Composites Part B: Engineering最新文献

{"title":"Temperature-sensitive polymer composite-enabled all-printed flexible temperature sensors for safety monitoring","authors":"Panwang Guo,&nbsp;Qun Liu,&nbsp;Xinyu Zhang,&nbsp;Jing Liang,&nbsp;Quancai Li,&nbsp;Ke Zheng,&nbsp;Wei Wu","doi":"10.1016/j.compositesb.2025.112474","DOIUrl":"10.1016/j.compositesb.2025.112474","url":null,"abstract":"<div><div>In recent years, flexible temperature sensors (FTSs) have attracted widespread attention in wearable devices, health monitoring, and electronic skin due to their inherent advantages. However, most FTSs still face significant challenges such as low sensitivity, poor linearity, substantial hysteresis, and difficulty achieving large-scale commercial production, further limiting their practical applications. Herein, an FTS with high-sensing performance is fabricated by screen-printing method using the composite material consisting of graphite, polyvinyl butyral, polyethylene glycol, and hexagonal boron nitride. The FTS exhibits a wide sensing range of 20–60 °C, high sensitivity, high resolution (0.1 °C), good linearity, and excellent stability and reliability. Additionally, by combining the sensor with thermochromic material, a novel FTS with optical visible signal (0–20 °C) and electrical sensing signal (20–60 °C) outputs is obtained, enabling real-time monitoring of the storage temperature of medicine and food packaging. The as-prepared FTS shows immense potential in intelligent packaging, wearable devices, and human healthcare monitoring.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"300 ","pages":"Article 112474"},"PeriodicalIF":12.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143768284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Torsional fatigue damage evolution mechanism and life prediction model of 3D braided carbon fiber composites","authors":"Jikang Li ,&nbsp;Zheng Liu ,&nbsp;Jinghui Wang ,&nbsp;Jingtai Yu ,&nbsp;Yajing Li ,&nbsp;Zhe Zhang ,&nbsp;Yebin Cai ,&nbsp;Xu Chen","doi":"10.1016/j.compositesb.2025.112473","DOIUrl":"10.1016/j.compositesb.2025.112473","url":null,"abstract":"<div><div>3D braided carbon fiber composite shafts hold significant promise for replacing traditional metal or polymer shafts, attributed to their high specific strength and excellent damage tolerance. This study delved into the torsional fatigue damage mechanism of 3D braided carbon fiber composite shafts and developed a life prediction model. The composite shafts were fabricated using 3D four directional braiding and vacuum assisted resin molding techniques. By conducting torsional fatigue tests in conjunction with 3D DIC (3D Digital Image Correlation), CT (Computed Tomography), and in-situ damage monitoring methods, the strain and damage evolution data throughout the fatigue process were acquired. The research results show that the braided structure gives rise to a periodic grid like strain distribution, and the high strain regions are associated with the locations of the braiding nodes. The stiffness degradation occurs in three phases: stable, linear, and accelerating. The damage commences from the fiber bundles on the specimen surface and undergoes an evolution process involving matrix fiber debonding, fiber buckling, and fiber fracture. The debonding cracks within the fiber bundle are the form of damage initiation. Fiber buckling has been proven to be a sign of rapid stiffness degradation. Through the bearing and damage analysis of fiber bundles, an energy based fatigue life prediction model was successfully applied. This model incorporates the stress and strain characteristics on critical fracture surfaces involving fiber resin debonding and fiber buckling fracture as core parameters. Experimental validation confirmed the accuracy of the model in predicting fatigue life under different braiding angles and various loading conditions.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"300 ","pages":"Article 112473"},"PeriodicalIF":12.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143768218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated design, modeling, and manufacturing of rasorber radome composites with electrically tunable transmission and wideband absorption properties","authors":"Jiaheng Yang ,&nbsp;Yongqiang Pang ,&nbsp;Guodong Cai ,&nbsp;Jiafu Wang ,&nbsp;Yongfeng Li ,&nbsp;Huaibin Zheng ,&nbsp;Zhuo Xu","doi":"10.1016/j.compositesb.2025.112467","DOIUrl":"10.1016/j.compositesb.2025.112467","url":null,"abstract":"<div><div>Integrated design, modeling, and manufacturing of rasorber radomes with electrically tunable transmission and wideband absorption properties are studied. The design principle of rasorber radomes is qualitatively analyzed based on the equivalent circuit theory. The prototypes are designed with a multi-layered configuration and constructed using quartz fiber dense skins, polymethacrylimide (PMI) foam cores, PIN diodes, carbon-based films, and the functional layers with copper patterns. The dynamic control of transmission is implemented by applying varying bias voltages to PIN diode elements. To obtain mechanical protection, the delicate PIN diodes are cured together with the preforms and embedded in the matrix. To stabilize the absorption out of the transmission band, the carbon-based films are overprinted at the reserved gaps of the copper patterns. The measured results demonstrate that as the bias voltage varies, within 2–4 GHz, the transmission of the rasorber radome dynamically varies from 0.8 (at 0 V) to 0.05 (at 50 V), while the absorption dynamically varies from 0.05 (at 0 V) to 0.7 (at 40 V). Within 8–22 GHz, the absorption is consistently more than 0.9, which is independent of the variation of bias voltages. The measured results align well with the simulated results. The rasorber radome can function as a radome to ensure normal operations of an enclosed antenna and also function as a radar absorber with variable absorption responses to avoid radar detection and tracking. Therefore, our proposal possesses considerable engineering application potential in stealth radome technology.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"300 ","pages":"Article 112467"},"PeriodicalIF":12.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143768283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing aqueous battery energy storage through electrochemically-driven reconstruction of electrode materials utilizing metal-oxygen clusters","authors":"Jinyue Song ,&nbsp;Jiale Lei ,&nbsp;Hongguang Fan,&nbsp;Yanpeng Wang,&nbsp;Yusheng Luo,&nbsp;Yongcheng Jin,&nbsp;Shuang Liu,&nbsp;Wei Liu","doi":"10.1016/j.compositesb.2025.112469","DOIUrl":"10.1016/j.compositesb.2025.112469","url":null,"abstract":"<div><div>The electrochemical reconstruction of electrode materials is a common phenomenon that occurs during electrochemical reactions, but the evolution process of materials during reconstruction is still a field rarely explored since the intricate and diverse initial electrode structures render the reconstruction process exceptionally complex. In this work, Bi₆ polyhedral clusters are used as building units to alleviate the impact of initial structures, providing an opportunity to reveal the electrochemically-driven reconstruction. By fine-tuning the composition by doping metal atoms (Fe, Cu, Zn), the electrochemically-driven reconstruction of Bi₆ polyhedral clusters resulted in the Cu/Zn co-doped Bi₂O₃/FeOOH nanosized heterostructure with distinctive structural features including competitive growth of heterogeneous grains, micro-zone stress, and diverse functionalities of metal ions. As an anode material, its assembled aqueous batteries achieve a high-level equilibrium of energy and power density with 102.2 Wh kg⁻¹ at the power density of 27.2 kW kg⁻¹. This study paves the way for the spontaneous construction of novel electrode materials through electrochemical reconstruction, promising accelerated advancements in high-performance electrochemical energy storage devices.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"300 ","pages":"Article 112469"},"PeriodicalIF":12.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Harnessing mussel-inspired phenolic-iron complexes for strengthening carbon fiber reinforced polymer composite interfaces","authors":"Wenlong Hu ,&nbsp;Lulu Yang ,&nbsp;Shuzheng Zhang ,&nbsp;Fuzheng Guo ,&nbsp;Fangxin Wang ,&nbsp;Shaohua Liu ,&nbsp;Yu Cang ,&nbsp;Bin Yang","doi":"10.1016/j.compositesb.2025.112466","DOIUrl":"10.1016/j.compositesb.2025.112466","url":null,"abstract":"<div><div>Carbon fiber reinforced polymer composites (CFRPs) offer exceptional specific strength and lightweight characteristics due to the high-performance nature of carbon fiber. However, carbon fiber's chemical inertness results in weak interactions with the polymer matrix, which hinders the overall performance of the composites. Improving the interfacial properties has been a longstanding challenge in CFRPs development. Introducing nanomaterials along with chemical agents at the interface can enhance both physical and chemical interactions, facilitating better load transfer and more uniform stress distribution. Despite this, surface modification remains a complex process, and the lack of anchor bonds limits the effectiveness of chemical interactions. In this work, inspired by the crack-resistance mechanism of byssal cuticle through metal coordination bonds, we introduce a metal-phenolic network comprising ferric iron (Fe³⁺) and tannic acid (TA) onto the carbon fiber surface using a simple one-pot deposition method. This approach significantly enhances the interfacial properties of the composite. The Fe³⁺-TA complex forms nano-sized aggregates on the fiber surface, with their morphology controllable by adjusting the precursor concentration and pH. The multiple reactive groups on TA allow for the incorporation of a silane coupling agent, effectively creating a chemical bridge between the carbon fiber and the matrix, further improving interfacial properties through synergistic chemical and physical interactions. This metal-phenolic network not only simultaneously strengthens and toughens the interface by promoting mechanical interlocking but also provides multiple chemical anchor sites to bridge the two components, offering new insights into strategies for interfacial strengthening and regulation.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"300 ","pages":"Article 112466"},"PeriodicalIF":12.7,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the stacking sequence and cutting parameters effect on hole morphology in hybrid FML composites","authors":"Mehmet Akif Doğan ,&nbsp;Ahmet Yapici ,&nbsp;Lokman Gemi ,&nbsp;Şakir Yazman ,&nbsp;Sezer Morkavuk ,&nbsp;Uğur Köklü","doi":"10.1016/j.compositesb.2025.112464","DOIUrl":"10.1016/j.compositesb.2025.112464","url":null,"abstract":"<div><div>Fiber metal laminates (FMLs) are widely used in a wide range of engineering applications, especially in the aerospace industry, due to their superior functional properties and low cost. In this experimental study, hybrid FML composite specimens consisting of five different Al2024/FRP/Al2024 stacked glass and carbon fiber layers were fabricated to investigate the effect of stacking sequences and cutting parameters on the drilling process. The drilling machinability properties of the specimens were investigated by considering the cutting force, torque, surface roughness and damage analyses in the hole after drilling and the results are presented comparatively. As a result of the experimental study, it was determined that the stacking sequences have a significant effect on the machinability. In terms of cutting forces, it was observed that the cutting force increased in carbon stacked areas and the cutting forces tended to decrease in glass stacks. In torque values, there is an increase in glass stacks and a decrease in carbon stacks. The highest roughness values were measured from all-glass stacked specimens. In hybrid composites, it was observed that glass stacks generally increased the surface roughness.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"300 ","pages":"Article 112464"},"PeriodicalIF":12.7,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel metal/biopolymer composite filaments for extrusion-based additive manufacturing using CuSn10 as example","authors":"Xueying Wei ,&nbsp;Axel Müller-Köhn ,&nbsp;Rüdiger Bähr ,&nbsp;Hanka Becker","doi":"10.1016/j.compositesb.2025.112468","DOIUrl":"10.1016/j.compositesb.2025.112468","url":null,"abstract":"<div><div>An innovative, broadly applicable metal/biopolymer composite filament with high metal fill ratio of 65 % for additive manufacturing using material extrusion achieving successfully sintered metal parts has been synthesized. Over the past decade, Material Extrusion (MEX) has gained popularity as a method for additive manufacturing of metal parts, particularly for producing green parts, due to its flexibility and cost-effectiveness. Specifically designed feedstocks for MEX process have to be provided to achieve high quality properties of metal parts. However, the development of composite filaments with required high-volume metal and MEX-compatible binder matrices remained limited. In this study, a metal/biopolymer composite filament is developed based on CuSn10 metal powder at 65 vol% combined with two novel binder matrices: the first consisted of the binders polylactic acid (PLA) and acetyl tributyl citrate (ATBC), while the second combined PLA, butenediol vinyl alcohol copolymer (BVOH), and ATBC as plasticizer. The binder components are biocompatible and environmentally sustainable. The green parts were successfully printed through MEX and then processed via thermal debinding and sintering in an open atmosphere. Both the debinding and sintering processes were successful and environmentally friendly. The filaments and the resulting metal parts were thoroughly characterized. The results revealed that the feedstock was extremely brittle without the plasticizer. Increasing the plasticizer content improved flowability but led to poorer surface roughness of the filament. Incorporating BVOH reduced the surface roughness and decrease viscosity. The optimal binder matrices were identified as PLA with 10 vol% ATBC and PLA/BVOH with 5 vol% ATBC. CuSn10 parts produced from these new filaments show significant improvements in the mechanical properties, relative density and porosity. This study is significant for metal production using MEX, with CuSn10 powder as a model, demonstrating an improved metal powder ratio of 65 vol% and exploring novel bio-based binder matrices that could potentially be applied to other metals as well.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"300 ","pages":"Article 112468"},"PeriodicalIF":12.7,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gradient structure regulation of liquid metal composite based on synergistic effect of metal coordination and acoustic field for soft electronics","authors":"Ruoxi Zhao ,&nbsp;Qiankun Zhang ,&nbsp;Xiaoyu Dong ,&nbsp;Xiaofeng Liu ,&nbsp;Kaka Li ,&nbsp;Chao Wu ,&nbsp;Yang Zhang ,&nbsp;Xinchao Sun ,&nbsp;Zhongjun Cheng ,&nbsp;Zhimin Xie ,&nbsp;Dongjie Zhang ,&nbsp;Yuyan Liu","doi":"10.1016/j.compositesb.2025.112462","DOIUrl":"10.1016/j.compositesb.2025.112462","url":null,"abstract":"<div><div>As candidates, liquid metal composites (LMCs) exhibit tunable physical and functional properties at various scales, broadening applications in flexible electronics. Herein, by the synergistic effect of metal coordination and acoustic field, a liquid metal composite (LMEPC) with tunable gradient structure is prepared. The gradient and bicontinuous structures of LMPEC result in the initial thermal and electrical conductivity anisotropy without pre-activation. The size of LM particles (LMPs) can be controlled from nano to micro scale due to the synergistic effect of metal coordination and acoustic field application, resulting in a transformation of the gradient structure. LMEPC exhibits enhanced electrical conductivity (0.0540 Ω), thermal conductivity (1.317 W K⁻¹ m⁻¹), mechanical property (1847.3 MPa), and programmable shape performance. These capabilities enable the design of multifunctional electronics. This work provides a new strategy to control the gradient structure of LMCs by the induction of metal coordination to broaden the horizon of applications.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"299 ","pages":"Article 112462"},"PeriodicalIF":12.7,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143737931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Damage mechanism and residual tensile strength of CFRP laminates subjected to high-velocity sand erosion","authors":"Shaorui Wang ,&nbsp;Jinke Li ,&nbsp;Junchao Cao ,&nbsp;Zhenqiang Zhao ,&nbsp;Jia Huang ,&nbsp;Jun Xing ,&nbsp;Chao Zhang","doi":"10.1016/j.compositesb.2025.112459","DOIUrl":"10.1016/j.compositesb.2025.112459","url":null,"abstract":"<div><div>Composite materials are used in the fan blades of advanced high bypass ratio aero-engines, and resistance to sand erosion is of significant importance for the design of these blades. This study investigates the sand erosion behavior of carbon fiber reinforced polymer (CFRP) composites under distinct impact velocities and erosion durations using rotary arm erosion testing apparatus. The damage evolution mechanism of CFRP laminates under sand erosion is quantitatively analyzed, while residual mechanical performance is also assessed. The experimental results show that continuous sand erosion typically results in erosion pits at the impact center and abrasion bands on the surface of CFRP laminates. It is found that as the erosion velocity increases, both the material strength and stiffness decrease significantly, with peak reductions of 64.7 % in tensile strength and 46.2 % in elastic modulus observed at the maximum tested velocity (200 m/s). An analytical model was developed to characterize the relationship between residual tensile strength and erosion damage parameters, which demonstrates good agreement with experimental results, with an average error below 7 %. The findings provide foundational experimental data on the erosion resistance and residual tensile properties of CFRP laminates, supporting the design and reliability assessment of erosion-resistant structures.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"300 ","pages":"Article 112459"},"PeriodicalIF":12.7,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In-situ hydrophobic protective layer for suppressing hydrogen evolution corrosion and enabling high-efficiency silicon-air batteries with wide temperature adaptability","authors":"Rong Yan ,&nbsp;Funing Bian ,&nbsp;Jicai Hu ,&nbsp;Shulin Gao ,&nbsp;Sujuan Hu","doi":"10.1016/j.compositesb.2025.112456","DOIUrl":"10.1016/j.compositesb.2025.112456","url":null,"abstract":"<div><div>Silicon (Si), with its high theoretical capacity, highly negative redox potential (−1.69 V <em>vs.</em> SHE), abundance, and low cost, has attracted widespread attention as an anode material for air batteries. However, the specific electric double layer (EDL) between the Si anode and electrolyte causes severe hydrogen evolution corrosion, resulting in a significant deviation of the specific capacity from its theoretical value. To address this issue, a low-cost and high-efficiency additive strategy was developed. By introducing a small amount of dodecyl dimethyl benzyl ammonium bromide (DDBAB), which features a (C₂H₅)₂N⁺ group that strongly interacts with OH⁻, and a hydrophobic C₁₂H₂₅ and C₂H₅, the EDL is altered and an <em>in-situ</em> hydrophobic protective layer is formed. This layer effectively repels active H₂O from the Si anode/electrolyte interface and increases the barriers to hydrogen evolution reactions (HER). As a result, the hydrogen evolution inhibition efficiency of Si anode reached 99.36 %. The aqueous silicon-air batteries (SABs) lasted from 173 h to 500 h, and the energy density and specific capacity enhanced by 2.6-fold and 2.7-fold, respectively. Due to the temperature-insensitive binding energy between DDBAB and the Si anode, the quasi-solid-state SABs (QSSSABs), using PAAK-M gel electrolyte, as a proof of concept, exhibit a high specific capacity of 324.54 Ah kg⁻¹, excellent stability across a wide temperature range (−10 °C to 60 °C), and great application potential.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"300 ","pages":"Article 112456"},"PeriodicalIF":12.7,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143746848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}