Jintao Ma , Wurui Ta , Jiangtao Yan , Zhiwen Jin , Yuanwen Gao , Youhe Zhou
{"title":"Damage mechanism of REBCO coated conductor in CORC cables under electromagnetic loading","authors":"Jintao Ma , Wurui Ta , Jiangtao Yan , Zhiwen Jin , Yuanwen Gao , Youhe Zhou","doi":"10.1016/j.engfracmech.2025.111001","DOIUrl":"10.1016/j.engfracmech.2025.111001","url":null,"abstract":"<div><div>The performance of Conductor on Round Core (CORC) cables in complex electromagnetic environments is crucial for the safe operation of large superconducting magnet systems. As a critical component, the delamination issue of rare-earth-barium-copper-oxide (REBCO) coated conductors plays an important role in the mechanical and electrical stability of CORC cables. In this paper, the distribution characteristics of current density, electromagnetic force, interfacial stress, and delamination damage of REBCO coated conductors in CORC cables under different background fields are presented using a combined electromagnetic damage model. The numerical results indicate that the magnitude and direction of the electromagnetic force vary periodically with the sinusoidal magnetic field. The frequency of the external magnetic field has minimal influence on the current density and electromagnetic force. When the magnetic field and the transport current intervene together, the interaction between the transport current and the shielding current induced by the magnetic field significantly changes the distribution of the current density and the electromagnetic force, which further affects the interfacial stress and the delamination propagation path of the cohesive layer. The magnitudes of current density and electromagnetic force are proportional to the slopes of the variation curves of the transport current and magnetic field. Notably, in both scenarios, the interfacial shear delamination stress shows a clear tendency to concentrate at the edges of REBCO coated conductor, which is the primary factor driving interfacial delamination and crack propagation. Therefore, accurately measuring the shear delamination strength of REBCO coated conductors is highly significant for determining their operational limits under multi-field conditions.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 111001"},"PeriodicalIF":4.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551710","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}
Lei Wang , Wenqi Yu , Kai Zhang , Zhiheng Liu , Zhaoran Wu , Zaixing Liu , Shihui Ma , Yanghui Li
{"title":"Strength characteristics of fractured methane hydrate-bearing sediments","authors":"Lei Wang , Wenqi Yu , Kai Zhang , Zhiheng Liu , Zhaoran Wu , Zaixing Liu , Shihui Ma , Yanghui Li","doi":"10.1016/j.engfracmech.2025.110986","DOIUrl":"10.1016/j.engfracmech.2025.110986","url":null,"abstract":"<div><div>A large number of fractures have been discovered in natural gas hydrate (NGH) reservoirs on land and under the seabed worldwide, and the presence of these fractures may trigger deformation and instability of the reservoirs during NGH extraction. However, the specific impact of fractures on the mechanical properties of NGH reservoirs is still unknown at present. Based on these, this paper studies the strength characteristics of fractured hydrate-bearing sediments (FHBSs) and fracture-free hydrate-bearing sediments (FFHBSs) during shear processes under different effective stresses and hydrate saturations, and compares the stress–strain relationships, failure strengths, cohesion and internal friction angle between FHBSs and FFHBSs. The research indicates that under the same condition, the strength of FFHBSs is generally higher than that of FHBSs. In the absence of gas hydrates, the cohesion and internal friction angle of FHBSs are the same as those of FFHBSs. As the hydrate saturation increases (20% and 40%), the cohesion of FHBSs is lower than that of FFHBSs, while the internal friction angle of FHBSs is larger than that of FFHBSs. The research in this paper enhances the comprehension of the mechanical behavior of FHBSs and provides theoretical guidance for reducing the risk of geological disasters during NGH extraction.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110986"},"PeriodicalIF":4.7,"publicationDate":"2025-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551709","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}
Chengyan Bai , Liang Lan , Lulu Jiang , Bo He , Yuzhou Li , Yongkang Zhang
{"title":"Improvement of low-cycle fatigue properties in electron beam powder bed fusion processed Ti-6Al-4V alloy by laser shock peening","authors":"Chengyan Bai , Liang Lan , Lulu Jiang , Bo He , Yuzhou Li , Yongkang Zhang","doi":"10.1016/j.engfracmech.2025.110992","DOIUrl":"10.1016/j.engfracmech.2025.110992","url":null,"abstract":"<div><div>In this study, laser shock peening (LSP) was applied to modify the surface microstructure and low-cycle fatigue (LCF) performance of electron beam powder bed fusion processed Ti-6Al-4V titanium alloy. The microstructure evolution, fatigue crack propagation, deformation behavior, and residual stress without and with LSP were compared to explore the role of gradient microstructure on the LCF behavior. The gradient microstructure induced by LSP is composed of nanograins and submicro-equiaxed grains. Moreover, the degree of work hardening near the surface of LSP-treated samples becomes higher after fatigue loading, which alleviates the cyclic softening behavior. The residual compressive stress within the surface layer experiences a 20 % reduction under high strain amplitude, yet there is still a uniformly distributed compressive residual stress layer at the deeper subsurface. A deeper gradient microstructure, work hardening layer, and compressive residual stress triggered via LSP can restrain the crack initiation and propagation, reduce the cyclic softening rate, and thus improve the LCF performance.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110992"},"PeriodicalIF":4.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551693","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":"A configurational stress-based model to predict mixed-mode fracture of rock under different environments","authors":"Chao Wang, Jili Feng","doi":"10.1016/j.engfracmech.2025.110941","DOIUrl":"10.1016/j.engfracmech.2025.110941","url":null,"abstract":"<div><div>This paper investigates mixed-mode fracture in rock under different environments. The principle of energy conservation provides a clear physical interpretation of the configurational stress tensor, revealing that its components represent the change in total energy induced by material element translation. The Mohr–Coulomb yield function is employed to define the boundary of crack-tip plastic zone. A novel configurational stress-based Mohr–Coulomb yield function is proposed, enhancing the accuracy of plastic zone size and shape assessment. Additionally, a fracture criterion is developed based on the local properties of the crack-tip plastic zone, and then the time factor of Burgers body is incorporated to elucidate the rheological fracture properties of rock. Utilizing this fracture criterion, the impacts of drying–wetting cycles, heating–cooling cycles, thermal treatment and chemical corrosion on rock fracture are investigated. The proposed fracture criterion accurately predicts crack initiation angles and fracture loads, aligning with predictions of the maximum tensile stress criterion and experiments. It is found that the fracture loads decrease with the number of drying–wetting and heating–cooling cycles. The crack-tip plastic zone is observed to expand over time, leading to a reduction in the fracture loading envelope. Furthermore, the fracture loading envelope generally decreases with increasing thermal treatment temperature, and the mixed-mode fracture resistance is the minimum in acidic environments. This paper provides a valuable reference for addressing the challenges of rock mixed-mode fracture under different environments.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110941"},"PeriodicalIF":4.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Influence of crystal orientation on mechanical properties and stress distribution in monocrystalline sapphire","authors":"Xingyu Wang, Wen Zheng, Huixin Xing, Xiaoyu Bao, Qingliang Zhao, Yinchuan Piao","doi":"10.1016/j.engfracmech.2025.110996","DOIUrl":"10.1016/j.engfracmech.2025.110996","url":null,"abstract":"<div><div>The deformation behavior of monocrystalline materials is intricately linked to the anisotropic nature of their mechanical characteristics, slip motion, and cleavage motion. To systematically analyze the deformation and fracture behavior of monocrystalline sapphire and address existing shortcomings in the detection of its mechanical properties, we conducted a series of nanoindentation experiments and analyses across various crystal orientations of sapphire. A model for the stress field was developed by considering slip motion, cleavage fracture, and the mechanical properties of monocrystalline sapphire. Our findings indicate that cracks propagate in specific directions and exhibit anisotropic characteristics. The hardness and elastic modulus of sapphire across distinct planes follow the order: R < N < C < M < A, while the fracture toughness exhibits the opposite trend. Results concerning the stress field distribution, Schmid factor, and cleavage factor reveal that the M and A planes are more susceptible to brittle cracking and cleavage fracture, whereas the R and N planes are more likely to undergo plastic deformation.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110996"},"PeriodicalIF":4.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551723","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":"Crack growth analysis of shear deformable plate under bending and tension","authors":"X.B. Yan, L. Ning, J.C. Wen, X. Li, P.H. Wen","doi":"10.1016/j.engfracmech.2025.110997","DOIUrl":"10.1016/j.engfracmech.2025.110997","url":null,"abstract":"<div><div>This paper presents a method for fatigue crack growth path prediction by using the Displacement Discontinuity Method (DDM) in shear deformable plate bending and tension. A novel crack extension segment technique is introduced to model crack growth path and the stress intensity factors at the crack tip are captured using the equivalent stress technique. All stress intensity factors (three for bending and two for in-plane loads) are evaluated accurately using the equivalent stress algorithm. The Paris law and the maximum principal stress criterion are adopted to define the growth rate and direction of the fatigue crack growth, respectively. The constant crack length increment with tangential approach is utilized in all numerical examples. Validations are demonstrated with ABAQUS for the numerical examples with an edge crack under combination of out-of-plane plate bending and in-plane tensile loads.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110997"},"PeriodicalIF":4.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551695","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}
Liangjie Gu , Guo-Qiang Zhu , Shuo Yu , Yangyi Zhou , Yan Zhang , Yao Hu
{"title":"Directional development mechanism of hard rock fracture under true triaxial stress: Insights from macroscopic and microscopic fracture perspectives","authors":"Liangjie Gu , Guo-Qiang Zhu , Shuo Yu , Yangyi Zhou , Yan Zhang , Yao Hu","doi":"10.1016/j.engfracmech.2025.111000","DOIUrl":"10.1016/j.engfracmech.2025.111000","url":null,"abstract":"<div><div>The excavation of hard rocks in deep engineering frequently leads to disasters such as rockbursts, spallings, and collapses. Traditional triaxial tests, which neglect the effect of the intermediate principal stress, fail to reveal the failure mechanism of deep hard rocks. Under true triaxial stress, the intermediate principal stress inhibits volumetric deformation and expansion of rocks, resulting in directional failure. However, the fracture characteristics of hard rocks remain qualitative, lacking a mechanistic explanation. Therefore, based on true triaxial compression tests, complemented by acoustic emission and scanning electron microscopy, the directional development mechanism of hard rock fracture under true triaxial conditions is interpreted from both macroscopic and microscopic fracture perspectives. The macroscopic results show that as the intermediate principal stress increases and the minimum principal stress decreases, the macroscopic failure angle increases, the roughness of the rock failure surface decreases, and the fracture plane becomes increasingly perpendicular to the minimum principal stress, leading to the directional development of fractures. Microscopically, the development of microcracks is suppressed by the intermediate principal stress. As the intermediate principal stress increases and the minimum principal stress decreases, microcracks extend more severely in directions parallel to the intermediate principal stress, reducing intergranular fracture and increasing transcrystalline fracture and the proportion of tensile cracks. The differences in macroscopic deformation and microscopic tensile and shear fractures induced by true triaxial stress reveal the mechanism of directional rock fracture.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 111000"},"PeriodicalIF":4.7,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143578374","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}
Bin Xie , Tianye Yu , Ruizhi Li , Zhongbing Luo , Konstantinos P. Baxevanakis , Ping Zhang
{"title":"Experimentally validated macro-mesoscopic simulation study on the fatigue short crack initiation and propagation in polycrystalline structure utilizing CP-XFEM","authors":"Bin Xie , Tianye Yu , Ruizhi Li , Zhongbing Luo , Konstantinos P. Baxevanakis , Ping Zhang","doi":"10.1016/j.engfracmech.2025.110995","DOIUrl":"10.1016/j.engfracmech.2025.110995","url":null,"abstract":"<div><div>The structural life assessment method based on short crack initiation and propagation is an important approach for predicting the fatigue life of engineering components. In this study, a macro-mesoscopic simulation method for short crack initiation and propagation in polycrystalline structures is developed utilizing the CP-XFEM approach. By incorporating random grain morphology and orientation, the model effectively captures the dispersion in crack initiation and propagation behaviors, including edge cracking, grain boundary cracking, and sub-surface cracking. The simulation uses the total cumulative plastic shear strain as the criterion for crack propagation and adopts the slip plane corresponding to the most active slip system to determine crack direction, accurately reflecting the slip-dominated propagation behavior of short cracks in Ni-based superalloys. The results demonstrate tortuous crack paths and fluctuating propagation rates along the slip direction. Comparison of simulation results with experimental data shows that the model predicts fatigue life with high accuracy, achieving error margins within 16% for verification group specimens. The alignment of life distribution between the test and verification groups further validates the reliability of this simulation approach for fatigue life prediction in engineering applications.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110995"},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551691","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}
Wei He , Mingming Xie , Mengqi Lei , Xing Sun , Lei Huang , Bo Liu , Huimin Xie , Jiaqiang Li , Qihong Fang
{"title":"High-temperature three-point bending fatigue test of laser repaired GH4169 superalloy based on BSL 3D DIC","authors":"Wei He , Mingming Xie , Mengqi Lei , Xing Sun , Lei Huang , Bo Liu , Huimin Xie , Jiaqiang Li , Qihong Fang","doi":"10.1016/j.engfracmech.2025.110968","DOIUrl":"10.1016/j.engfracmech.2025.110968","url":null,"abstract":"<div><div>Laser repair (LR) is an important branch of additive manufacturing and one of the core technologies in strategic emerging industries like equipment remanufacturing. Fatigue failure analysis of LR parts in service is the basis for an in-depth application of LR technology in aerospace, etc. The advanced digital image correlation (DIC) method can provide strong support due to its advantages such as full-field, non-contact, and in-situ deformation measurement. However, the extreme service environments and the non-uniformity of core LR structures bring challenges. This paper investigates the fatigue crack growth behavior of the LR nickel-based superalloy GH4169 at 650 °C using the high-temperature bi-prism-based single-lens (BSL) 3D<!--> <!-->DIC system, which primarily comprises a double telecentric lens, a bi-prism, and a CMOS camera equipped with a narrow bandpass filter. A fatigue-DIC synchronization technique and an automatic crack tip localization algorithm for numerous high-temperature DIC images are developed, which performs well even under crack branching conditions. Experimental results demonstrate that the automatic localization algorithm achieves an error within 5 % and a computational speed within 3 s per image, effectively addressing the aforementioned challenges and improving analysis efficiency. A new parameter named crack opening ratio (COR) is then applied for the crack closure effect characterization. The evolution laws of the<!--> <!-->crack closure effect throughout the whole high-temperature fatigue process for pure substrate, pure deposited, and LR specimens are comparatively analyzed, and the influence of the LR interface on the crack growth behavior is clarified. Furthermore, as one major fatigue crack growth model, Paris’ law is modified by considering the crack closure effect.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"319 ","pages":"Article 110968"},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551692","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}
Chen Wang , Yibo Shang , Liucheng Zhou , Zhenhua Zhao , Xiaosheng Zhang , Lingfeng Wang , Bin Li , Weifeng He , Wei Chen
{"title":"High cycle fatigue limit assessment of foreign object damaged aerofoil blades considering the residual stress induced by impact","authors":"Chen Wang , Yibo Shang , Liucheng Zhou , Zhenhua Zhao , Xiaosheng Zhang , Lingfeng Wang , Bin Li , Weifeng He , Wei Chen","doi":"10.1016/j.engfracmech.2025.110993","DOIUrl":"10.1016/j.engfracmech.2025.110993","url":null,"abstract":"<div><div>Foreign object damage (FOD) is a critical factor that impacts the operational safety of aero-engine fan blades and is both frequent and inevitable. Therefore, it is necessary to develop an accurate high cycle fatigue (HCF) limit prediction model to enhance the reliability of assessment criteria for fan blades after FOD. Notch and residual stress are the key factors affecting HCF performance. In this paper, FOD tests were conducted to obtain notched airfoil blades and tested their HCF limits. Furthermore, the residual and vibration stress near the aerofoil blade notch were obtained by combining numerical simulation and experiments. The evolution of the residual stress was determined so that the actual stress field near the notch was accurately reconstructed, and the location of the dangerous point was obtained then, based on the theory of critical distance (TCD), an HCF limit prediction model was established and compared with the current Peterson and TCD models without considering residual stress. The results show that the TCD model considering residual stress can accurately predict the HCF limit of FOD aerofoil blades, with an error of 9.70 %±8.66 %, which is lower than the Peterson model (19.60 %±17.56 %) and the TCD model without residual stress (16.58 %±11.62 %).</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"318 ","pages":"Article 110993"},"PeriodicalIF":4.7,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143528794","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}