Engineering Failure Analysis最新文献

{"title":"Ballast failures restored and detecting methodology for lateral resistance of ballast bed during dynamic stabilization","authors":"Zhihai Zhang ,&nbsp;Hong Xiao ,&nbsp;Chaozhi Ma ,&nbsp;Fengzhuang Tong ,&nbsp;Dong Ding ,&nbsp;Jianguo Li","doi":"10.1016/j.engfailanal.2025.109665","DOIUrl":"10.1016/j.engfailanal.2025.109665","url":null,"abstract":"<div><div>Stabilization can effectively restore the bearing capacity and lateral deformation resistance of the failed ballast bed. However, unreasonable operating modes can also affect the lateral stability of the ballast bed and the status of the line. To improve the quality of stabilizing operations and save the construction cost of new railways, the paper established a stabilizing machine-ballasted track model based on the DEM-MFBD algorithm, and carefully analyzed the contact separation, reorganization and migration characteristics of ballast particles during the stabilizing. The microscopic movement mechanism of ballast particles is revealed. Based on the mapping relationship between the PSD of the lateral vibration characteristics of the stabilizing machine and the ballast bed resistance, a new method for detecting the lateral resistance of the ballast is proposed. This detection method realizes the rapid acquisition and data transmission of the ballast bed status, and uses a stabilizing machine as the force source, without the need to add a reaction force device. Therefore, it is more efficient than traditional detection methods. Finally, a multi-point track panel lateral resistance index is proposed, the stabilizing operation effect is evaluated, and the optimal operation mode is given. The results show that the effects of the front and rear stabilizers on the ballast bed should be considered during on-site stabilization, and the operating frequency of the first stabilizer should be appropriately reduced to increase the number of contacts between ballast particles and improve the stability of the ballast bed after the stabilization. The new method for detecting the lateral resistance of the ballast bed can be used to easily obtain the mechanical state of the ballast bed before and after stabilizing operation under different line conditions. More stabilization times does not necessarily mean better results. This study provides effective guidance for improving the performance ballast bed and adjusting the alignment of ballasted track on newly built railways.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"176 ","pages":"Article 109665"},"PeriodicalIF":4.4,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143899948","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":"Macro-modeling of CFRP strengthening in U-shaped masonry walls under combined vertical and out-of-plane loads","authors":"Fahimeh Yavartanoo ,&nbsp;Chang-Soo Kim ,&nbsp;Damon Bolhassani ,&nbsp;Thomas H.-K. Kang","doi":"10.1016/j.engfailanal.2025.109664","DOIUrl":"10.1016/j.engfailanal.2025.109664","url":null,"abstract":"<div><div>Unreinforced masonry (URM) structures are a critical component of architectural heritage and remain widely used in residential buildings, particularly in developing regions. However, their vulnerability to seismic events necessitates effective retrofitting techniques to improve structural performance. Among various retrofitting methods, fiber-reinforced polymer (FRP) materials, particularly carbon-FRP (CFRP), have shown significant promise in enhancing the strength and ductility of masonry walls. While extensive research has been conducted on the retrofitting of rectangular URM walls, studies addressing the retrofitting performance of U-shaped walls under out-of-plane loading remain comparatively limited, despite their frequent occurrence in practice. Additionally, while vertical loads are known to influence structural behavior, their specific effects on the response of CFRP-retrofitted URM walls require further investigation. This paper presents a comprehensive numerical study investigating the out-of-plane behavior of U-shaped URM walls retrofitted with CFRP strips. A macro-modeling approach with nonlinear homogenized materials using the finite element method is employed to simulate different retrofit configurations, including horizontal, vertical, square mesh, diagonal strips, and fully covered wall faces. The effects of one-side versus both-side attachment, CFRP thickness, and varying vertical loads are also examined to identify optimal retrofitting strategies. Through a systematic evaluation of these variables, this study aims to provide deeper insights into their impact on ultimate wall strength while identifying cost-effective retrofitting solutions. To achieve this, a new parameter is introduced to quantitatively assess the cost-effectiveness of each retrofitting case. The results demonstrate that CFRP retrofitting significantly enhances the out-of-plane strength and overall structural response, with vertical load playing a critical role in modifying strength enhancement. Among the various configurations, the grid layout with extended horizontal strips attached to the side walls was found to provide the highest strength ratio while maintaining a favorable cost-effectiveness balance, making it the most efficient retrofitting strategy. The findings offer valuable insights into the design and application of CFRP-based retrofitting techniques, contributing to advancing knowledge in masonry strengthening and providing engineers and practitioners with data-driven guidance for selecting optimal retrofit strategies.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"177 ","pages":"Article 109664"},"PeriodicalIF":4.4,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143912116","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":"Microstructural evolution and mechanical behavior of TA5 titanium alloy joint in low-temperature friction stir welding with various cooling rates","authors":"Yu Su ,&nbsp;Mengran Zhou ,&nbsp;Wenya Li ,&nbsp;Xiawei Yang ,&nbsp;Qingyu Shi ,&nbsp;Yangyu Xiong ,&nbsp;Pengcheng Wang ,&nbsp;Gaoqiang Chen","doi":"10.1016/j.engfailanal.2025.109667","DOIUrl":"10.1016/j.engfailanal.2025.109667","url":null,"abstract":"<div><div>This study investigates the effects of cooling methods and welding parameters on the microstructural evolution and mechanical properties of TA5 titanium alloy joints fabricated via low-temperature friction stir welding (FSW) with forced cooling. The proposed technique reduces heat input by applying forced cooling to the weld surface, thereby promoting high-quality joint formation under controlled thermal conditions. The results show that forced cooling minimizes grain growth and reduces joint oxidation by lowering peak welding temperatures. Specifically, the application of forced cooling, particularly liquid nitrogen cooling (LNC), enhances grain refinement within the stir zone (SZ), leading to significant improvements in tensile strength, hardness, and impact toughness. Microstructural analysis reveals that the SZ undergoes dynamic recrystallization, producing fine α-phase grains, while the heat-affected zone (HAZ) exhibits partial grain coarsening. Additionally, forced cooling mitigates the temperature gradient along the joint thickness direction, thereby reducing microstructural inhomogeneity. A comprehensive analysis of the welding parameters demonstrates that excessive heat input at high rotation speeds can cause grain coarsening, which negatively impacts the joint’s impact toughness. The optimal welding parameters (900 rpm–50 mm/min) under LNC conditions yield the best mechanical properties, with superior joint strength and toughness. These findings provide valuable insights into optimizing FSW for titanium alloys, enhancing their industrial applicability in demanding environments.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"176 ","pages":"Article 109667"},"PeriodicalIF":4.4,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902241","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 fractographic study of fatigue failures in combat aircraft trailing edge flap hinge lug bores in both test and service assets","authors":"Ben Main ,&nbsp;Simon Barter ,&nbsp;Ingrid Kongshavn ,&nbsp;Ricardo Filipe do Rosario ,&nbsp;Jason Rogers ,&nbsp;Mirco Figliolino","doi":"10.1016/j.engfailanal.2025.109668","DOIUrl":"10.1016/j.engfailanal.2025.109668","url":null,"abstract":"<div><div>This paper presents an overview and comparison of two fractography investigations of cracking in combat aircraft trailing edge flap hinge lug bores. One, a retired service asset and the second, a full-scale durability test article in a fleet repaired configuration. Since these hinge lugs are a primary structure with the potential for fatigue failure to lead to flap separation from the wing in-flight, a detailed understanding of the root cause, crack morphology and growth were required to manage these structures in-service.</div><div>The root cause of fatigue crack nucleation and growth in the service assets was found to be corrosion whilst in the full-scale durability test it was mechanical damage or fretting associated with the application of the fleet representative bushing repair scheme. The implications of each root cause were examined along with the crack morphologies, and proposals for in-service inspection and the prevention or the delay of damage formation are discussed.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"176 ","pages":"Article 109668"},"PeriodicalIF":4.4,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143902240","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 numerical simulation method for fragments distribution of concrete subjected to blast loading","authors":"Shuai Yang ,&nbsp;Zengyou Liang ,&nbsp;Xiangzhao Xu ,&nbsp;Jianguo Ning","doi":"10.1016/j.engfailanal.2025.109606","DOIUrl":"10.1016/j.engfailanal.2025.109606","url":null,"abstract":"<div><div>Concrete is widely employed in the construction of buildings and critical infrastructure, however, such structures are highly vulnerable to blast loads during their service. The concrete structures undergo fracture and fragmentation failure when subjected to blast loading, the resulting secondary concrete fragments possess substantial kinetic energy and destructive potential, capable of inflicting significant collateral damage to personnel and equipment within the affected area. This study focuses on high-energy secondary fragments generated under blast loading, a numerical investigation is conducted using the LS-DYNA simulation software, the high explosive model, air medium model, and concrete Karagozian&amp;Case (KC) material model are integrated with the Arbitrary Lagrangian–Eulerian (ALE) method to simulate concrete fragmentation behavior under multiple blast scenarios. The fragmentation morphology is characterized for both lateral and top detonation, furthermore, a specialized analysis plugin is developed through secondary programming to complete the identification and data output for concrete fragments across various particle sizes. The effective extraction and quantitative statistics methods for fragmentation parameters information are proposed, moreover, the accuracy of the present numerical simulation method is verified with the comparative of the experimental and theoretical results. Parametric analysis are performed to investigate the influence of concrete strength grade and charge mass on fragmentation behavior, the quantitative distribution and percentage composition of secondary fragments are determined in different particle size ranges. The identification statistical program and fragmentation information extraction method developed in this study can solve the problems for quantitative prediction on concrete fragmentation behavior, which are meaningful for the damage assessment and mining engineering.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"176 ","pages":"Article 109606"},"PeriodicalIF":4.4,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143891362","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":"Root cause failure analysis of 320 MW steam turbine: Visual, metallurgical, and mechanical approach","authors":"Mostafa Soltanloo ,&nbsp;Mohammad Hossein Babaee ,&nbsp;Mohammad Porhonar ,&nbsp;Yazdan Shajari ,&nbsp;Zahra-Sadat Seyedraoufi ,&nbsp;Mohammad Reza Jahangiri","doi":"10.1016/j.engfailanal.2025.109670","DOIUrl":"10.1016/j.engfailanal.2025.109670","url":null,"abstract":"<div><div>The 320 MW turbine with a regular rotation speed of 3000 rpm experienced a failure after an overhaul. Four months after installing new blades, it was found that one of the moving blades was completely fragmented and several others were misaligned. The moving blade was connected to the rotor through dowel pins and three drilled holes via the shrink fit method. For microstructural studies, both intact and failed samples were undergone macro and microstructural studies by visual evaluation, Optical Microscope (OM), Field Emission Scanning Electron Microscope (FESEM), and X-ray Spectroscopy (EDS). Also, strain distribution analysis was carried out by modeling to study the failure. In order to evaluate the mechanical properties, the hardness test of the pins and Curtis wheel blades were carried out as well as the impact test. Stress Corrosion Cracking (SCC) mechanism was dominant failure cause of the pin. The broken pieces of the pin vibrated inside the blade and caused severe wear. Oscillatory wear provoked fatigue cracks on the blades. Therefore, fatigue cracks formed and grew, and subsequently, fracture occurred on the surface blade. As a result, the chain reaction of failure began with SCC in pin and subsequently led to pin fracture, fretting caused by the pin on the blade, fatigue cracking on the blade, and complete failure of the blade. Besides, the fragmented parts of the blade shattered and caused damage to the rotor.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"177 ","pages":"Article 109670"},"PeriodicalIF":4.4,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143931969","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":"Nonlinear characteristics analysis of encased differential gear train containing tooth crack fault","authors":"Jingjing Wang ,&nbsp;Dan Wang ,&nbsp;Chunlei Wang ,&nbsp;Rupeng Zhu","doi":"10.1016/j.engfailanal.2025.109659","DOIUrl":"10.1016/j.engfailanal.2025.109659","url":null,"abstract":"<div><div>The encased differential gear train features a high speed-ratio and a compact structure, enabling coaxial reverse rotation of twin rotors. However, gear cracks can reduce stability and may lead to safety incidents. Additionally, nonlinear factors complicate vibration responses, posing challenges for fault diagnosis. Therefore, investigating the nonlinear behavior and stability of the cracked system is crucial and significant. The dynamic model of the encased differential gear train is proposed and validated through an experiment, considering nonlinear factors involving time-varying mesh stiffness, tooth backlash, and comprehensive transmission error. Responses of sun gears in both stages, under healthy and cracked conditions, are analyzed using bifurcation diagrams, phase diagrams, Poincaré diagrams, time series, and FFT spectra at different input speeds. Results show that the system exhibits chaotic, quasi-3-periodic, and 3 T-periodic motions with varying speeds under healthy conditions. Impacts of crack on system responses vary with input speeds, and stable motion rather than chaotic is preferable for fault diagnosis. Crack propagation destabilizes the system. Moreover, the differential stage is more sensitive to the encased-stage crack than the encased stage itself. The influence of transverse stiffness of the intermediate shaft on the system stability is also examined, indicating that the system becomes more stable with increased stiffness under both normal and fault conditions. Notably, with a 50 % increase in stiffness, the sun gear in the differential stage becomes stable under fault conditions. This study investigates crack-induced responses in this single-input, dual-output planetary gear train, providing valuable insights for mechanical design from the perspective of reliability and fault diagnosis in multi-stage gear systems.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"177 ","pages":"Article 109659"},"PeriodicalIF":4.4,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143903429","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 dislocation density on the fracture behavior of pipeline steel after plastic deformation damage","authors":"Nan Wang ,&nbsp;Chao Wang ,&nbsp;Xianrong Liu ,&nbsp;Yongnan Chen ,&nbsp;Gang Wu ,&nbsp;Lixia Zhu ,&nbsp;Jinheng Luo","doi":"10.1016/j.engfailanal.2025.109663","DOIUrl":"10.1016/j.engfailanal.2025.109663","url":null,"abstract":"<div><div>Plastic deformation damage is one of the key factors affecting the safety of pipeline steel in service. In this paper, the fracture behavior of steels after plastic damage is revealed, as well as the mechanism of action between dislocation motion and micro-voids growth is clarified. It shows that the fracture mechanisms of steels are related to the dislocation density after plastic damage. When the dislocation density of steel is low (1.75 <span><math><mo>×</mo></math></span> 10¹¹ ∼ 3.98 <span><math><mo>×</mo></math></span> 10¹³ m⁻²), it provides favorable conditions for the dislocation movement at plastic zone, and promotes intergrowth between neighboring microvoids. As the dislocation density increases to 1.29 <span><math><mo>×</mo></math></span> 10¹⁴ ∼ 2.72 <span><math><mo>×</mo></math></span> 10¹⁴ m⁻², it inhibits growth and coalescence between neighboring voids due to the lack of movable dislocations at plastic zone, which is not conductive to crack blunting by dislocation slip. The crack tip is connected to the micro-voids by cleavage planes, and the main crack will grow along the interface through the micro-voids in a relatively flat path, accelerating the fracture of pipeline steels. This work will contribute to better understand the failure mechanisms of steel materials and provide a new idea for the protection after plastic deformation damage.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"177 ","pages":"Article 109663"},"PeriodicalIF":4.4,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143903430","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":"Investigation of mechanical characteristics of decay-like degraded FRP rods and residual life prediction","authors":"Shuqi Liu ,&nbsp;Te Li ,&nbsp;Zhou Zuo ,&nbsp;Ruixiang Tao ,&nbsp;Ting Lei ,&nbsp;Qian Wang ,&nbsp;Chao Wu ,&nbsp;Xidong Liang","doi":"10.1016/j.engfailanal.2025.109657","DOIUrl":"10.1016/j.engfailanal.2025.109657","url":null,"abstract":"<div><div>Decay-like fracture accidents have posed significant threats to the safe operation of the power transmission lines, and the time interval between the intermediate stage of decay-like degradation and final fracture remains challenging to predict. The present work investigated the residual mechanical strengths of several 500 kV composite insulators that exhibited decay-like degradation, and their degradation extent was quantified by analyzing the cross-sectional degradation areas of the fiber reinforced polymer (FRP) core rods using parallel light illumination method. A clear negative correlation was observed between the cross-sectional decay-like degradation areas and the residual mechanical strengths. Moreover, visual examination and microscopic observation of the fracture spots were conducted, and the fracture modes of different samples were classified as either decay-like fractures or splitting fractures. The macroscopic and microscopic morphologies of the fracture spot of individual sample reflected its unique fracture cause (pure mechanical fracture or stress corrosion fracture), which is directly related to the mechanical strength exhibited by the sample. Additionally, acoustic emission (AE) technique was employed during the tensile fracture test, and the signals were categorized via clustering algorithm. Finally, the correlation between the farthest heating location and the residual mechanical strength was analyzed. It was proposed that a farthest heating location exceeding the 4th large shed can significantly increase the risk of fracture for the in-service decay-like degraded composite insulators.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"176 ","pages":"Article 109657"},"PeriodicalIF":4.4,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143894760","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":"Vibration fatigue failure analysis and life prediction of high-speed turnout point rails","authors":"Gao Yuan,&nbsp;Wang Shuguo,&nbsp;Yi Qiang","doi":"10.1016/j.engfailanal.2025.109658","DOIUrl":"10.1016/j.engfailanal.2025.109658","url":null,"abstract":"<div><div>The degradation of rails web and rail foot, stemming from the propagation of cracks within the regions not directly impacted by contact stress from wheel-rail contact of turnout, has manifested as a typical fatigue in the railway infrastructure. Owing to the uncertainty regarding the main contributing factors and inadequate maintenance strategies, a comprehensive failure analysis and accurate life prediction are of pressing necessity. In this study, a novel transient wheel-rail rolling contact model incorporating explicit integration algorithms to investigate dynamic interactions in high-speed railway turnouts with pre-existing cracks is established. The model captures the temporal evolution of vertical and tangential contact force on crack surfaces within non-contact material zones of point rails during impact. Through integration of rain flow counting methodology and cumulative damage theory, the study predicts fatigue life while simultaneously observing microscopic crack propagation characteristics, the prediction of fatigue life is consistent with experiment results, the analytical results demonstrate significant speed-dependent interactions: increasing operational velocities amplify mutual constraint effects between crack surfaces, which will intensify contact forces and stress intensity factors (K_I/K_II) while reducing K_III, accelerating fatigue life degradation and driving dual-phase transgranular/intergranular crack propagation in rail substrates.</div></div>","PeriodicalId":11677,"journal":{"name":"Engineering Failure Analysis","volume":"176 ","pages":"Article 109658"},"PeriodicalIF":4.4,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143891456","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}