Pub Date : 2025-03-08DOI: 10.1016/j.engfailanal.2025.109513
Jacek Hulimka, Jan Kubica, Marta Kałuża, Rafał Krzywoń
Among numerous causes of failures of large-format facilities, the loads caused by weather phenomena count among most frequent. Failures are typically caused by snow or wind load, while damage due to rainstorm is rarer. The study shows one such case when, after around 6 months of operation, part of the large-area roof of a production and storage hall collapsed. The failure occurred after 13 min of heavy rainstorm; however, the conducted analysis showed that the rain volume was within the ranges specified by the relevant standards. A detailed analysis was conducted of the design assumptions, structural calculations and the original design documentation, showing a number of design and construction errors, the effects of which compounded. The most critical error was the underestimation of the water load on the exterior sections of the roof, combined with too high roof attic and the absence of overflow scuppers. The result was a gradual failure involving the profiled sheet deck sections, followed by exterior purlins and expansion joint purlins, and some reinforced concrete columns. The study provides a detailed description of the failure, presenting the results of the authors’ own structural calculations and specifying the design and construction errors. The sequence of events of the failure is also reconstructed. Finally, the proposed recommendation are outlined.
{"title":"Partial damage to the hall during a heavy rainfall","authors":"Jacek Hulimka, Jan Kubica, Marta Kałuża, Rafał Krzywoń","doi":"10.1016/j.engfailanal.2025.109513","DOIUrl":"10.1016/j.engfailanal.2025.109513","url":null,"abstract":"<div><div>Among numerous causes of failures of large-format facilities, the loads caused by weather phenomena count among most frequent. Failures are typically caused by snow or wind load, while damage due to rainstorm is rarer. The study shows one such case when, after around 6 months of operation, part of the large-area roof of a production and storage hall collapsed. The failure occurred after 13 min of heavy rainstorm; however, the conducted analysis showed that the rain volume was within the ranges specified by the relevant standards. A detailed analysis was conducted of the design assumptions, structural calculations and the original design documentation, showing a number of design and construction errors, the effects of which compounded. The most critical error was the underestimation of the water load on the exterior sections of the roof, combined with too high roof attic and the absence of overflow scuppers. The result was a gradual failure involving the profiled sheet deck sections, followed by exterior purlins and expansion joint purlins, and some reinforced concrete columns. The study provides a detailed description of the failure, presenting the results of the authors’ own structural calculations and specifying the design and construction errors. The sequence of events of the failure is also reconstructed. Finally, the proposed recommendation are outlined.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"174 ","pages":"Article 109513"},"PeriodicalIF":4.4,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601404","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}
Pub Date : 2025-03-08DOI: 10.1016/j.engfailanal.2025.109510
Ali Pourfathi, Mohammad Saeed Shahriari, Mohammad Amin Amjadi
The blades in the turbine section of gas turbomachines experience high temperatures and, more importantly, mechanical loading stresses, which lead to blade microstructure degradation during service. Regarding this, one of the most economical techniques is to repair or refurbish these blades rather than replacing them with new ones. In the present work, the feasibility of repairing a stage of as-received super-exposed blades in the fourth stage of the turbine hot section is studied. Several samples are prepared from the as-received blades; afterward, a few samples are rejuvenated with standard heat treatment. Later, for both as-received and rejuvenated samples, metallurgical analysis of microstructure, such as optical microscopy and scanning electron microscopy, is performed. In addition, mechanical tests, such as high-temperature and room-temperature tensile tests, creep tests, and their fractography, are conducted. Finally, the results associated with both rejuvenated and as-received samples are compared with the minimum standard criteria provided by the original equipment manufacturer (OEM). It has been shown that the microstructure and mechanical properties of the as-received samples indicate that the blade is fully retired. Later, using the rejuvenation technique, the microstructure and mechanical behavior of the blades are restored not completely but favorably (around 30% recovery), and the lifetime of the rejuvenated blades can be extended for another working sequence.
{"title":"On the possibility of repairing super-exposed IN792 gas turbine blades","authors":"Ali Pourfathi, Mohammad Saeed Shahriari, Mohammad Amin Amjadi","doi":"10.1016/j.engfailanal.2025.109510","DOIUrl":"10.1016/j.engfailanal.2025.109510","url":null,"abstract":"<div><div>The blades in the turbine section of gas turbomachines experience high temperatures and, more importantly, mechanical loading stresses, which lead to blade microstructure degradation during service. Regarding this, one of the most economical techniques is to repair or refurbish these blades rather than replacing them with new ones. In the present work, the feasibility of repairing a stage of as-received super-exposed blades in the fourth stage of the turbine hot section is studied. Several samples are prepared from the as-received blades; afterward, a few samples are rejuvenated with standard heat treatment. Later, for both as-received and rejuvenated samples, metallurgical analysis of microstructure, such as optical microscopy and scanning electron microscopy, is performed. In addition, mechanical tests, such as high-temperature and room-temperature tensile tests, creep tests, and their fractography, are conducted. Finally, the results associated with both rejuvenated and as-received samples are compared with the minimum standard criteria provided by the original equipment manufacturer (OEM). It has been shown that the microstructure and mechanical properties of the as-received samples indicate that the blade is fully retired. Later, using the rejuvenation technique, the microstructure and mechanical behavior of the blades are restored not completely but favorably (around 30% recovery), and the lifetime of the rejuvenated blades can be extended for another working sequence.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"174 ","pages":"Article 109510"},"PeriodicalIF":4.4,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143592035","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}
Pub Date : 2025-03-08DOI: 10.1016/j.engfailanal.2025.109509
Jan Kubica , Janusz Brol , Karolina Kurtz , Marek Węglorz
This work presents a case study exploring the structural safety risk to the timber roof structures of the swimming pool halls in one of the oldest Polish water parks, which was built in 2001.
The superstructures of the roofs of these two swimming pool halls were made of glued laminated timber girders, in the form of two independent but similar structures with single-slope roofs. The superstructure consisted of main curved girders and straight intermediate girders with a span at the support axes of 25.0 m and a height at the ridge of approximately 11.3 m above floor level. The substructure of this roof structure consisted of continuous, multi-span (min. two-span) purlins, made from glued laminated timber, and single-span bracing purlins. The roof cover was laid on the purlins, and was made of 1.0 m wide sandwich panels consisting of an 80 mm thick polyurethane core and two sheet metal cladding layers. On the inside, the roof panels had an almost flat surface (with slight profiling), while on the outside, they had a trapezoidal shape. They were related to the use of insulated longitudinal joints. Two transverse joints of the roof sandwich panels were provided.
After two decades of constant service, numerous leaks and moisture stains were observed in both structural elements of the timber roof, due to roof leakage and incorrect hygrothermal behaviour of the roofing panels. Buckling of the sandwich roof panels caused this problem. The structure showed a lack of proper fastening of the purlins to the main and intermediate girders made of glued laminated timber, which could have led to the roof being lifted in the event of strong wind exposure (due to wind suction on the roof surface). This situation resulted in the need for a comprehensive assessment of the timber roof safety, rechecking of the load-bearing capacity of their structures, and the formulation of repair recommendations.
{"title":"Safety risk to the timber roof structure of swimming pool halls after two decades of constant use","authors":"Jan Kubica , Janusz Brol , Karolina Kurtz , Marek Węglorz","doi":"10.1016/j.engfailanal.2025.109509","DOIUrl":"10.1016/j.engfailanal.2025.109509","url":null,"abstract":"<div><div>This work presents a case study exploring the structural safety risk to the timber roof structures of the swimming pool halls in one of the oldest Polish water parks, which was built in 2001.</div><div>The superstructures of the roofs of these two swimming pool halls were made of glued laminated timber girders, in the form of two independent but similar structures with single-slope roofs. The superstructure consisted of main curved girders and straight intermediate girders with a span at the support axes of 25.0 m and a height at the ridge of approximately 11.3 m above floor level. The substructure of this roof structure consisted of continuous, multi-span (min. two-span) purlins, made from glued laminated timber, and single-span bracing purlins. The roof cover was laid on the purlins, and was made of 1.0 m wide sandwich panels consisting of an 80 mm thick polyurethane core and two sheet metal cladding layers. On the inside, the roof panels had an almost flat surface (with slight profiling), while on the outside, they had a<!--> <!-->trapezoidal shape. They were related to the use of insulated longitudinal joints. Two transverse joints of the roof sandwich panels were provided.</div><div>After two decades of constant service, numerous leaks and moisture stains were observed in both structural elements of the timber roof, due to roof leakage and incorrect hygrothermal behaviour of the roofing panels. Buckling of the sandwich roof panels caused this problem. The structure showed a lack of proper fastening of the purlins to the main and intermediate girders made of glued laminated timber, which could have led to the roof being lifted in the event of strong wind exposure (due to wind suction on the roof surface). This situation resulted in the need for a comprehensive assessment of the timber roof safety, rechecking of the load-bearing capacity of their structures, and the formulation of repair recommendations.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"174 ","pages":"Article 109509"},"PeriodicalIF":4.4,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143592036","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}
Pub Date : 2025-03-07DOI: 10.1016/j.engfailanal.2025.109502
Chengxing Yang , Yujia Huo , Kangpei Meng , Wei Zhou , Jun Yang , Zhao Nan
This study presents an investigation into the fatigue failure mechanisms of platform screen doors (PSDs) subjected to aerodynamic loads generated by high-speed subway trains. A comprehensive finite element model is developed, integrating with fast Fourier transform (FFT) techniques to isolate and evaluate pulsating wind frequencies that impact the structural behavior of PSDs. The extracted wind frequencies and transient vibration responses are analyzed to determine their effects on structural stability. A load-stress transmission model is introduced to convert aerodynamic load data into structural stress time histories, enabling detailed fatigue assessments. Additionally, a stress distribution model is constructed to capture variations in maximum stress under different train speeds and distances from the track centerline. The Brittle Cracking model is applied to assess potential damage to glass components, revealing that the wind load frequency remains significantly lower than the structure’s natural frequency, thereby preventing resonance-induced failure. To evaluate long-term performance, fatigue damage assessments of critical components (such as the bottom support, door frame, and bottom plate) are conducted using both Miner’s cumulative damage criterion and a nonlinear damage model based on fatigue driving force energy. The analysis demonstrates that the maximum equivalent damage values for these components are within safe limits over a 30-year design life, with values of 0.59, 0.06, and 0.27 for the linear model, and 0.65, 0.07, and 0.29 for the nonlinear model. The study concludes by proposing an optimized design for the bottom support structure, reducing structural damage by about 45%. This research provides innovative insights into improving the durability, safety, and performance of PSDs under dynamic aerodynamic loading, contributing both to theoretical advancements and practical applications in urban transit infrastructure.
{"title":"Fatigue failure analysis of platform screen doors under subway aerodynamic loads using finite element modeling","authors":"Chengxing Yang , Yujia Huo , Kangpei Meng , Wei Zhou , Jun Yang , Zhao Nan","doi":"10.1016/j.engfailanal.2025.109502","DOIUrl":"10.1016/j.engfailanal.2025.109502","url":null,"abstract":"<div><div>This study presents an investigation into the fatigue failure mechanisms of platform screen doors (PSDs) subjected to aerodynamic loads generated by high-speed subway trains. A comprehensive finite element model is developed, integrating with fast Fourier transform (FFT) techniques to isolate and evaluate pulsating wind frequencies that impact the structural behavior of PSDs. The extracted wind frequencies and transient vibration responses are analyzed to determine their effects on structural stability. A load-stress transmission model is introduced to convert aerodynamic load data into structural stress time histories, enabling detailed fatigue assessments. Additionally, a stress distribution model is constructed to capture variations in maximum stress under different train speeds and distances from the track centerline. The Brittle Cracking model is applied to assess potential damage to glass components, revealing that the wind load frequency remains significantly lower than the structure’s natural frequency, thereby preventing resonance-induced failure. To evaluate long-term performance, fatigue damage assessments of critical components (such as the bottom support, door frame, and bottom plate) are conducted using both Miner’s cumulative damage criterion and a nonlinear damage model based on fatigue driving force energy. The analysis demonstrates that the maximum equivalent damage values for these components are within safe limits over a 30-year design life, with values of 0.59, 0.06, and 0.27 for the linear model, and 0.65, 0.07, and 0.29 for the nonlinear model. The study concludes by proposing an optimized design for the bottom support structure, reducing structural damage by about 45%. This research provides innovative insights into improving the durability, safety, and performance of PSDs under dynamic aerodynamic loading, contributing both to theoretical advancements and practical applications in urban transit infrastructure.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"174 ","pages":"Article 109502"},"PeriodicalIF":4.4,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143601405","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}
Water hydraulic high-speed on/off valves (WHSVs) are critical components in digital water hydraulic systems due to their exceptional responsiveness and sealing performance. However, frequent high-speed impact on the valve port of the WHSV can lead to progressive seal failure, severely compromising system reliability. This study integrates experimental and numerical simulation results to reveal the impact failure mechanisms of the valve port of the WHSV. The changes in the leakage flow and morphology of the valve port under different numbers of impacts are analyzed by experiment. Meanwhile, an explicit dynamic finite element method is employed to simulate the stress and deformation behavior of the valve seat during impacts, which utilizes precise initial impact parameters derived from an accurate mathematical model of the WHSV, ensuring the reliability and accuracy of the simulation analysis. The experimental results show a significant increase in the leakage of the valve port with the number of impacts. Simulation results indicate that the equivalent plastic strain of the valve port increases with the number of impacts but ultimately tends to saturate. The inner chamfer sharp edge of the valve port is identified as the critical region for stress concentration and plastic deformation, as predicted by simulations and confirmed by experimental observations of fatigue-induced cracks and gaps. Comprehensive analysis results reveal that the root cause of the impact failure of the valve port lies in localized plastic deformation, enlarging the sealing contact area and thus reducing the sealing pressure. Moreover, cracks and gaps near the inner chamfer sharp edge increase the flow area of the valve port and aggravate leakage.
{"title":"Repeated impact failure mechanisms in valve port for water hydraulic high-speed on/off valve: Experimental and numerical analysis","authors":"Lingkang Meng, Zhenyao Wang, Jiangxiong Li, Xianchun Jiang, Weican Wang, Yinshui Liu, Defa Wu","doi":"10.1016/j.engfailanal.2025.109503","DOIUrl":"10.1016/j.engfailanal.2025.109503","url":null,"abstract":"<div><div>Water hydraulic high-speed on/off valves (WHSVs) are critical components in digital water hydraulic systems due to their exceptional responsiveness and sealing performance. However, frequent high-speed impact on the valve port of the WHSV can lead to progressive seal failure, severely compromising system reliability. This study integrates experimental and numerical simulation results to reveal the impact failure mechanisms of the valve port of the WHSV. The changes in the leakage flow and morphology of the valve port under different numbers of impacts are analyzed by experiment. Meanwhile, an explicit dynamic finite element method is employed to simulate the stress and deformation behavior of the valve seat during impacts, which utilizes precise initial impact parameters derived from an accurate mathematical model of the WHSV, ensuring the reliability and accuracy of the simulation analysis. The experimental results show a significant increase in the leakage of the valve port with the number of impacts. Simulation results indicate that the equivalent plastic strain of the valve port increases with the number of impacts but ultimately tends to saturate. The inner chamfer sharp edge of the valve port is identified as the critical region for stress concentration and plastic deformation, as predicted by simulations and confirmed by experimental observations of fatigue-induced cracks and gaps. Comprehensive analysis results reveal that the root cause of the impact failure of the valve port lies in localized plastic deformation, enlarging the sealing contact area and thus reducing the sealing pressure. Moreover, cracks and gaps near the inner chamfer sharp edge increase the flow area of the valve port and aggravate leakage.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"174 ","pages":"Article 109503"},"PeriodicalIF":4.4,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579683","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}
Pub Date : 2025-03-07DOI: 10.1016/j.engfailanal.2025.109471
Rowin J.M. Bol , Yading Xu , Mladena Luković , Branko Šavija
The use of 3D printed polymers in the form of lattice reinforcement can enhance the mechanical properties of cementitious composites. Methods like Fused Deposition Modelling (FDM) 3D printing enable their creation, but this process has a large (negative) effect on their mechanical properties, with a large dependency on the printing direction. Continuing on our previous study concerned with modelling the anisotropic behaviour of 3D printed polymeric reinforcement, this work focuses on the reinforcement-matrix bond. Because of the layer-by-layer filament extrusion process of the 3D printing technique, the edges of FDM 3D printed polymers are typically composed of ellipses. Based on this, it is hypothesized that morphological effects as a result of the 3D printing technique enhance the bond between 3D printed reinforcement and cementitious matrix: The elliptic geometry potentially facilitates interlocking with the cementitious mortar, thereby possibly enhancing the bond behaviour in certain directions. To investigate the geometrical directional-dependent features at the edges of 3D printed polymers in more detail, micro-scale models are developed. Geometrical effects induced by different printing configurations are studied. The simulation results are verified through meso-scale pull-out experiments. The interlocking effects as a result of the 3D printing technique show to be significant seeing a bond strength increase of up to 56 % in one of the print configurations compared to the direction without any geometrical effects.
{"title":"Does printing direction influence the bond between 3D printed polymeric reinforcement and cementitious matrix?","authors":"Rowin J.M. Bol , Yading Xu , Mladena Luković , Branko Šavija","doi":"10.1016/j.engfailanal.2025.109471","DOIUrl":"10.1016/j.engfailanal.2025.109471","url":null,"abstract":"<div><div>The use of 3D printed polymers in the form of lattice reinforcement can enhance the mechanical properties of cementitious composites. Methods like Fused Deposition Modelling (FDM) 3D printing enable their creation, but this process has a large (negative) effect on their mechanical properties, with a large dependency on the printing direction. Continuing on our previous study concerned with modelling the anisotropic behaviour of 3D printed polymeric reinforcement, this work focuses on the reinforcement-matrix bond. Because of the layer-by-layer filament extrusion process of the 3D printing technique, the edges of FDM 3D printed polymers are typically composed of ellipses. Based on this, it is hypothesized that morphological effects as a result of the 3D printing technique enhance the bond between 3D printed reinforcement and cementitious matrix: The elliptic geometry potentially facilitates interlocking with the cementitious mortar, thereby possibly enhancing the bond behaviour in certain directions. To investigate the geometrical directional-dependent features at the edges of 3D printed polymers in more detail, micro-scale models are developed. Geometrical effects induced by different printing configurations are studied. The simulation results are verified through meso-scale pull-out experiments. The interlocking effects as a result of the 3D printing technique show to be significant seeing a bond strength increase of up to 56<!--> <!-->% in one of the print configurations compared to the direction without any geometrical effects.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"174 ","pages":"Article 109471"},"PeriodicalIF":4.4,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143591443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-06DOI: 10.1016/j.engfailanal.2025.109499
Zhe Zhu , Yong Lu , Tianjie Huang , Jinbin Zhao , Chen Chen , Hongchi Ma , Zhiyong Liu , Xuequn Cheng , Xiaogang Li
The localized corrosion and stress corrosion cracking (SCC) initiation induced by Ca-modified inclusions in EH500 high-strength steel was investigated in acidic marine environment. The inclusions are mainly spherical (Ca,Al)O-CaS complex compounds with Al and Ca uniformly distributed. The CaS part of the inclusion as well as interfacial matrix can be preferentially dissolved to form microcrevice which resulted in chemical dissolution of the oxide part and formation of corrosion pits. The inclusion-induced corrosion pits could be overwhelmed by uniform corrosion in stress-free condition, whereas they could further induce SCC initiation under high level of tensile stress.
研究了 EH500 高强度钢在酸性海洋环境中由 Ca 改性夹杂物诱发的局部腐蚀和应力腐蚀开裂（SCC）。夹杂物主要是球形（Ca,Al）O-CaS 复合物，其中 Al 和 Ca 分布均匀。夹杂物中的 CaS 部分以及界面基质会优先溶解形成微裂隙，从而导致氧化物部分的化学溶解并形成腐蚀坑。在无应力条件下，夹杂物引起的腐蚀坑可被均匀腐蚀所淹没，而在高拉伸应力条件下，夹杂物引起的腐蚀坑可进一步诱发 SCC。
{"title":"Localized corrosion and stress corrosion cracking initiation induced by calcium-modified complex inclusions in harsh marine environment","authors":"Zhe Zhu , Yong Lu , Tianjie Huang , Jinbin Zhao , Chen Chen , Hongchi Ma , Zhiyong Liu , Xuequn Cheng , Xiaogang Li","doi":"10.1016/j.engfailanal.2025.109499","DOIUrl":"10.1016/j.engfailanal.2025.109499","url":null,"abstract":"<div><div>The localized corrosion and stress corrosion cracking (SCC) initiation induced by Ca-modified inclusions in EH500 high-strength steel was investigated in acidic marine environment. The inclusions are mainly spherical (Ca,Al)O-CaS complex compounds with Al and Ca uniformly distributed. The CaS part of the inclusion as well as interfacial matrix can be preferentially dissolved to form microcrevice which resulted in chemical dissolution of the oxide part and formation of corrosion pits. The inclusion-induced corrosion pits could be overwhelmed by uniform corrosion in stress-free condition, whereas they could further induce SCC initiation under high level of tensile stress.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"174 ","pages":"Article 109499"},"PeriodicalIF":4.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620659","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}
Pub Date : 2025-03-06DOI: 10.1016/j.engfailanal.2025.109500
Mi Zhao , Yi-Ming Nie , Qing-Peng Ding , Jia-Xu Shen , Zhi-Dong Gao , Xiu-Li Du
Increasing numbers of complex structures are being constructed with the acceleration of urbanization. The complex dynamic characteristics pose challenges to the seismic design of large chassis. This paper investigates the seismic response and damage evolution of complex structures using linear and nonlinear dynamic explicit analysis under obliquely incident SV waves. A two-dimensional finite element model considering soil-structure interaction (SSI) is developed using fiber beam elements. Elastic and elastoplastic damage constitutive models are employed. A comprehensive numerical analysis is conducted to investigate the influence of key parameters, including incidence angles, ground motion characteristics, and site types, on the seismic response and damage evolution of complex structures. The results of this study indicate that, in the elastic stage, the seismic response of the frame-shear wall structure is reduced in the case of oblique incidence compared to vertical incidence. Specifically, the inter-story drift ratio is reduced by 60% at an incidence angle of 30°. In comparison to vertical incidence, the inter-story drift ratio and horizontal acceleration of the underground structure are reduced under oblique incidence. Conversely, in the elastic stage, the beam-end vertical displacement ratio and vertical acceleration exhibit increases of 57% and 36%, respectively. In the elastoplastic stage, as the incidence angle increases, the damage to the beams of the underground structure becomes more significant, while the damage to the frame-shear wall structure relatively decreases. Low-frequency ground motion and soft soil amplify the structural response compared to high-frequency and hard soil.
{"title":"Effects of oblique incidence of SV waves on seismic response and damage evolution of integrated underground–aboveground complexes","authors":"Mi Zhao , Yi-Ming Nie , Qing-Peng Ding , Jia-Xu Shen , Zhi-Dong Gao , Xiu-Li Du","doi":"10.1016/j.engfailanal.2025.109500","DOIUrl":"10.1016/j.engfailanal.2025.109500","url":null,"abstract":"<div><div>Increasing numbers of complex structures are being constructed with the acceleration of urbanization. The complex dynamic characteristics pose challenges to the seismic design of large chassis. This paper investigates the seismic response and damage evolution of complex structures using linear and nonlinear dynamic explicit analysis under obliquely incident SV waves. A two-dimensional finite element model considering soil-structure interaction (SSI) is developed using fiber beam elements. Elastic and elastoplastic damage constitutive models are employed. A comprehensive numerical analysis is conducted to investigate the influence of key parameters, including incidence angles, ground motion characteristics, and site types, on the seismic response and damage evolution of complex structures. The results of this study indicate that, in the elastic stage, the seismic response of the frame-shear wall structure is reduced in the case of oblique incidence compared to vertical incidence. Specifically, the inter-story drift ratio is reduced by 60% at an incidence angle of 30°. In comparison to vertical incidence, the inter-story drift ratio and horizontal acceleration of the underground structure are reduced under oblique incidence. Conversely, in the elastic stage, the beam-end vertical displacement ratio and vertical acceleration exhibit increases of 57% and 36%, respectively. In the elastoplastic stage, as the incidence angle increases, the damage to the beams of the underground structure becomes more significant, while the damage to the frame-shear wall structure relatively decreases. Low-frequency ground motion and soft soil amplify the structural response compared to high-frequency and hard soil.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"174 ","pages":"Article 109500"},"PeriodicalIF":4.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579350","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}
Pipeline leakage is a common issue encountered in urban areas, significantly contributing to the deterioration of tunnel structures and even posing a risk of ground collapse. This study investigates the mechanical response of tunnel structures influenced by adjacent pipeline leakages through indoor tests. A scaled tunnel model with a simulated lining system was constructed, and pipeline leakage scenarios were replicated by introducing controlled water pressures at the predefined location. The deformation and stress redistribution in the lining under varying leakage locations and durations were monitored. Experimental results reveal that the location of the pipeline leakage concerning the tunnel had a great impact on the distribution of the leakage zone. The presence of the tunnel affected the expansion of seepage water from the pipeline in the strata. The pipe leakage above the tunnel resulted in a maximum surface settlement of 2.66 mm, whereas the horizontal movement of the pipe leakage location reduced the surface settlement by 10–15 %. Change in location of pipeline leakage induced uneven deformation of the strata, and the settlement progression behavior exhibited an initial gradual development stage (0–2 h), accelerated subsidence stage (2–10 h), and stabilization stage (10–14 h). Uniform settlement of the strata due to pipeline leakage led to a dynamic mechanical response of the lining structure, and the internal forces of the lining structure also manifested obvious asymmetric features. Lining leakage resulted in a 41.9 % and 22.1 % increase in bending moment and axial force of the lining structure, respectively. The lining structure bias caused by pipeline leakage will deteriorate the mechanical behavior of the tunnel structure. The findings of this paper can provide a reference for the prevention and control of leakage of adjacent pipelines in subway tunnels.
{"title":"Indoor tests on the mechanical response of tunnel lining under the influence of pipeline leakage","authors":"Sulei Zhang, Linghui Li, Xiaofei Chen, Chang Liu, Mingqing Du, Yongjun Zhang","doi":"10.1016/j.engfailanal.2025.109501","DOIUrl":"10.1016/j.engfailanal.2025.109501","url":null,"abstract":"<div><div>Pipeline leakage is a common issue encountered in urban areas, significantly contributing to the deterioration of tunnel structures and even posing a risk of ground collapse. This study investigates the mechanical response of tunnel structures influenced by adjacent pipeline leakages through indoor tests. A scaled tunnel model with a simulated lining system was constructed, and pipeline leakage scenarios were replicated by introducing controlled water pressures at the predefined location. The deformation and stress redistribution in the lining under varying leakage locations and durations were monitored. Experimental results reveal that the location of the pipeline leakage concerning the tunnel had a great impact on the distribution of the leakage zone. The presence of the tunnel affected the expansion of seepage water from the pipeline in the strata. The pipe leakage above the tunnel resulted in a maximum surface settlement of 2.66 mm, whereas the horizontal movement of the pipe leakage location reduced the surface settlement by 10–15 %. Change in location of pipeline leakage induced uneven deformation of the strata, and the settlement progression behavior exhibited an initial gradual development stage (0–2 h), accelerated subsidence stage (2–10 h), and stabilization stage (10–14 h). Uniform settlement of the strata due to pipeline leakage led to a dynamic mechanical response of the lining structure, and the internal forces of the lining structure also manifested obvious asymmetric features. Lining leakage resulted in a 41.9 % and 22.1 % increase in bending moment and axial force of the lining structure, respectively. The lining structure bias caused by pipeline leakage will deteriorate the mechanical behavior of the tunnel structure. The findings of this paper can provide a reference for the prevention and control of leakage of adjacent pipelines in subway tunnels.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"174 ","pages":"Article 109501"},"PeriodicalIF":4.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611334","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}
Pub Date : 2025-03-06DOI: 10.1016/j.engfailanal.2025.109504
İrfan Kocaman , Esma Eroğlu , Merve Ertosun Yıldız , Mehmet Akif Yıldız , Ömer Mercimek , Sedanur Çetin
This study aims to evaluate the seismic behavior of the historical Kabasakal Mosque in Gaziantep and to understand the effects of reinforced concrete (RC) elements added after the 1950s. Considering the increasing threats to Turkey’s cultural heritage structures, the significance of scientific approaches in the preservation of historical buildings is emphasized. Initially, a detailed finite element model (R-Model) representing the current state of the mosque was developed. The material properties of the reinforced concrete elements were defined based on literature research and material behavior of similar structures. Subsequently, to reconstruct the mosque’s original state, other historical masonry mosques from the same period and region were studied. The architectural similarities and typological features of these structures were compiled. Based on this data, another finite element model (O-Model), entirely composed of masonry elements representing the mosque’s original condition, was created. In both models, macro modeling techniques were employed, and geometric details and material properties were meticulously defined. As part of the modeling studies, modal analyses, nonlinear pushover analyses, and nonlinear time-history analyses were conducted. Modal analysis results revealed that reinforced concrete elements increased the structural stiffness, elevating the modal frequencies and thereby altering the vibration characteristics of the structure. Pushover analyses showed that while reinforced concrete elements contributed marginally to the horizontal force capacity of the structure, they partially reduced displacement demands. Dynamic analyses indicated that the R-Model exhibited a more uniform stress distribution and improved damage mechanisms due to the reinforced concrete elements. However, in scaled 1.25 analyses, significant damage mechanisms were observed in both O-Model and R-Model. This finding demonstrates that while reinforced concrete interventions provide some level of improvement for the structure, they offer limited protection under large-scale earthquake scenarios. Specifically, the R-Model exhibited a “box effect” created by the reinforced concrete slab between the narthex and the north wall, preventing localized collapses. Nevertheless, critical damage mechanisms persisted in other regions of the structure. The results underscore the necessity of meticulous planning for strengthening interventions in the preservation of historical structures. This study highlights the effectiveness of finite element modeling techniques in analyzing historical masonry structures and shows that reinforced concrete elements improve local damage mechanisms. However, the impact of strengthening methods on the global seismic performance requires further investigation.
{"title":"Reinforced concrete interventions on the collapse mechanism of historical masonry structures with detailed finite element analyses: Kabasakal Mosque","authors":"İrfan Kocaman , Esma Eroğlu , Merve Ertosun Yıldız , Mehmet Akif Yıldız , Ömer Mercimek , Sedanur Çetin","doi":"10.1016/j.engfailanal.2025.109504","DOIUrl":"10.1016/j.engfailanal.2025.109504","url":null,"abstract":"<div><div>This study aims to evaluate the seismic behavior of the historical Kabasakal Mosque in Gaziantep and to understand the effects of reinforced concrete (RC) elements added after the 1950s. Considering the increasing threats to Turkey’s cultural heritage structures, the significance of scientific approaches in the preservation of historical buildings is emphasized. Initially, a detailed finite element model (R-Model) representing the current state of the mosque was developed. The material properties of the reinforced concrete elements were defined based on literature research and material behavior of similar structures. Subsequently, to reconstruct the mosque’s original state, other historical masonry mosques from the same period and region were studied. The architectural similarities and typological features of these structures were compiled. Based on this data, another finite element model (O-Model), entirely composed of masonry elements representing the mosque’s original condition, was created. In both models, macro modeling techniques were employed, and geometric details and material properties were meticulously defined. As part of the modeling studies, modal analyses, nonlinear pushover analyses, and nonlinear time-history analyses were conducted. Modal analysis results revealed that reinforced concrete elements increased the structural stiffness, elevating the modal frequencies and thereby altering the vibration characteristics of the structure. Pushover analyses showed that while reinforced concrete elements contributed marginally to the horizontal force capacity of the structure, they partially reduced displacement demands. Dynamic analyses indicated that the R-Model exhibited a more uniform stress distribution and improved damage mechanisms due to the reinforced concrete elements. However, in scaled 1.25 analyses, significant damage mechanisms were observed in both O-Model and R-Model. This finding demonstrates that while reinforced concrete interventions provide some level of improvement for the structure, they offer limited protection under large-scale earthquake scenarios. Specifically, the R-Model exhibited a “box effect” created by the reinforced concrete slab between the narthex and the north wall, preventing localized collapses. Nevertheless, critical damage mechanisms persisted in other regions of the structure. The results underscore the necessity of meticulous planning for strengthening interventions in the preservation of historical structures. This study highlights the effectiveness of finite element modeling techniques in analyzing historical masonry structures and shows that reinforced concrete elements improve local damage mechanisms. However, the impact of strengthening methods on the global seismic performance requires further investigation.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"174 ","pages":"Article 109504"},"PeriodicalIF":4.4,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579349","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}
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