The behavior and response of ceramic matrix composites (CMCs), in particular silicon carbide fiber reinforced silicon carbide matrix (SiC/SiC), is affected by many factors such as variation of fiber volume fraction, residual stresses resulting from processing of the composites at high temperature, random microstructures, and the presence of matrix flaws (e.g., voids, pores, cracks etc.) as well as general material nonlinearity and heterogeneity that occurs randomly in a composite. Residual stresses arising from the phase change of constituents are evaluated in this paper and it is shown that they do influence composite strength and need to be properly accounted for. Additionally, the microstructures (location of fiber centers, coating thickness etc.) of advanced CMCs are usually disordered (or random) and fiber diameter and strength typically have a distribution. They rarely resemble the ordered fiber packing (square, rectangular, or hexagonal) that is generally assumed in micromechanics-based models with periodic boundary conditions for computational expediency. These issues raise the question of how should one model such systems effectively? Can an ordered hexagonal packed repeating unit cell (RUC) accurately represent the random microstructure behavior? How many fibers need to be included to enable accurate representation? Clearly, the number of fibers within an RUC must be limited to insure a balance between accuracy and efficiency. NASA’s in-house micromechanics-based code MAC/GMC provides a framework to analyze such RUCs for the overall composite behavior and the FEAMAC computer code provides linkage of MAC/GMC to the commercial FEA code, ABAQUS. The appropriate level of discretization of the RUC as well as the analysis method employed, i.e., Generalized Method of Cells (GMC) or High Fidelity Generalized Method of Cells (HFGMC), is investigated in this paper in the context of a unidirectional as well as a cross-ply laminated CMC. Results including effective composite properties, proportional limit stress (an important design parameter) and fatigue are shown utilizing both GMC as well as HFGMC. Finally, a few multiscale analyses are performed on smooth bar test coupons as well as test coupons with features such as open-hole and double notches using FEAMAC. Best practices and guidance are provided to take these phenomena into account and keep a proper balance between fidelity (accuracy) and efficiency. Following these guidelines can account for important physics of the problem and provide significant advantages when performing large multiscale composite structural analyses. Finally, to demonstrate the multiscale analysis framework, a CMC gas turbine engine vane structure is analyzed involving a progressive damage model.
{"title":"Micromechanics-Based Modeling of SiC/SiC Ceramic Matrix Composites and Structures","authors":"S. Mital, S. Arnold, B. Bednarcyk, E. Pineda","doi":"10.21926/rpm.2302025","DOIUrl":"https://doi.org/10.21926/rpm.2302025","url":null,"abstract":"The behavior and response of ceramic matrix composites (CMCs), in particular silicon carbide fiber reinforced silicon carbide matrix (SiC/SiC), is affected by many factors such as variation of fiber volume fraction, residual stresses resulting from processing of the composites at high temperature, random microstructures, and the presence of matrix flaws (e.g., voids, pores, cracks etc.) as well as general material nonlinearity and heterogeneity that occurs randomly in a composite. Residual stresses arising from the phase change of constituents are evaluated in this paper and it is shown that they do influence composite strength and need to be properly accounted for. Additionally, the microstructures (location of fiber centers, coating thickness etc.) of advanced CMCs are usually disordered (or random) and fiber diameter and strength typically have a distribution. They rarely resemble the ordered fiber packing (square, rectangular, or hexagonal) that is generally assumed in micromechanics-based models with periodic boundary conditions for computational expediency. These issues raise the question of how should one model such systems effectively? Can an ordered hexagonal packed repeating unit cell (RUC) accurately represent the random microstructure behavior? How many fibers need to be included to enable accurate representation? Clearly, the number of fibers within an RUC must be limited to insure a balance between accuracy and efficiency. NASA’s in-house micromechanics-based code MAC/GMC provides a framework to analyze such RUCs for the overall composite behavior and the FEAMAC computer code provides linkage of MAC/GMC to the commercial FEA code, ABAQUS. The appropriate level of discretization of the RUC as well as the analysis method employed, i.e., Generalized Method of Cells (GMC) or High Fidelity Generalized Method of Cells (HFGMC), is investigated in this paper in the context of a unidirectional as well as a cross-ply laminated CMC. Results including effective composite properties, proportional limit stress (an important design parameter) and fatigue are shown utilizing both GMC as well as HFGMC. Finally, a few multiscale analyses are performed on smooth bar test coupons as well as test coupons with features such as open-hole and double notches using FEAMAC. Best practices and guidance are provided to take these phenomena into account and keep a proper balance between fidelity (accuracy) and efficiency. Following these guidelines can account for important physics of the problem and provide significant advantages when performing large multiscale composite structural analyses. Finally, to demonstrate the multiscale analysis framework, a CMC gas turbine engine vane structure is analyzed involving a progressive damage model.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46579956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sumita A. Jain, D. Chan, Noufa Khan, Yena Park, Densen Cao
Zinc pyrithione (ZPT) is used to prevent microbial degradation and deterioration of manufacturing starting materials such as plastics, polymers, and latexes. The main objective of this study was to evaluate the anti-bacterial properties of ZPT. Currently, there is insufficient data on the effect of ZPT on viability of commonly encountered bacterial pathogens. We tested the efficacy of ZPT manufactured in the form of film rolls as an anti-bacterial protective layer by using the ASTM–recommended protocol on growth of Enterococcus faecalis and Escherichia coli. The bacterial cultures were added to three materials provided by Cao Inc. containing either the base with no active ingredient, ZPT-A, or different amounts of active ingredient, ZPT-B (2.5%) and ZPT-C (5%). Following overnight incubation, bacterial growth was assessed by counting their colony forming units (CFUs). Growth of both E. faecalis and E. coli were strongly inhibited by ZPT-B and ZPT-C relative to growth on the control ZPT-A. Inhibition of E. faecalis was close to complete by ZPT-B and ZPT-C while E. coli growth was inhibited by greater than 95% in a dose dependent manner. This is the first report of zinc pyrithione, here in the form of thin film, inhibiting growth of common bacterial pathogens. ZPT rolls therefore show promise as an effective antibacterial layer for use as a protective barrier, for example on door handles and counters, from clinical to global public health settings.
{"title":"Efficacy of Zinc Pyrithione as A Novel Anti-Bacterial Coating Agent","authors":"Sumita A. Jain, D. Chan, Noufa Khan, Yena Park, Densen Cao","doi":"10.21926/rpm.2302024","DOIUrl":"https://doi.org/10.21926/rpm.2302024","url":null,"abstract":"Zinc pyrithione (ZPT) is used to prevent microbial degradation and deterioration of manufacturing starting materials such as plastics, polymers, and latexes. The main objective of this study was to evaluate the anti-bacterial properties of ZPT. Currently, there is insufficient data on the effect of ZPT on viability of commonly encountered bacterial pathogens. We tested the efficacy of ZPT manufactured in the form of film rolls as an anti-bacterial protective layer by using the ASTM–recommended protocol on growth of Enterococcus faecalis and Escherichia coli. The bacterial cultures were added to three materials provided by Cao Inc. containing either the base with no active ingredient, ZPT-A, or different amounts of active ingredient, ZPT-B (2.5%) and ZPT-C (5%). Following overnight incubation, bacterial growth was assessed by counting their colony forming units (CFUs). Growth of both E. faecalis and E. coli were strongly inhibited by ZPT-B and ZPT-C relative to growth on the control ZPT-A. Inhibition of E. faecalis was close to complete by ZPT-B and ZPT-C while E. coli growth was inhibited by greater than 95% in a dose dependent manner. This is the first report of zinc pyrithione, here in the form of thin film, inhibiting growth of common bacterial pathogens. ZPT rolls therefore show promise as an effective antibacterial layer for use as a protective barrier, for example on door handles and counters, from clinical to global public health settings.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43747417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nanomaterials are now used in almost every field of science; as conductors and electrodes in electronics, as nanodelivery systems in health screenings and drug delivery, as nanofibrils in filtering and textile industry, as nanoparticles in biosensor fabrication for toxin and pathogen detection, and in packaging materials in the food industry. Synthetic materials and plastics accumulate in the environment causing increasing health concerns for their use in food and pharmaceutical products. Therefore, researchers now try to find new greener fabrication methods for nanomaterials. In this review, some of the most recent studies were summarized and discussed where novel green nanomaterials were synthesized from plant or animal-based polymers. The focus has been given on the synthesis of 1) nanodelivery systems for bioactive and drug delivery in the form of nanoparticles, nanotubes and nanofibers, 2) nanophotonic film or nanofiber-based biosensors for food toxin and pathogen detection, and 3) functional nanocomposite films. The studies summarized here give the reader a clear understanding of the science behind creating green nanomaterial-based systems and how they are used in various applications.
{"title":"Nanomaterials with Plant or Animal Origin for Greener Biodelivery and Biosensor Applications: A Review","authors":"H. Turasan, T. Rouf, T. Yılmaz, J. Kokini","doi":"10.21926/rpm.2302023","DOIUrl":"https://doi.org/10.21926/rpm.2302023","url":null,"abstract":"Nanomaterials are now used in almost every field of science; as conductors and electrodes in electronics, as nanodelivery systems in health screenings and drug delivery, as nanofibrils in filtering and textile industry, as nanoparticles in biosensor fabrication for toxin and pathogen detection, and in packaging materials in the food industry. Synthetic materials and plastics accumulate in the environment causing increasing health concerns for their use in food and pharmaceutical products. Therefore, researchers now try to find new greener fabrication methods for nanomaterials. In this review, some of the most recent studies were summarized and discussed where novel green nanomaterials were synthesized from plant or animal-based polymers. The focus has been given on the synthesis of 1) nanodelivery systems for bioactive and drug delivery in the form of nanoparticles, nanotubes and nanofibers, 2) nanophotonic film or nanofiber-based biosensors for food toxin and pathogen detection, and 3) functional nanocomposite films. The studies summarized here give the reader a clear understanding of the science behind creating green nanomaterial-based systems and how they are used in various applications.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45981647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Adamovich, Eugenia Buryanskaya, Anthon Elfimov, I. Maklakova, O. Gradov, M. Gradova, Theodor K. Orehov
In this paper, starting with an introductory review of the applications of liquid crystals and polymer-dispersed liquid crystal systems in (bio)sensors and microfluidics, the possibilities of visualizing self-organization products of liquid crystalline media or field-induced instabilities of liquid crystalline systems are considered. In particular illustrated cases, it is proposed to use FemtoScan software-containing metrological complexes to visualize instabilities in liquid crystalline systems and products of self-organization in liquid crystalline media.
{"title":"Towards Femtoscan-Assisted Analysis of Liquid Crystal Self-Organization on Different Polymer and Glass Surfaces for Lab-on-a-Chip and Lab-on-a-Dish Applications, Including Optofluidic and Flexoelectric Ones","authors":"E. Adamovich, Eugenia Buryanskaya, Anthon Elfimov, I. Maklakova, O. Gradov, M. Gradova, Theodor K. Orehov","doi":"10.21926/rpm.2302022","DOIUrl":"https://doi.org/10.21926/rpm.2302022","url":null,"abstract":"In this paper, starting with an introductory review of the applications of liquid crystals and polymer-dispersed liquid crystal systems in (bio)sensors and microfluidics, the possibilities of visualizing self-organization products of liquid crystalline media or field-induced instabilities of liquid crystalline systems are considered. In particular illustrated cases, it is proposed to use FemtoScan software-containing metrological complexes to visualize instabilities in liquid crystalline systems and products of self-organization in liquid crystalline media.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43647176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abolfath Askarian Khoob, Mohammad Javad Ramezani, S. Mousavi
This study intends to determine the behavior of glass laminate aluminum-reinforced epoxy (GLARE) and glass fiber-reinforced polymer (GFRP) composites under a low-velocity impact test. Experimental tests and numerical simulations are considered for this investigation. All samples are made by the hand lay-up method. Moreover, specimens are produced with a 7075-T6 aluminium sheet with a 0.5 mm thickness, resin 3001, and E-glass fiber. The drop weight test performs the low-velocity impact at 6.7 J and 10 J impact energy levels and the heights of 1.0 m and 1.5 m. Numerical simulation is also conducted by ANSYS software to compare the results obtained by the experimental tests. Generally, results show that maximum deflections of the GLARE samples are significantly lower as compared to GFRP ones by 87% and 83.5% for 1.0 m and 1.5 m drop heights, respectively. Experimental results demonstrate that although aluminum sheets prevent damage to the fibers in GFRP, delamination and fractures between layers are observed in GFRP samples. An appropriate agreement is also obtained between the FE results and experimental data.
{"title":"Low-Velocity Impact Resistance of Glass Laminate Aluminium Reinforced Epoxy (GLARE) Composite","authors":"Abolfath Askarian Khoob, Mohammad Javad Ramezani, S. Mousavi","doi":"10.21926/rpm.2302021","DOIUrl":"https://doi.org/10.21926/rpm.2302021","url":null,"abstract":"This study intends to determine the behavior of glass laminate aluminum-reinforced epoxy (GLARE) and glass fiber-reinforced polymer (GFRP) composites under a low-velocity impact test. Experimental tests and numerical simulations are considered for this investigation. All samples are made by the hand lay-up method. Moreover, specimens are produced with a 7075-T6 aluminium sheet with a 0.5 mm thickness, resin 3001, and E-glass fiber. The drop weight test performs the low-velocity impact at 6.7 J and 10 J impact energy levels and the heights of 1.0 m and 1.5 m. Numerical simulation is also conducted by ANSYS software to compare the results obtained by the experimental tests. Generally, results show that maximum deflections of the GLARE samples are significantly lower as compared to GFRP ones by 87% and 83.5% for 1.0 m and 1.5 m drop heights, respectively. Experimental results demonstrate that although aluminum sheets prevent damage to the fibers in GFRP, delamination and fractures between layers are observed in GFRP samples. An appropriate agreement is also obtained between the FE results and experimental data.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45479618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aadharshini G, Nisha Gupta, P. Saha, Pallab Bhattacharya
Energy storage devices (ESD) including batteries, and supercapacitors are becoming progressively imperative in the transition to a renewable energy future, as they enable the integration of intermittent renewable sources into the grid and provide backup power during outages. There are already reviews available on various energy storage materials and systems. However, the challenges in the choice of suitable materials and fabrication technology are yet to establish for the commercialization of affordable and efficient ESDs in every aspect of practical needs. Therefore, we realize that the review on the newly developed two-dimensional (2D) MXenes-based energy storage electrodes and devices fabricated through suitably advanced 3D printing technology is the need of the hour, and will be able to attract broad audiences of the related field. MXenes are a class of 2D materials having lamella structures that have shown great promise for energy storage applications due to their versatile redox behavior, high surface area, high electrical conductivity, and ability to accommodate intercalated ions. However, the processing of 2D MXenes suffers from serious agglomeration due to weak Van der Waals attraction and reduces its actual energy storage performances. In a few recent studies, it is observed that advanced 3D printing has enabled the fabrication of MXenes with complex and customized geometries, opening up new possibilities for developing high-performance energy storage devices. Therefore, this review is important for a comprehensive discussion on this topic. So, in this review, we discuss the recent breakthroughs in 3D printed MXene-based batteries and supercapacitors, the advantages of using 3D printing for the fabrication of tailor-designed MXenes-based ESDs, existing challenges, and the opportunities available for further exploration towards the successful commercialization of ESDs. Overall, this review is an insightful articulation for the future seeking to stay at the forefront of this exciting and rapidly-expanding field.
包括电池和超级电容器在内的能源存储设备(ESD)在向可再生能源的未来过渡中变得越来越重要，因为它们能够将间歇性可再生能源整合到电网中，并在停电时提供备用电源。已经有关于各种储能材料和系统的评论。然而，在选择合适的材料和制造技术方面的挑战尚未建立，以实现在实际需求的各个方面负担得起和高效的esd商业化。因此，我们意识到，对新开发的二维(2D) mxenes储能电极和通过适当先进的3D打印技术制造的器件的回顾是迫切需要的，并且将能够吸引相关领域的广泛受众。MXenes是一类具有片层结构的二维材料，由于其多功能氧化还原行为、高表面积、高导电性和容纳插入离子的能力，在储能应用中显示出巨大的前景。然而，由于Van der Waals引力较弱，二维MXenes在加工过程中存在严重的团聚现象，降低了其实际储能性能。在最近的一些研究中，可以观察到先进的3D打印已经能够制造具有复杂和定制几何形状的MXenes，为开发高性能储能设备开辟了新的可能性。因此，这一综述对于全面讨论这一主题具有重要意义。因此，在这篇综述中，我们讨论了3D打印基于mxenes的电池和超级电容器的最新突破，使用3D打印制造定制的基于mxenes的esd的优势，现有的挑战，以及进一步探索成功商业化的esd的机会。总的来说，这篇综述是对未来寻求保持在这个令人兴奋和快速发展的领域的前沿的有见地的阐述。
{"title":"3D Printing of MXenes-Based Electrodes for Energy Storage Applications","authors":"Aadharshini G, Nisha Gupta, P. Saha, Pallab Bhattacharya","doi":"10.21926/rpm.2302020","DOIUrl":"https://doi.org/10.21926/rpm.2302020","url":null,"abstract":"Energy storage devices (ESD) including batteries, and supercapacitors are becoming progressively imperative in the transition to a renewable energy future, as they enable the integration of intermittent renewable sources into the grid and provide backup power during outages. There are already reviews available on various energy storage materials and systems. However, the challenges in the choice of suitable materials and fabrication technology are yet to establish for the commercialization of affordable and efficient ESDs in every aspect of practical needs. Therefore, we realize that the review on the newly developed two-dimensional (2D) MXenes-based energy storage electrodes and devices fabricated through suitably advanced 3D printing technology is the need of the hour, and will be able to attract broad audiences of the related field. MXenes are a class of 2D materials having lamella structures that have shown great promise for energy storage applications due to their versatile redox behavior, high surface area, high electrical conductivity, and ability to accommodate intercalated ions. However, the processing of 2D MXenes suffers from serious agglomeration due to weak Van der Waals attraction and reduces its actual energy storage performances. In a few recent studies, it is observed that advanced 3D printing has enabled the fabrication of MXenes with complex and customized geometries, opening up new possibilities for developing high-performance energy storage devices. Therefore, this review is important for a comprehensive discussion on this topic. So, in this review, we discuss the recent breakthroughs in 3D printed MXene-based batteries and supercapacitors, the advantages of using 3D printing for the fabrication of tailor-designed MXenes-based ESDs, existing challenges, and the opportunities available for further exploration towards the successful commercialization of ESDs. Overall, this review is an insightful articulation for the future seeking to stay at the forefront of this exciting and rapidly-expanding field.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46011185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. S. Sun, Nahid Farzana, Dinesha Kuruppuarachchi, Mohammadamin Azimi, Huayuan Zhong
Infrastructure degradation attributable to concrete deterioration and corrosion of reinforcing steel has been a long-standing challenge to the owners and engineers. This problem becomes more evident when concrete structures are subject to aggressively corrosive environments. The use of advanced materials such as ultra-high performance concrete (UHPC) and carbon fiber reinforced polymer (CFRP) bars has a strong potential to overcome this challenge and help build new infrastructure that is durable and sustainable. However, structural behavior of members using both UHPC and CFRP bars has not been studied thoroughly in the United States and overseas, and no codes or specifications are readily available for structural engineers to follow. This paper presented an initial attempt to explore this topic by addressing the bond behavior between UHPC and CFRP bars through pullout tests. The test results showed that the UHPC specimens exhibited gradually increased slippage after the peak load and demonstrated superior bond performance in comparison with the conventional concrete specimens. Flexural tests were also conducted to compare the structural behavior of two large-scale beams, which were made of conventional concrete reinforced by steel bars and UHPC reinforced by CFRP bars, respectively. Test results showed that the UHPC beam did not exhibit as much ductility as the conventional beam, as predicted. However, there was still sufficient warning of impending failure in a form of extensive cracking and substantial deflection attributable to the bridging effect of the steel fibers. Further, flexural strength analysis of the UHPC beam using CFRP bars was discussed satisfying strain compatibility and force equilibrium, which provided a guidance for structural engineers to design such members. The research approach adopted in this paper may be applicable to study UHPC beams using other types of FRP materials.
{"title":"Experimental and Analytical Studies of an Ultra-high Performance Concrete Beam Using Carbon Fiber Reinforced Polymer Bars","authors":"C. S. Sun, Nahid Farzana, Dinesha Kuruppuarachchi, Mohammadamin Azimi, Huayuan Zhong","doi":"10.21926/rpm.2302019","DOIUrl":"https://doi.org/10.21926/rpm.2302019","url":null,"abstract":"Infrastructure degradation attributable to concrete deterioration and corrosion of reinforcing steel has been a long-standing challenge to the owners and engineers. This problem becomes more evident when concrete structures are subject to aggressively corrosive environments. The use of advanced materials such as ultra-high performance concrete (UHPC) and carbon fiber reinforced polymer (CFRP) bars has a strong potential to overcome this challenge and help build new infrastructure that is durable and sustainable. However, structural behavior of members using both UHPC and CFRP bars has not been studied thoroughly in the United States and overseas, and no codes or specifications are readily available for structural engineers to follow. This paper presented an initial attempt to explore this topic by addressing the bond behavior between UHPC and CFRP bars through pullout tests. The test results showed that the UHPC specimens exhibited gradually increased slippage after the peak load and demonstrated superior bond performance in comparison with the conventional concrete specimens. Flexural tests were also conducted to compare the structural behavior of two large-scale beams, which were made of conventional concrete reinforced by steel bars and UHPC reinforced by CFRP bars, respectively. Test results showed that the UHPC beam did not exhibit as much ductility as the conventional beam, as predicted. However, there was still sufficient warning of impending failure in a form of extensive cracking and substantial deflection attributable to the bridging effect of the steel fibers. Further, flexural strength analysis of the UHPC beam using CFRP bars was discussed satisfying strain compatibility and force equilibrium, which provided a guidance for structural engineers to design such members. The research approach adopted in this paper may be applicable to study UHPC beams using other types of FRP materials.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45829654","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study evaluates the influence of different loading angles and the area of loading on the ensuing stress distribution and the physical response of a natural central incisor tooth, using a 3D finite element analysis. The CAD model of the incisor tooth assembly (including enamel, dentin, periodontal ligament, pulp, gingiva and jaw bone) was subject to an external (chewing) load of 100 N, over four different areas and at four different angles along the vertical. It was observed that the tooth experiences high von-Mises equivalent stresses and high bending when the load applied is closer to the incisal edge of the crown. Also, the stresses on the dentin, in general, increased with the increase in the loading angle regardless of the area of loading; with the highest stress (~70 MPa) generated at 45° angle. The percentage change observed in dentin von-Mises stresses was higher than that of enamel when the loading angle was increased from 0° to 45°, because of the higher stiffness of enamel and structural differences in enamel and dentin. The numerical results indicated that applying loads on incisal edge would simulate a severe loading condition for the incisor tooth.
{"title":"Physiological Response of a Natural Central Incisor Tooth to Various Loading Conditions: A 3D Finite Element Study","authors":"D. Nikam, Abbas S. Milani","doi":"10.21926/rpm.2302017","DOIUrl":"https://doi.org/10.21926/rpm.2302017","url":null,"abstract":"This study evaluates the influence of different loading angles and the area of loading on the ensuing stress distribution and the physical response of a natural central incisor tooth, using a 3D finite element analysis. The CAD model of the incisor tooth assembly (including enamel, dentin, periodontal ligament, pulp, gingiva and jaw bone) was subject to an external (chewing) load of 100 N, over four different areas and at four different angles along the vertical. It was observed that the tooth experiences high von-Mises equivalent stresses and high bending when the load applied is closer to the incisal edge of the crown. Also, the stresses on the dentin, in general, increased with the increase in the loading angle regardless of the area of loading; with the highest stress (~70 MPa) generated at 45° angle. The percentage change observed in dentin von-Mises stresses was higher than that of enamel when the loading angle was increased from 0° to 45°, because of the higher stiffness of enamel and structural differences in enamel and dentin. The numerical results indicated that applying loads on incisal edge would simulate a severe loading condition for the incisor tooth.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41790610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Mahboob, Omid Hassanshahi, Abdulqaiyoum Hakimi, M. Safi
The largest proportion of the material used in multistory buildings, and thus its carbon impact, is attributed to their slabs being the main contributor of weight. Because of their high strength and concrete self-weight reduction, composite beams with hollow-core slabs were created for their technical and economic benefits, making this system inexpensive and with a reduced environmental impact, thereby lowering carbon emissions. Geometrically, the hollow slab has a sequence of T and L form pieces on both sides. Hollow slabs are a newer roof feature with a little study undertaken in mechanical characteristics that prove its benefits and downsides in construction. It also has sufficient rigidity. In this work, numerous 19 hollow slabs and flat slabs are modeled using the finite element method, and the findings are compared in terms of hollow slab behavior and economic cost. It demonstrates that reducing the concrete beneath the hollow slab promotes cost-efficiency and the effective use of concrete and steel resources and various approaches for this form of the hollow slab are provided. Implementing a modern double-side beam slab is possible using the presented methods in this paper. It opens a door for creating structures with high stiffness and strength versus vertical and lateral load, along with low material volume.
{"title":"Evaluating the Performance of Hollow Core Slabs (HCS)-Concrete and Simplifying Their Implementation","authors":"A. Mahboob, Omid Hassanshahi, Abdulqaiyoum Hakimi, M. Safi","doi":"10.21926/rpm.2302016","DOIUrl":"https://doi.org/10.21926/rpm.2302016","url":null,"abstract":"The largest proportion of the material used in multistory buildings, and thus its carbon impact, is attributed to their slabs being the main contributor of weight. Because of their high strength and concrete self-weight reduction, composite beams with hollow-core slabs were created for their technical and economic benefits, making this system inexpensive and with a reduced environmental impact, thereby lowering carbon emissions. Geometrically, the hollow slab has a sequence of T and L form pieces on both sides. Hollow slabs are a newer roof feature with a little study undertaken in mechanical characteristics that prove its benefits and downsides in construction. It also has sufficient rigidity. In this work, numerous 19 hollow slabs and flat slabs are modeled using the finite element method, and the findings are compared in terms of hollow slab behavior and economic cost. It demonstrates that reducing the concrete beneath the hollow slab promotes cost-efficiency and the effective use of concrete and steel resources and various approaches for this form of the hollow slab are provided. Implementing a modern double-side beam slab is possible using the presented methods in this paper. It opens a door for creating structures with high stiffness and strength versus vertical and lateral load, along with low material volume.","PeriodicalId":87352,"journal":{"name":"Recent progress in materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43969791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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