The elongation of the bolt hole is an important parameter for assessing the failure of bolted joints. However, direct experimental measurement using strain gauges and extensometers is difficult. This article shows that digital image correlation (DIC) can overcome the difficulties and provide important indications of the failure mechanisms of bolted joints. Hole elongation was measured using DIC in the following carbon/epoxy composite configurations: standard open-hole tensile (OHT) and filled-hole tensile (FHT), single-lap shear only-bolted (OB), and single-lap shear hybrid-bolted/bonded (HBB) joints. For each configuration, the hole-elongation changes were tracked for cross-ply (CP) and quasi-isotropic (QI) stacking sequences with two thicknesses. In the tensile load direction for OHT and FHT cases, CP showed a greater hole elongation than QI. However, the opposite trend was observed in the transverse direction. In OB joints, bypass loads contributed more to the hole elongation than bearing action. In HBB joints, it has been observed that the adhesive significantly reduces hole elongation, particularly for CP configurations. Moreover, it was found that in HBB joints, hole elongation was independent of laminate lay-up, while it was very determinative in OB joints.
{"title":"Bolt-Hole Elongation of Woven Carbon-Epoxy Composite Plates and Joints Using the Digital Image Correlation Technique","authors":"Masoud Mehrabian, A. Lakis, R. Boukhili","doi":"10.3390/jcs8050180","DOIUrl":"https://doi.org/10.3390/jcs8050180","url":null,"abstract":"The elongation of the bolt hole is an important parameter for assessing the failure of bolted joints. However, direct experimental measurement using strain gauges and extensometers is difficult. This article shows that digital image correlation (DIC) can overcome the difficulties and provide important indications of the failure mechanisms of bolted joints. Hole elongation was measured using DIC in the following carbon/epoxy composite configurations: standard open-hole tensile (OHT) and filled-hole tensile (FHT), single-lap shear only-bolted (OB), and single-lap shear hybrid-bolted/bonded (HBB) joints. For each configuration, the hole-elongation changes were tracked for cross-ply (CP) and quasi-isotropic (QI) stacking sequences with two thicknesses. In the tensile load direction for OHT and FHT cases, CP showed a greater hole elongation than QI. However, the opposite trend was observed in the transverse direction. In OB joints, bypass loads contributed more to the hole elongation than bearing action. In HBB joints, it has been observed that the adhesive significantly reduces hole elongation, particularly for CP configurations. Moreover, it was found that in HBB joints, hole elongation was independent of laminate lay-up, while it was very determinative in OB joints.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":"123 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140986366","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}
Yoshitora Wadayama, Ai Kaneda, Taiga Imae, Daisuke Nakane, T. Akitsu
Microdroplets generated in microfluidic devices are attracting attention as a new chemical reaction field and are expected to improve reactivity. One of the effects of microscaling is that the ratio of the force that acts on the diffusion and movement of substances to gravity is different from that of ordinary solvents. Recently, we proposed a hypothesis for determining reaction acceleration through micro-miniaturization: If a reaction is inhibited by setting the volume and viscosity of the solution to conditions that are unfavorable to the reaction on a normal scale, that reaction can be promoted in microfluidics. Therefore, for the purpose of this verification, (1) we used an amino acid Schiff base copper(II) complex with an azobenzene group to demonstrate the polarization-induced orientation in a polymer film (the redirection that is mechanically maintained in a soft matter matrix). Numerical data on optical anisotropy parameters were reported. (2) When the reaction is confirmed to be promoted in laminar flow in a microfluidic device and its azo derivative, a copper(II) complex is used to increase the solvent viscosity or diffusion during synthesis on a normally large scale. We will obtain and discuss data on the investigation of changing the solvent volume as a region. The range of experimental conditions for volume and viscosity did not lead to an improvement in synthetic yield, nor did (3) the comparison of solvents and viscosity for single-crystal growth of amino acid Schiff base copper(II) complexes having azobenzene groups. A solvent whose viscosity was measured was used, but microcrystals were obtained using the diffusion method.
{"title":"Verification of the Inverse Scale Effect Hypothesis on Viscosity and Diffusion by Azo-Amino Acid Schiff Base Copper Complexes","authors":"Yoshitora Wadayama, Ai Kaneda, Taiga Imae, Daisuke Nakane, T. Akitsu","doi":"10.3390/jcs8050177","DOIUrl":"https://doi.org/10.3390/jcs8050177","url":null,"abstract":"Microdroplets generated in microfluidic devices are attracting attention as a new chemical reaction field and are expected to improve reactivity. One of the effects of microscaling is that the ratio of the force that acts on the diffusion and movement of substances to gravity is different from that of ordinary solvents. Recently, we proposed a hypothesis for determining reaction acceleration through micro-miniaturization: If a reaction is inhibited by setting the volume and viscosity of the solution to conditions that are unfavorable to the reaction on a normal scale, that reaction can be promoted in microfluidics. Therefore, for the purpose of this verification, (1) we used an amino acid Schiff base copper(II) complex with an azobenzene group to demonstrate the polarization-induced orientation in a polymer film (the redirection that is mechanically maintained in a soft matter matrix). Numerical data on optical anisotropy parameters were reported. (2) When the reaction is confirmed to be promoted in laminar flow in a microfluidic device and its azo derivative, a copper(II) complex is used to increase the solvent viscosity or diffusion during synthesis on a normally large scale. We will obtain and discuss data on the investigation of changing the solvent volume as a region. The range of experimental conditions for volume and viscosity did not lead to an improvement in synthetic yield, nor did (3) the comparison of solvents and viscosity for single-crystal growth of amino acid Schiff base copper(II) complexes having azobenzene groups. A solvent whose viscosity was measured was used, but microcrystals were obtained using the diffusion method.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":" 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140994168","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 simple higher-order model (HOM) is presented in this study for the bending analysis of an intact or delaminated composite and sandwich beam. This model adopts the concept of sub-laminates to simulate multilayered structures, and each sub-laminate takes cubic variation for axial displacement and linear variation for transverse displacement through the thickness. A sub-laminate possesses displacement components at its surfaces (bottom and top) that provide a straightforward way to improve the accuracy of prediction by stacking several sub-laminates. Thus, analysts will have the flexibility to balance the computational cost and the accuracy by selecting an appropriate sub-lamination scheme. The proposed model was implemented by developing a C0 beam element that has only displacement unknowns. The model was used to solve numerical examples of composite and sandwich beams to demonstrate its performance.
{"title":"Analysis of Intact/Delaminated Composite and Sandwich Beams Using a Higher-Order Modeling Technique","authors":"Yuan Feng, Abdul H. Sheikh, Guanzhen Li","doi":"10.3390/jcs8050175","DOIUrl":"https://doi.org/10.3390/jcs8050175","url":null,"abstract":"A simple higher-order model (HOM) is presented in this study for the bending analysis of an intact or delaminated composite and sandwich beam. This model adopts the concept of sub-laminates to simulate multilayered structures, and each sub-laminate takes cubic variation for axial displacement and linear variation for transverse displacement through the thickness. A sub-laminate possesses displacement components at its surfaces (bottom and top) that provide a straightforward way to improve the accuracy of prediction by stacking several sub-laminates. Thus, analysts will have the flexibility to balance the computational cost and the accuracy by selecting an appropriate sub-lamination scheme. The proposed model was implemented by developing a C0 beam element that has only displacement unknowns. The model was used to solve numerical examples of composite and sandwich beams to demonstrate its performance.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":" 28","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140991634","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}
In recent times, there has been a notable surge in the interest in promoting environmentally conscious products, particularly within the building industry where the focus has shifted towards sustainable materials. In this study, as a sustainable building material, ceiling tiles have been fabricated as a composite board containing waste materials, namely waste paper, sawdust, recycled polyethylene terephthalate (PET), and epoxy resin, and characterized comprehensively through physical and mechanical tests, density, thickness swelling (TS), modulus of elasticity (MOE), modulus of rupture (MOR), and flexural strength (FS) for product stability. A total of nine composites were fabricated with different ratios through molding techniques, and the characterization results were compared to determine the optimized stable ratio of composite composition. The composition of 25% waste paper, 15% sawdust, 10% recycled PET, and 50% epoxy resin presented the maximum FS compared to the other composite ratios. Water absorption (WA) and thickness swelling were evaluated after immersion durations of 1–24 h. The findings revealed that as the density increased, the sawdust content within the matrix decreased from 25–35%. Concurrently, an increase in recycled PET content resulted in decreased water absorption and thickness swelling. Significantly, the MOE, MOR, and FS demonstrated optimal values at 864.256 N/mm2, 12.786 N/mm2, and 4.64 MPa, respectively. These observations represent the excellent qualities of this hybrid composite board, particularly in terms of sustainability, stability, and water absorption capacity. Moreover, its lightweight nature and ability to support ceiling loads further enhance its appeal for construction applications. This study not only advances the discourse on sustainable construction materials but also fosters opportunities for broader acceptance and innovation within the industry.
{"title":"Influence of Physical–Mechanical Strength and Water Absorption Capacity on Sawdust–Waste Paper–Recycled Plastic Hybrid Composite for Ceiling Tile Application","authors":"Berhanu Tolessa Amena, Nazia Hossain","doi":"10.3390/jcs8050176","DOIUrl":"https://doi.org/10.3390/jcs8050176","url":null,"abstract":"In recent times, there has been a notable surge in the interest in promoting environmentally conscious products, particularly within the building industry where the focus has shifted towards sustainable materials. In this study, as a sustainable building material, ceiling tiles have been fabricated as a composite board containing waste materials, namely waste paper, sawdust, recycled polyethylene terephthalate (PET), and epoxy resin, and characterized comprehensively through physical and mechanical tests, density, thickness swelling (TS), modulus of elasticity (MOE), modulus of rupture (MOR), and flexural strength (FS) for product stability. A total of nine composites were fabricated with different ratios through molding techniques, and the characterization results were compared to determine the optimized stable ratio of composite composition. The composition of 25% waste paper, 15% sawdust, 10% recycled PET, and 50% epoxy resin presented the maximum FS compared to the other composite ratios. Water absorption (WA) and thickness swelling were evaluated after immersion durations of 1–24 h. The findings revealed that as the density increased, the sawdust content within the matrix decreased from 25–35%. Concurrently, an increase in recycled PET content resulted in decreased water absorption and thickness swelling. Significantly, the MOE, MOR, and FS demonstrated optimal values at 864.256 N/mm2, 12.786 N/mm2, and 4.64 MPa, respectively. These observations represent the excellent qualities of this hybrid composite board, particularly in terms of sustainability, stability, and water absorption capacity. Moreover, its lightweight nature and ability to support ceiling loads further enhance its appeal for construction applications. This study not only advances the discourse on sustainable construction materials but also fosters opportunities for broader acceptance and innovation within the industry.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":" 44","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140990104","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}
Corrosion of conventional steel reinforcement is responsible for numerous structurally deficient bridges, which is a multi-billion-dollar challenge that creates a vicious cycle of maintenance, repair, and replacement of infrastructure. Repair of existing structures with fiber-reinforced polymer (FRP) has become widespread due to multiple advantages. Carbon FRP’s superior tensile strength and stiffness make it particularly effective in shear and flexural strengthening of reinforced concrete (RC) beams. This experimental study incorporates carbon fiber polymer composite bars and wraps to study and report on the flexural behavior of RC beams. By employing a combination of CFRP bar and wrap for strengthening RC beams, this study observed an approximate 95% improvement in flexural load capacity relative to control RC beams without strengthening. This substantial enhancement highlights the effectiveness of integrating CFRP in structural applications. Nevertheless, the key observation is the failure mode due to this combination providing significant insights into the changes facilitated by this combination approach.
{"title":"An Experimental Study Incorporating Carbon Fiber Composite Bars and Wraps for Concrete Performance and Failure Insight","authors":"Ali Akbarpour, Jeffery Volz, Shreya Vemuganti","doi":"10.3390/jcs8050174","DOIUrl":"https://doi.org/10.3390/jcs8050174","url":null,"abstract":"Corrosion of conventional steel reinforcement is responsible for numerous structurally deficient bridges, which is a multi-billion-dollar challenge that creates a vicious cycle of maintenance, repair, and replacement of infrastructure. Repair of existing structures with fiber-reinforced polymer (FRP) has become widespread due to multiple advantages. Carbon FRP’s superior tensile strength and stiffness make it particularly effective in shear and flexural strengthening of reinforced concrete (RC) beams. This experimental study incorporates carbon fiber polymer composite bars and wraps to study and report on the flexural behavior of RC beams. By employing a combination of CFRP bar and wrap for strengthening RC beams, this study observed an approximate 95% improvement in flexural load capacity relative to control RC beams without strengthening. This substantial enhancement highlights the effectiveness of integrating CFRP in structural applications. Nevertheless, the key observation is the failure mode due to this combination providing significant insights into the changes facilitated by this combination approach.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":" 20","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140994958","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}
Natural biological nanocomposites, like nacre, demonstrate extraordinary fracture toughness, surpassing their base materials, attributed to their intricate staggered hierarchical architectures integrating hard and soft phases. The enhancement of toughness in these composites is often linked to the crack-deflection mechanism. Leveraging the core design principles that enhance durability, resilience, and robustness in organic materials, this paper describes the use of computational modeling and simulation to perform a three-point bending test on a 3D staggered nanocomposite intentionally crafted to mimic the detailed microstructure of nacre. We adopted a previously proposed interfacial zone model that conceptualizes the “relatively soft” layer as an interface between the “hard” mineral tablets and the microstructure’s interlayer spaces to examine how the microstructure and interface characteristics affect the mechanical responses and failure mechanisms. By comparing the model’s predictions with experimental data on natural nacre, the simulations unveil the mechanisms of tablet separation through adjacent layer sliding and crack deflection across interfacial zones. This study offers a robust numerical method for investigating the fracture toughening mechanisms and damage evolution and contributes to a deeper understanding of the complex interplays within biomimetic materials.
{"title":"Computational Investigation of the Mechanical Response of a Bioinspired Nacre-like Nanocomposite under Three-Point Bending","authors":"Xing Yang, Md Jalal Uddin Rumi, Xiaowei Zeng","doi":"10.3390/jcs8050173","DOIUrl":"https://doi.org/10.3390/jcs8050173","url":null,"abstract":"Natural biological nanocomposites, like nacre, demonstrate extraordinary fracture toughness, surpassing their base materials, attributed to their intricate staggered hierarchical architectures integrating hard and soft phases. The enhancement of toughness in these composites is often linked to the crack-deflection mechanism. Leveraging the core design principles that enhance durability, resilience, and robustness in organic materials, this paper describes the use of computational modeling and simulation to perform a three-point bending test on a 3D staggered nanocomposite intentionally crafted to mimic the detailed microstructure of nacre. We adopted a previously proposed interfacial zone model that conceptualizes the “relatively soft” layer as an interface between the “hard” mineral tablets and the microstructure’s interlayer spaces to examine how the microstructure and interface characteristics affect the mechanical responses and failure mechanisms. By comparing the model’s predictions with experimental data on natural nacre, the simulations unveil the mechanisms of tablet separation through adjacent layer sliding and crack deflection across interfacial zones. This study offers a robust numerical method for investigating the fracture toughening mechanisms and damage evolution and contributes to a deeper understanding of the complex interplays within biomimetic materials.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":"63 s241","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141002374","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}
Hemodialysis (HD) is a life-sustaining membrane-based therapy that is essential for managing kidney failure. However, it can have significant physical and psychological effects on patients due to chronic or acute consequences related to membrane bioincompatibility. End-stage renal disease (ESRD) patients on hemodialysis have a high incidence of psychiatric illness, particularly depression and anxiety disorders, and poor quality of life has been observed. Dialysis can also lead to physical symptoms of its own, such as fatigue, loss of appetite, anemia, low blood pressure, and fluid overload, in addition to the symptoms associated with kidney failure. Therefore, this critical review aims to comprehensively understand the impact of dialysis membrane bioincompatibility and the use of varying molecular weight cut-off membranes on the physical and psychological symptoms experienced by dialysis patients. We analyzed the latest research on the correlation between major inflammatory biomarkers released in patients’ blood due to membrane incompatibility, as well as the critical influence of low levels of hemoglobin and vital proteins such as human serum albumin due to the use of high-cut-off membranes and correlated these factors with the physical and psychological symptoms experienced by dialysis patients. Furthermore, our study aims to provide valuable insights into the impact of dialysis on critical symptoms, higher hospitalization rates, and the quality of life of First Nations, as well as child and youth dialysis patients, in addition to diabetic dialysis patients. Our goal is to identify potential interventions aiming to optimize the dialysis membrane and minimize its negative effects on patients, ultimately improving their well-being and long-term outcomes.
{"title":"Quality of Life of Dialysis Patients: Exploring the Influence of Membrane Hemocompatibility and Dialysis Practices on Psychosocial and Physical Symptoms","authors":"Victoria Doan, Ahmed Shoker, A. Abdelrasoul","doi":"10.3390/jcs8050172","DOIUrl":"https://doi.org/10.3390/jcs8050172","url":null,"abstract":"Hemodialysis (HD) is a life-sustaining membrane-based therapy that is essential for managing kidney failure. However, it can have significant physical and psychological effects on patients due to chronic or acute consequences related to membrane bioincompatibility. End-stage renal disease (ESRD) patients on hemodialysis have a high incidence of psychiatric illness, particularly depression and anxiety disorders, and poor quality of life has been observed. Dialysis can also lead to physical symptoms of its own, such as fatigue, loss of appetite, anemia, low blood pressure, and fluid overload, in addition to the symptoms associated with kidney failure. Therefore, this critical review aims to comprehensively understand the impact of dialysis membrane bioincompatibility and the use of varying molecular weight cut-off membranes on the physical and psychological symptoms experienced by dialysis patients. We analyzed the latest research on the correlation between major inflammatory biomarkers released in patients’ blood due to membrane incompatibility, as well as the critical influence of low levels of hemoglobin and vital proteins such as human serum albumin due to the use of high-cut-off membranes and correlated these factors with the physical and psychological symptoms experienced by dialysis patients. Furthermore, our study aims to provide valuable insights into the impact of dialysis on critical symptoms, higher hospitalization rates, and the quality of life of First Nations, as well as child and youth dialysis patients, in addition to diabetic dialysis patients. Our goal is to identify potential interventions aiming to optimize the dialysis membrane and minimize its negative effects on patients, ultimately improving their well-being and long-term outcomes.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":"19 23","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141004888","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 paper develops a thermoelectric (TE)–piezoelectric (PE) hybrid structure with the PE layer acting as both a support membrane and a sensor for the TE film for microelectronics applications. The TE and PE layers are assumed to be perfectly bonded mechanically and thermally but electrically shielded and insulated with each other. The thermo-electro-mechanical responses of the hybrid bilayer under the TE generator operation conditions are obtained, and the influence of the PE layer on the TE energy conversion efficiency is investigated. The numerical results for a Bi2Te3/PZT-5H bilayer structure show that large compressive stresses develop in both the PE and TE layers. With a decrease in the PE layer thickness, the magnitude of the maximum compressive stress in the PE layer increases whereas the maximum magnitude of the stress in the TE layer decreases. The numerical result of the TE energy conversion efficiency shows that increasing the PE layer thickness leads to lower energy conversion efficiencies. A nearly 40% reduction in the peak efficiency is observed with a PE layer of the same thickness as that of the TE layer. These results suggest that design of TE films with supporting/sensing membranes must consider both aspects of energy conversion efficiency and the thermomechanical reliability of both the TE and PE layers.
本文开发了一种热电（TE）-压电（PE）混合结构，其中 PE 层既是微电子应用中 TE 薄膜的支撑膜，又是传感器。假定 TE 层和 PE 层在机械和热学上完美结合，但在电气上相互屏蔽和绝缘。获得了混合双层膜在 TE 发电机工作条件下的热-电-机械响应，并研究了 PE 层对 TE 能量转换效率的影响。Bi2Te3/PZT-5H 双层结构的数值结果表明，PE 层和 TE 层都产生了较大的压应力。随着 PE 层厚度的减小，PE 层的最大压应力增大，而 TE 层的最大应力减小。TE 能量转换效率的数值结果表明，增加 PE 层厚度会降低能量转换效率。当 PE 层的厚度与 TE 层的厚度相同时，峰值效率会降低近 40%。这些结果表明，在设计带有支撑/传感膜的 TE 薄膜时，必须同时考虑 TE 层和 PE 层的能量转换效率和热机械可靠性。
{"title":"Thermomechanical Responses and Energy Conversion Efficiency of a Hybrid Thermoelectric–Piezoelectric Layered Structure","authors":"Zhihe Jin, Jia-shi Yang","doi":"10.3390/jcs8050171","DOIUrl":"https://doi.org/10.3390/jcs8050171","url":null,"abstract":"This paper develops a thermoelectric (TE)–piezoelectric (PE) hybrid structure with the PE layer acting as both a support membrane and a sensor for the TE film for microelectronics applications. The TE and PE layers are assumed to be perfectly bonded mechanically and thermally but electrically shielded and insulated with each other. The thermo-electro-mechanical responses of the hybrid bilayer under the TE generator operation conditions are obtained, and the influence of the PE layer on the TE energy conversion efficiency is investigated. The numerical results for a Bi2Te3/PZT-5H bilayer structure show that large compressive stresses develop in both the PE and TE layers. With a decrease in the PE layer thickness, the magnitude of the maximum compressive stress in the PE layer increases whereas the maximum magnitude of the stress in the TE layer decreases. The numerical result of the TE energy conversion efficiency shows that increasing the PE layer thickness leads to lower energy conversion efficiencies. A nearly 40% reduction in the peak efficiency is observed with a PE layer of the same thickness as that of the TE layer. These results suggest that design of TE films with supporting/sensing membranes must consider both aspects of energy conversion efficiency and the thermomechanical reliability of both the TE and PE layers.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":"32 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141010435","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}
Fly ash has been utilized as a reinforcing material in the production of aluminum matrix composites, and in this investigation, Al-Si (LM6) fly ash composites were fabricated using the compocasting method. Various compositions of fly ash were incorporated into the samples (4, 5 and 6 wt%), and the preparation temperature ranged from 560 to 800°C. This study investigated the thermal (CTE and DTA) and chemical properties (XRD) of fly ash reinforcement and the aluminum melt in the composites. The results revealed that composites with 5 wt% of fly ash exhibited the lowest CTE value compared to those with 4 and 6 wt%. This observation was corroborated by XRD analysis, indicating a reaction between the fly ash particles and the aluminum melt. However, the DTA analysis did not find a significant impact of the addition of fly ash on the melting temperature of the prepared composites. In contrast, this study identified and investigated the existence of reaction effects between the fly ash particles and the aluminum melt.
{"title":"Chemical and Thermal Analysis of Fly Ash-Reinforced Aluminum Matrix Composites (AMCs)","authors":"Siti Syazwani Nordin, Ervina Efzan Binti Mhd Noor, Palanisamy Chockalingam","doi":"10.3390/jcs8050170","DOIUrl":"https://doi.org/10.3390/jcs8050170","url":null,"abstract":"Fly ash has been utilized as a reinforcing material in the production of aluminum matrix composites, and in this investigation, Al-Si (LM6) fly ash composites were fabricated using the compocasting method. Various compositions of fly ash were incorporated into the samples (4, 5 and 6 wt%), and the preparation temperature ranged from 560 to 800°C. This study investigated the thermal (CTE and DTA) and chemical properties (XRD) of fly ash reinforcement and the aluminum melt in the composites. The results revealed that composites with 5 wt% of fly ash exhibited the lowest CTE value compared to those with 4 and 6 wt%. This observation was corroborated by XRD analysis, indicating a reaction between the fly ash particles and the aluminum melt. However, the DTA analysis did not find a significant impact of the addition of fly ash on the melting temperature of the prepared composites. In contrast, this study identified and investigated the existence of reaction effects between the fly ash particles and the aluminum melt.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":"25 37","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141019648","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}
Yi-Sheng Jhao, Ouyang Hao, Chien-Chao Huang, Fuqian Yang, Sanboh Lee
Polylactic acid (PLA) is considered a promising biodegradable polymer alternative. Due to its high brittleness, composite materials made by melt blending thermoplastic polyurethane (TPU) with PLA can enhance the toughness of PLA. To understand the forced aging caused by stress relaxation in polymer materials, this study explains the stress relaxation experiments of PLA/TPU blends with different mass ratios under applied strain through mechanical model simulations. The Kelvin representation of the standard linear solid model (SLSM) is used to analyze the stress relaxation data of TPU/PLA blends, successfully explaining that the Young’s moduli (E1 and E2) of springs decrease with increasing temperature and TPU content. The viscosity coefficient of the PLA/TPU blends decreases with increasing temperature, and its reciprocal follows the Arrhenius law. For TPU/PLA blends with increased concentration of TPU, the activation energy for stress relaxation shows a linear decrease, confirmed by the glass transition point measured by DMA, indicating that it does not involve chemical reactions.
{"title":"A Mechanical Model for Stress Relaxation of Polylactic Acid/Thermoplastic Polyurethane Blends","authors":"Yi-Sheng Jhao, Ouyang Hao, Chien-Chao Huang, Fuqian Yang, Sanboh Lee","doi":"10.3390/jcs8050169","DOIUrl":"https://doi.org/10.3390/jcs8050169","url":null,"abstract":"Polylactic acid (PLA) is considered a promising biodegradable polymer alternative. Due to its high brittleness, composite materials made by melt blending thermoplastic polyurethane (TPU) with PLA can enhance the toughness of PLA. To understand the forced aging caused by stress relaxation in polymer materials, this study explains the stress relaxation experiments of PLA/TPU blends with different mass ratios under applied strain through mechanical model simulations. The Kelvin representation of the standard linear solid model (SLSM) is used to analyze the stress relaxation data of TPU/PLA blends, successfully explaining that the Young’s moduli (E1 and E2) of springs decrease with increasing temperature and TPU content. The viscosity coefficient of the PLA/TPU blends decreases with increasing temperature, and its reciprocal follows the Arrhenius law. For TPU/PLA blends with increased concentration of TPU, the activation energy for stress relaxation shows a linear decrease, confirmed by the glass transition point measured by DMA, indicating that it does not involve chemical reactions.","PeriodicalId":502935,"journal":{"name":"Journal of Composites Science","volume":"18 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141036085","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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