Engineering Fracture Mechanics最新文献

{"title":"Unveiling the effect of confinement on reinforcement-concrete bond behavior using discrete lattice model","authors":"Xun Liu ,&nbsp;Dawei Gu ,&nbsp;Jinlong Pan ,&nbsp;Mladena Luković","doi":"10.1016/j.engfracmech.2025.111510","DOIUrl":"10.1016/j.engfracmech.2025.111510","url":null,"abstract":"<div><div>Understanding the bond behavior between reinforcement and concrete under varying confinement conditions is essential for the design and performance assessment of reinforced concrete structures. This study employs a discrete lattice model to investigate the reinforcement-concrete bond mechanism, focusing on crack propagation, fracture processes, and stress distribution. Experimental data involving lap-spliced reinforcement bond test under different confinement conditions serve as benchmarks. In the model, concrete, reinforcement, and their interface are discretized into beam elements, while the interface properties remain constant and independent of confinement conditions. A key finding is that generating the lattice mesh through the Delaunay triangulation scheme enables the model to reproduce realistic strut-cracking patterns and conical stress transfer phenomena, thereby capturing stirrup-induced passive confinement effects without modifying interface properties. The results clarify the role of stirrup confinement in restricting concrete dilatancy and bond splitting, while bond failure is shown to depend on concrete fracture under weak confinement and on interface failure only under strong confinement. Overall, this study not only validates the discrete lattice approach for reinforced concrete bond modeling but also provides deeper insights into lap-splice failure mechanisms, offering a robust framework for structural assessment and design.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"328 ","pages":"Article 111510"},"PeriodicalIF":5.3,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921808","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":"Modeling the transition from ductile to brittle fracture induced by hydrogen-assisted mechanical degradation in quenching and partitioning (Q&P) steel","authors":"Geonjin Shin ,&nbsp;Jinheung Park ,&nbsp;Sang Yoon Song ,&nbsp;Kijung Kim ,&nbsp;Hye-Jin Kim ,&nbsp;Seok Su Sohn ,&nbsp;Myoung-Gyu Lee","doi":"10.1016/j.engfracmech.2025.111491","DOIUrl":"10.1016/j.engfracmech.2025.111491","url":null,"abstract":"<div><div>Hydrogen embrittlement (HE) critically threatens the structural integrity of advanced high-strength steels (AHSS), particularly quenching and partitioning (Q&amp;P) steels, due to their high susceptibility to hydrogen-assisted fracture. This study presents a unified fracture modeling framework that quantitatively captures the ductile-to-brittle transition in hydrogen-charged Q&amp;P steel under diverse stress states. The model combines a Hosford–Coulomb (HC) criterion for ductile failure with a hydrogen-sensitive maximum principal stress (MPS) criterion for brittle fracture, each accounting for stress triaxiality and Lode angle effects. The framework is embedded within a finite-strain chemo-mechanical formulation, incorporating stress-assisted hydrogen diffusion, reversible trapping, and lattice dilation, which are systematically implemented via a user-defined element (UEL) subroutine in ABAQUS. Model calibration and validation are performed using slow strain-rate tensile (SSRT) tests across distinct specimen geometries, capturing a broad range of stress states. Fractographic analyses confirm the model’s ability to reproduce experimentally observed transitions from ductile to brittle fracture. The model accurately predicts fracture initiation sites, modes, and hydrogen-concentration-dependent degradation in both monotonic and non-monotonic loading scenarios, including step-load conditions. The unified criterion offers a computationally efficient and mechanistically grounded tool for evaluating hydrogen-assisted fracture in high-strength steels, with direct implications for structural design in hydrogen-exposed environments.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"328 ","pages":"Article 111491"},"PeriodicalIF":5.3,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144989091","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 novel method for obtaining fatigue parameters of rubber materials considering the crack path deviation","authors":"Pengshu Chen,&nbsp;Ziheng Wu,&nbsp;Zicheng Shi,&nbsp;Ziran Li,&nbsp;Yang Wang","doi":"10.1016/j.engfracmech.2025.111517","DOIUrl":"10.1016/j.engfracmech.2025.111517","url":null,"abstract":"<div><div>This study evaluates the formula for calculating the energy release rate of pure shear specimens through theoretical analysis and finite element simulations, revealing its applicability only to crack without path deviation. The classical method based on this formula may not be suitable for obtaining the fatigue parameters of rubber when crack path deviates during fatigue crack growth (FCG) experiments. Thus, a novel method is proposed that uses the J-integral to calculate the energy release rate at different positions along the fatigue crack path. This method can accurately obtain fatigue parameters considering the influence of crack path deviation. In addition, the fatigue parameters from both the classical and novel methods in the FCG experiment were used to predict the rubber’s lifetime in tensile fatigue tests. It was found that the predicted lifetime from the novel method was closer to the experimental result, suggesting that the fatigue parameters derived from this method can accurately characterize the fatigue performance of rubber, even when the crack path deviates.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"328 ","pages":"Article 111517"},"PeriodicalIF":5.3,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144997238","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":"Thermomechanical analysis of ultrasonically welded copper-magnesium sheets with Ni and Zn interlayers","authors":"Zeshan Abbas ,&nbsp;Lun Zhao ,&nbsp;Liya Li ,&nbsp;Ming Li ,&nbsp;He Shengli ,&nbsp;Chenhui Zhang","doi":"10.1016/j.engfracmech.2025.111507","DOIUrl":"10.1016/j.engfracmech.2025.111507","url":null,"abstract":"<div><div>This paper presents a thermo-mechanical analysis of ultrasonically welded Cu-Mg sheets with incorporation of Ni and Zn interlayers. The experimental and simulation methods were employed to investigate the thermal mechanisms during welding process. The analysis reveals the variation in interface temperatures, acoustic softening effects and heat fields related to plastic deformation. The accuracy of simulation model is validated through these findings. Microscopic analysis indicates that after 0.4 sec of welding, Ni interlayer on Mg sheet at the center of joint interface partially melts and forms a liquid phase. The average friction coefficient at the weld interface is approximately 0.5. The maximum temperature at the interface can exceed 600 °C and approach the melting point of welded sheets. Plastic deformation begins after 0.45 sec and occurs mainly at Mg sheet interface. The grain size of Mg alloy at interface in this experiment ranges from 4 to 5 μm which is notably finer than the average grain size of 20 μm observed in base materials. The distribution and intensity of deformation fields provide valuable insights into how the Ni and Zn interlayers influence the mechanical integrity and overall performance of weld. Ni interlayer significantly improves mechanical properties of Cu-Mg welded joints, achieving higher load-bearing capacity (7865 N vs. 3688 N), tensile strength (80.23 MPa to 1821.26 MPa vs. 885.15 MPa to 1318.05 MPa) and fracture resistance (8.23 MPa to 1350.55 MPa vs. 6.20 MPa to 350.48 MPa) compared to Zn interlayer.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"328 ","pages":"Article 111507"},"PeriodicalIF":5.3,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144919984","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":"Spontaneous fracture in shape memory polymers: Temperature-activated and constraint-induced fracture from programming","authors":"Shikun Lin ,&nbsp;Jiefeng Xie ,&nbsp;Jiayang Liu ,&nbsp;Junkai Liang ,&nbsp;Fangyu Chen ,&nbsp;Taolin Sun ,&nbsp;Yuan-Fang Zhang","doi":"10.1016/j.engfracmech.2025.111516","DOIUrl":"10.1016/j.engfracmech.2025.111516","url":null,"abstract":"<div><div>Shape memory polymers (SMPs), distinguished by their unique properties such as variable stiffness and shape memory effect, have exhibited extensive application potential. However, despite the promising applications of SMPs, their viscoelastic fracture behavior and mechanism, particularly under various loading conditions and thermal stimuli, remain insufficiently explored. This study investigates the thermo-activated viscoelastic fracture behavior of SMPs under constrained recovery and the variations in fracture toughness under different loading conditions. Thermally responsive SMPs were fabricated, and pure shear fracture tests were conducted, revealing that fracture toughness decreases significantly with increasing temperature and decreasing loading rate, attributed to reduced viscoelastic dissipation. Notably, spontaneous crack propagation is observed in stretch-programmed SMPs under thermal activation, with higher programmed stretch ratios leading to lower self-rupture temperatures. To explain this phenomenon, a viscoelastic fracture framework is established incorporating temperature-dependent relaxation and recovery strain, validated by experiments and finite element simulations. The proposed energy release rate model accurately predicts critical rupture temperatures, providing a reliable framework for failure prediction in programmable smart materials. This work bridges thermomechanical behavior and fracture mechanics, offering design insights for SMP-based structures in soft robotics and biomedical applications.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"328 ","pages":"Article 111516"},"PeriodicalIF":5.3,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144926458","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":"Channel fracture model and criterion","authors":"Boris Margolin,&nbsp;Alexander Sorokin,&nbsp;Victoria Shvetsova,&nbsp;Eduard Zernov,&nbsp;Natalia Pirogova,&nbsp;Andrey Buchatsky","doi":"10.1016/j.engfracmech.2025.111511","DOIUrl":"10.1016/j.engfracmech.2025.111511","url":null,"abstract":"<div><div>The experimental study results of the deformation and fracture properties are represented for austenitic 18Cr-9Ni steel (analog of AISI 304 steel) irradiated at 400 °C up to damage dose of 15 dpa. The fracture properties are obtained for smooth round bars and notched round bars under uniaxial tension over temperature range from 20 °C up to 500 °C, and the fracture surfaces are examined by SEM to analyze the main fracture mechanisms with emphasis on specific fracture mechanism of irradiated austenitic steels – channel fracture. Fractions of various fracture modes are estimated depending on stress triaxiality and test temperature. It is shown that the channel fracture fraction depends significantly on the stress triaxiality and increases when the stress triaxiality increases. The main features of the channel fracture surface and the channel fracture facets are studied. It is found that the channel fracture surface is characterized by flat shear facets terraced on which the exits of secondary deformation channels are revealed that locate regularly on the distance of 1–2 μm each other. On the basis of the obtained experimental data the channel fracture model is proposed and the channel fracture criterion is formulated for irradiated austenitic steels. Procedure for the criterion parameter determination is developed on the basis of the test results of standard tensile round bar and notched round bar tested at one temperature over the channel fracture temperature range. Numerical values of the criterion parameters are found from the test results obtained. The proposed channel fracture criterion is verified as applied to the irradiated 18Cr-9Ni steel by comparison of the experimental and calculated values of the fracture strain for specimens with various stress triaxialities and for specimens tested at different temperatures.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"328 ","pages":"Article 111511"},"PeriodicalIF":5.3,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144933594","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":"Effect of epoxy grouting-induced interfacial bond strength on the critical loading angle and mixed-mode I-II fracture behavior of fractured sandstone","authors":"Guiquan Liu ,&nbsp;Guoqing Chen ,&nbsp;Qingbo Hu ,&nbsp;Xing Zhu ,&nbsp;Tao Wen ,&nbsp;Nan Jiang","doi":"10.1016/j.engfracmech.2025.111514","DOIUrl":"10.1016/j.engfracmech.2025.111514","url":null,"abstract":"<div><div>Understanding the fracture behavior of grouted fractured rock masses is critical for enhancing structural stability and fracture control. This study investigates the mixed-mode I–II fracture behavior of fractured sandstone grouted with epoxy resin, focusing on the effects of grout strength and loading angle. A theoretical model—termed the Critical Loading Angle Model (C-LAM)—was developed to predict the critical loading angle (<em>β</em>_c) for pure Mode II fracture, incorporating grout–rock interfacial cohesion. Brazilian splitting tests were conducted on center-cracked Brazilian disc (CCBD) specimens grouted with epoxy grout at varying mix proportions. Fracture processes were monitored using acoustic emission and digital image correlation techniques. The results show that both interfacial bond strength and crack inclination modulate the internal stress field and jointly influence the fracture behavior. High-strength grout enhanced interfacial cohesion, forming a reinforced zone that redirected the main crack to bypass the grouted region. In contrast, low-strength grout led to plastic-dominated failure, with crack morphology resembling that of ungrouted specimens. Crack inclination further affected fracture response, with the main crack either bypassing or penetrating the grout depending on the loading angle. The C-LAM model predicts a nonlinear decrease in <em>β</em>_c with increasing interfacial cohesion, indicating an inverse correlation. Crack-type classification based on internal and external monitoring data validated the model’s predictive capability. These findings elucidate the mechanism by which grouting modifies fracture mode transitions and provide a predictive framework for Mode II failure in reinforced rock systems.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"328 ","pages":"Article 111514"},"PeriodicalIF":5.3,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144926777","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":"Development of a thermomechanical model for fracture under monotonic and cyclic loading with enhanced strain accuracy","authors":"A. Cornejo ,&nbsp;B. Alcayde ,&nbsp;S. Jiménez ,&nbsp;L.G. Barbu ,&nbsp;S. Oller","doi":"10.1016/j.engfracmech.2025.111437","DOIUrl":"10.1016/j.engfracmech.2025.111437","url":null,"abstract":"<div><div>Fatigue is a critical issue in many engineering applications, particularly in components subjected to cyclic loading. The complexity of fatigue is further exacerbated by thermal effects, which significantly influence material degradation and failure mechanisms. Addressing the challenge of accurately simulating high cycle fatigue failure under thermomechanical conditions is essential for improving the reliability and safety of structures in thermally aggressive environments.</div><div>In this work, we present a staggered thermomechanical approach, grounded in enhanced accuracy mixed finite elements, coupled with a high cycle fatigue constitutive law. This model is generalized to incorporate thermal effects, enabling a more reliable prediction of fatigue damage in materials subjected to cyclic thermal and mechanical loads. The staggered strategy efficiently decouples the thermal and mechanical fields, improving computational performance without compromising accuracy.</div><div>Furthermore, we make use of an advanced time-stepping strategy, which significantly reduces the overall computational cost by optimizing the progression of the simulation through cycles, especially in regimes where fatigue evolves slowly. This approach allows for a more efficient analysis of long-term fatigue behaviour under varying thermal conditions.</div><div>The proposed method has been validated through multiple examples, demonstrating its effectiveness and precision in predicting fatigue life and crack propagation in thermomechanical environments.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"328 ","pages":"Article 111437"},"PeriodicalIF":5.3,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144926457","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":"Revisiting asphalt mixture cracking Performance: Development of a work of Fracture-Based crack propagation resistance Index from IDEAL-CT","authors":"Yaowen Pei,&nbsp;Hussain U. Bahia,&nbsp;Runhua Zhang,&nbsp;Rui Wang,&nbsp;Ruitao Xie","doi":"10.1016/j.engfracmech.2025.111513","DOIUrl":"10.1016/j.engfracmech.2025.111513","url":null,"abstract":"<div><div>Due to its simplicity and efficiency, the Indirect Tensile Asphalt Cracking Test (IDEAL-CT) has been widely adopted to characterize the cracking performance of asphalt mixtures. However, the Cracking Tolerance Index (CT-Index), a key parameter derived from IDEAL-CT, exhibits critical limitations due to its over-reliance on the slope value at 75 % peak load point in the post-peak stage of the Load-Displacement curve. This over-reliance on a single point slope falls short of effectively accounting for the cumulative cracking propagation resistance, resulting in inconsistencies in evaluating the effects of air voids, and polymer/fiber modifications. To address this limitation, this study includes a proposed Cracking Propagation Resistance Index (CPR-Index), derived from the Work of Fracture versus Displacement curve, to characterize the average cumulative energy required for crack propagation during the post-peak stage. A comprehensive experimental program was conducted on asphalt mixtures with varying design factors to compare the capacity of the CPR-Index and CT-Index parameters, including air voids, polymer and fiber modifications, binder content, recycled asphalt content, and aging conditions. The variability of the two indices was also compared. The following findings can be drawn from the analysis of results: (1) the CPR-Index decreases with increasing air voids, effectively capturing the expected impact of mixture density on cracking resistance; (2) CPR-Index demonstrates superior sensitivity to polymer and fiber modifications, accurately reflecting their roles in improving cracking resistance as validated through the binder cracking test; (3) CPR-Index shows trends consistent with the CT-Index for binder content, RAP/RAS content, and aging conditions; (4) Pearson’s correlation analysis shows a strong relationship (R² = 0.71–0.92) between the CPR-Index and binder fatigue life measured from the binder time sweep test, and; (5) the CPR-Index exhibits better repeatability, with a coefficient of variation about 10 %, thus effectively reducing variation between replicate measurements.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"328 ","pages":"Article 111513"},"PeriodicalIF":5.3,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144916738","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":"Phase-field modeling of flexible piezoelectric composites incorporating interfacial failure","authors":"Shihao Lv ,&nbsp;Xin Li ,&nbsp;Luqiao Qi ,&nbsp;Jian Hua ,&nbsp;Shichao Xing ,&nbsp;Yan Shi ,&nbsp;Takahiro Shimada ,&nbsp;Cun-Fa Gao","doi":"10.1016/j.engfracmech.2025.111512","DOIUrl":"10.1016/j.engfracmech.2025.111512","url":null,"abstract":"<div><div>Within the finite-deformation framework, a unified modeling approach is developed for flexible piezoelectric composites based on the phase-field cohesive zone model (PF-CZM), accounting for both bulk fracture and interfacial failure. Unlike previous studies that primarily address brittle composites under small deformations, this work focuses on stretchable flexible piezoelectric materials exhibiting pronounced geometric and material nonlinearities, which lead to strongly coupled governing equations and increased computational complexity. An interface phase-field parameter is introduced to describe diffuse interfaces, while a crack phase-field parameter governs crack propagation. The model accommodates various cohesive softening laws to simulate interfacial failure and captures the influence of interface strength on overall fracture performance. The numerical framework is implemented in ABAQUS, with a HETVAL subroutine used for the diffuse interface modeling and UEL for fracture simulations. When damage is primarily localized within the matrix, neglecting the interface effects significantly reduces computational cost without compromising accuracy. In cases involving interfacial failure, the model effectively investigates the role of interface strength in crack propagation and fracture characteristics. Numerical results demonstrate the effects of interface strength, applied electric fields, and inclusion size on fracture behavior. Higher interface strength enhances peak load capacity and resistance to failure, with weaker interfaces favoring interfacial cracking and stronger interfaces promoting matrix cracking. Furthermore, in flexible piezoelectric materials bonded to soft substrates, interfacial debonding may be triggered by applied electric fields, a phenomenon supported by both numerical simulation and experimental observation.</div></div>","PeriodicalId":11576,"journal":{"name":"Engineering Fracture Mechanics","volume":"328 ","pages":"Article 111512"},"PeriodicalIF":5.3,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144933168","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}