure should withstand high loading capacities with excellent resistance to fire. A new Q345 fire-resistant (Q345FR) steel has been recently developed in China. The residual mechanical properties of steel structures are critical indicators for assessing structural damage and reusability, so in-depth research is urgently needed. Considering temperatures ranging from room temperature to 900 °C, as well as air and water cooling methods, the residual elastic modulus, yield stress, ultimate tensile strength and ultimate strain were explored. Comparison of the residual mechanical properties of Q345FR steel with other structural steels confirmed their close relation to temperatures and cooling methods through testing. The loss of its mechanical properties could be ignored when the temperature is up to 600 °C and the aforementioned cooling methods are used. When the temperature is above 600 °C, the exposed temperatures and cooling methods impact the residual mechanical properties of Q345FR steel significantly. Q345FR steel boasts the comprehensive advantages of excellent strength, high ductility and fire resistance. The prediction equations are offered for predicting such properties of Q345FR steel to accurately evaluate its residual mechanical properties exposed to high temperatures.</p></div>","PeriodicalId":596,"journal":{"name":"International Journal of Steel Structures","volume":"24 4","pages":"799 - 812"},"PeriodicalIF":1.1,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141549218","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}