Jan Kubica , Janusz Brol , Karolina Kurtz , Marek Węglorz
{"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}
Chengxing Yang , Yujia Huo , Kangpei Meng , Wei Zhou , Jun Yang , Zhao Nan
{"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}
{"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}
Rowin J.M. Bol , Yading Xu , Mladena Luković , Branko Šavija
{"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}
Zhe Zhu , Yong Lu , Tianjie Huang , Jinbin Zhao , Chen Chen , Hongchi Ma , Zhiyong Liu , Xuequn Cheng , Xiaogang Li
{"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}
Mi Zhao , Yi-Ming Nie , Qing-Peng Ding , Jia-Xu Shen , Zhi-Dong Gao , Xiu-Li Du
{"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}
{"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}
İrfan Kocaman , Esma Eroğlu , Merve Ertosun Yıldız , Mehmet Akif Yıldız , Ömer Mercimek , Sedanur Çetin
{"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}
Zilong Zhou , Zhen Wang , Ruishan Cheng , Jiaming Wang
{"title":"Experimental and numerical study on blast-induced rock damage and fragmentation under low temperatures","authors":"Zilong Zhou , Zhen Wang , Ruishan Cheng , Jiaming Wang","doi":"10.1016/j.engfailanal.2025.109497","DOIUrl":"10.1016/j.engfailanal.2025.109497","url":null,"abstract":"<div><div>Low temperatures in cold regions have significant effects on rock blasting performance, e.g., blast-induced rock fragmentation. However, very limited study has explored the influences of sub-zero temperatures on blast-induced rock response. The present study employs experimental tests and numerical simulation to examine the damage and fragmentation of rock subjected to blasting under low-temperature conditions. The small-scale blasting tests of rocks at room temperature (i.e., 20 °C) and different low temperatures (i.e., from −10°C to −40°C) are first conducted to examine low temperatures’ effects on blast-induced rock fragmentation by using the three-parameter Generalized Extreme Value (GEV) function and the fractal theory. The findings indicate that the average sizes of blast-induced rock fragments first increase and then fall as the rock temperatures drop from 20 °C to − 40 °C, and the least uniform fragment size distribution is presented at −30 °C. Moreover, the numerical models of a full-scale deep borehole are established to examine the effects of different low-temperature gradient characteristics in rock mass on the damage and fragmentation of rocks caused by blasting. It is observed that the blast-induced damage of the multi-gradient low-temperature rock mass first decreases and then increases with rock depths approaching the ground surface. In addition, it is noted that rock damage and fragmentation induced by blasting can significantly differ with changing multi-gradient low-temperature conditions in a rock mass (e.g., different multi-gradient low-temperature ranges, multi-gradient low-temperature depths in rock mass, and numbers of multi-gradient low-temperature layers). The findings can be used as a reference for fine rock blasting design under low-temperature conditions.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"174 ","pages":"Article 109497"},"PeriodicalIF":4.4,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579345","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}
Jihua Liu , Junjie Ou , Jianbin Li , Zihua Yu , Chenggang He , Peng Li , Guiyuan Zhou , Youjie Chen
{"title":"Initiation and propagation mechanism of fish-scale-like fatigue cracks on a U75V quenched rail","authors":"Jihua Liu , Junjie Ou , Jianbin Li , Zihua Yu , Chenggang He , Peng Li , Guiyuan Zhou , Youjie Chen","doi":"10.1016/j.engfailanal.2025.109468","DOIUrl":"10.1016/j.engfailanal.2025.109468","url":null,"abstract":"<div><div>After rails are returned to service following rehabilitative grinding, severe rolling contact fatigue damage characterized by fish-scale-like oblique cracks occurs on the inner side of the U75VH rail tread. Metallurgical tests were performed on the damaged surfaces and cross-sections to analyse the initiation and propagation mechanisms of the fish-scale-like cracks. The results indicated that the rapid initiation of the microcracks could be attributed mainly to the generation of a thin white etching layer (WEL) during rail grinding. Microcracks initially propagated along the interface of the WEL and matrix, growing horizontally or downward in a “wavy” form and ultimately manifesting as fish-scale-like oblique cracks on the contact surface. Moreover, the WEL was rapidly removed and became much thinner under severe alternating wheel-rail stresses. The longitudinal profile of the fish-scale-like cracks could be divided into “circuitous cracks” and “downward cracks”. The circuitous cracks propagated at a small angle and tended to propagate to the surface in a wave-like pattern, thus resulting in spalling pits. Conversely, the downward cracks tended to propagate deeper into the matrix. Most branch cracks from the main cracks initiated at the peak of the upper crack face. The main propagation mechanism of the branching cracks and the main crack was transcrystalline fracture.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"174 ","pages":"Article 109468"},"PeriodicalIF":4.4,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143579344","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}