Archives of Civil and Mechanical Engineering最新文献

{"title":"Nonlinear dynamical analyses of complex-profiled plates with nanostructured ferroelectromagnetic face sheets subjected to magneto-electro-thermo-elastic coupling","authors":"Ngo Hai Minh,&nbsp;Nguyen Cong Tan,&nbsp;Nguyen Manh Dzung,&nbsp;Manh Cuong Nguyen,&nbsp;Dinh Gia Ninh","doi":"10.1007/s43452-025-01141-6","DOIUrl":"10.1007/s43452-025-01141-6","url":null,"abstract":"<div><p>This paper presents an analysis of the free vibration and nonlinear dynamic response of a complex-profiled nanocomposite plate (CPNP), akin to a car door plate. The materials utilized in this study comprise a core composed of carbon nanotube-reinforced nanocomposite (CNTRC), integrated with two face sheets made of magneto-electro-elastic materials <span>({text{BaTiO}}_{3}-text{ Co}{text{Fe}}_{2}{text{O}}_{4})</span>. Four different types of carbon nanotube (CNT) distributions are considered for the core layer, while <span>({text{BaTiO}}_{3}-text{ Co}{text{Fe}}_{2}{text{O}}_{4})</span> is incorporated in each face sheet, with a volume fraction set to 0.5. The distribution of reinforcements throughout the plate's thickness is assumed to be uniform and functionally graded. The plate features a rectangular shape with one edge that varies according to a mathematical function, such as a linear, exponential, or sinusoidal profile. Equations of motion, incorporating geometric nonlinearities defined by von Karman–Donnell and applying Galerkin’s method, are derived to obtain the dynamic and chaotic characteristics of the complex structure. The results obtained are validated against previous documents and finite element methods (FEM) to confirm the accuracy and reliability of the calculation method presented in this paper. The influence of material and geometrical parameters, as well as electro-thermo-magneto fields, are scrutinized within this study. The outcomes presented in this paper hold promise for applications in the aerospace, automobile, and mechanical industries.</p></div>","PeriodicalId":55474,"journal":{"name":"Archives of Civil and Mechanical Engineering","volume":"25 3","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143698555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-term bond performance of fiber-reinforced polymer (FRP) bars to concrete in marine environments: a comprehensive review","authors":"Yi-xin Zhang,&nbsp;Kun-yu Hu,&nbsp;Jun-jie Zeng,&nbsp;Wei Hou","doi":"10.1007/s43452-025-01162-1","DOIUrl":"10.1007/s43452-025-01162-1","url":null,"abstract":"<div><p>Fiber-reinforced polymer (FRP) bars, which possess advantages such as lightweight, high strength, and corrosion resistance, have become increasingly popular as replacements for steel reinforcement in reinforced concrete (RC) structures, particularly in harsh marine environments. The long-term durability of bond of FRP bars to concrete is critical for FRP-RC members to be widely used under marine environments. This review comprehensively examines the existing studies on the bond performance between FRP bars and concrete across various marine environments and explores long-term degradation mechanisms of the interfaces. The hydrolysis of external resin and infiltration of corrosive ions into internal fibers are key factors influencing the durability of FRP bars. From a multiscale perspective, we emphasize the impact of moisture absorption and surface characteristics on the bond durability of FRP bars, particularly under fully submerged conditions. Deep-ribbed FRP bars initially possess higher bond strength owing to enhanced mechanical anchorage with concrete from greater rib height. However, these bars experience a more significant reduction in bond strength compared to shallow-ribbed and sand-coated types as the sand layer falls away from the bar. Prolonged exposure shifts damage mode from the bar–concrete interface to shear failure within the fiber–resin interface.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":55474,"journal":{"name":"Archives of Civil and Mechanical Engineering","volume":"25 3","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143676236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of nickel content on the structure parameters and magnetic properties of austenitic ductile iron castings","authors":"Magdalena Bork,&nbsp;Robert Chulist,&nbsp;Marcin Górny,&nbsp;Maciej Kowalczyk,&nbsp;Jan Marosz","doi":"10.1007/s43452-025-01173-y","DOIUrl":"10.1007/s43452-025-01173-y","url":null,"abstract":"<div><p>Ductile austenitic cast irons are a series of cast irons, which typically contain nickel in the range of 18–36% weight. Its addition in an amount higher than 18 wt% allows the austenitic metallic matrix to be obtained in castings. Consequently, the material has relatively good mechanical properties with elongation exceeding 40% and can operate in a wide temperature range from 77 to 1123 K. Despite its wide range of excellent mechanical properties and corrosion resistance, the important area of magnetic properties of austenitic ductile iron is still largely unknown. Therefore, the main aim of this study was to show the role of nickel and chromium content in shaping the magnetic properties and correlate it with the structural and microstructural features such as chemical order, lattice parameters distribution of graphite nodules and primary austenitic dendrite structure including the microsegregation process. In this context, austenitic ductile iron with the addition of 21, 25, 28, and 35 wt% of nickel with and without the addition of chromium at the level of 2.5 wt% was investigated. Material characterization was carried out utilizing optical and scanning electron microscopy, including electron backscatter diffraction, high-energy synchrotron X-ray radiation, and magnetic properties using vibrating sample magnetometer (VSM). The investigation of the magnetic properties revealed that the nickel content strongly influences the magnetic characteristic of the analysed ductile cast iron, contributing to a better understanding of its potential uses in various industrial applications.</p></div>","PeriodicalId":55474,"journal":{"name":"Archives of Civil and Mechanical Engineering","volume":"25 3","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143676426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parameter optimisation and performance analysis of tuned mass negative stiffness inerter dampers for vibration isolation systems","authors":"Yu-ji Tai,&nbsp;Liang-kun Liu,&nbsp;Ya-feng Li,&nbsp;Hai-ying Bao,&nbsp;Shi-long Wang","doi":"10.1007/s43452-025-01171-0","DOIUrl":"10.1007/s43452-025-01171-0","url":null,"abstract":"<div><p>A novel vibration isolator, the tuned mass negative stiffness inerter damper (TMNID), is constructed by adding a negative stiffness element to a tuned mass damper inerter to further enhance the vibration isolation performance of existing vibration isolators. The transmissibility of a single-degree-of-freedom system (SDOF) with a TMNID and the parameter range of negative stiffness are derived. Based on the <i>H</i>_<i>∞</i> and <i>H</i>₂ norms, the analytical solutions of the optimal parameters of the TMNID are derived. The parameter variation rule and sensitivity of the TMNID are analysed. Enhancing the inertance-mass ratio, mass ratio or decreasing the negative stiffness ratio can raise the optimal parameters, and decreasing the negative stiffness ratio can improve the isolation performance of the TMNID system. The maximum transmissibility of the TMNID system is most sensitive to the stiffness ratio, while the performance measure is highly dependent on the negative stiffness ratio and inertance-mass ratio. Finally, the isolation control effect of TMNID for base excitations is evaluated using a SDOF and an isolated building as examples. For the same inertance-mass ratio, the isolation control effect of TMNID is better than that of TID, TVMD and TMDI, and its effect enhances as inertance-mass ratio increases or the negative stiffness ratio decreases, which is attributed to negative stiffness effect increasing the energy dissipation of TMNID and reducing the natural frequency of the controlled system.</p></div>","PeriodicalId":55474,"journal":{"name":"Archives of Civil and Mechanical Engineering","volume":"25 3","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143676447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 on the mechanism of improving the forming quality of cavitation water jet micro-punching by using a rubber membrane","authors":"Fuzhu Li,&nbsp;Wei Meng,&nbsp;Stefano Mori,&nbsp;Yun Wang,&nbsp;Chunju Wang,&nbsp;Yuqin Guo","doi":"10.1007/s43452-025-01174-x","DOIUrl":"10.1007/s43452-025-01174-x","url":null,"abstract":"<div><p>Cavitation water jet micro-punching (CWJP) is a high-strain-rate micro-punching technique that utilizes high-energy shock waves generated by the collapse of cavitation bubbles to perform micro-punching on metal foils. However, defects such as brittle fracture, warpage deformation, and edge tearing often occur in the micro-punched holes due to the reverse impact of high-speed backflow. To solve this issue, a novel rubber membrane-assisted cavitation water jet micro-punching (RA-CWJP) technique was proposed in the present work, in which a flexible rubber membrane was introduced as a soft punch to prevent cavitation water jet from entering the die hole. Comparative experiments of the CWJP and RA-CWJP processes were conducted on 50 μm-thick T2 copper foils. The forming quality of micro-punched holes in both processes was evaluated based on microscopic morphology (fracture surface and cross section), shape, and dimensional accuracy. Additionally, the effect of high-speed backflow on the CWJP process was analyzed in detail. Fluid–solid coupling numerical simulations were conducted to better understand the improvement mechanism of the rubber membrane on the forming quality of micro-punched holes. The research results show that applying a 200 μm-thick rubber membrane to the CWJP process prevents brittle fractures, warpage, and edge tearing caused by the reverse impact force of backflow. Meanwhile, the rubber membrane also increases the depth of the shearing zone, and reduces both the rollover zone and burr formation. Compared to the CWJP process, the shape and dimensional accuracy of micro-punched holes formed by the RA-CWJP process increased by 16.1%–63.5% and 45.4%–82.2%, respectively. In the RA-CWJP process, the excellent fluidity and compressibility of the rubber membrane enable precise shearing separation of the copper foil along the die edge. Furthermore, the rubber membrane reduces elastic recovery after punching through enhanced plastic deformation, significantly improving the dimensional accuracy.</p></div>","PeriodicalId":55474,"journal":{"name":"Archives of Civil and Mechanical Engineering","volume":"25 3","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143676384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coupling effect of short-fiber kind and matrix strength on uniaxial tensile behavior of textile-reinforced high-ductility concrete (TRHDC)","authors":"Zhiyan Wu,&nbsp;Mingke Deng,&nbsp;Zhengtao Qiu,&nbsp;Tong Li,&nbsp;Zhifang Dong","doi":"10.1007/s43452-025-01169-8","DOIUrl":"10.1007/s43452-025-01169-8","url":null,"abstract":"<div><p>To improve the textile strength utilization and the tensile performance of textile-reinforced composite (TRC), high-ductility concrete (HDC) was employed as a substitute for conventional concrete, resulting in the development of textile-reinforced high-ductility concrete (TRHDC). This study investigated the tensile behavior of TRHDC produced with two short fibers and three matrices. The effects of matrix strength on TRHDC incorporating polyvinyl alcohol (PVA) and polyethylene (PE) fibers were compared in terms of crack pattern, tensile stress–strain curve, tensile strength, and strain energy. TRC specimens were fabricated to examine the differences in tensile behavior between TRC and TRHDC. Experimental results showed that TRHDC exhibited a preferred multiple-cracking pattern and better tensile performance compared to TRC. Short PE fibers were more pronounced in improving tensile behavior than PVA fibers. Matrix strength influenced the tensile behavior of TRHDC differently depending on whether PVA or PE fibers were added. For TRHDC incorporating short PVA fibers, tensile strength and strain energy decreased with matrix strength, whereas the opposite trend was observed for TRHDC incorporating PE fibers. Finally, calculation models for predicting the tensile strength of TRHDC incorporating PVA or PE fibers were established, considering the effects of textile reinforcing ratio and matrix strength.</p></div>","PeriodicalId":55474,"journal":{"name":"Archives of Civil and Mechanical Engineering","volume":"25 3","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143655370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of novel 3D shear thickening fluid reinforcements in the mechanical behavior of hybrid composites under impact loading","authors":"Telmo R. M. Fernandes,&nbsp;Gabriel F. Serra,&nbsp;R. J. Alves de Sousa,&nbsp;Fábio A. O. Fernandes","doi":"10.1007/s43452-025-01166-x","DOIUrl":"10.1007/s43452-025-01166-x","url":null,"abstract":"<div><p>Cork composites and shear thickening fluids (STFs) have been investigated for applications from ballistic protection to personal protective equipment. Cork-STF structures have also been developed, mainly based on cork-layered structures interfacially reinforced with STF. The STF interface improves impact mitigation, but usually marginally. This work explores the effect of 3D STF reinforcements in cork-based hybrid composites for enhanced impact mitigation. The composite structures consist of adhesively bound cork composite layers containing an STF reinforcement. The variables were the STF reinforcement’s depth, area, and shape (circular and hexagonal). The samples were subjected to 10 J impacts. The impact force reduction obtained with the 3D STF structures was significant. This was verified even for 2 mm-thick STF reinforcements, achieving an average reduction of 20.3% compared to neat cork. The 30 mm cylindrical reinforcement with a 5 mm depth achieved the highest impact force reduction of 59.7%. The hexagonal-shaped reinforcement with a 16.5 mm side length achieved a 57.5% impact force reduction for the same area. Another finding was the 25% optimum ratio between reinforcement depth and sample thickness. Although higher ratios imply higher STF volume, the optimum threshold was 25%. Overall, 3D STF reinforcement in composite structures demonstrates excellent potential for protective structures.</p><h3>Graphical abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":55474,"journal":{"name":"Archives of Civil and Mechanical Engineering","volume":"25 3","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s43452-025-01166-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143645382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface generation and grinding forces in ultra-small-grinding (USG) of single-crystal silicon with different crystal orientations","authors":"Kefeng Song,&nbsp;Jun Cheng,&nbsp;Zhaozhi Guo,&nbsp;Jingyu Li,&nbsp;Chuang Zhang","doi":"10.1007/s43452-025-01151-4","DOIUrl":"10.1007/s43452-025-01151-4","url":null,"abstract":"<div><p>To explore the influence of crystal anisotropy of single-crystal silicon on ultra-small-grinding (USG), the surface generation and grinding forces of single-crystal silicon chips with different crystal orientations in USG were investigated. The geometric structures of single-crystal silicon in different crystal orientations and crystal planes were analyzed. A grinding force model of single-crystal silicon considering crystal structure was proposed in this study. Grinding experiments were conducted on commercial single-crystal silicon chips with crystal orientation &lt; 100 &gt; , &lt; 111 &gt; , and &lt; 110 &gt; by the USG tools with a diameter of 100 µm. Experimental results were used to validate the grinding force model proposed in this study. Under the same grinding parameters, the normal grinding force of crystal orientation &lt; 111 &gt; is the smallest of the three crystal orientations. Thanks to its high symmetry, regular atomic arrangement and smaller crystal layers per volume, the grinding surface of crystal orientation &lt; 100 &gt; has the smallest edge chipping, the least surface defect, and the shallowest defect in the three crystal orientations.</p></div>","PeriodicalId":55474,"journal":{"name":"Archives of Civil and Mechanical Engineering","volume":"25 2","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143602103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 and analysis of time-dependent creep and relaxation behavior of polymeric materials using fractional derivative three-component standard viscoelastic models and nanoindentation experimental data","authors":"Maziar Zahed,&nbsp;Rossana Dimitri,&nbsp;Francesco Tornabene,&nbsp;Hossein Ashrafi","doi":"10.1007/s43452-025-01165-y","DOIUrl":"10.1007/s43452-025-01165-y","url":null,"abstract":"<div><p>In the modeling of viscoelastic materials, two-component elements such as the Maxwell or Kelvin models, which consist of a spring and a dashpot arranged in series or parallel configurations, fail to accurately capture the complex behavior of polymer materials. To address this limitation, this study employs fractional derivative equations within the frameworks of three-component Zener and Boltzmann models to simulate the viscoelastic response of polymeric substances. Two distinct numerical methods are utilized to identify and estimate the parameters of these fractional derivative models. In the first method, model parameters are derived by fitting experimental data to hysteresis loops and their corresponding equations. The second method leverages time-series data, applying the least squares technique to determine the models' parameters and coefficients. Additionally, a data-fitting approach is employed to align the proposed mathematical models with experimental results from nanoindentation tests, ensuring their validation and accuracy. Key outcomes include the extraction of storage and loss moduli: the storage modulus consistently increased with rising dimensionless frequency across all fractional derivative orders. In contrast, the loss modulus initially increased to a dimensionless frequency of one before exhibiting a decreasing trend. Hysteresis loops, representing the energy dissipated per unit volume of material, revealed a reduction in damping with lower fractional derivative orders. Moreover, both methods demonstrated a small relative error when subjected to noise, indicating their robustness and high accuracy in estimating viscoelastic parameters from laboratory data within a narrow range of excitation frequencies.</p></div>","PeriodicalId":55474,"journal":{"name":"Archives of Civil and Mechanical Engineering","volume":"25 2","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143594506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Creep properties and a time-dependent damage constitutive model of sandstone considering the effect of initial damage","authors":"Yunchen Deng,&nbsp;Yi Luo,&nbsp;Hangli Gong,&nbsp;Han Luo,&nbsp;Ping Chen,&nbsp;Qiaoliang Li,&nbsp;Xinping Li","doi":"10.1007/s43452-025-01164-z","DOIUrl":"10.1007/s43452-025-01164-z","url":null,"abstract":"<div><p>In deep mining, retained rock with different degrees of initial damage may demonstrate significant rheological behaviors under high geostress. Traditional linear models fail to describe the non-linear accelerated creep properties of rocks and cannot characterize the influence of initial damage on creep properties. Considering this, creep tests were conducted on sandstone with different degrees of initial damage. In addition, a time-dependent damage model of rocks considering the effect of initial damage was established in conjunction with the improved Burgers model, Cowper–Symonds (CS) model, and theory of damage mechanics. The results indicate that creep stress affects the creep strain, and it determines the extent of the influence of initial damage on the creep strain in sandstone. The initial damage significantly influences the accelerated creep stage, and the creep failure stress linearly reduces and the time-dependent creep deformation time shortens with the rising degree of initial damage. The influence of initial damage on creep failure of samples is weakened with increasing confining pressure. The proposed time-dependent damage model of rocks considering the effect of initial damage overcomes the deficiency of traditional linear models in characterizing influences of accelerated creep and initial damage on creep properties. Based on the differential form of the time-dependent damage model, the secondary development of the time-dependent damage model is realized through the user-defined window of ANSYS/LS-DYNA, and the validity and correctness of the model are verified based on the experimental results and numerical examples. The research results provide theoretical guidance and reference for the study of creep mechanical properties and creep damage models, and also provide an important tool for the long-term stability prediction of caverns in practical engineering, which has significant engineering value and application potential.</p></div>","PeriodicalId":55474,"journal":{"name":"Archives of Civil and Mechanical Engineering","volume":"25 2","pages":""},"PeriodicalIF":4.4,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}