Structures最新文献

{"title":"Data-driven prediction of load transfer function for high neck flexible flange bolts in lattice wind turbine towers","authors":"Hang Du ,&nbsp;Chuannan Xiong ,&nbsp;Kaoshan Dai ,&nbsp;Junlin Heng ,&nbsp;Yuxiao Luo ,&nbsp;Ke Fan ,&nbsp;Bin Wang ,&nbsp;Ji Li","doi":"10.1016/j.istruc.2025.110224","DOIUrl":"10.1016/j.istruc.2025.110224","url":null,"abstract":"<div><div>The load transfer function (LTF) of flange bolt connections is crucial for evaluating the fatigue life of lattice wind turbine towers. Traditional LTF methods face accuracy challenges due to larger flange sizes with increasing turbine hub heights. This study validates the Schmidt/Neuper method and introduces a machine learning (ML) approach to calculate bolt internal forces. After validating the finite element model (FEM) through static testing, the study compares the LTFs of integral flange connections and simplified models with the Schmidt/Neuper method, identifying its limitations. A parameter correlation analysis leads to the creation of a FEM database, from which various machine learning models: Linear Regression (LR), k-Nearest Neighbors (KNN), Support Vector Regression (SVR), Decision Tree (DT), Gaussian Process Regression (GPR), Random Forest (RF), CatBoost (CB), and XGBoost (XG) are developed and tested. A user-friendly graphical interface is provided. The finding reveals the limitations of Schmidt/Neuper method, mainly due to its assumption of a single bolt joint and neglecting load distribution, leading to inaccuracies. The ML approach improves LTF prediction accuracy, providing a more reliable method for fatigue life assessment in flange bolt connections.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110224"},"PeriodicalIF":4.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 seismic performance of precast high-strength RC beam-column joint with embedded channel steel and UHPC","authors":"Shujun Hu ,&nbsp;Hongwei Xu ,&nbsp;Sizhi Zeng ,&nbsp;Tao Chen ,&nbsp;Kang He","doi":"10.1016/j.istruc.2025.110235","DOIUrl":"10.1016/j.istruc.2025.110235","url":null,"abstract":"<div><div>To further improve the seismic performance, economic and seismic resilience of prefabricated reinforced concrete (RC) beam-column joints, an innovative prefabricated high-strength RC beam-column joint (PHBCJ) with ultra-high strength concrete (UHPC) and embedded channel steel has been developed, which integrates the 500 MPa high-strength rebar, 120 MPa UHPC and embedded channel steel (ECS). To evaluate its performance, one high-strength cast-in-place RC beam-column joint and four PHBCJ specimens with varying rebar strength, concrete strength and ECS, along with two repaired PHBCJ specimens, were tested under cyclic loading, simulating rare and ultimate seismic conditions. Finite element models were established and verified with test results. Key parameters such as failure modes, hysteresis curves, skeleton curves, secant stiffness, energy dissipation capacity and strain-displacement behavior were analyzed. The results indicate that the incorporating UHPC and ECS effectively prevents cracking occurs in the joint region, confining damage primarily to the beam ends. The PHBCJ with HRB500 rebar and ECS demonstrated superior bearing capacity and cost efficiency. Moreover, the seismic performance of PHBCJs with grouted sleeve connections between the precast upper and lower columns, combined with post-poured concrete in the joint region, closely resembled that of cast-in-place specimen. Additionally, the repaired joints exhibited nearly identical seismic performance to their pre-damage condition. In the PHBCJ with post-pored UHPC, damage was localized at the end of beam, reducing the affected area and severity, thereby enhancing repair efficiency and economic viability. Overall, the novel PHBCJ successfully meets the key design principles, including “strong joint weak component,” “strong column weak beam,” “strong shear weak bending,” and “plastic hinge relocation away from the column,” ensuring improved seismic performance and seismic resilience capacity, which align well with the seismic demands of modern structures.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110235"},"PeriodicalIF":4.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Refined FE-based cross-section analysis for line element simulation of WAAM steel members considering anisotropy","authors":"Hao-Yi Zhang ,&nbsp;An-Rui Liang ,&nbsp;Si-Wei Liu ,&nbsp;Yao-Peng Liu ,&nbsp;Siu-Lai Chan","doi":"10.1016/j.istruc.2025.110236","DOIUrl":"10.1016/j.istruc.2025.110236","url":null,"abstract":"<div><div>Wire-arc additive manufacturing (WAAM) has emerged as a promising technique for fabricating large-scale 3D-printed steel structures. However, the development of its full potential is constrained by the current line element-based second-order analysis method for steel structures, which fails to account for the material anisotropy inherent in WAAM. This study addresses this limitation by reformulating the cross-sectional properties utilized in line elements, incorporating an anisotropic material model that accounts for the effect of the printing direction. A 2D finite element analysis (FEA) is employed for numerical solutions of the cross-sectional properties, which are then implemented into a 7-degrees-of-freedom (DOF) Timoshenko line element. The proposed method is validated through comparisons with benchmark results from sophisticated finite element analyses (SFEA). This research provides a novel approach to accurately model WAAM steel members in second-order analysis, which has been incorporated into the MSASect2 software for both research and educational purposes.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110236"},"PeriodicalIF":4.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cyclic loading behavior and restoring force model of disc-spring self-centering beam-column joints","authors":"Yi Ru ,&nbsp;Chao Dou ,&nbsp;Li-ji Huang ,&nbsp;Long-he Xu","doi":"10.1016/j.istruc.2025.110244","DOIUrl":"10.1016/j.istruc.2025.110244","url":null,"abstract":"<div><div>This study theoretically investigated a new type of prefabricated Disc spring Self-centering Steel beam-column Joints (DsSCSJs). It incorporates the disc-spring device to produce restoring force and web friction cover plates to provide energy dissipation capacity, while confining plastic damage primarily to the upper flange cover plates at the splicing connection of the main beams. The spliced beam segment rotates about the center of the upper flange cover plates, reducing the adverse impact of the \"beam elongation\" effect in traditional self-centering frames. Based on the previous cyclic loading tests of the joints, this paper mainly investigates the working mechanism and hysteretic performance of the new joint by using the verified finite element analysis (FEA). The effects of key factors on the hysteretic behavior and self-centering ability were explored, including disc-spring stiffness, web plate friction, flange cover plate thickness, bolt slip, and connection detailing. Subsequently, a moment-rotation restoring force model of the joint was established from theoretical derivations, with detailing suggestions proposed. The results showed that the finite element model and analysis were in good agreement with the test results, revealing its working mechanism and performance. The proposed theoretical restoring force model can accurately simulate the cyclic loading behavior of joints. A pin connection in the self-centering device results in lower stress concentrations and better self-centering ability in the DsSCSJ. To attain complete self-centering, the pre-compression bending moment produced by the disc spring should be greater than the friction moment and the plastic resistance moment of the beam flange cover plates. The residual deformation of the joints is primarily caused by the bolt slippage and possible local yielding at the beam-column connection, and consequently the self-centering ability of the DsSCSJ can be effectively improved by diminishing bolt slip and preventing the beam-column connection yielding by proper design and construction detailing.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110244"},"PeriodicalIF":4.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advanced computational framework for fragility analysis of elevated steel tanks using hybrid and ensemble machine learning techniques","authors":"Mohammad Reza Akbarzadeh ,&nbsp;Vahid Jahangiri ,&nbsp;Babak Naeim ,&nbsp;Ali Asgari","doi":"10.1016/j.istruc.2025.110205","DOIUrl":"10.1016/j.istruc.2025.110205","url":null,"abstract":"&lt;div&gt;&lt;div&gt;This research examines the elevated steel tanks’ seismic fragility with emphasis on the impact of significant structural and ground motion characteristics on the parameters of the fragility curve. Focusing on prediction accuracy by sophisticated machine learning techniques and the underlying variable importance in driving the fragility response, the research introduces meaningful insights toward seismic design and retrofitting. The fragility curve is developed for several Engineering Demand Parameters (EDPs) containing Base Shear &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;V&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, Overturning Moment &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;M&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, Tower Displacement &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;X&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;s&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, vertical liquid surface displacement &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;v&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, meridional tank wall stress (Sigma), Elephant Foot Buckling &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;pb&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, and base isolation displacement &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;U&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. A detailed sensitivity analysis is conducted using the Fourier Amplitude Spectrum Technique (FAST) to assess the impact of input characteristics on the median &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;θ&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and dispersion &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; parameters of the fragility curve. For tanks that are not isolated, geometric characteristics like slenderness (S) and liquid height (H) play greater roles than material characteristics like the density of steel &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;ρ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;steel&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, emphasizing the structural superiority of geometry to material weight in seismic behavior. Likewise, environmental and ground motion inputs like peak ground acceleration (PGA) and site conditions (Field) show different types and magnitudes of impacts across the EDPs. For isolated tanks, sensitivity patterns change, with the damping ratio &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mfenced&gt;&lt;mrow&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;ξ&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/mfenced&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, isolation base period &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;T&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, and viscous behavior (ν), demonstrating significant impact on some, like &lt;span&gt;&lt;math&gt;&lt;msub&gt;&lt;mrow&gt;&lt;mi&gt;U&lt;/mi&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mi&gt;b&lt;/mi&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt; and Sigma, while others like H and R show minimal impact. These results highlight the variable-specific nature of fragility behavior, providing","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110205"},"PeriodicalIF":4.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 bond properties between corroded grout sleeves and concrete in a chloride environment","authors":"Qing-long Wang ,&nbsp;Qin Zhang ,&nbsp;Jia Li ,&nbsp;Wen-Jie Li ,&nbsp;Jun Huang ,&nbsp;Hai-Tao Zhao","doi":"10.1016/j.istruc.2025.110227","DOIUrl":"10.1016/j.istruc.2025.110227","url":null,"abstract":"<div><div>To study the bond mechanism between corroded grout sleeves and concrete, 18 grout sleeve concrete bond specimens were prepared for central pull-out tests. Three key parameters, including corrosion levels, grout sleeve diameters, and protective layer thicknesses, were evaluated. The results revealed that the bond properties between grout sleeves and concrete were significantly degraded as corrosion levels increased, and the bond strength was decreased by up to 84.54 % compared to the specimens without corrosion in this study. Meanwhile, the bond specimens exhibited penetrating cracks due to the corrosion of grout sleeves with the relatively large diameters, and pronounced macro-penetrating cracks were observed when the corrosion level was approximately 5 %. Finally, to predict the bond stress-slip responses between corroded grout sleeves and concrete, an analytical model was developed. The proposed predictive model shows excellent agreement with the measured bond stress-slip curves, which also demonstrates better applicability than existing bond-slip models proposed on the basis of studies on concrete and corroded reinforcing bars with the relatively small diameters.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110227"},"PeriodicalIF":4.3,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097163","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fracture properties and sustainability assessment of strain-hardening alkali activated composites of up to 100 % rubber aggregate","authors":"Hongshu Pan ,&nbsp;Zeming Yang ,&nbsp;Minglang Xue ,&nbsp;Jiaying Su ,&nbsp;Xiaocai Yan ,&nbsp;Zhanbiao Chen ,&nbsp;Jiaxiang Lin ,&nbsp;Yongchang Guo","doi":"10.1016/j.istruc.2025.110221","DOIUrl":"10.1016/j.istruc.2025.110221","url":null,"abstract":"<div><div>Strain-hardening alkali-activated composites (SHAAC) are eco-friendly materials with ductile fracture characteristics. This study investigates the effects of rubber powder (RP) replacement ratios (0–100 %) on the ductile fracture performance of rubberized SHAAC (R-SHAAC), focusing on the underlying toughening mechanisms. The ductile fracture process was quantified with initiation fracture energy <em>J</em>_IC and failure fracture energy <em>J</em>_IF. The RP toughening mechanism was revealed with matrix-cracking fracture energy <em>J</em>_m, fiber bridging fracture energy <em>J</em>_b, and composite fracture energy <em>J</em>_c. RP enhances R-SHAAC's fracture performance through three mechanisms: reduced matrix toughness, crack bridging, and improved fiber dispersion. R-SHAAC specimens exhibit ductile failure with a primary crack surrounded by dense microcracks. RP extends the steady-state multi-crack propagation phase, increasing <em>J</em>_IF by up to 89.9 % compared to the baseline. For most mixtures, <em>J</em>_m/<em>J</em>_c exceeds 60 %, indicating that matrix cracking is the primary mode of energy dissipation. However, RP replacement ratio above 75 % triggers over-saturated cracking, which shortens the steady-state cracking phase and advancing the onset of instability. In addition, the Technique for Order of Preference by Similarity to Ideal Solution analysis identified the mixture with a 25 % RP replacement ratio as the optimal balance between mechanical performance and sustainability. This study clarifies the influence of RP modification on SHAAC’s ductile fracture behavior, providing insights into toughening mechanisms and enabling the evaluation of R-SHAAC designs for sustainable, high-performance construction applications.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110221"},"PeriodicalIF":4.3,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of prestressed CFRP plates to improve the flexural capacity of full size box girders for bridge","authors":"Yong Li ,&nbsp;Ziming Zhou ,&nbsp;Weibing Xu ,&nbsp;Mengfei Xie","doi":"10.1016/j.istruc.2025.110230","DOIUrl":"10.1016/j.istruc.2025.110230","url":null,"abstract":"<div><div>With the growing prevalence of heavy-duty vehicles, highway bridges now subjected to service loads exceeding their original design load ratings. This discrepancy not only affects the service condition of highway bridges but also accelerate the deterioration of the bridge, leading the bridge to the need for reconstruction or repair to increase its rated load capacity. Consequently, bridge strengthening becomes imperative. In contrast to the traditional methods of enlarging sections or paste steel plates, prestressed carbon fiber reinforced polymer (CFRP) plates are used to strengthen bridges and improve cracking moment and flexural capacity without significantly increasing structural weight or reducing vertical clearance. Two full-scale prestressed concrete box girders with a total length of 25 m from a bridge requiring higher load ratings were selected as test specimens. A theoretical analysis of the two girders was conducted, and their mechanical behavior was evaluated through numerical simulation and flexural destructive testing. The results demonstrated that the strengthening increased the actual cracking moment and ultimate flexural capacity of the girder by 12.6 % and 13.6 % respectively. The ratio of ultimate load stress to allowable stress of the strengthened girder under a higher vehicle load rating was close to that of the unstrengthened girder under the original vehicle load rating, Which proved that prestressed CFRP plate strengthening effectively meets the requirements for increasing the vehicle load rating of the girder.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110230"},"PeriodicalIF":4.3,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical and theoretical investigation on the cyclic behavior of self-centering CFDST column-steel beam joints","authors":"Xueyuan Yan,&nbsp;Jitao Yu,&nbsp;Genliang Wang,&nbsp;Wenhui Chen,&nbsp;Shen Shi","doi":"10.1016/j.istruc.2025.110206","DOIUrl":"10.1016/j.istruc.2025.110206","url":null,"abstract":"<div><div>In this paper, a self-centering joint between the concrete-filled double steel tubular (CFDST) column and the steel beam is proposed. The joint was self-centered by prestressed strands when unloading, and energy was dissipated during loading by friction. This work is a numerical and theoretical exploratory study based on a modeling approach already validated by experiments, aiming to investigate the mechanical behavior of the novel self-centering joint and optimize its design parameters. The reasonableness of the joint model was verified by numerical simulation with ABAQUS finite element software, and the damage modes, hysteresis curves, and energy dissipation capacity of the joint were analyzed. A mechanism-based semi-theoretical restoring force model was established. Performed a parametric analysis on the primary factors influencing the mechanical behavior of the joint. The results indicated that there was a contradiction between self-centering performance and energy dissipation in the joint, and the ratio <em>β</em> between the moment resistance provided by the strands and that provided by the friction devices in the decompression moment of the joint played a key role in moderating the relationship between the two. A value of <em>β</em> between 1 and 1.5 was recommended for a balance between the two. The restoring force model of the joint provided a well-predicted mechanical behavior of the joint. The modified rigid model was more consistent with the numerical results. This study provided theoretical support and optimized design parameters for the design of CFDST column-steel beam joints with favorable self-centering performance and energy dissipation capability. The parameter analysis showed that increasing strand prestress increased the bearing capacity but potentially resulted in stress loss; an increase in friction force improved the bearing capacity and energy dissipation capacity, yet it augmented residual deformation; and an enlargement of the cross-sectional area bolstered both the bearing capacity and stiffness, albeit it also led to stress loss.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110206"},"PeriodicalIF":4.3,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 assessment of optimized hybrid strengthening techniques for unreinforced masonry columns under axial compression","authors":"Galal Elsamak ,&nbsp;Mohamed Ghalla ,&nbsp;Mohamed H. El-Naqeeb ,&nbsp;Ehab A. Mlybari ,&nbsp;Rabeea W. Bazuhair ,&nbsp;Mohamed Emara","doi":"10.1016/j.istruc.2025.110222","DOIUrl":"10.1016/j.istruc.2025.110222","url":null,"abstract":"<div><div>This study presents a comprehensive experimental and numerical investigation into the axial performance of unreinforced masonry (URM) columns strengthened with various hybrid retrofitting techniques. Thirteen full-scale brick masonry columns were tested under monotonic axial compression to evaluate the effects of strain-hardening cementitious composites (SHCC) jacketing, near-surface mounted (NSM) steel bars, and embedded steel/glass fiber reinforced polymer (GFRP) mesh. The experimental program examined load–displacement behavior, failure modes, ultimate capacity, ductility, and energy absorption. Results demonstrated that hybrid strengthening combining NSM bars and mesh-reinforced SHCC jacketing achieved up to 70 % increase in load capacity and double the energy absorption compared to the unstrengthened reference. A validated finite element model, developed in ABAQUS using cohesive damage and embedded interaction approaches, accurately replicated the experimental response, with an average experimental-to-numerical load ratio of 0.95 and displacement ratio of 0.90. Parametric studies showed that increasing longitudinal reinforcement ratio in hybrid systems enhanced axial capacity by up to 39 %, while increasing transverse mesh ratio improved strength by 25 % before plateauing. These findings highlight the synergistic role of axial and transverse reinforcement in improving strength and ductility and offer a reliable modeling framework for optimizing retrofit designs of URM columns in seismic and structural upgrade applications.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"81 ","pages":"Article 110222"},"PeriodicalIF":4.3,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145097410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}