Pub Date : 2026-01-19DOI: 10.1016/j.engfailanal.2026.110594
Min Lou , Bin Wu , Yangyang Wang , Weixing Liang , Yu Han
This study investigates the multi-crack propagation characteristics and predicts the fatigue life of six Q355B tubular T-joint specimens subjected to in-plane bending, utilizing a combination of experimental and numerical approaches. A series of static tensile tests and fatigue tests are conducted to study the fatigue behavior of tubular T-joints under varying bending load conditions in terms of fatigue crack trajectory, failure morphology and remaining fatigue life. Thereinto, fatigue crack growth is monitored using the beach mark technique, and the fracture morphology at different stages during the crack propagation is examined using scanning electron microscopy. A numerical investigation is carried out to capture the multiple crack coalescence and to predict the remaining fatigue life during the crack propagation process. These studies reveal that two cracks initiate at the brace near crown and propagate toward its depth direction, coalesce into a long crack, continuing to grow circumferentially along the weld toe in the case of a curved morphology. Reasonably good agreements are achieved between experimental and simulated results, with the average error of the whole fatigue life less than 13%. There is generally good agreement between experimental and predicted results in fatigue crack trajectory, failure morphology, and remaining fatigue life.
{"title":"Multi-crack propagation characteristics and fatigue life prediction of tubular T-joints subjected to in-plane bending","authors":"Min Lou , Bin Wu , Yangyang Wang , Weixing Liang , Yu Han","doi":"10.1016/j.engfailanal.2026.110594","DOIUrl":"10.1016/j.engfailanal.2026.110594","url":null,"abstract":"<div><div>This study investigates the multi-crack propagation characteristics and predicts the fatigue life of six Q355B tubular T-joint specimens subjected to in-plane bending, utilizing a combination of experimental and numerical approaches. A series of static tensile tests and fatigue tests are conducted to study the fatigue behavior of tubular T-joints under varying bending load conditions in terms of fatigue crack trajectory, failure morphology and remaining fatigue life. Thereinto, fatigue crack growth is monitored using the beach mark technique, and the fracture morphology at different stages during the crack propagation is examined using scanning electron microscopy. A numerical investigation is carried out to capture the multiple crack coalescence and to predict the remaining fatigue life during the crack propagation process. These studies reveal that two cracks initiate at the brace near crown and propagate toward its depth direction, coalesce into a long crack, continuing to grow circumferentially along the weld toe in the case of a curved morphology. Reasonably good agreements are achieved between experimental and simulated results, with the average error of the whole fatigue life less than 13%. There is generally good agreement between experimental and predicted results in fatigue crack trajectory, failure morphology, and remaining fatigue life.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"187 ","pages":"Article 110594"},"PeriodicalIF":5.7,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025778","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 : 2026-01-18DOI: 10.1016/j.engfailanal.2026.110586
Feili Yang , Wei Zhang , Dongsheng Zhang , Yuezhang Zhu , Jingcheng Wang , Beihai Huang , Yanpeng Wang , Mingzhao Dong , Jinfeng Mao
To address severe deformation and control difficulties of underlying roadway groups under fully mechanized top-coal caving (FMTCC)–induced dynamic pressure, this study investigates the 885 FMTCC face and the underlying roadway group of the 88 panel at Zhuxianzhuang Coal Mine through field measurements, numerical simulations, and engineering practice. In situ borehole stress monitoring combined with quantitative borehole peering analysis was used to clarify the stress distribution and fracture development characteristics of the floor under mining. Using a coupled FLAC3D–PFC3D approach, a numerical model was developed to analyze the differentiated failure characteristics of the floor under FMTCC-induced disturbance. Moreover, the failure mechanisms of underlying roadway groups were elucidated. The results revealed that the floor surrounding rock first underwent stress concentration and then stress unloading as the working face advanced. The stress response of different strata varies markedly with burial depth and lithology. All the underlying roadways underwent four evolutionary stages—undisturbed, mining induced failure, disturbance stability transition, and final stabilization—and the intensity of disturbance-induced failure decreases markedly with increasing vertical distance. Building on these findings, a differentiated surrounding rock control technology centered on the “Unloading–Grouting–Anchoring” concept was proposed for underlying roadways at different vertical distances. Field applications show that roadway deformation is effectively controlled across all distances, with an average cross-sectional area retention exceeding 92.6% in major production roadways, confirming the effectiveness of the proposed technology under FMTCC-induced dynamic pressure.
{"title":"Failure mechanism and differential stability control of surrounding rock in an underlying roadway group under fully mechanized top-coal caving: A case study","authors":"Feili Yang , Wei Zhang , Dongsheng Zhang , Yuezhang Zhu , Jingcheng Wang , Beihai Huang , Yanpeng Wang , Mingzhao Dong , Jinfeng Mao","doi":"10.1016/j.engfailanal.2026.110586","DOIUrl":"10.1016/j.engfailanal.2026.110586","url":null,"abstract":"<div><div>To address severe deformation and control difficulties of underlying roadway groups under fully mechanized top-coal caving (FMTCC)–induced dynamic pressure, this study investigates the 885 FMTCC face and the underlying roadway group of the 88 panel at Zhuxianzhuang Coal Mine through field measurements, numerical simulations, and engineering practice. In situ borehole stress monitoring combined with quantitative borehole peering analysis was used to clarify the stress distribution and fracture development characteristics of the floor under mining. Using a coupled FLAC3D–PFC3D approach, a numerical model was developed to analyze the differentiated failure characteristics of the floor under FMTCC-induced disturbance. Moreover, the failure mechanisms of underlying roadway groups were elucidated. The results revealed that the floor surrounding rock first underwent stress concentration and then stress unloading as the working face advanced. The stress response of different strata varies markedly with burial depth and lithology. All the underlying roadways underwent four evolutionary stages—undisturbed, mining induced failure, disturbance stability transition, and final stabilization—and the intensity of disturbance-induced failure decreases markedly with increasing vertical distance. Building on these findings, a differentiated surrounding rock control technology centered on the “Unloading–Grouting–Anchoring” concept was proposed for underlying roadways at different vertical distances. Field applications show that roadway deformation is effectively controlled across all distances, with an average cross-sectional area retention exceeding 92.6% in major production roadways, confirming the effectiveness of the proposed technology under FMTCC-induced dynamic pressure.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"187 ","pages":"Article 110586"},"PeriodicalIF":5.7,"publicationDate":"2026-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075807","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}
Bolted L-shaped component connections, which are typical configurations in bolted flange splicing joints for columns, are subjected to cyclic tension–compression from wind-induced vibration in high-rise buildings, leading to fatigue failure risks. To investigate the fatigue performance of Grade 10.9 M20 bolts, axial cyclic loading fatigue tests were conducted on 20 specimens with different flange thicknesses. Experimental results revealed that all fatigue failures occurred at the root of the first engaged thread or within the thread engagement region, with preload decay exceeding 30% prior to fracture. A refined finite element model incorporating thread was developed to conduct parametric analyses, demonstrating that the fatigue life significantly improves with increasing flange thickness, column wall thickness, bolt edge distance, and preload. Furthermore, a nominal stress calculation method accounting for bending-axial coupling effects was proposed, and an S–N curve describing the relationship between stress range and fatigue life was established with good fitting accuracy. Comparative analysis against fatigue design recommendations in EN 1993-1-9, ANSI/AISC 360-16, and GB 50017-2017 highlighted conservative predictions of the above codes. Macroscopic fracture morphology analysis of the high-strength bolts was carried out to further elucidate the fatigue failure mechanisms.
{"title":"Fatigue performance of Grade 10.9 M20 high-strength bolts in L-shaped component connections","authors":"Xu-Ze Feng, Xue-Chun Liu, Xuesen Chen, Wei Zhou, Yong-Li Tao, Ai-lin Zhang","doi":"10.1016/j.engfailanal.2026.110583","DOIUrl":"10.1016/j.engfailanal.2026.110583","url":null,"abstract":"<div><div>Bolted L-shaped component connections, which are typical configurations in bolted flange splicing joints for columns, are subjected to cyclic tension–compression from wind-induced vibration in high-rise buildings, leading to fatigue failure risks. To investigate the fatigue performance of Grade 10.9 M20 bolts, axial cyclic loading fatigue tests were conducted on 20 specimens with different flange thicknesses. Experimental results revealed that all fatigue failures occurred at the root of the first engaged thread or within the thread engagement region, with preload decay exceeding 30% prior to fracture. A refined finite element model incorporating thread was developed to conduct parametric analyses, demonstrating that the fatigue life significantly improves with increasing flange thickness, column wall thickness, bolt edge distance, and preload. Furthermore, a nominal stress calculation method accounting for bending-axial coupling effects was proposed, and an <em>S–N</em> curve describing the relationship between stress range and fatigue life was established with good fitting accuracy. Comparative analysis against fatigue design recommendations in EN 1993-1-9, ANSI/AISC 360-16, and GB 50017-2017 highlighted conservative predictions of the above codes. Macroscopic fracture morphology analysis of the high-strength bolts was carried out to further elucidate the fatigue failure mechanisms.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"187 ","pages":"Article 110583"},"PeriodicalIF":5.7,"publicationDate":"2026-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025775","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 : 2026-01-16DOI: 10.1016/j.engfailanal.2026.110587
Hyeok-Jun Kwon , Hongseok Kim , Youngchan Kim , Dooyoul Lee
This study analyzed two extremely rare internal object damage (IOD) events in the prevalent J85 engine, which are attributable to the long-term operation of its compressor parts. In both cases, the damaged parts (retaining ring, compressor 7th stator vane) were made of the same alloy 718 material, and the presence of material defects was investigated first. The first case involved a retaining ring fasten pin that fractured in half, collided, and stuck to the rotor blade’s leading edge. The root cause of pin failure was confirmed as a microstructural defect. The second case, a compressor 7th stator vane fracture, was linked to resonance that depleted its fatigue life and led to premature failure. In particular, changes in vibration modes occurring during aeroengine operation, along with microstructural defects, might be the main causes of fatigue crack initiation and propagation. Each unique IOD case can provide valuable insights into advanced gas turbine aeroengine design and operation.
{"title":"Failure analyses of J85 engine compressor caused by Alloy 718 internal object debris","authors":"Hyeok-Jun Kwon , Hongseok Kim , Youngchan Kim , Dooyoul Lee","doi":"10.1016/j.engfailanal.2026.110587","DOIUrl":"10.1016/j.engfailanal.2026.110587","url":null,"abstract":"<div><div>This study analyzed two extremely rare internal object damage (IOD) events in the prevalent J85 engine, which are attributable to the long-term operation of its compressor parts. In both cases, the damaged parts (retaining ring, compressor 7th stator vane) were made of the same alloy 718 material, and the presence of material defects was investigated first. The first case involved a retaining ring fasten pin that fractured in half, collided, and stuck to the rotor blade’s leading edge. The root cause of pin failure was confirmed as a microstructural defect. The second case, a compressor 7th stator vane fracture, was linked to resonance that depleted its fatigue life and led to premature failure. In particular, changes in vibration modes occurring during aeroengine operation, along with microstructural defects, might be the main causes of fatigue crack initiation and propagation. Each unique IOD case can provide valuable insights into advanced gas turbine aeroengine design and operation.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"187 ","pages":"Article 110587"},"PeriodicalIF":5.7,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146001772","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 : 2026-01-16DOI: 10.1016/j.engfailanal.2026.110575
Flavia da Cruz Gallo , Mariel Ojeda-Tuz , Ciaran O’Rourke , Ryan Catarelli , Jennifer Bridge
Multiple aluminum light poles in Florida failed during recent hurricanes at wind speeds below design specifications, raising concerns about structural integrity and manufacturing quality. This study investigates the failure of cast A356-T6 aluminum alloy bases through combined metallurgical analysis and finite element modeling. Computed Tomography (CT) and metallography revealed critical porosity levels (5.9 – 8.2 %) exceeding ASTM acceptance thresholds, along with microstructural variability near bolt holes. Local hardness and tensile testing indicated reduced yield strength, approximately 20 – 25 % relative to nominal A356-T6 values, consistent with casting defects and installation-induced pre-strain, significantly narrowing the safety margin under hurricane winds. Fracture morphology confirmed monotonic overload rather than fatigue. A full-scale finite element model of the Lake Jessup Bridge base assembly was developed to evaluate stress distribution under design-level and hurricane-level wind loading while incorporating measured material properties and installation irregularities. Simulations showed that when porosity-reduced strength was combined with geometric stress risers and uneven leveling-nut preload, localized stresses exceeded the experimentally measured yield strength (∼116 MPa) even under wind speeds below design thresholds. This study is the first to integrate CT-quantified porosity, field installation audits, tensile testing, and wind-driven structural modeling to explain premature hurricane-induced failures of cast aluminum pole bases. The findings demonstrate that premature failures resulted from the synergistic interaction of casting defects, geometric vulnerability, and installation-induced overloads rather than a single governing mechanism. Recommendations include stricter casting quality control, torque-limiting installation protocols, and minor design modifications aimed at reducing stress concentrations and improving reliability of aluminum infrastructure in hurricane-prone regions.
{"title":"Failure analysis of cast aluminum A356-T6 light pole bases following Catastrophic Hurricane Exposure: Microstructural, Mechanical, and Fractographic investigations","authors":"Flavia da Cruz Gallo , Mariel Ojeda-Tuz , Ciaran O’Rourke , Ryan Catarelli , Jennifer Bridge","doi":"10.1016/j.engfailanal.2026.110575","DOIUrl":"10.1016/j.engfailanal.2026.110575","url":null,"abstract":"<div><div>Multiple aluminum light poles in Florida failed during recent hurricanes at wind speeds below design specifications, raising concerns about structural integrity and manufacturing quality. This study investigates the failure of cast A356-T6 aluminum alloy bases through combined metallurgical analysis and finite element modeling. Computed Tomography (CT) and metallography revealed critical porosity levels (5.9 – 8.2 %) exceeding ASTM acceptance thresholds, along with microstructural variability near bolt holes. Local hardness and tensile testing indicated reduced yield strength, approximately 20 – 25 % relative to nominal A356-T6 values, consistent with casting defects and installation-induced pre-strain, significantly narrowing the safety margin under hurricane winds. Fracture morphology confirmed monotonic overload rather than fatigue. A full-scale finite element model of the Lake Jessup Bridge base assembly was developed to evaluate stress distribution under design-level and hurricane-level wind loading while incorporating measured material properties and installation irregularities. Simulations showed that when porosity-reduced strength was combined with geometric stress risers and uneven leveling-nut preload, localized stresses exceeded the experimentally measured yield strength (∼116 MPa) even under wind speeds below design thresholds. This study is the first to integrate CT-quantified porosity, field installation audits, tensile testing, and wind-driven structural modeling to explain premature hurricane-induced failures of cast aluminum pole bases. The findings demonstrate that premature failures resulted from the synergistic interaction of casting defects, geometric vulnerability, and installation-induced overloads rather than a single governing mechanism. Recommendations include stricter casting quality control, torque-limiting installation protocols, and minor design modifications aimed at reducing stress concentrations and improving reliability of aluminum infrastructure in hurricane-prone regions.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"187 ","pages":"Article 110575"},"PeriodicalIF":5.7,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146001771","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 : 2026-01-16DOI: 10.1016/j.engfailanal.2026.110584
Rehan Khan , Moiz Ahmad , Shahbaz Ali , Faez Qahtani , Tariq Talha , Saeed Alqaed , Jawed Mustafa , Syed Osama Safdar
Erosion is a critical factor that significantly reduces the service life of rotor blades in centrifugal pumps operating under sand particle-laden flows. In this study, a carbon steel blade from a submerged centrifugal pump experienced severe damage after only a few days of continuous operation at the Centre for Erosion-Corrosion Research. The most prominent damage was observed along the outer edges and raised guide vanes of the impeller blade, with localized wall thinning. To investigate the underlying failure mechanisms, a comprehensive analysis was conducted combining visual inspection, scanning electron microscopy (SEM), 3D surface scanning, energy-dispersive spectroscopy (EDS), and laser profilometry measurements. Numerical simulations were performed using computational fluid dynamics (CFD) coupled with the discrete phase model (DPM) to model particle-laden flow behavior and identify critical erosion zones. Unlike prior studies focused solely on simulation or idealized models, this work integrates real-world failure evidence with validated CFD-DPM modeling to establish a direct correlation between physical degradation and predicted erosion. The results revealed that erosion in high-impact regions was nearly twice as severe as in low-impact areas, primarily driven by high turbulence intensity and repeated impingement of 300 µm sand particles at flow velocities exceeding 5 m/s. A maximum erosion rate of 3.8 × 10−5 kg/m2·s was observed. This study provides new insights into the spatial relationship between flow-induced turbulence and material loss, contributing valuable data for improving pump blade durability and predictive wear modeling in abrasive fluid environments.
{"title":"Failure analysis of a centrifugal pump impeller in erosive flow conditions","authors":"Rehan Khan , Moiz Ahmad , Shahbaz Ali , Faez Qahtani , Tariq Talha , Saeed Alqaed , Jawed Mustafa , Syed Osama Safdar","doi":"10.1016/j.engfailanal.2026.110584","DOIUrl":"10.1016/j.engfailanal.2026.110584","url":null,"abstract":"<div><div>Erosion is a critical factor that significantly reduces the service life of rotor blades in centrifugal pumps operating under sand particle-laden flows. In this study, a carbon steel blade from a submerged centrifugal pump experienced severe damage after only a few days of continuous operation at the Centre for Erosion-Corrosion Research. The most prominent damage was observed along the outer edges and raised guide vanes of the impeller blade, with localized wall thinning. To investigate the underlying failure mechanisms, a comprehensive analysis was conducted combining visual inspection, scanning electron microscopy (SEM), 3D surface scanning, energy-dispersive spectroscopy (EDS), and laser profilometry measurements. Numerical simulations were performed using computational fluid dynamics (CFD) coupled with the discrete phase model (DPM) to model particle-laden flow behavior and identify critical erosion zones. Unlike prior studies focused solely on simulation or idealized models, this work integrates real-world failure evidence with validated CFD-DPM modeling to establish a direct correlation between physical degradation and predicted erosion. The results revealed that erosion in high-impact regions was nearly twice as severe as in low-impact areas, primarily driven by high turbulence intensity and repeated impingement of 300 µm sand particles at flow velocities exceeding 5 m/s. A maximum erosion rate of 3.8 × 10<sup>−5</sup> kg/m<sup>2</sup>·s was observed. This study provides new insights into the spatial relationship between flow-induced turbulence and material loss, contributing valuable data for improving pump blade durability and predictive wear modeling in abrasive fluid environments.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"187 ","pages":"Article 110584"},"PeriodicalIF":5.7,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075809","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}
Computer modeling and simulation are important tools used for solving problems in engineering applied to industry. Proper modeling and simulation testing of the systems under analysis allow for design adjustments before manufacturing, which leads to reductions in time and costs. This project conducts a comprehensive analysis aimed at mitigating excessive vibration in two induced draft fans operating in a thermoelectric power plant. The tools used for the analysis include instrumentation through accelerometers, estimation of stiffness and damping parameters by the Sommerfeld methodology, as well as computer modeling and simulation. The instrumentation enabled estimation of the rotor’s natural frequencies, validated through computer simulation. Finite element analysis (FEA), guided by the Sommerfeld methodology, enhanced simulation accuracy. Sommerfeld curves, reconstructed from low-resolution 1965 printed sources (original digital data unavailable), were digitized and subsequently reconstructed using the Smoothing Spline algorithm for continuous and coherent profiles. At the end of this study, we present a redesign solution, validated through computer modeling and simulation, to reduce excessive vibration in two induced draft fans of a thermoelectric power plant.
{"title":"Simulation-driven estimation of stiffness and damping coefficients using Sommerfeld curves for vibration reduction in induced draft fans","authors":"Erick-Alejandro González-Barbosa , Jose-Juan Vázquez-Martínez , Gerardo Trejo-Caballero , Hector Castro-Mosqueda , Fernando Jurado Pérez , Alfonso Ramírez-Pedraza , José-Joel González-Barbosa","doi":"10.1016/j.engfailanal.2026.110578","DOIUrl":"10.1016/j.engfailanal.2026.110578","url":null,"abstract":"<div><div>Computer modeling and simulation are important tools used for solving problems in engineering applied to industry. Proper modeling and simulation testing of the systems under analysis allow for design adjustments before manufacturing, which leads to reductions in time and costs. This project conducts a comprehensive analysis aimed at mitigating excessive vibration in two induced draft fans operating in a thermoelectric power plant. The tools used for the analysis include instrumentation through accelerometers, estimation of stiffness and damping parameters by the Sommerfeld methodology, as well as computer modeling and simulation. The instrumentation enabled estimation of the rotor’s natural frequencies, validated through computer simulation. Finite element analysis (FEA), guided by the Sommerfeld methodology, enhanced simulation accuracy. Sommerfeld curves, reconstructed from low-resolution 1965 printed sources (original digital data unavailable), were digitized and subsequently reconstructed using the Smoothing Spline algorithm for continuous and coherent profiles. At the end of this study, we present a redesign solution, validated through computer modeling and simulation, to reduce excessive vibration in two induced draft fans of a thermoelectric power plant.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"186 ","pages":"Article 110578"},"PeriodicalIF":5.7,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145972854","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 : 2026-01-14DOI: 10.1016/j.engfailanal.2026.110581
Pengfei Ma , Yangyang Zhang , Lichao Nie , Zhiqiang Li , Zhicheng Song , Yuancheng Li
Collapse is likely when long, deeply buried tunnels intersect water-rich fractured basalt. Single-method forecasting cannot resolve the spatial distribution of water-bearing structures or the progressive failure process. Using the Xianglu Mountain Tunnel as a case study, we propose a mechanism-analysis framework in which integrated geophysical prospecting provides priors for a Peridynamic (PD) numerical model. Specifically, Seismic ahead prospecting yields spatial distributions of elastic modulus, Poisson’s ratio, and density ahead of the face. Direct current resistivity delineates low-resistivity anomalies and, through an empirical resistivity–permeability relationship, enables quantitative inversion of the pre-excavation seepage field. These geophysical products are then injected as prior fields into a PD-based excavation–seepage failure model. The simulations indicate progressive damage of the confining rock layer (aquiclude) under multi-factor coupling until the damage zone coalesces and collapse occurs. Comparison with field observations shows close agreement in the predicted affected extent, demonstrating that the integrated approach explains collapse during excavation in water-rich basalt tunnels and provides a reliable pathway for advanced prevention and control of similar geohazards in deeply buried tunnels.
{"title":"Collapse mechanism of deep-buried long water-rich basalt tunnels based on integrated geophysical prospecting: A case study in Yunnan, China","authors":"Pengfei Ma , Yangyang Zhang , Lichao Nie , Zhiqiang Li , Zhicheng Song , Yuancheng Li","doi":"10.1016/j.engfailanal.2026.110581","DOIUrl":"10.1016/j.engfailanal.2026.110581","url":null,"abstract":"<div><div>Collapse is likely when long, deeply buried tunnels intersect water-rich fractured basalt. Single-method forecasting cannot resolve the spatial distribution of water-bearing structures or the progressive failure process. Using the Xianglu Mountain Tunnel as a case study, we propose a mechanism-analysis framework in which integrated geophysical prospecting provides priors for a Peridynamic (PD) numerical model. Specifically, Seismic ahead prospecting yields spatial distributions of elastic modulus, Poisson’s ratio, and density ahead of the face. Direct current resistivity delineates low-resistivity anomalies and, through an empirical resistivity–permeability relationship, enables quantitative inversion of the pre-excavation seepage field. These geophysical products are then injected as prior fields into a PD-based excavation–seepage failure model. The simulations indicate progressive damage of the confining rock layer (aquiclude) under multi-factor coupling until the damage zone coalesces and collapse occurs. Comparison with field observations shows close agreement in the predicted affected extent, demonstrating that the integrated approach explains collapse during excavation in water-rich basalt tunnels and provides a reliable pathway for advanced prevention and control of similar geohazards in deeply buried tunnels.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"187 ","pages":"Article 110581"},"PeriodicalIF":5.7,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025776","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 : 2026-01-14DOI: 10.1016/j.engfailanal.2026.110579
Jiaxin Lei , Yangyong Luoze , Haoyao Xia , Jianing Liu , Caiyou Zhao , Ping Wang
With the continuous increase in train operating speeds, rolling contact fatigue on rail surfaces has become a major concern, especially in welded regions where geometric irregularities and material mismatches intensify stress concentrations and accelerate crack growth. This study integrates ABAQUS and FRANC3D through a fracture-mechanics-based submodeling approach to simulate surface crack propagation in welded rails with realistic 3D weld geometry. The developed model clarifies how crack geometry and weld irregularities jointly affect fatigue behavior under rolling contact loads. The results indicate that surface cracks mainly propagate through a mixed Mode II–III shear mechanism. A 45° inclination angle represents the most critical propagation orientation. Increasing the surface crack length from 2 mm to 6 mm shortens fatigue life by 57.7%, while extending the crack length to 8 mm elevates the peak Mode III stress-intensity factor to 811 MPa, promoting inward growth. In the weld zone, the deeper crack front propagates faster, causing semicircular cracks to evolve into elongated ellipses. A strong interaction is observed between weld wavelength, depth and crack phase position: shorter wavelengths and deeper undulations markedly increase the Mode II stress-intensity factor, with the fastest propagation occurring at 3/8 of the weld wavelength—where fatigue life drops to 44% of that at 7/8 of the wavelength. The findings clarify the shear-dominated crack evolution mechanism and provide theoretical guidance for weld-grinding thresholds and fatigue-life assessment of welded rails in high-speed railway applications.
{"title":"Analysis of mechanical behavior and propagation mechanisms of rail cracks considering the influence of three-dimensional weld geometry","authors":"Jiaxin Lei , Yangyong Luoze , Haoyao Xia , Jianing Liu , Caiyou Zhao , Ping Wang","doi":"10.1016/j.engfailanal.2026.110579","DOIUrl":"10.1016/j.engfailanal.2026.110579","url":null,"abstract":"<div><div>With the continuous increase in train operating speeds, rolling contact fatigue on rail surfaces has become a major concern, especially in welded regions where geometric irregularities and material mismatches intensify stress concentrations and accelerate crack growth. This study integrates ABAQUS and FRANC3D through a fracture-mechanics-based submodeling approach to simulate surface crack propagation in welded rails with realistic 3D weld geometry. The developed model clarifies how crack geometry and weld irregularities jointly affect fatigue behavior under rolling contact loads. The results indicate that surface cracks mainly propagate through a mixed Mode II–III shear mechanism. A 45° inclination angle represents the most critical propagation orientation. Increasing the surface crack length from 2 mm to 6 mm shortens fatigue life by 57.7%, while extending the crack length to 8 mm elevates the peak Mode III stress-intensity factor to 811 MPa, promoting inward growth. In the weld zone, the deeper crack front propagates faster, causing semicircular cracks to evolve into elongated ellipses. A strong interaction is observed between weld wavelength, depth and crack phase position: shorter wavelengths and deeper undulations markedly increase the Mode II stress-intensity factor, with the fastest propagation occurring at 3/8 of the weld wavelength—where fatigue life drops to 44% of that at 7/8 of the wavelength. The findings clarify the shear-dominated crack evolution mechanism and provide theoretical guidance for weld-grinding thresholds and fatigue-life assessment of welded rails in high-speed railway applications.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"187 ","pages":"Article 110579"},"PeriodicalIF":5.7,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146001770","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 : 2026-01-14DOI: 10.1016/j.engfailanal.2026.110582
Fanghuai Chen , Benkun Tan , Haitao Tang , Haiping Zhang , Yuan Luo , Xinhui Xiao , Yang Liu , Naiwei Lu
This paper presents an efficient predictive framework based on a random forest (RF) surrogate model for estimating fatigue crack propagation life in double-sided rib-to-deck (RD) welded joints in orthotropic steel decks (OSDs). A comprehensive training dataset for the RF surrogate model of stress intensity factor (SIF) was generated through extensive fatigue crack propagation simulations. The predictive accuracy of the RF surrogate model was rigorously validated, and SHAP-based feature analysis was employed to interpret the influence of input variables. The RF surrogate model was then used to estimate the fatigue life of the welded toe in double-sided RD welded joints, and the effects of initial crack geometry on fatigue life were investigated. The results indicate that the initial surface crack at the weld toe is a mode I-dominated mixed-mode crack and exhibits crack flattening during propagation. The RF surrogate model demonstrates high predictive accuracy for SIF, achieving high R2 values and low prediction errors across both training and validation datasets. SHAP analysis identifies applied stress as the primary influencer of SIF, with crack depth and half-length as secondary factors. Increases in initial crack depth and half-length significantly reduce fatigue crack propagation life. This study confirms the robustness of the RF model as a computationally efficient alternative to finite element methods (FEM), providing valuable insights for fatigue assessment and maintenance planning of OSDs.
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