Experimental Mechanics最新文献

{"title":"A Deep Learning-Driven Fast Scanning Method for Micro-Computed Tomography Experiments on CMCs","authors":"R.Q. Zhu,&nbsp;G.H. Niu,&nbsp;Z.L. Qu,&nbsp;P.D. Wang,&nbsp;D.N. Fang","doi":"10.1007/s11340-024-01081-x","DOIUrl":"10.1007/s11340-024-01081-x","url":null,"abstract":"<div><h3>Background</h3><p><i>In-situ</i> micro-computed tomography (µCT) technology is an attractive approach to investigate the evolution process of damage inside ceramic matrix composites (CMCs) during high-temperature service. The evolution process is highly time-sensitive under temperature-induced loads, and fast scanning is very necessary for <i>in-situ</i> µCT tests.</p><h3>Objective</h3><p>The objective of this work is to provide a fast scanning method for in situ µCT tests on CMCs with complex microstructures by the innovation of a reconstruction algorithm.</p><h3>Method</h3><p>To overcome the severe degradation of the reconstructed image quality resulting from sparse CT scans, a deep-learning-based multi-domain sparse reconstruction method was proposed. Three sub-networks including the projection-domain, image-domain, and fusion network were constructed in the multi-domain method to make full use of the information from the projection and image domain.</p><h3>Results</h3><p>The proposed deep-learning-based sparse reconstruction method provided satisfactory µCT images on C/SiC composites with acceptable quality. The scanning time was reduced by 6 times. All selected evaluation metrics of the proposed method are higher than those of other single-domain methods and traditional iterative method. The segmentation accuracy of the µCT images obtained by the proposed method can meet the subsequent quantitative analysis. An <i>in-situ</i> tensile test of CMCs is conducted to further evaluate the performance in the practical application of <i>in-situ</i> experiments. The results indicate that the weak and thin micro-cracks can still be effectively retained and recovered. A detailed workflow to implement the method generally is also provided.</p><h3>Conclusions</h3><p>Based on the deep-learning-based multi-domain sparse reconstruction method, the process of <i>in-situ</i> µCT tests can be greatly accelerated with little loss of the reconstructed image quality.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 7","pages":"1053 - 1072"},"PeriodicalIF":2.0,"publicationDate":"2024-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141098652","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":"Characterization on Fracture Toughness of Cermet Coating Coupling Instrumented Indentation and X‑Ray Computed Tomography","authors":"R. Huang,&nbsp;Y. Zheng,&nbsp;S. Luo,&nbsp;H. Bai,&nbsp;P. Wang,&nbsp;Y. Chen,&nbsp;Z. Qu","doi":"10.1007/s11340-024-01075-9","DOIUrl":"10.1007/s11340-024-01075-9","url":null,"abstract":"<div><h3>Background</h3><p>The surface brittle fracture of cermet coating seriously restricts its application. Accurate evaluation of the fracture toughness of cermet coating is a prerequisite for improving its life.</p><h3>Objective</h3><p>This paper aims to propose an accurate characterization method for fracture toughness of cermet coating.</p><h3>Methods</h3><p>By coupling instrumented indentation and X‑ray computed tomography (XCT), the indentation-induced fracture behaviors under various loads within WC-12%Co coatings were studied. The three-dimensional subsurface crack morphologies and the damage evolution within the coating were nondestructively observed by XCT. The indentation response was correlated with the damage evolution. The impact of substrate effects on indentation-induced fracture behaviors was further studied using finite element analysis (FEA).</p><h3>Results</h3><p>The Palmqvist shape of the indentation crack under low loads was successfully identified. The first pop-in event in the load-displacement (<i>P</i>-<i>h</i>) curve was determined to be triggered by bottom cracking, marking the onset of the multiple fracture mode. Laugier’s equation offered a stable and reliable estimation of fracture toughness for the coating in the radial cracking mode.</p><h3>Conclusions</h3><p>XCT plays a crucial role in selecting the appropriate equation for indentation toughness calculation. The critical indentation depth for the first pop-in was suggested as the threshold for reliably extracting intrinsic fracture toughness of cermet coatings. Numerical results revealed a constant linear relationship between the critical depth and coating thickness, and a high sensitivity of the critical depth to yield stress of the substrate. The proposed analytical procedure holds potential for generalization to diverse cermet coatings on metal substrates.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 7","pages":"1037 - 1051"},"PeriodicalIF":2.0,"publicationDate":"2024-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141103656","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":"Experimental Examination of Additively Manufactured Patterns on Structural Nuclear Materials for Digital Image Correlation Strain Measurements","authors":"K.A. Novich,&nbsp;T.L. Phero,&nbsp;S.E. Cole,&nbsp;C.M. Greseth,&nbsp;M.D. McMurtrey,&nbsp;D. Estrada,&nbsp;B.J. Jaques","doi":"10.1007/s11340-024-01076-8","DOIUrl":"10.1007/s11340-024-01076-8","url":null,"abstract":"<div><h3>Background</h3><p>There are a limited number of commercially available sensors for monitoring the deformation of materials <i>in-situ</i> during harsh environment applications, such as those found in the nuclear and aerospace industries. Such sensing devices, including weldable strain gauges, extensometers, and linear variable differential transformers, can be destructive to material surfaces being investigated and typically require relatively large surface areas to attach (&gt; 10 mm in length). Digital image correlation (DIC) is a viable, non-contact alternative to <i>in-situ</i> strain deformation. However, it often requires implementing artificial patterns using splattering techniques, which are difficult to reproduce.</p><h3>Objective</h3><p>Additive manufacturing capabilities offer consistent patterns using programmable fabrication methods.</p><h3>Methods</h3><p>In this work, a variety of small-scale periodic patterns with different geometries were printed directly on structural nuclear materials (i.e., stainless steel and aluminum tensile specimens) using an aerosol jet printer (AJP). Unlike other additive manufacturing techniques, AJP offers the advantage of materials selection. DIC was used to track and correlate strain to alternative measurement methods during cyclic loading, and tensile tests (up to 1100 µɛ) at room temperature.</p><h3>Results</h3><p>The results confirmed AJP has better control of pattern parameters for small fields of view and facilitate the ability of DIC algorithms to adequately process patterns with periodicity. More specifically, the printed 100 μm spaced dot and 150 μm spaced line patterns provided accurate measurements with a maximum error of less than 2% and 4% on aluminum samples when compared to an extensometer and commercially available strain gauges.</p><h3>Conclusion</h3><p>Our results highlight a new pattern fabrication technique that is form factor friendly for digital image correlation in nuclear applications.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 7","pages":"1005 - 1020"},"PeriodicalIF":2.0,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-024-01076-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141121419","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":"Experiments on Low–Cycle Ductile Damage and Failure Under Biaxial Loading Conditions","authors":"S. Gerke,&nbsp;Z. Wei,&nbsp;M. Brünig","doi":"10.1007/s11340-024-01074-w","DOIUrl":"10.1007/s11340-024-01074-w","url":null,"abstract":"<div><h3>Background</h3><p>The damage and failure behavior of ductile metals depends on the stress state as well as on the loading history. Biaxial experiments with suitable specimens can be used to targeted generate different loading conditions, thus allowing the investigation of a wide variety of load cycles with different stress states.</p><h3>Objective</h3><p>In the biaxial experiments with the newly presented HC-specimen cyclic shear loads are superimposed by various constant compressive and tensile loads. Buckling during compressive loading in both axes is avoided by an additional newly introduced downholder.</p><h3>Methods</h3><p>The strain fields at the surfaces of the biaxial specimens are evaluated by digital image correlation (DIC), and after failure the corresponding fracture surfaces are analyzed by scanning electron microscopy (SEM). Associated numerical simulations employing the presented material model provide information on the current stress states.</p><h3>Results</h3><p>The introduced downholder successfully prevents buckling during compressive loading. The strain fields detect a clear influence of the shear direction and a tensile superposition of the cyclic shear load leads to more brittle and a compressive superposition to more ductile behavior. The accompanying numerical calculations reveal the associated, different stress states.</p><h3>Conclusions</h3><p>The new experimental program with biaxially loaded specimens for the investigation of damage and failure behavior under cyclic loading enables the targeted examination of a wide variety of load cycles and is thus suitable for the comprehensive analysis of these phenomena.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 7","pages":"1021 - 1036"},"PeriodicalIF":2.0,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-024-01074-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141119106","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":"On the Cover: High Speed Impact Testing of UHMWPE Composite Using Orthogonal Arrays","authors":"","doi":"10.1007/s11340-024-01083-9","DOIUrl":"10.1007/s11340-024-01083-9","url":null,"abstract":"","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 6","pages":"783 - 783"},"PeriodicalIF":2.0,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141064181","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 Residue Gas Inflation Technique for Space Borne Inflatable Boom with Different Folding Patterns","authors":"S. D. Shinde,&nbsp;S. H. Upadhyay","doi":"10.1007/s11340-024-01072-y","DOIUrl":"10.1007/s11340-024-01072-y","url":null,"abstract":"<div><h3>Background</h3><p>The last two decades have seen a growing trend toward the use of inflatable membranes for spaceborne structures. The spaceborne inflatable membrane structures are the promising solution for the compact and lightweight reflector antenna. The inflation technique is used for pressurizing the inflatable membrane structure once the satellite reaches to its predefined orbit.</p><h3>Objective</h3><p>The objective of the study is to demonstrate the use of the residue gas inflation technique for the complete deployment of the inflatable thin membrane boom with different folding patterns. The study also aims to find out generalized relation to calculate the safe mass of residue gases to be kept inside spaceborne membrane boom.</p><h3>Method</h3><p>The novel analytical relation for the safe mass of residue gases that can be carried for any size of the inflatable boom is established. A comparative study is performed to investigate the effect of variation in a folding pattern on the proposed inflation technique. Experimental, numerical, and analytical approaches were employed for the proposed study.</p><h3>Result</h3><p>The results show that the total inflation time is inversely proportional to the mass of the residue gases. Through the comparative study, it has been observed that the change in the inflation time is negligible for different folding patterns with the same mass of residue gas. The result confirms that the safe mass of residue gas is successfully deploying the inflatable boom in the vacuum environmental condition keeping the stresses in the boom in the tolerance limit.</p><h3>Conclusions</h3><p>The findings of this research provide insights into a simple and cost-effective design solution for the inflation system along with safe mass of the residue gases which can be used for any size of spaceborne inflatable boom.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 7","pages":"971 - 980"},"PeriodicalIF":2.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140941899","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":"Experimental Study of Nitinol Springs: Apparatus and Results","authors":"I. Alexandron,&nbsp;G. deBotton","doi":"10.1007/s11340-024-01059-9","DOIUrl":"10.1007/s11340-024-01059-9","url":null,"abstract":"<div><h3>Background</h3><p>The behavior of shape memory alloys that admit large reversible deformations in response to thermal excitation has been extensively studied in recent years. Yet, the number of works dealing with springs made from these alloys is rather limited in spite of their attractiveness in various applications.</p><h3>Objective</h3><p>To bridge this gap we designed and constructed an experimental system for characterizing the behavior of the springs. It enables precise control of the three state variables: temperature, elongation, and force.</p><h3>Methods</h3><p>Control of the sample temperature is achieved by immersing it in a water-filled thermal bath, where the water temperature is adjusted using a <i>thermoelectric Peltier</i> device. A tension-compression motorized unit sets the spring elongation and a force gauge is used for measuring the force exerted on the spring. The data is continuously monitored and acquired with a self-coded LabVIEW program. An important aspect is the calibration procedure developed for identifying the spring load-free state and ensuring the repetitiveness of the measurements.</p><h3>Results</h3><p>Experiments in which the elongation or the force were measured as a function of the temperature demonstrate the role of the phase transformations. Isothermal experiments enabled to characterize the variations of the force versus the elongation at different temperatures.</p><h3>Conclusions</h3><p>The proposed system facilitates the execution of highly accurate experiments through which the complex history-dependent behavior of shape memory springs can be revealed and studied.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 7","pages":"981 - 994"},"PeriodicalIF":2.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-024-01059-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140937059","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":"Curved Polymeric Sandwich Composites Subjected to Air Shock: An Experimental Investigation","authors":"A. Pandey,&nbsp;P. Wanchoo,&nbsp;H. Matos,&nbsp;A. Shukla","doi":"10.1007/s11340-024-01069-7","DOIUrl":"10.1007/s11340-024-01069-7","url":null,"abstract":"<div><h3>Background</h3><p>The vulnerability of polymeric composite sandwich structures in marine applications to air explosions highlights a significant gap in our understanding of the dynamic behavior of the curved sandwich structures, which is essential for design improvements.</p><h3>Objective</h3><p>This study aims to explore the dynamic response and failure mechanisms of curved sandwich composite panels subjected to air-blast loading, providing insights into their structural integrity under such conditions.</p><h3>Methods</h3><p>Experiments were performed using laboratory-simulated air shocks generated by a shock tube, employing high-speed photography and digital image correlation to measure deflections on the back surface of the panels. The panels, made with PVC closed-cell foam cores of two densities (H45 and H130), were tested across three curved geometries (radii of 112 mm, 305 mm, and infinity) under various boundary conditions.</p><h3>Results</h3><p>Findings indicate an increase in deformation with a decreased radius of curvature under simple support conditions, a trend that reverses under arrested displacement conditions. Moreover, a reduced radius significantly enhances panel strength and resistance to interfacial damage, with the primary failure mode transitioning from core shear cracking to interfacial debonding as core density increases.</p><h3>Conclusions</h3><p>The study reveals that the radius of curvature, boundary conditions, and core density significantly affect curved sandwich panels’ dynamic response and performance. Panels with smaller radii and higher core densities exhibit increased strength, though boundary conditions introduce variable effects on deformation behavior.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 6","pages":"945 - 961"},"PeriodicalIF":2.0,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-024-01069-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140885871","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":"Temperature Dependent Dynamic Response of Open-Cell Polyurethane Foams","authors":"D. Morrison,&nbsp;J. Morton,&nbsp;M. Foster,&nbsp;L. Lamberson","doi":"10.1007/s11340-024-01054-0","DOIUrl":"10.1007/s11340-024-01054-0","url":null,"abstract":"<div><h3>Background</h3><p>Polyurethane foams have many uses ranging from comfort fitting seats and shoes to protective inserts in helmets and sports equipment. Current military helmet designs employ foam pads of varying densities and bulk material properties to help absorb energy from impacts ranging from quasi-static to ballistic level strain-rates.</p><h3>Objective</h3><p>This study aims to analyze the thermomechanical uniaxial compression behavior of a high density liner foam pad and a low density liner foam pad used in the Advanced Combat Helmet. These experiments were conducted under strain-rates of <span>(10^2)</span> s<span>(^{-1})</span> and under temperature conditions ranging from -20 to 40 °C. This temperature range was chosen to simulate desert and arctic conditions, with a strain-rate regime chosen to represent loads that would occur often throughout the life of the helmet, such as drops, bumps from riding in a vehicle, or heavy collisions from falling.</p><h3>Method</h3><p>Multiple experimental apparatuses were used in this study, including a Shimadzu TCE-N300 thermostatic chamber (used to create the varying temperature environments) and a custom-built drop-test system (used to induce intermediate strain-rates). Every experiment was paired with two accelerometers and a high speed camera used for Digital Image Correlation (DIC) to analyze sample deformation and resultant acceleration. The foam’s mechanical response and energy absorption properties were investigated from the measured stress-strain curves. Additionally, each foam composition was analyzed with X-ray computed micro-tomography (XCT) to investigate microstructure properties pre and post-mortem.</p><h3>Results</h3><p>Results show that temperature decreased the energy absorption of the low density composition by 48% ± 5% as temperature changed from -20 °C to 40 °C, while energy absorption increased by 53% ± 16% for the high density composition over the same temperature.</p><h3>Conclusion</h3><p>A comparison between the loading response and the material’s density characteristics revealed that the foam’s mechanical properties are heavily dependent on strain-rate applications, as well as environmental factors including temperature. Several important characteristics surrounding each foam composition’s deformation mechanics and damage tolerance as a result of temperature are discussed.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 6","pages":"929 - 943"},"PeriodicalIF":2.0,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-024-01054-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140838508","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":"Towards a Reliable Uncertainty Quantification in Residual Stress Measurements with Relaxation Methods: Finding Average Residual Stresses is a Well-Posed Problem","authors":"M. Beghini,&nbsp;T. Grossi","doi":"10.1007/s11340-024-01066-w","DOIUrl":"10.1007/s11340-024-01066-w","url":null,"abstract":"<div><h3>Background</h3><p>In a previous work, the problem of identifying residual stresses through relaxation methods was demonstrated to be mathematically ill-posed. In practice, it means that the solution process is affected by a bias-variance tradeoff, where some theoretically uncomputable bias has to be introduced in order to obtain a solution with a manageable signal-to-noise ratio.</p><h3>Objective</h3><p>As a consequence, an important question arises: how can the solution uncertainty be quantified if a part of it is inaccessible? Additional physical knowledge could—in theory—provide a characterization of bias, but this process is practically impossible with presently available techniques.</p><h3>Methods</h3><p>A brief review of biases in established methods is provided, showing that ruling them out would require a piece of knowledge that is never available in practice. Then, the concept of average stresses over a distance is introduced, and it is shown that finding them generates a well-posed problem. A numerical example illustrates the theoretical discussion</p><h3>Results</h3><p>Since finding average stresses is a well-posed problem, the bias-variance tradeoff disappears. The uncertainties of the results can be estimated with the usual methods, and exact confidence intervals can be obtained.</p><h3>Conclusions</h3><p>On a broader scope, we argue that residual stresses and relaxation methods expose the limits of the concept of point-wise stress values, which instead works almost flawlessly when a natural unstressed state can be assumed, as in classical continuum mechanics (for instance, in the theory of elasticity). As a consequence, we are forced to focus on the effects of stress rather than on its point-wise evaluation.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 6","pages":"851 - 874"},"PeriodicalIF":2.0,"publicationDate":"2024-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-024-01066-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140614848","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}