IF 3.9 2区工程技术

Structures Pub Date : 2024-11-02 DOI: 10.1016/j.istruc.2024.107542

{"title":"Numerical simulation of strengthening/deterioration and damage development of cementitious materials under sulfate attack environment","authors":"","doi":"10.1016/j.istruc.2024.107542","DOIUrl":"10.1016/j.istruc.2024.107542","url":null,"abstract":"<div><div>Cementitious materials exposed to sulfate environments often suffer from the combined effects of external sulfate attack and dry wet cycling. In order to predict the long-term performance of cement-based materials in sulfur rich environments, this paper aims to establish a numerical model that can reasonably characterize the degradation process of cementitious materials in sulfate environments. Using this model, we can address durability problems common to cementitious materials in real sulphate environments, such as determining the degree of corrosion, predicting the durability life of materials, and calculating the time to failure. The model consists of three parts: transportation, chemical reactions, and material damage. We establish the degradation model for cement-based materials in sulfate environments by considering ion diffusion, water convection, chemical reactions, accumulation of corrosion products, and the development of material strengthening/degradation. Compared with existing sulfate corrosion models, this model not only considers ettringite, but also takes into account the volume changes of gypsum formation, calcium leaching, and salt crystallization precipitation, which can more reasonably simulate the sulfate corrosion process in real environments. The model can reasonably simulate the distribution pattern of ion concentration, hydration products and corrosion products in the cementitious material, and on this basis calculate the porosity of the cementitious material. In order to make the simulation results more applicable to experimental and non-destructive testing results, the model uses easily obtainable relative dynamic elastic modulus to evaluate the degree of material strengthening/degradation and predict the durability life of the material.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572588","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}

引用次数: 0

Computer vision-based substructure isolation method for localized damage identification 基于计算机视觉的局部损伤识别下部结构隔离方法

IF 3.9 2区工程技术

Structures Pub Date : 2024-11-02 DOI: 10.1016/j.istruc.2024.107660

{"title":"Computer vision-based substructure isolation method for localized damage identification","authors":"","doi":"10.1016/j.istruc.2024.107660","DOIUrl":"10.1016/j.istruc.2024.107660","url":null,"abstract":"<div><div>In recent years, vision-based structural damage identification techniques have garnered significant attention due to their simplicity and cost-effectiveness. Nevertheless, dynamic response-based vision methods face challenges related to the limitations of the field of view (FOV), i.e., the extent of the FOV is often sacrificed in order to ensure sufficient monitoring accuracy, which reduces the amount of data available for structural health monitoring (SHM). This study presents a solution to this problem by employing the substructure isolation method (SIM), which focuses on local vibrations of the structure and enables local damage identification by isolating the area of interest. Additionally, a method combining kernelized correlation filter (KCF) with sub-pixel template matching is used to extract vibration information recorded by visual sensor. This strategy balances both the efficiency and accuracy of displacement extraction. In numerical simulations, the performance of the SIM based on acceleration response and displacement response is compared, demonstrating the potential compatibility of visual sensors with the SIM. Finally, the effectiveness of the proposed vision-based local damage identification method is validated through vibration testing of a shear frame model.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572589","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}

引用次数: 0

Development of design formulas for predicting deflection in corrugated blast walls under explosion loads 开发用于预测爆炸荷载下波纹防爆墙挠度的设计公式

IF 3.9 2区工程技术

Structures Pub Date : 2024-11-01 DOI: 10.1016/j.istruc.2024.107698

{"title":"Development of design formulas for predicting deflection in corrugated blast walls under explosion loads","authors":"","doi":"10.1016/j.istruc.2024.107698","DOIUrl":"10.1016/j.istruc.2024.107698","url":null,"abstract":"<div><div>A corrugated blast wall is a passive explosion protection system designed to safeguard people, structures, and surrounding areas from the cascading effects of explosion accidents. In designing these walls, maximum and/or permanent deflection is a crucial criterion for assessing blast resistance and ensuring structural integrity. Engineers typically use numerical methods, such as finite element analysis (FEA), or analytical methods, like single-degree-of-freedom (SDOF) analysis, to calculate deflections. However, these methods have certain limitations, including the need for specialized techniques, time consumption, and potential inaccuracies due to simplifications.</div><div>This study aims to develop design formulas that reduce the time required while enhancing accuracy in determining maximum and permanent deflections of corrugated blast walls under various explosion loads. The formulas were derived from 14,400 FEA cases, which assessed the blast wall’s capacity to withstand explosion loads across various design configurations, including height, thickness, and shape of the corrugated blast wall. Additionally, a Pressure-Impulse (PI) curve is plotted to illustrate the relationship between pressure and its duration during an explosion, aiding in the optimization of blast wall designs for maximum effectiveness in mitigating blast effects.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572592","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}

引用次数: 0

Experimental and numerical studies on the seismic behavior of spherical reticulated shells with sliding isolation bearings 带滑动隔离支座的球形网状壳体地震行为的实验和数值研究

IF 3.9 2区工程技术

Structures Pub Date : 2024-11-01 DOI: 10.1016/j.istruc.2024.107645

{"title":"Experimental and numerical studies on the seismic behavior of spherical reticulated shells with sliding isolation bearings","authors":"","doi":"10.1016/j.istruc.2024.107645","DOIUrl":"10.1016/j.istruc.2024.107645","url":null,"abstract":"<div><div>Spherical reticulated shells are spatial structures widely used for important public buildings with concerns of seismic behaviors. To assess the feasibility of friction pendulum bearings (FPBs) for seismic response control in reticulated shell structures, a 1/10 scale single-layer spherical reticulated shell model with small-scale FPBs was designed and fabricated. A shaking table was used to generate triaxial dynamic and seismic inputs for the test structures with and without isolators, and their natural vibration characteristics and seismic responses were measured. Based on the experimental results, significant increase of the fundamental natural period of the test structure was achieved using the sliding isolation system. The damping ratio also improved for the sliding isolated structure. Moreover, seismic response of the isolated test structure was significantly lower than that of the test model with fixed roof bearings. Following the experimental study, an OpenSees-based numerical simulation was conducted to capture the seismic behavior of the isolated test structure. The numerical and experimental responses agreed well. The modeling method was extended to full-sized reticulated shell structures using FPB systems. The effects of the FPB parameters (radius of curvature and friction coefficient) on the seismic behavior of the structures were numerically analyzed, indicating that the friction coefficient is the most critical parameter governing the structural responses. The seismic fragility of FPB-isolated full-sized reticulated shell structures considering various friction properties was investigated to provide beneficial design recommendations for the engineering practices of such isolated structures.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572591","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}

引用次数: 0

Repairing thermally shocked reinforced concrete beams using innovative CFRP sheets anchorage systems 利用创新的 CFRP 片材锚固系统修复热冲击钢筋混凝土梁

IF 3.9 2区工程技术

Structures Pub Date : 2024-11-01 DOI: 10.1016/j.istruc.2024.107675

{"title":"Repairing thermally shocked reinforced concrete beams using innovative CFRP sheets anchorage systems","authors":"","doi":"10.1016/j.istruc.2024.107675","DOIUrl":"10.1016/j.istruc.2024.107675","url":null,"abstract":"<div><div>The primary objective of this study is to investigate the effect of using a CFRP sheet to strengthen/repair thermally shocked lightweight aggregate concrete (LWAC) and normal-weight aggregate concrete (NWAC) beams. It also aims, to evaluate the effectiveness of using an innovative anchorage system on the behavior of CFRP- repaired NWAC and LWAC beams. Eight LWAC beams, in addition to four NWAC beams, were cast, with dimensions of 150 mm × 200 mm × 1150 mm (width × height × length) with a 28-day compressive strength of 30 MPa. Seven LWAC beams and three NWAC beams were heated to 600 °C, followed by 15 min of rapid cooling in water, and six thermally shocked LWAC and one NWAC thermally shocked specimens were repaired with CFRP sheet and different anchorage systems of CFRP sheets and ropes. The anchorage systems used in this study were fan NSM-CFRP rope, four U-Wrapping ropes, one or two fan/ five U-Wrapping ropes, and four U-Wrapping sheets. After that, a four-point loading test was performed on all specimens. Test results illustrated that when CFRP sheets were applied on thermally shocked LWAC and NWAC beams, the mechanical performance of both damaged LWAC and NWAC specimens drastically increased. Furthermore, all innovative anchorage systems considerably enhanced the ultimate load by a percentage of (30 %−84.2 %), stiffness by (14.8 %−59.2 %), and toughness by (6.14 %−22 %) of CFRP-repaired NWAC and LWAC beams compared with thermally shocked LWAC and NWAC beams. Specifically, For LWAC specimens, the best method of repair was the one using a bottom CFRP sheet with two fans and five U-wrapping NSM-CFRP ropes, which increased the ultimate load, stiffness, and toughness by a percentage of roughly 84.2 %, 59.2 %, and 21.93 %, respectively, compared with thermally shocked LWAC beam.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572587","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}

引用次数: 0

Machine learning-based prediction of seismic response of elevated steel tanks 基于机器学习的高架钢罐地震响应预测

IF 3.9 2区工程技术

Structures Pub Date : 2024-11-01 DOI: 10.1016/j.istruc.2024.107649

{"title":"Machine learning-based prediction of seismic response of elevated steel tanks","authors":"","doi":"10.1016/j.istruc.2024.107649","DOIUrl":"10.1016/j.istruc.2024.107649","url":null,"abstract":"<div><div>Seismic response analysis assesses structural safety and integrity during earthquakes and guides design for optimal performance, compliance with regulations, and risk mitigation. This study proposes a novel approach utilizing machine learning (ML) techniques to predict the seismic response of elevated steel tanks accurately. ML is a powerful tool that can handle complexity, improve accuracy, provide data-driven insights, and optimize designs for predicting seismic responses of structures. Moreover, this study evaluates various ML models containing Random Forest, Support Vector Regression, Adaptive Boosting, LightGBM, Histogram-based Gradient Boosting, XGBoost, CatBoost, Bagging Regression, and Decision Trees to identify the most effective predictive model. In general, the developed ML-based predictive models provide a promising tool for engineers involved in the seismic design and retrofitting of elevated steel tanks, aiding in optimizing designs and enhancing structural safety and resilience against seismic hazards. As a result, the HGB model obtained the most suitable performance compared to other developed models with higher R<sup>2</sup> and lower RMSE. In addition, a sensitivity analysis was performed based on SHAP values, and it was found that the height of the liquid and the intensity measure were the most influential variables in the seismic response of the tank.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572585","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}

引用次数: 0

Multivariate risk assessment for offshore structures by Gaidai risk evaluation method under an accumulation of fatigue damage, utilizing novel deconvolution scheme 利用新型解卷积方案，采用疲劳损伤累积下的 Gaidai 风险评估方法，对海上结构进行多变量风险评估

IF 3.9 2区工程技术

Structures Pub Date : 2024-11-01 DOI: 10.1016/j.istruc.2024.107691

{"title":"Multivariate risk assessment for offshore structures by Gaidai risk evaluation method under an accumulation of fatigue damage, utilizing novel deconvolution scheme","authors":"","doi":"10.1016/j.istruc.2024.107691","DOIUrl":"10.1016/j.istruc.2024.107691","url":null,"abstract":"<div><div>Current study presents a state-of-the-art structural spatiotemporal multimodal risk assessment methodology, that is particularly well-suited for multimodal structural dynamics, either recorded physically or numerically simulated over a representative timelapse. Offshore Jacket-type offshore platform, operating in Bohai Bay waters had been selected for the method’s verification. This investigation had shown that, in the presence of in-situ environmental stressors, it is possible to appropriately estimate dynamic structural system’s failure and damage risks. High dimensionality of engineering dynamic structural systems, alomg with nonlinear nonstationary inter-correlations between critical structural components, often present challenges for contemporary reliability methods, mostly limited to univariate and bivariate systems. Operating Jacket platform, subjected to in situ wave loads, had been chosen for this case study to benchmark advocated risk evaluation methodology. Number of hotspot stresses had been selected to represent multivariate structural system. Advocated multimodal method had been proven to be suitable for robust assessment of operational failure/damage risks, as well as for accurate structural life projection. Novel non-parametric deconvolution extrapolation scheme had been employed, providing enhanced numerical stability. Given increased safety concerns within offshore, naval, marine engineering, advocated multimodal reliability methodology may be utilized for safer and economically more viable structural design.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572586","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}

引用次数: 0

Exploring the viability of copper slag geopolymer concrete in structural applications: A study on strength variability and seismic risk assessment 探索铜渣土工聚合物混凝土在结构应用中的可行性：强度变化和地震风险评估研究

IF 3.9 2区工程技术

Structures Pub Date : 2024-11-01 DOI: 10.1016/j.istruc.2024.107670

{"title":"Exploring the viability of copper slag geopolymer concrete in structural applications: A study on strength variability and seismic risk assessment","authors":"","doi":"10.1016/j.istruc.2024.107670","DOIUrl":"10.1016/j.istruc.2024.107670","url":null,"abstract":"<div><div>This study explores the use of copper slag (CS) as a sustainable alternative to natural sand (NS) in geopolymer concrete (GPC) for structural applications. Despite the potential of CS to promote environmental sustainability by repurposing industrial waste, its adoption in the construction industry remains limited. To address this gap, the study focuses on two main aspects: (i) modelling the uncertainty in the strength properties of CS-based GPC, and (ii) assessing the performance of CS-based GPC in seismic-resistant reinforced concrete (RC) framed buildings. The results show that the compressive strength of CS-based GPC is best represented by the Gumbel max and Gamma distributions, while the splitting tensile strength is well-modelled by Gamma and lognormal distributions. The flexural strength follows Gumbel max and Weibull distributions. These findings provide valuable data for probabilistic structural analysis and reliability-based design. Additionally, the seismic performance of RC frames made with GPC containing CS was found to be comparable to that of control frames with NS, confirming the viability of CS-based GPC in seismic-resistant structures. This research demonstrates that CS can be effectively utilized in GPC without compromising structural safety, contributing to more sustainable concrete construction practices.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572593","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}

引用次数: 0

Vibration modeling of variable thickness cylindrical shallow shells using extended Kantorovich method 使用扩展康托洛维奇法建立变厚度圆柱浅壳的振动模型

IF 3.9 2区工程技术

Structures Pub Date : 2024-11-01 DOI: 10.1016/j.istruc.2024.107554

{"title":"Vibration modeling of variable thickness cylindrical shallow shells using extended Kantorovich method","authors":"","doi":"10.1016/j.istruc.2024.107554","DOIUrl":"10.1016/j.istruc.2024.107554","url":null,"abstract":"<div><div>The current study aims to analytically model the vibration of variable thickness thin cylindrical shallow shells. First, Hamilton’s principle is used to derive the governing equations of motion of the system. The extended Kantorovich method (EKM) is then employed to study the corresponding eigenvalue problem. Using a single-term Galerkin approximation, the partial differential equations are converted to two sets of linear ordinary differential equations which are solved iteratively to find the system's natural frequencies and mode shapes. The findings of the study indicate that conducting only two iterations is sufficient to attain highly converged solutions. Studying the effect of element numbers on solution convergence shows that around ten elements provide a reasonable compromise between the solution accuracy and computational cost. The EKM results for thickness variations in either circumferential or axial directions are closely validated with FEA. Moreover, the EKM solutions match well with the results of other studies. In the end, by performing a parametric study, the effect of minimum to maximum thickness ratio on the first four natural frequencies of the shell is identified. The approach presented in this research can be employed as an efficient tool for fast and accurate design optimization of shallow shells.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":null,"pages":null},"PeriodicalIF":3.9,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572590","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}

引用次数: 0

Study on crack growth path of API-5L X80 welded joints based on inhomogeneous mechanical properties 基于不均匀力学性能的 API-5L X80 焊接接头裂纹生长路径研究

IF 3.9 2区工程技术

Structures Pub Date : 2024-10-31 DOI: 10.1016/j.istruc.2024.107713

引用次数: 0

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