Structures最新文献

{"title":"Hencky bar-chain model for in-plane buckling analysis of arches","authors":"J.M. Zhang ,&nbsp;C.M. Wang ,&nbsp;W.H. Pan ,&nbsp;H.L. Du","doi":"10.1016/j.istruc.2025.109775","DOIUrl":"10.1016/j.istruc.2025.109775","url":null,"abstract":"<div><div>This paper introduces a generalized Hencky bar-chain model (HBM) framework for analyzing in-plane bifurcation buckling of arches with arbitrary shapes, loading and support conditions. By discretizing the arch into rigid segments connected by frictionless hinges and elastic rotational springs, the HBM and the adoption of the energy approach simplifies the complex buckling analysis into a set of algebraic equations for the governing eigenvalue equation, eliminating the need to derive and solve the governing differential equations. The HBM can also readily accommodates variations such as nonuniform member properties, localized structural changes, and differing support elevations, enhancing its adaptability. The developed HBM is applied for solving various arch buckling problems, each illustrating the model's versatility in handling complex structural scenarios. Furthermore, extensive buckling analyses for different arch shapes, loading, and boundary conditions reveal consistent trends in buckling loads relative to the height-to-span ratio. These insights facilitate the development of approximate arch buckling formulas through curve fitting of accurate results, allowing engineers to rapidly predict the buckling loads.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"80 ","pages":"Article 109775"},"PeriodicalIF":3.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680455","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":"Axial capacity of helical piles-A state of the art review of field test and design guidelines","authors":"Debarshi Das,&nbsp;AHM Muntasir Billah","doi":"10.1016/j.istruc.2025.109749","DOIUrl":"10.1016/j.istruc.2025.109749","url":null,"abstract":"<div><div>Helical piles (HPs) have been widely utilized in North America and other regions to support various superstructures, including power transmission towers, residential and commercial buildings, and pedestrian bridges. This study provides a comprehensive overview of various experimental investigations, field testing, and numerical studies that have been undertaken to analyse the behaviour of HPs in different soil conditions and under different loading scenarios. Additionally, this article delivers a concise overview of the design features of HPs, including current design recommendations, their benefits, and limitations, as well as HP's axial and lateral capacity estimate techniques. It also compares several design codes for predicting the axial capacity of HPs, including CFEM (Canada), AC 358 (USA), AS 2159 (Australia), and Practice Note-28 (New Zealand), highlighting their key similarities and differences. Analysis of existing field test data indicates that HPs can achieve capacities of up to 2500 kN in compression and 2000 kN in tension. Moreover, in recent times, HPs have been used in relatively few bridge construction projects in North America. This paper summarizes existing design practices, compares HP capacities reported in the literature, and identifies current trends in the application of HPs as an alternative deep foundation system in bridge foundations.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"80 ","pages":"Article 109749"},"PeriodicalIF":3.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686685","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":"Research on operational load identification for offshore wind turbine based on step function assumption theory","authors":"Qi Jiang ,&nbsp;Xiaofeng Dong ,&nbsp;Jijian Lian ,&nbsp;Huan Zhou","doi":"10.1016/j.istruc.2025.109724","DOIUrl":"10.1016/j.istruc.2025.109724","url":null,"abstract":"<div><div>The operation of offshore wind farm (OWF) faces critical challenges owing to harsh environmental conditions, complex excitation loads and difficult accessibility. As an effective means to ensure stable and safe operation, structural health monitoring requires the load time history data to evaluate the fatigue and remaining life-time of the structure. However, continuous load monitoring is very difficult in practical engineering. Therefore, a time-domain load identification method was proposed based on the step function assumption theory in view of the dynamic characteristics and load features of offshore wind turbine (OWT) in this research. Firstly, the correctness of the proposed load identification method was verified by several validation cases of the spring-mass damping model. The influence of noise on the accuracy of load identification has also been discussed. Subsequently, a 5 MW OWT numerical model supported by monopile established by the aeroelastic code FAST was also used to complete the further verification for the new time domain load identification method. The comparison between the inversely calculated and computed loads demonstrated the applicability of the load calculation procedure for the OWT structure. Finally, taking a 3.3 MW OWT supported by the bucket foundation as an example, the measured displacement was used as the input to identify the operational loads and analyze the load characteristics under different control activities and wind speeds. It is shown in the results that the identified operational load first increases and then decreases as the wind speed increases, which reaches a maximum of 410.96 kN when the wind speed is approximately the rated wind speed. Meanwhile, the engineering applicability of the new load identification method for OWT structure was further demonstrated by comparing the load inversion based on the measured strain data obtained from 3.3 OWT with the minimal error of 1.32 % and average error of 4.35 %. The proposed approach can identify loads online for OWTs in the operational period, which can provide scientific guidance for the structural design, safety evaluation and operational strategy adjustment in the future.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"80 ","pages":"Article 109724"},"PeriodicalIF":3.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680367","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":"Lateral-torsional bucking of parabolic arches in Cartesian coordinate system","authors":"Chang-Fu Hu ,&nbsp;Shun-Shun Zhu ,&nbsp;Wen-Jun Luo ,&nbsp;Jian-Ping Zhou ,&nbsp;Li Li ,&nbsp;Qi-Han Wang","doi":"10.1016/j.istruc.2025.109638","DOIUrl":"10.1016/j.istruc.2025.109638","url":null,"abstract":"<div><div>For circular arch structures in the Polar coordinate system, extensive investigations have been carried out on their lateral-torsional buckling behavior. However, studies on the lateral-torsional buckling of parabolic arches within the Cartesian coordinate are absent in existing literature. To address this research gap and advance engineering applications, a general theoretical framework within the Cartesian coordinate system is proposed to analyze the arch structures for their lateral-torsional buckling behaviors. In addition, the proposed method comprises four key components: a) Derivation of out-of-plane bending, torsion and shear strain-deformation relationships within the Cartesian coordinate system, based on the Timoshenko beam hypothesis; b) Formulation of a lateral-torsional buckling deformation function and derivation of energy equations for the arch and load system based on this function; c) Analytical solutions for the lateral-torsional buckling loads of parabolic arches under the uniformly distributed loading along the span are derived using the Rayleigh-Ritz method, leading to the formulation of corresponding energy equations; d) The proposed method is validated by comparing its analytical results with estimations obtained through finite element analysis and the theoretical predictions of circular arches. The findings demonstrate that the proposed out-of-plane bending, torsion and shear strain-deformation relationships, coupled with the lateral-torsional buckling deformation function, yield closed-form solutions for parabolic arches in the Cartesian coordinate system. Furthermore, the analytical predictions present excellent agreement with numerical results than the circular arches.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"80 ","pages":"Article 109638"},"PeriodicalIF":3.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680457","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":"Multiobjective optimization of steel and concrete composite slabs via MOPSO algorithm","authors":"Isabela Maia da Silva,&nbsp;Élcio C. Alves,&nbsp;Adenilcia F.G. Calenzani","doi":"10.1016/j.istruc.2025.109722","DOIUrl":"10.1016/j.istruc.2025.109722","url":null,"abstract":"<div><div>The use of composite steel-concrete slabs has increased in recent years due to their rapid execution, reduced need for shoring, and optimization of concrete and steel usage, which are the materials that contribute the most to greenhouse gas emissions in the construction industry. This study aims to present formulation of a multi-objective problem for composite steel-concrete slabs, considering the minimization of CO₂ emissions and final costs, as well as maximization of their load capacity. The design constraints considered were the prescriptions of Brazilian standards for the concrete's pre and post-curing phases, using the Effective Width Method (EWM) for the pre-curing analysis. To solve the problem, the Multi-Objective Particle Swarm Optimization (MOPSO) method was used to generate and analyze Pareto frontiers. The multi-objective formulation was validated using problems from the literature, and an analysis of solutions proposed by manufacturers was conducted for different spans. Additionally, an equation correlating CO₂ emissions and cost was proposed. The results indicate that MOPSO efficiently found optimal solutions, providing nearly the same results as those reported in the literature when using a single-objective formulation. With the proposed formulation, the load capacity of the slabs can be increased by more than 30 % compared to the manufacturer’s solutions while reducing CO₂ emissions and final structure costs due to additional reinforcement. Furthermore, solutions were obtained for spans exceeding the maximum span provided by the manufacturer by using concretes with a compressive strength greater than 30 MPa. According to the results, the optimization problem constraints are: the verification of the steel form against bending moments before concrete curing and the verification of the composite section against longitudinal shear after concrete curing.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"80 ","pages":"Article 109722"},"PeriodicalIF":3.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680355","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":"Influence of pre-damage on the axial compressive performance of masonry columns retrofitted with TRC","authors":"Boxue Wang ,&nbsp;Shiping Yin ,&nbsp;Aojie Xing","doi":"10.1016/j.istruc.2025.109743","DOIUrl":"10.1016/j.istruc.2025.109743","url":null,"abstract":"<div><div>Masonry columns are critical load-bearing components of masonry structures; however, due to the inherent brittleness of masonry, they are susceptible to sudden failure under seismic and other hazardous events. Furthermore, in-service masonry columns often possess a certain degree of internal damage, leading to its existing bearing capacity may not meet the requirements. Retrofitting predamaged masonry columns is an effective approach to enhance the safety and structural integrity of these elements. To investigate the repair effectiveness of textile reinforced concrete (TRC) on pre-damaged masonry columns and to elucidate the influence of the degree of pre-damage on the retrofitting effectiveness of TRC systems, axial compression tests were conducted on 18 masonry columns. The study analyzed the effects of damage degree and the number of TRC layers on failure modes, load-bearing capacity, deformation, and energy absorption. Results indicate that the TRC system transforms the failure mode of pre-damaged masonry columns from brittle to ductile, characterized by progressive fiber cracking at corners instead of sudden collapse. The TRC system significantly enhances both the load-bearing and deformation capacities of damaged columns. Compared to intact masonry columns, the load-bearing capacity of TRC-repaired columns increased by 37.4–71.6 %, while deformation capacity improved by 18.3–49.2 %. Pre-damage diminishes the reinforcing effectiveness of the TRC system, with retrofitting effectiveness deteriorating as damage degree increases; nevertheless, even severely damaged columns exhibit markedly superior post-repair performance relative to intact columns. In addition, increasing the number of TRC facing layers further improves the load-bearing capacity, deformation, and energy absorption of the retrofitted columns. Finally, a strength analysis model for TRC-confined pre-damaged columns, incorporating internal damage effects, is proposed and shows good agreement with experimental results.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"80 ","pages":"Article 109743"},"PeriodicalIF":3.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680368","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":"Shear behavior of ECC-environmentally friendly timber composite beams","authors":"Long Liu ,&nbsp;Shiyao Zhang ,&nbsp;Yu Wang ,&nbsp;Chong Liu ,&nbsp;Xiaoze Yang ,&nbsp;Liang Cui ,&nbsp;Songqiang Wan ,&nbsp;Chunling Yan ,&nbsp;Chenjie Hao ,&nbsp;Hongbo Xiao ,&nbsp;Menghao Ming","doi":"10.1016/j.istruc.2025.109733","DOIUrl":"10.1016/j.istruc.2025.109733","url":null,"abstract":"<div><div>This study innovatively introduces the Engineered Cementitious Composite (ECC)-Timber Beam (ETB) structure, which involves applying ECC to the sides of timber beams. Its primary objective is to enhance the shear bearing capacity and ductility of eco-friendly timber beams. Through systematic experimental investigations, the effects of stud spacing, shear-span ratio (SSR), and ECC layer thickness on the mechanical properties and failure mechanisms of ETB were thoroughly examined. Furthermore, numerical simulation methods were employed to analyze these parameters. A multiple linear regression analysis was conducted to establish the quantitative relationships between ultimate load, shear stiffness, and each parameter. The results demonstrated that the ultimate load, shear stiffness, and displacement ductility of ETB were significantly enhanced. Specifically, compared with TB-1, the ultimate load of ETB-T20-S50 increased by 28.62 %, the shear stiffness improved by 64.69 %, and the displacement ductility coefficient rose by 123.49 %. Numerical simulations revealed that the ultimate load of ETB exhibits negative correlations with the studied parameters, whereas the shear stiffness shows positive correlations.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"80 ","pages":"Article 109733"},"PeriodicalIF":3.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686688","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":"Dynamic analysis of monopile offshore wind turbine in soft clays under combined horizontal and vertical seismic waves","authors":"Wang Pi-guang ,&nbsp;Fang Yun-wen ,&nbsp;Wang Bao-xin ,&nbsp;Cheng Xing-lei ,&nbsp;Li Yun-qi","doi":"10.1016/j.istruc.2025.109725","DOIUrl":"10.1016/j.istruc.2025.109725","url":null,"abstract":"<div><div>The monopile offshore wind turbine (MOWT) is often located in the earthquake-prone areas. Previous studies have mostly focused on the dynamic response of MOWT under horizontal seismic action. However, earthquakes are usually accompanied by vertical seismic action. This paper aims to study the effect of vertical earthquake on the horizontal seismic response of MOWT. Cyclic simple shear tests and free-field seismic response simulations of soil elements are conducted using four types of soil constitutive models including the elastoplastic single bounding surface model proposed by some of the authors which is validated by comparing their calculation results. The single bounding surface model is used firstly to analyze the influence of vertical earthquake on horizontal seismic response of free-field. Subsequently, the influence of vertical earthquake on the horizontal seismic response of MOWT system is investigated. It is found that the vertical earthquake aggravates the plastic deformation of soil, and significantly increases the dynamic response of structure, especially the rotation angle of pile at the mud surface and tower top. In the seismic design of MOWT, the existence of vertical earthquake should be considered properly.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"80 ","pages":"Article 109725"},"PeriodicalIF":3.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680350","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":"Effectiveness of UHPC reinforced with steel rebars for flexural strengthening of RC T-beams in an idealized negative moment region","authors":"Laurencius Nugroho ,&nbsp;Yanuar Haryanto ,&nbsp;Fu-Pei Hsiao ,&nbsp;Hsuan-Teh Hu ,&nbsp;Pu-Wen Weng ,&nbsp;Chia-Chen Lin ,&nbsp;Stefanus Adi Kristiawan ,&nbsp;Senot Sangadji","doi":"10.1016/j.istruc.2025.109728","DOIUrl":"10.1016/j.istruc.2025.109728","url":null,"abstract":"<div><div>Ultra-high-performance concrete (UHPC) exhibits exceptional properties, making it an effective material for strengthening applications. This study aims to assess the effectiveness of UHPC layers in flexurally strengthening reinforced concrete T-beams in the negative moment region. Flexural tests were conducted to evaluate the load-carrying capacity, deformation characteristics, and failure modes of the specimens. Two strengthening approaches were investigated: one using 13 mm diameter steel rebars (SB-U13) and the other using 16 mm diameter steel rebars (SB-U16). The performance of these beams was compared to a control specimen. The results show that the hybrid strengthening strategies effectively delayed crack initiation and slowed crack propagation as the load increased. The ultimate load capacity improved by 85.43 % for SB-U13 and 119.96 % for SB-U16, compared to the control beam. Significant increases in stiffness and toughness were also observed, though a slight reduction in ductility occurred as a trade-off. An analytical procedure was developed to estimate the moment capacity of the strengthened beams, closely aligning with the experimental data. A finite element model was then performed, and its predictions were validated. Finally, a parametric study examined the effects of concrete compressive strength, steel reinforcement ratio, and UHPC layer thickness on the structural behavior of the beams.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"80 ","pages":"Article 109728"},"PeriodicalIF":3.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680353","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":"Investigations on dynamic responses of shield tunnels subjected to external explosions","authors":"Mengtao Xia ,&nbsp;Zhouhong Zong ,&nbsp;Hao Lu ,&nbsp;Yi Li ,&nbsp;Haimin Qian ,&nbsp;Chao Ma ,&nbsp;Minqian Sun ,&nbsp;Minghong Li","doi":"10.1016/j.istruc.2025.109754","DOIUrl":"10.1016/j.istruc.2025.109754","url":null,"abstract":"<div><div>Over the past few decades, a large number of shield tunnels have been constructed owing to their advantages, which include reducing construction time, saving labor costs, and improving efficiency on site. Many researches have been conducted to investigate the performance of shield tunnels under static load. However, there are few researches on shield tunnels under blast loading. This study focuses on the dynamic responses of a full-scale shield tunnel subjected to external explosions. A high-fidelity finite element model, which incorporates soil, air, segmental linings, bolts, steel rebars, and internal structures, is established and validated. Additionally, a 3D-to-3D mapping algorithm is employed to accurately reproduce the initial stress state of the shield tunnel before explosions. It is found that the dominant failure characteristics are the failures of connections between the flue panel and the shield lining, opening and dislocation of joints of the charged ring, plastic deformation of bolts, and concrete damage in the tensile regions, such as the back surface of the tunnel crown and the front surface of the spandrel. Besides, the parameter analysis reveals that increasing the standoff distance, while maintaining a constant scaled distance, will cause more significant damage. Decreasing the standoff distance while keeping the charge weight constant may cause additional failure modes in addition to flexural deformation, such as local crater damage. Furthermore, the blast resistance of the shield tunnel increases with burial depth up to a certain point, after which it begins to decrease. Finally, based on the function and repairability of tunnels, a damage criterion with four damage levels for shield tunnels subjected to external explosions is proposed. This study can contribute to the design and protection of shield tunnel structures against external explosions.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"80 ","pages":"Article 109754"},"PeriodicalIF":3.9,"publicationDate":"2025-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144680352","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}