Chi Zhan, Mingzhe Li, R. Mccoy, Linda Zhao, Weiyi Lu
Re-entrant honeycombs with negative Poisson’s ratio have shown great potential as lightweight energy absorbers for various applications. However, due to its bending-dominated behavior, the structural stability and energy absorption capacity of reentrant honeycombs are yet to be further improved. It has been demonstrated that hierarchical structures exhibit a combination of lightweight and superior mechanical properties. We hypothesize that by introducing the triangular hierarchical substructures into the conventional cell walls, the bending-dominated behavior of re-entrant honeycombs can be converted into the stretching-dominated one. Consequently, the overall structural stability of the hierarchical re-entrant honeycombs can be promoted through local deformation of hierarchy, which can potentially benefit the energy absorption capacity of the resulted structure. To test our hypothesis, we first fabricate the hierarchical reentrant honeycombs with length scale ranging from micrometer to centimeter using Polyjet 3D-printing technique. Regular reentrant honeycombs with solid struts have been fabricated as baseline structures. The mechanical performance of the honeycombs has been characterized through uniaxial quasi-static compression tests. Besides, the local deformation mechanisms of the hierarchical structure have been revealed by the Digital Image Correlation (DIC). In comparison to the regular re-entrant honeycomb, the global failure strain of hierarchical re-entrant honeycomb is enhanced by 36%. This is due to the improved structural stability from local fracture and densification of the triangular hierarchy. Both the regular and hierarchical honeycombs exhibit the same specific energy absorption capacity. As predicted by the existing scaling laws, the hierarchical re-entrant honeycomb has great potential to outperform regular one by optimizing the relative density of the structure. A finite element model of the hierarchical re-entrant honeycomb has been developed by using commercial software Abaqus/CAE 2020. The model has been calibrated by the experimental data. Within the elastic region, the simulated deformation modes show good agreement with experimental observations. When the relative density of the regular re-entrant honeycombs equals to the hierarchical ones, the model predicts that the hierarchical re-entrant honeycombs have superior energy absorption performance with enhanced stiffness and yield strength in comparison to the regular ones. In conclusion, this study has demonstrated that by introducing hierarchical structure into re-entrant honeycomb, the structural stability has been improved. Furthermore, the hierarchical structure endows re-entrant honeycomb with lightweight yet competitive energy absorption capacity.
{"title":"3D-Printed Hierarchical Re-Entrant Honeycomb With Improved Structural Stability Under Quasi-Static Compressive Loading","authors":"Chi Zhan, Mingzhe Li, R. Mccoy, Linda Zhao, Weiyi Lu","doi":"10.1115/imece2021-68961","DOIUrl":"https://doi.org/10.1115/imece2021-68961","url":null,"abstract":"\u0000 Re-entrant honeycombs with negative Poisson’s ratio have shown great potential as lightweight energy absorbers for various applications. However, due to its bending-dominated behavior, the structural stability and energy absorption capacity of reentrant honeycombs are yet to be further improved. It has been demonstrated that hierarchical structures exhibit a combination of lightweight and superior mechanical properties. We hypothesize that by introducing the triangular hierarchical substructures into the conventional cell walls, the bending-dominated behavior of re-entrant honeycombs can be converted into the stretching-dominated one. Consequently, the overall structural stability of the hierarchical re-entrant honeycombs can be promoted through local deformation of hierarchy, which can potentially benefit the energy absorption capacity of the resulted structure.\u0000 To test our hypothesis, we first fabricate the hierarchical reentrant honeycombs with length scale ranging from micrometer to centimeter using Polyjet 3D-printing technique. Regular reentrant honeycombs with solid struts have been fabricated as baseline structures. The mechanical performance of the honeycombs has been characterized through uniaxial quasi-static compression tests. Besides, the local deformation mechanisms of the hierarchical structure have been revealed by the Digital Image Correlation (DIC). In comparison to the regular re-entrant honeycomb, the global failure strain of hierarchical re-entrant honeycomb is enhanced by 36%. This is due to the improved structural stability from local fracture and densification of the triangular hierarchy. Both the regular and hierarchical honeycombs exhibit the same specific energy absorption capacity. As predicted by the existing scaling laws, the hierarchical re-entrant honeycomb has great potential to outperform regular one by optimizing the relative density of the structure.\u0000 A finite element model of the hierarchical re-entrant honeycomb has been developed by using commercial software Abaqus/CAE 2020. The model has been calibrated by the experimental data. Within the elastic region, the simulated deformation modes show good agreement with experimental observations. When the relative density of the regular re-entrant honeycombs equals to the hierarchical ones, the model predicts that the hierarchical re-entrant honeycombs have superior energy absorption performance with enhanced stiffness and yield strength in comparison to the regular ones.\u0000 In conclusion, this study has demonstrated that by introducing hierarchical structure into re-entrant honeycomb, the structural stability has been improved. Furthermore, the hierarchical structure endows re-entrant honeycomb with lightweight yet competitive energy absorption capacity.","PeriodicalId":23837,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications","volume":"55 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79431109","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}
P. Capela, S. Carvalho, S. Costa, S. Souza, M. Pereira, L. Carvalho, J. Gomes, D. Soares
Grinding wheels are used in manufacturing industry to shape and finish different types of materials. To achieve this purpose, the wear resistance of grinding materials and the capacity to promote wear on the opposing surface determine the performance of the grinding part. During the grinding operations high temperatures are developed in the wheel/piece contact which can cause several problems like working material microstructural changes, internal defects (fissures...). In the last years, superficial structured wheels have been developed in order to reduce contact temperature and improve the grinding efficiency and the quality of the produced surface. In this work, two types of channels structures were produced on the surface of a vitrified alumina abrasive composite with: hexagonal and spiral geometries (active area of 95.3 and 91.6%, respectively). The obtained composites produced were characterized in terms of physical properties (density and porosity) and geometric channel features. In order to evaluate the changes on the wear rate and surface morphology pin-on-disc wear tests were performed under lubricated conditions at constant load (20 N) and sliding speed (0.5 m.s−1), at room temperature. An alumina rod (∅5 mm) was used as counterface material creating particularly hard contact conditions. The wear rate of both mating surfaces was measured by gravimetric method. The worn surfaces were characterized by SEM analysis and the tribological results were correlated with the physical properties of the composites and the introduced cooling channels. The dominant wear mechanisms, as identified by SEM analysis, were fine scale abrasive wear of the protruding load carrying particles, which is featured by the formation of wear flats, together with debonding of ceramic particles from the composite contact surface. Comparing with traditional wheels (without cooling channels), a decrease of the wear rate on disc side of 35 and 42% was obtained for, respectively, spiral and hexagonal channel geometries. On the alumina opposite counterface, the wear rate increases 10 and 47% for, respectively, hexagonal and spiral geometries. A significant improvement on the abrasive performance (a wear rate decreases on the abrasive wheel and an increase on the counterface) was achieved with the addition of the two types of channel geometries. The best combination of results (composite and counterface) was obtained for the spiral configuration of the cooling channels (grinding ratio of 0.86).
{"title":"Wear Behavior of Grinding Wheels With Superficial Cooling Channels","authors":"P. Capela, S. Carvalho, S. Costa, S. Souza, M. Pereira, L. Carvalho, J. Gomes, D. Soares","doi":"10.1115/imece2021-72319","DOIUrl":"https://doi.org/10.1115/imece2021-72319","url":null,"abstract":"\u0000 Grinding wheels are used in manufacturing industry to shape and finish different types of materials. To achieve this purpose, the wear resistance of grinding materials and the capacity to promote wear on the opposing surface determine the performance of the grinding part. During the grinding operations high temperatures are developed in the wheel/piece contact which can cause several problems like working material microstructural changes, internal defects (fissures...). In the last years, superficial structured wheels have been developed in order to reduce contact temperature and improve the grinding efficiency and the quality of the produced surface.\u0000 In this work, two types of channels structures were produced on the surface of a vitrified alumina abrasive composite with: hexagonal and spiral geometries (active area of 95.3 and 91.6%, respectively). The obtained composites produced were characterized in terms of physical properties (density and porosity) and geometric channel features. In order to evaluate the changes on the wear rate and surface morphology pin-on-disc wear tests were performed under lubricated conditions at constant load (20 N) and sliding speed (0.5 m.s−1), at room temperature. An alumina rod (∅5 mm) was used as counterface material creating particularly hard contact conditions. The wear rate of both mating surfaces was measured by gravimetric method. The worn surfaces were characterized by SEM analysis and the tribological results were correlated with the physical properties of the composites and the introduced cooling channels. The dominant wear mechanisms, as identified by SEM analysis, were fine scale abrasive wear of the protruding load carrying particles, which is featured by the formation of wear flats, together with debonding of ceramic particles from the composite contact surface. Comparing with traditional wheels (without cooling channels), a decrease of the wear rate on disc side of 35 and 42% was obtained for, respectively, spiral and hexagonal channel geometries. On the alumina opposite counterface, the wear rate increases 10 and 47% for, respectively, hexagonal and spiral geometries. A significant improvement on the abrasive performance (a wear rate decreases on the abrasive wheel and an increase on the counterface) was achieved with the addition of the two types of channel geometries. The best combination of results (composite and counterface) was obtained for the spiral configuration of the cooling channels (grinding ratio of 0.86).","PeriodicalId":23837,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85344998","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}
M. Vilarinho, P. Araújo, J. Teixeira, Elisabete Silva, Dionísio Silveira, D. Soares, M. Paiva, Daniel Ribeiro, Marisa Branco
The protection of human life and goods assumes a growing concern in all forms of activities. The fire and smoke curtains act as a physical barrier to prevent the fire from spreading between spaces as well as to staunch the smoke and heat transfer to adjacent areas, while causing minimal interference. Usually, curtains are based on fiber structures that can be coated to enhance their protective capabilities. Also, the fiber structure can be developed into a complex pattern of 2D and 3D threads, with single or multiple materials that can be tailored to optimize its behavior. The thermal and fire protection depends on the fibers, fabric pattern and coatings. The present paper reports the development of novel coated structures of fibers used for fire protection curtains. Basalt and glass fibers are used as yarn materials. Following the certification standards the samples were assessed for their thermal resistance by measuring the temperature differential they provide while their integrity is evaluated. The sample is placed under stress in an attempt to mimic its own weight effect when in service. The temperature is monitored using thermocouples which are placed at both sides of the fabric and the integrity parameter is assessed through the occurrence of fabric rupture and smoke and/or odor release motivated by its deterioration. Regarding the uncoated samples, the one composed of glass-fiber in both directions presents the best thermal performance. The addition of an alumina coating significantly improves the performance of all samples. However, while a thinner (0.05 μm) alumina layer provides better results for the sample with glass-fiber in both warp and weft directions, the behavior of samples composed of glass-fiber and basalt is superior when a thicker (0.3 μm) alumina layer is used. In both cases, an alumina coating application results in an increase of the gradient temperature (between curtain inside/outside temperatures) of about 38.0% (310.0 °C vs. 427.0 °C for the first and 386.0 °C vs. 526.0 °C for the latter.
在所有形式的活动中，对人的生命和财产的保护日益受到关注。防火和防烟帘作为物理屏障，防止火灾在空间之间蔓延，并阻止烟雾和热量传递到邻近区域，同时造成最小的干扰。通常，窗帘是基于纤维结构，可以涂覆以增强其防护能力。此外，纤维结构可以发展成2D和3D螺纹的复杂图案，可以使用单一或多种材料进行定制以优化其性能。隔热和防火性能取决于纤维、织物图案和涂层。本文报道了用于防火窗帘的新型纤维涂层结构的发展。玄武岩纤维和玻璃纤维是纱线的原料。根据认证标准，通过测量样品提供的温差来评估样品的耐热性，同时评估样品的完整性。样品被置于压力下，试图模拟其在使用时的重量效应。使用放置在织物两侧的热电偶来监测温度，并通过织物破裂的发生以及由其劣化引起的烟雾和/或气味释放来评估完整性参数。对于未包覆的样品，双向玻璃纤维组成的样品表现出最好的热性能。氧化铝涂层的加入显著提高了所有样品的性能。然而，当氧化铝层较薄(0.05 μm)时，经向和纬向玻璃纤维样品的性能都较好，而当氧化铝层较厚(0.3 μm)时，玻璃纤维和玄武岩样品的性能都较好。在这两种情况下，氧化铝涂层的应用导致梯度温度(窗帘内外温度之间)增加约38.0%(310.0°C vs. 427.0°C, 386.0°C vs. 526.0°C)。
{"title":"Influence of Coating on High Performance Heat Resistant Textile Curtains","authors":"M. Vilarinho, P. Araújo, J. Teixeira, Elisabete Silva, Dionísio Silveira, D. Soares, M. Paiva, Daniel Ribeiro, Marisa Branco","doi":"10.1115/imece2021-73307","DOIUrl":"https://doi.org/10.1115/imece2021-73307","url":null,"abstract":"\u0000 The protection of human life and goods assumes a growing concern in all forms of activities. The fire and smoke curtains act as a physical barrier to prevent the fire from spreading between spaces as well as to staunch the smoke and heat transfer to adjacent areas, while causing minimal interference. Usually, curtains are based on fiber structures that can be coated to enhance their protective capabilities. Also, the fiber structure can be developed into a complex pattern of 2D and 3D threads, with single or multiple materials that can be tailored to optimize its behavior. The thermal and fire protection depends on the fibers, fabric pattern and coatings.\u0000 The present paper reports the development of novel coated structures of fibers used for fire protection curtains. Basalt and glass fibers are used as yarn materials.\u0000 Following the certification standards the samples were assessed for their thermal resistance by measuring the temperature differential they provide while their integrity is evaluated. The sample is placed under stress in an attempt to mimic its own weight effect when in service. The temperature is monitored using thermocouples which are placed at both sides of the fabric and the integrity parameter is assessed through the occurrence of fabric rupture and smoke and/or odor release motivated by its deterioration.\u0000 Regarding the uncoated samples, the one composed of glass-fiber in both directions presents the best thermal performance. The addition of an alumina coating significantly improves the performance of all samples. However, while a thinner (0.05 μm) alumina layer provides better results for the sample with glass-fiber in both warp and weft directions, the behavior of samples composed of glass-fiber and basalt is superior when a thicker (0.3 μm) alumina layer is used. In both cases, an alumina coating application results in an increase of the gradient temperature (between curtain inside/outside temperatures) of about 38.0% (310.0 °C vs. 427.0 °C for the first and 386.0 °C vs. 526.0 °C for the latter.","PeriodicalId":23837,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86509342","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}
High yield HY-100 steel is a unique alloy and well known for its employment in heavy construction. HY-100 offers good characteristics like ductility, notch toughness, corrosion resistance, and weldability. The physical characteristics and molecular structure of HY-100 steel are also well known; however, there is little known about the effect of high-velocity projectiles impact on this metal alloy’s crystalline structure and material phase. The effects of high-speed velocity impact on the crystalline structure and material phase changes are studied herein experimentally. The results of an impact on the crystalline structure are assessed by impacting HY-100 steel plates (15.4 × 15.4 × 1.27 cm) with Lexan projectiles. A two-stage light gas gun accelerates these projectiles to a velocity of 6.70 km/s at the point of the impact. The impacted plates’ surfaces are prepared as required for inspection by the Electron Back Scatter Diffraction (EBSD) microscope. Ten regions on each impacted plate area are examined and analyzed after impact. These regions are selected from the area immediately under the impact crater to locations that are not physically affected by the impact. Observations of collected EBSD images show that the predominant phase is Body-Centered Cubic (BCC). Moreover, Face-Centered Cubic (FCC) and Hexagonal-Close-Packed (HCP) phases are also indexed. The samples are also post-impact examined for molecular structure allocation changes. The results were then tabulated according to the regions relative to the impact crater. In this study, traces of HCP were found at some locations in all post-impact stages. This study also indicates that the BCC crystalline structure remained the dominant phase structure after impact, and it is valid with all test samples and all levels of shock loading. At this velocity, the damage zone develops within 5 microseconds due to impacting momentum. HY-100 steel materials go through a reversible phase change when subject to elevated temperature and high quasi-static pressure.
{"title":"Crystalline Phase Changes Due to High-Speed Projectiles Impact on HY100 Steel","authors":"Muna Y. Slewa","doi":"10.1115/imece2021-69956","DOIUrl":"https://doi.org/10.1115/imece2021-69956","url":null,"abstract":"High yield HY-100 steel is a unique alloy and well known for its employment in heavy construction. HY-100 offers good characteristics like ductility, notch toughness, corrosion resistance, and weldability. The physical characteristics and molecular structure of HY-100 steel are also well known; however, there is little known about the effect of high-velocity projectiles impact on this metal alloy’s crystalline structure and material phase. The effects of high-speed velocity impact on the crystalline structure and material phase changes are studied herein experimentally. The results of an impact on the crystalline structure are assessed by impacting HY-100 steel plates (15.4 × 15.4 × 1.27 cm) with Lexan projectiles. A two-stage light gas gun accelerates these projectiles to a velocity of 6.70 km/s at the point of the impact. The impacted plates’ surfaces are prepared as required for inspection by the Electron Back Scatter Diffraction (EBSD) microscope. Ten regions on each impacted plate area are examined and analyzed after impact. These regions are selected from the area immediately under the impact crater to locations that are not physically affected by the impact. Observations of collected EBSD images show that the predominant phase is Body-Centered Cubic (BCC). Moreover, Face-Centered Cubic (FCC) and Hexagonal-Close-Packed (HCP) phases are also indexed. The samples are also post-impact examined for molecular structure allocation changes. The results were then tabulated according to the regions relative to the impact crater. In this study, traces of HCP were found at some locations in all post-impact stages. This study also indicates that the BCC crystalline structure remained the dominant phase structure after impact, and it is valid with all test samples and all levels of shock loading. At this velocity, the damage zone develops within 5 microseconds due to impacting momentum. HY-100 steel materials go through a reversible phase change when subject to elevated temperature and high quasi-static pressure.","PeriodicalId":23837,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73665207","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}
Palladium hydride (Pd-H) is a metallic palladium that can absorb substantial amount of H at room temperature. Because this H absorption is recoverable, it can be utilized in a variety of energy applications. When Pd is alloyed with silver (Ag), sulfur poisoning remains a problem, but adding Ag improves Pd mechanical properties, boosts hydrogen permeability and solubility, and narrows the Pd-H system miscibility gap region. Pd alloyed with copper (Cu) has a lower H permeability and solubility compared to pure Pd and Pd-Ag alloys, but adding Cu gives better sulfur and carbon monoxide poisoning resistance and hydrogen embrittlement resistance, as well as better mechanical properties and a wider operating temperature range than pure Pd. These findings show that alloying Pd with a mix of Ag and Cu to make Pd-Ag-Cu ternary alloys improves Pd’s overall performance while also lowering its cost. Thus, in this paper, we provide the first embedded atom method potentials (EAM) for the quaternary hydrides Pd1-y-zAgyCuzHx. The EAM potentials can capture the preferred H occupancy locations, and determine the trends for the cohesive energies, lattice constants and elastic constants during MD simulations. The potentials also captured the existence of a miscibility gap for the Pd1-y-zAgyCuzHx and predicted it to narrow and disappear when Ag and Cu concentration increases, as was predicted by the experimental findings.
{"title":"Potentials for PdAgCu Metal Hydrides Energy Simulations","authors":"I. Hijazi, Chaonan Zhang, Robert Fuller","doi":"10.1115/imece2021-71494","DOIUrl":"https://doi.org/10.1115/imece2021-71494","url":null,"abstract":"\u0000 Palladium hydride (Pd-H) is a metallic palladium that can absorb substantial amount of H at room temperature. Because this H absorption is recoverable, it can be utilized in a variety of energy applications. When Pd is alloyed with silver (Ag), sulfur poisoning remains a problem, but adding Ag improves Pd mechanical properties, boosts hydrogen permeability and solubility, and narrows the Pd-H system miscibility gap region. Pd alloyed with copper (Cu) has a lower H permeability and solubility compared to pure Pd and Pd-Ag alloys, but adding Cu gives better sulfur and carbon monoxide poisoning resistance and hydrogen embrittlement resistance, as well as better mechanical properties and a wider operating temperature range than pure Pd. These findings show that alloying Pd with a mix of Ag and Cu to make Pd-Ag-Cu ternary alloys improves Pd’s overall performance while also lowering its cost. Thus, in this paper, we provide the first embedded atom method potentials (EAM) for the quaternary hydrides Pd1-y-zAgyCuzHx. The EAM potentials can capture the preferred H occupancy locations, and determine the trends for the cohesive energies, lattice constants and elastic constants during MD simulations. The potentials also captured the existence of a miscibility gap for the Pd1-y-zAgyCuzHx and predicted it to narrow and disappear when Ag and Cu concentration increases, as was predicted by the experimental findings.","PeriodicalId":23837,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications","volume":"36 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81430963","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}
The interaction between the CNT network and the surrounding polymer and between BP and the surrounding polymer occurs via interphase with different morphology than the bulk matrix. This interphase’s properties have not been given enough attention in the literature, and the purpose of this study is to investigate the interphase properties experimentally and analytically. Atomic Force Microscopy based Peak Force Quantitative Nanomechanics Mapping (PFQNM) technique with the high lateral resolution was used for the characterization of the interphase in 3-phase polymer matrix nano-composites at the nanoscale. Details of the calibration parameters such as probe stiffness, spring constant, tip radius, tapping force, deformation level, synchronous distance, drive3 amplitude sensitivity (DDS3), and deflection sensitivity were discussed. AFM Multimode 8, scanner type J with a maximum scanning window of 125μm × 125μm, was used. The Derjaguin, Muller, Toropov (DMT) equation was applied to the retract curve to calculate the elastic modulus. BP is heterogeneous at the nanoscale due to nonuniform resin impregnation. The average interphase thickness for the CNT network is 27nm in BP, higher than ∼10nm between epoxy and fiber, confirming stronger interphase. The CNT network size in BP nanocomposite is influenced by the inter-bundle and intra-bundle pores in the BP. The Kolarik, Quali, and Takayanagi models for interphase of the CNT network were investigated.
{"title":"Experimental Approach and Conventional Analytical Techniques to the Carbon Nanotube Network Interphase in 3-Phase Polymer Matrix Nano-Composites","authors":"Masoud Yekani Fard, Joel Swanstrom","doi":"10.1115/imece2021-70589","DOIUrl":"https://doi.org/10.1115/imece2021-70589","url":null,"abstract":"\u0000 The interaction between the CNT network and the surrounding polymer and between BP and the surrounding polymer occurs via interphase with different morphology than the bulk matrix. This interphase’s properties have not been given enough attention in the literature, and the purpose of this study is to investigate the interphase properties experimentally and analytically. Atomic Force Microscopy based Peak Force Quantitative Nanomechanics Mapping (PFQNM) technique with the high lateral resolution was used for the characterization of the interphase in 3-phase polymer matrix nano-composites at the nanoscale. Details of the calibration parameters such as probe stiffness, spring constant, tip radius, tapping force, deformation level, synchronous distance, drive3 amplitude sensitivity (DDS3), and deflection sensitivity were discussed. AFM Multimode 8, scanner type J with a maximum scanning window of 125μm × 125μm, was used. The Derjaguin, Muller, Toropov (DMT) equation was applied to the retract curve to calculate the elastic modulus. BP is heterogeneous at the nanoscale due to nonuniform resin impregnation. The average interphase thickness for the CNT network is 27nm in BP, higher than ∼10nm between epoxy and fiber, confirming stronger interphase. The CNT network size in BP nanocomposite is influenced by the inter-bundle and intra-bundle pores in the BP. The Kolarik, Quali, and Takayanagi models for interphase of the CNT network were investigated.","PeriodicalId":23837,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90457665","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 manuscript introduces the challenges in the fabrication of graphene sheet reinforced non-crimp fabric (NCF) composite laminates and their influence on the interlaminar strength of the composite laminates. In the current work, the laminates were fabricated using non-crimp carbon fabric prepreg along with 50,120 and 240 μm thick graphene sheets at the mid-plane. Double Cantilever Beam (DCB) tests are done as per ASTM 5528 using INSTRON electromechanical testing system. Modified Beam Theory method used to compute Mode I fracture toughness, using load, displacement, specimen dimension, and crack opening displacement. The graphene sheets are brittle; little bonding between the graphene and matrix observed during the fabrication process results in a fragile interface. To overcome this problem, graphene sheets were converted into a lattice structure. The lattice structure used in the present research had horizontal, vertical, and square grids. Effects of sheet thickness, grid pattern were evaluated by Mode I fracture toughness, with and without nanoengineered enhanced laminates. Axio Image upright microscope used to compare the bonding at the midplane after the DCB test. The results indicate that the composite laminates fabricated using lattice graphene structure had better interlaminar strength than the laminates fabricated with straight graphene sheets.
{"title":"Fabrication, Processing and Characterization of Carbon Fibre Reinforced Laminated Composite Embedded With Graphene Lattice Sheets","authors":"V. Jadhav, A. Kelkar","doi":"10.1115/imece2021-71191","DOIUrl":"https://doi.org/10.1115/imece2021-71191","url":null,"abstract":"\u0000 This manuscript introduces the challenges in the fabrication of graphene sheet reinforced non-crimp fabric (NCF) composite laminates and their influence on the interlaminar strength of the composite laminates. In the current work, the laminates were fabricated using non-crimp carbon fabric prepreg along with 50,120 and 240 μm thick graphene sheets at the mid-plane. Double Cantilever Beam (DCB) tests are done as per ASTM 5528 using INSTRON electromechanical testing system. Modified Beam Theory method used to compute Mode I fracture toughness, using load, displacement, specimen dimension, and crack opening displacement.\u0000 The graphene sheets are brittle; little bonding between the graphene and matrix observed during the fabrication process results in a fragile interface. To overcome this problem, graphene sheets were converted into a lattice structure. The lattice structure used in the present research had horizontal, vertical, and square grids. Effects of sheet thickness, grid pattern were evaluated by Mode I fracture toughness, with and without nanoengineered enhanced laminates. Axio Image upright microscope used to compare the bonding at the midplane after the DCB test. The results indicate that the composite laminates fabricated using lattice graphene structure had better interlaminar strength than the laminates fabricated with straight graphene sheets.","PeriodicalId":23837,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications","volume":"122 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87730428","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}
Climate change and its related effects are imposing severe stress on the current freshwater supplies. This has been exacerbated due to the growth in population, rapid industrialization, and increased energy demand. Increased water requirement is a global challenge. Although more than 70% of the Earth is covered by water, much of it is unusable for human use. Freshwater reservoirs, ponds, and subterranean aquifers account for just 2.5% of the world’s overall freshwater availability. Unfortunately, these water supplies are not very unevenly spread. Therefore, the need to augment these supplies through the desalination of seawater or brackish water. Reverse osmosis (RO) is currently the most widespread method of desalination. However, the unit cost of water is still high partly due to the thin-film composite (TFC) polymer membranes used in the current desalination system. Thus the need for low-cost nanomaterials for Water Desalination and Purification. A promising way to meet this demand is to use two-dimensional (2D) nanoporous materials such as graphene and MoS2 to minimize energy consumption during the desalination process. New nanotechnology methodologies that apply reverse osmosis have been developed. Among some of these technologies is using 2D materials such as graphene and MoS2, which have been studied extensively for water desalination. Single-layer nanoporous 2D materials such as graphene and MoS2 promises better filtrations in the water channel. Although single-layer MoS2 (SL_MoS2) membrane have much promise in the RO desalination membrane, multilayer MoS2 are simpler to make and more cost-efficient. Building on the SL_MoS2 membrane knowledge, we have used the molecular dynamics method (MD) to explore the effects of multilayer MoS2 in water desalination. This comparison is made as a function of the pore size, water flow rate and salt rejection. In addition, we also looked at the effect of the increased interlayer spacing between layers of the nanoporous 2D membrane and then made the comparison. The ions rejection follows the trend trilayer> bilayer> monolayer from results obtained, averaging over all three membrane types studied for the MoS2, the ions rejection follows the trend trilayer > bilayer > monolayer. We find that the thin, narrow layer separation plays a vital role in the successful rejection of salt ions in bilayers and trilayers membranes. These findings will help build and proliferate tunable nanodevices for filtration and other applications.
{"title":"Multilayer Separation Effects on MoS2 Membranes in Water Desalination","authors":"P. Oviroh, S. Oyinbo, Sina Karimzadeh, T. Jen","doi":"10.1115/imece2021-69156","DOIUrl":"https://doi.org/10.1115/imece2021-69156","url":null,"abstract":"\u0000 Climate change and its related effects are imposing severe stress on the current freshwater supplies. This has been exacerbated due to the growth in population, rapid industrialization, and increased energy demand. Increased water requirement is a global challenge. Although more than 70% of the Earth is covered by water, much of it is unusable for human use. Freshwater reservoirs, ponds, and subterranean aquifers account for just 2.5% of the world’s overall freshwater availability. Unfortunately, these water supplies are not very unevenly spread. Therefore, the need to augment these supplies through the desalination of seawater or brackish water.\u0000 Reverse osmosis (RO) is currently the most widespread method of desalination. However, the unit cost of water is still high partly due to the thin-film composite (TFC) polymer membranes used in the current desalination system. Thus the need for low-cost nanomaterials for Water Desalination and Purification. A promising way to meet this demand is to use two-dimensional (2D) nanoporous materials such as graphene and MoS2 to minimize energy consumption during the desalination process. New nanotechnology methodologies that apply reverse osmosis have been developed. Among some of these technologies is using 2D materials such as graphene and MoS2, which have been studied extensively for water desalination.\u0000 Single-layer nanoporous 2D materials such as graphene and MoS2 promises better filtrations in the water channel. Although single-layer MoS2 (SL_MoS2) membrane have much promise in the RO desalination membrane, multilayer MoS2 are simpler to make and more cost-efficient. Building on the SL_MoS2 membrane knowledge, we have used the molecular dynamics method (MD) to explore the effects of multilayer MoS2 in water desalination. This comparison is made as a function of the pore size, water flow rate and salt rejection. In addition, we also looked at the effect of the increased interlayer spacing between layers of the nanoporous 2D membrane and then made the comparison.\u0000 The ions rejection follows the trend trilayer> bilayer> monolayer from results obtained, averaging over all three membrane types studied for the MoS2, the ions rejection follows the trend trilayer > bilayer > monolayer. We find that the thin, narrow layer separation plays a vital role in the successful rejection of salt ions in bilayers and trilayers membranes. These findings will help build and proliferate tunable nanodevices for filtration and other applications.","PeriodicalId":23837,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86932905","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}
Multi-scale modelling is a cornerstone for the relatively new class of hierarchical materials which can perform multifunctional tasks, owing to their electrical, magnetic or thermal properties. Careful design strategies are to be devised, in-order to maintain their multi-functionality over the expected range of operation. In this study, we focus on these materials, which can be manufactured using a specialized technique of additive manufacturing, known as fused deposition modelling (FDM), owing to its flexibility and compatibility, working with polymer based materials. A review has been made on the various parameters affecting the manufacturing process, and how these variations can affect the properties of the end product. Future research directions are also pointed out, including stimuli responsive printing technique, popularly known as 4D printing and integration of neural networks into the manufacturing process which can improve the overall design lifecycle efficiency. This can involve autonomous production of test specimen, and revert back the data for model improvement, thereby enhancing predictive capabilities. The major focus of this work is on how we can use our current knowledge and techniques in the design of efficient and effective multifunctional composite materials from the bottoms-up approach.
{"title":"Multiscale Modelling of Multifunctional Composites: A Review","authors":"S. Suresh Babu, A. Mourad","doi":"10.1115/imece2021-73276","DOIUrl":"https://doi.org/10.1115/imece2021-73276","url":null,"abstract":"\u0000 Multi-scale modelling is a cornerstone for the relatively new class of hierarchical materials which can perform multifunctional tasks, owing to their electrical, magnetic or thermal properties. Careful design strategies are to be devised, in-order to maintain their multi-functionality over the expected range of operation. In this study, we focus on these materials, which can be manufactured using a specialized technique of additive manufacturing, known as fused deposition modelling (FDM), owing to its flexibility and compatibility, working with polymer based materials. A review has been made on the various parameters affecting the manufacturing process, and how these variations can affect the properties of the end product. Future research directions are also pointed out, including stimuli responsive printing technique, popularly known as 4D printing and integration of neural networks into the manufacturing process which can improve the overall design lifecycle efficiency. This can involve autonomous production of test specimen, and revert back the data for model improvement, thereby enhancing predictive capabilities. The major focus of this work is on how we can use our current knowledge and techniques in the design of efficient and effective multifunctional composite materials from the bottoms-up approach.","PeriodicalId":23837,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83001475","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}
Anthony Bombik, Sung Yeon Sara Ha, A. Nasrollahi, M. Haider, F. Chang
Multi-functional Energy Storage Composites (MESC) are composite sandwich structures where battery stack layers are placed between two layers of CFRP and sealed by low-density polyethylene (LDPE), forming a unified material. Because the layered Li-ion stacks have negligible out-of-plain shear stiffness, the two CFRP sheets on both sides of the battery are connected using LDPE rivets that pass through holes cut through the battery layers. The shear transfer mechanism of the rivets substantially enhances the shear stiffness and strength of the MESC. As the first step of preparing a guide for MESC design, the highly coupled mechanical and electrical behavior of MESC was studied through experiments. Several MESC cells were tested under three-point-bending loads. The load, deformation, and electric potential of the MESC were measured, and the electrical and mechanical failures were observed. A finite element model was developed to simulate the electro-chemo-mechanical coupling effect in MESC. In this model, a new constitutive relation of the battery material is proposed and verified by the experimental results. The resulting model can be used to simulate MESCs with various configurations and material properties to provide a design guideline of MESCs in multiple applications.
{"title":"Mechanical-Electrical Behavior of Multifunctional Energy Storage Composites","authors":"Anthony Bombik, Sung Yeon Sara Ha, A. Nasrollahi, M. Haider, F. Chang","doi":"10.1115/imece2021-71456","DOIUrl":"https://doi.org/10.1115/imece2021-71456","url":null,"abstract":"\u0000 Multi-functional Energy Storage Composites (MESC) are composite sandwich structures where battery stack layers are placed between two layers of CFRP and sealed by low-density polyethylene (LDPE), forming a unified material. Because the layered Li-ion stacks have negligible out-of-plain shear stiffness, the two CFRP sheets on both sides of the battery are connected using LDPE rivets that pass through holes cut through the battery layers. The shear transfer mechanism of the rivets substantially enhances the shear stiffness and strength of the MESC. As the first step of preparing a guide for MESC design, the highly coupled mechanical and electrical behavior of MESC was studied through experiments. Several MESC cells were tested under three-point-bending loads. The load, deformation, and electric potential of the MESC were measured, and the electrical and mechanical failures were observed. A finite element model was developed to simulate the electro-chemo-mechanical coupling effect in MESC. In this model, a new constitutive relation of the battery material is proposed and verified by the experimental results. The resulting model can be used to simulate MESCs with various configurations and material properties to provide a design guideline of MESCs in multiple applications.","PeriodicalId":23837,"journal":{"name":"Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications","volume":"8 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91425023","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：