Engineering Failure Analysis最新文献

{"title":"3D X-ray microscopy and mechanical analysis of thermal cycling-induced degradation in solder joints","authors":"Dorottya Varga ,&nbsp;Péter János Szabó ,&nbsp;Attila Szlancsik","doi":"10.1016/j.engfailanal.2025.110102","DOIUrl":"10.1016/j.engfailanal.2025.110102","url":null,"abstract":"<div><div>This study investigates the thermal fatigue behavior of Innolot-soldered chip resistors mounted on printed circuit boards, subjected to accelerated thermal cycling between −40 °C and 125 °C in accordance with the IPC-9701B standard. The degradation of solder joints was analyzed using high-resolution 3D X-ray microscopy at intervals of 500 cycles up to 2500 cycles, complemented by mechanical shear testing and scanning electron microscopy (SEM). Key evaluation metrics included crack length, solder-to-total volume ratio, void diameter, and void compactness. Results showed that crack lengths increased with thermal cycles in some cases across the whole joint, although growth patterns varied across different planes, underscoring the importance of three-dimensional analysis. The solder-to-total volume ratio demonstrated a linear decrease with an initial incubation phase, serving as a robust indicator of joint degradation. Voids became larger and more deformed, with compactness decreasing due to thermal cycling. The peak shear force was significantly reduced in the most degraded component (11.3 N) compared to the other samples (27.7 N and 28.6 N). This can be explained by the highest average crack length, the void growth or with volume loss, however the SEM images revealed another significant factor, which is failure happened in the bulk solder mainly while in the other two cases in the intermetallic layer.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"182 ","pages":"Article 110102"},"PeriodicalIF":5.7,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045007","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":"Experimental and numerical study on flexural behavior of functionally graded UHPFRC-HSC beams","authors":"Ahmed M. Yousef,&nbsp;Nazeeh H. Atef,&nbsp;Ahmed M. Tahwia","doi":"10.1016/j.engfailanal.2025.110108","DOIUrl":"10.1016/j.engfailanal.2025.110108","url":null,"abstract":"<div><div>The flexural behavior of Functionally Graded Reinforced Concrete (FGRC) beams using Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) with High-Strength Concrete (HSC) was investigated experimentally and numerically. Ten simply supported beams were subjected to four-point bending tests, with two varying ratios of longitudinal tensile reinforcement (<em>ρ_l</em>), to represent low and high ratios. The FGRC beams incorporate UHPFRC with a compressive strength of 157.2 MPa and HSC with 76.8 MPa. The UHPFRC layer was strategically placed in either the compression and tension zones or only in the compression zone of the beam. Experimental findings showed that FGRC beams demonstrated comparable ductility and strength to UHPFRC reference beams but at a much lower cost. FGRC beams with layers of UHPFRC on both the upper and lower layers, which make up 40 % of the total beam height, a beam with a high reinforcement ratio (<em>ρ_l</em> = 4.0 %) exhibited ductility of 261.6 % compared to HSC reference beam. It also carried 91.6 % of the flexural capacity of the pure UHPFRC beam. When the layers of UHPFRC accounted for 66.7 % of the beam’s height, the FGRC beams showed a notable increase in ductility, reaching 286.3 % compared to the HSC reference beam, and were able to carry 96.9 % of the load capacity of the UHPFRC beam. Raising <em>ρ_l</em> from 1.38 % to 4.0 % in the tested beams significantly improved flexural strength while maintaining good ductility. Design codes provided conservative flexural strength estimates, while sectional analysis per AFGC-2013, JSCE-2008, and KCI-2012 accurately predicted FGRC beam strength. The proposed numerical model showed a significant alignment with the test results of the simply supported UHPFRC-HSC beams.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"182 ","pages":"Article 110108"},"PeriodicalIF":5.7,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045008","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":"Uprooting collapse mechanism of RC structures in earthquakes","authors":"Eleni Smyrou ,&nbsp;Eren Vuran ,&nbsp;İhsan E. Bal","doi":"10.1016/j.engfailanal.2025.110105","DOIUrl":"10.1016/j.engfailanal.2025.110105","url":null,"abstract":"<div><div>The Kahramanmaraş Earthquake Sequence of February 6, 2023, stands as the deadliest earthquake in Turkey during the era of instrumental seismology. A significant factor in this tragedy is the large building stock of Turkey, comprised of reinforced concrete (RC) buildings, many of which are vulnerable attributing to the widespread destruction. The weaknesses in the Turkish RC building stock have been well-documented, as they have repeatedly manifested in past earthquakes. However, given the progress in seismic codes and hazard maps over the past two decades, greatly advanced because of the 1999 earthquake, the widespread collapse of buildings constructed after 2000 was largely unexpected.</div><div>This paper focuses on a specific type of collapse mechanism repeatedly observed during post-earthquake reconnaissance missions. Termed here as the “uprooting collapse”, this mechanism differs from the more common pancake-style collapses typically seen in substandard Turkish RC buildings. The possible causes behind the uprooting collapse are explored using an actual case study from the earthquake zone, supported by parametric analyses on RC frame buildings designed in accordance with the Turkish Seismic Code. The results indicate that when specific conditions align, such as high velocity demands, flexible load-bearing systems, improper structural member design, and a high height-to-width ratio, a total collapse in an uprooting fashion becomes possible even if construction quality standards and design code requirements are met.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"182 ","pages":"Article 110105"},"PeriodicalIF":5.7,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045113","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":"Measured dynamic load distribution of high-speed train axlebox bearing with spalling-type faults","authors":"Yilei Li ,&nbsp;Yu Hou ,&nbsp;Xi Wang ,&nbsp;Guojie Cai ,&nbsp;Zhixiang Zhao ,&nbsp;Qiang Li","doi":"10.1016/j.engfailanal.2025.110103","DOIUrl":"10.1016/j.engfailanal.2025.110103","url":null,"abstract":"<div><div>Determining the residual safe service life of high-speed train axlebox bearings with spalling faults has become an increasingly critical concern for Chinese railway operators. Crucially, measured dynamic load distributions within bearings exhibiting incipient spalling enable predictive modeling of spall progression and remaining usable life. This study employed a strain-based methodology to quantify internal dynamic load distributions within axlebox bearings with spalling-type faults. By establishing definitive spatiotemporal mappings between strain response characteristics and fault-specific signatures (outer-ring, inner-ring, roller), decoupled identification of all three fault types is achieved. The result of measured dynamic load distribution indicates that outer ring faults induce M-distributed radial loads that amplify adjacent stresses, accelerating spalling propagation. The bearing row with inner ring/roller faults maintain arched distributions but exhibit wider contact load fluctuations than the faultless row, while compound faults manifest hybrid signatures. Besides, compared to the significant impact of bearing misalignment, spalling-type faults exert negligible influence on inter-row load allocation. Position-specific contact load spectra are compiled based on measured roller-raceway contact load histories, providing critical inputs for failure progression models across various bearing fault types.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"182 ","pages":"Article 110103"},"PeriodicalIF":5.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145026734","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":"Failure behavior analysis of the main shaft threaded joint of ultra-deep top drive drilling rig under complex loading conditions","authors":"Haotian Liu ,&nbsp;Bo Wang ,&nbsp;Bin Ding ,&nbsp;Tanmin Zheng ,&nbsp;Chengwei Wen ,&nbsp;Hang Zhang","doi":"10.1016/j.engfailanal.2025.110090","DOIUrl":"10.1016/j.engfailanal.2025.110090","url":null,"abstract":"<div><div>This study aims to address the issues of premature failure and fatigue cracking of ultra-deep top drive main shaft threaded joint under complex and extreme operating conditions. A three-dimensional finite element model of the main shaft threaded joint is developed based on API standards to systematically investigate the stress distribution characteristics under complex combined loads, including make-up torque, axial tension, drilling fluid pressure, and radial disturbance. Fatigue life prediction was then carried out using Fe-safe with multiple multiaxial fatigue models, and the influence of surface roughness and residual stress was quantified. The results indicate that the root of the first thread is a high-risk region for stress concentration and fatigue failure, where the maximum stress reaches 972.6 MPa under the axial load of a 15,000 m drill string. According to the Brown–Miller model, failure occurs after 27,073 cycles. Validity of the simulation predictions is confirmed by representative field failure cases. The findings of this study provide a theoretical basis and engineering reference for fatigue life prediction and reliability design of tapered threaded joints in ultra-deep top drive drilling systems.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"182 ","pages":"Article 110090"},"PeriodicalIF":5.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045111","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":"Interrelationship among wear, debris, and friction-induced stick-slip vibration at high-speed train brake interfaces in humid environments","authors":"Zhaolin Liu ,&nbsp;Suiyue Ma ,&nbsp;Zhanpeng Wang ,&nbsp;Zaiyu Xiang ,&nbsp;Bin Tang ,&nbsp;Xiaocui Wang ,&nbsp;Deqiang He","doi":"10.1016/j.engfailanal.2025.110104","DOIUrl":"10.1016/j.engfailanal.2025.110104","url":null,"abstract":"<div><div>During the friction braking process of high-speed trains, the strong friction between the brake discs and brake pads can cause significant wear on the pads, resulting in a large amount of wear debris that participates in the friction at the braking interface. Particularly in humid environments, the strong friction can induce significant friction-induced stick–slip vibrations (FISSV). Additionally, the humid environment promotes oxidation reactions, leading to the formation of harder wear debris that induces abrasive wear. Both abrasive wear and the impacts of FISSV can cause damage to the braking interface, posing significant challenges to the operational safety of the pads. Therefore, in humid operating environments, it is essential to fully consider the interactions among wear, debris, and vibrations at the braking interface of high-speed trains. However, the relationships among these three factors have not been clearly understood. To address this issue, we designed smooth and grooved discs and conducted simulated tests of FISSV in a humid environment to investigate the damage mechanisms of wear debris and FISSV on the braking interface in such conditions. The results indicate that under humid environments, the wear debris generated at the interface is difficult to compact due to the action of water films, and its oxidation reaction is accelerated. These combined effects hinder the formation of large-area contact plateaus, resulting in lower interface stiffness and inducing high-frequency FISSV. Furthermore, the abrasive wear caused by high-hardness oxidized debris and the impact effects of FISSV further damage contact plateaus, generating more debris. This forms a vicious cycle of interface wear-debris generation-intensified FISSV-aggravated wear. By designing grooves to collect debris, the amount of free-flowing debris at the friction interface is effectively reduced, allowing the load to be borne mainly by the disc and the pad matrix. This forms higher-stiffness contact, significantly suppresses FISSV intensity, alters the wear mechanism, breaks the abrasive wear-dominated vicious cycle, and demonstrates the role of controlling debris behavior in improving the tribological performance of brake interfaces in humid environments.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"182 ","pages":"Article 110104"},"PeriodicalIF":5.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045109","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":"Failure analysis and radial load characteristic study of a magnetic-levitated marine mixed flow pump","authors":"Gong Cheng,&nbsp;Fangxu Sun,&nbsp;Shiyu Fang,&nbsp;Xingyu Wu,&nbsp;Yingsan Wei","doi":"10.1016/j.engfailanal.2025.110079","DOIUrl":"10.1016/j.engfailanal.2025.110079","url":null,"abstract":"<div><div>Marine centrifugal pumps pose significant challenges in maintenance and spare part replacement, making the extension of their maintenance-free operation period and service life a long-standing research objective. The magnetic levitated pump equipped with active magnetic bearings (AMBs) enables a non-contact, wear-free support mechanism while eliminating internal mechanical seals, thereby substantially enhancing maintenance-free operation duration and prolonging service life. Targeting at a novel marine magnetic levitated mixed-flow pump unit, this study investigates a bearing overload failure observed during pre-deployment testing in inclined position. The study attributed the cause to the sharply increased radial load on the pump shaft under part-load conditions based on experimental data analysis. Subsequently, a full-scale Computational Fluid Dynamics (CFD) analysis was conducted to numerically calculate the radial load, and the accuracy of the numerical method was validated with experimental data. Furthermore, by extracting and analyzing the radial forces and flow field distribution characteristics of the primary radial force source—the impeller-diffuser structure—under varying flow rates, the intrinsic mechanism behind the sudden increase in radial forces within the impeller-volute structure under low-flow conditions was elucidated. Finally, the applicability of the similarity law in predicting impeller radial loads at different rotational speeds was numerically and experimentally validated. The findings of this research hold significant implications not only for the design and lifespan optimization of magnetic levitated pump units but also for pumps utilizing conventional mechanical bearings, particularly those deployed in marine environments where non-horizontal installation or operation under tilting and swaying conditions is required.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"182 ","pages":"Article 110079"},"PeriodicalIF":5.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045006","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":"Study on the subzero temperature dynamic fracture behavior of saturated rocks and development of a fracture toughness modified model","authors":"Cuigang Chen ,&nbsp;Zilong Zhou ,&nbsp;Xin Cai ,&nbsp;Jifeng Yuan ,&nbsp;Peiyu Wang ,&nbsp;Fanjunhui Mo ,&nbsp;Chunping Lin","doi":"10.1016/j.engfailanal.2025.110093","DOIUrl":"10.1016/j.engfailanal.2025.110093","url":null,"abstract":"<div><div>Rocks in high-altitude cold regions are subjected to prolonged subzero temperatures and intense diurnal temperature variations, leading to complex fracture behaviors that threaten slope stability and engineering safety. To investigate the dynamic fracture characteristics and underlying microscopic mechanisms of saturated rocks under different freezing conditions, dynamic tests were conducted on marble, granite, and sandstone using a Split Hopkinson Pressure Bar (SHPB) system combined with high-speed photography and digital image correlation (DIC). Scanning electron microscopy (SEM) was used to observe fracture surface morphology at various subzero temperatures. Based on the experimental results, an empirical fracture toughness correction model was proposed, integrating the dual effects of freezing-induced densification and frost heave damage. The results reveal significant lithological differences in fracture responses: the fracture toughness and energy of marble and granite peak near –10 °C and then decrease, while sandstone shows a continuous increase as temperature drops. Crack propagation velocity also exhibits strong temperature dependence, peaking at –10 °C for marble and granite, and rising steadily for sandstone. Subzero temperatures promote roughening and increased frost-induced cracking in marble and granite, especially below –10 °C, while sandstone shows a densification trend with noticeable frost cracking only at –40 °C. The fracture behavior of porous sandstone is mainly governed by pore ice formation, while dense granite and marble are primarily affected by thermal contraction. The proposed model achieves high fitting accuracy across all rock types, effectively capturing the complex evolution of fracture toughness under freezing conditions. This study provides theoretical support for understanding rock fracture in cold-region slopes and contributes to stability evaluation and engineering design.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"182 ","pages":"Article 110093"},"PeriodicalIF":5.7,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045110","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":"Evaluation of the anti-collision performance of reinforced concrete protective wall for railway bridges under high-speed train impact","authors":"Jun Chen ,&nbsp;Biao Wei ,&nbsp;Binqi Xiao ,&nbsp;Mingyu Chen ,&nbsp;Xianglin Zheng ,&nbsp;Zhixing Yang ,&nbsp;Lizhong Jiang","doi":"10.1016/j.engfailanal.2025.110097","DOIUrl":"10.1016/j.engfailanal.2025.110097","url":null,"abstract":"<div><div>With the expansion of railway bridge networks, the exposure of train operations to elevated environments has grown; in such settings, any derailment carries higher consequence severity, underscoring the need to predict post-derailment collision dynamics. This study focuses on a typical Chinese dual-track ballastless railway bridge system and develops a multi-scale dynamic collision model for high-speed trains and reinforced concrete protective wall (RCPW). The model employs a mass-spring-damper system to represent the vehicle’s non-impact dynamics and applies a zoned hybrid approach that integrates fiber-beam and three-dimensional solid elements, thereby enabling accurate RCPW damage simulation while reducing computational time by approximately 70 %. Furthermore, a novel bogie motion plane method is introduced, which analyzes the train’s dynamic behavior from wheel-track board contact failure to collision by computing spatial angles and displacement time histories. An augmented uniform design sampling approach, combined with a Gaussian process surrogate model and Sobol sensitivity analysis, is employed to establish for evaluate the train-RCPW coupling effect. Key findings reveal that (1) lateral train speed (<em>v_x</em>) governs collision patterns—<em>v_x</em> ≤ 2.5 km/h results in an initial collision with the base slab followed by a secondary collision with the RCPW, while <em>v_x</em> ≥ 7.7 km/h leads to a direct collision with the RCPW—and (2) optimizing the yield strength of longitudinal reinforcement is more effective for energy dissipation than increasing concrete compressive strength.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"182 ","pages":"Article 110097"},"PeriodicalIF":5.7,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145026623","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":"Tensile and fatigue behaviors of additively manufactured Ti-6Al-4V: Influence of surface texture and removal","authors":"Nabeel Ahmad ,&nbsp;Behnam Salehnasab ,&nbsp;Erfan Maleki ,&nbsp;Kevin Stonaker ,&nbsp;Cindy Ashforth ,&nbsp;Shuai Shao ,&nbsp;Nima Shamsaei","doi":"10.1016/j.engfailanal.2025.110088","DOIUrl":"10.1016/j.engfailanal.2025.110088","url":null,"abstract":"<div><div>This study examined the influence of four different surface material removal treatments on the tensile and fatigue behaviors of laser powder bed fused Ti-6Al-4V specimens. These treatments included direct polished, shallow machined and polished, deep machined, and deep machined and polished. X-ray computed tomography was used to characterize the surface textures and volumetric defects of each condition, and scanning electron microscopy was used for fractography of all failed specimens. The results showed that tensile ductility and fatigue resistance were strongly influenced by the type of material removal methods. Direct polishing did not improve the tensile ductility nor fatigue lives due to remnant surface valleys. While the combined shallow machined and polished specimens exhibited significant improvement in ductility due to adequate removal of surface anomalies, fatigue lives were only modestly enhanced due to the persistence of surface-connected volumetric defects. However, deep machined and combined deep machined and polished treatments led to considerable improvement in both ductility and fatigue resistance, which was ascribed to complete removal of surface and subsurface defects. In addition, fatigue life was modeled and estimated using a fatigue notch factor approach, which yielded reasonably accurate predictions for the untreated, polished, and shallow machined and polished specimens.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"182 ","pages":"Article 110088"},"PeriodicalIF":5.7,"publicationDate":"2025-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145045114","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}