Artificial intelligence (AI) techniques are increasingly used for structural health monitoring (SHM) of polymer composite structures. However, to be confident in the trustworthiness of AI models, the models must be reliable, interpretable, and explainable. The use of explainable artificial intelligence (XAI) is critical to ensure that the AI model is transparent in the decision‐making process and that the predictions it provides can be trusted and understood by users. However, existing SHM methods for polymer composite structures lack explainability and transparency, and therefore reliable damage detection. Therefore, an interpretable deep learning model based on an explainable vision transformer (X‐ViT) is proposed for the SHM of composites, leading to improved repair planning, maintenance, and performance. The proposed approach has been validated on carbon fiber reinforced polymers (CFRP) composites with multiple health states. The X‐ViT model exhibited better damage detection performance compared to existing popular methods. Moreover, the X‐ViT approach effectively highlighted the area of interest related to the prediction of each health condition in composites through the patch attention aggregation process, emphasizing their influence on the decision‐making process. Consequently, integrating the ViT‐based explainable deep‐learning model into the SHM of polymer composites provided improved diagnostics along with increased transparency and reliability.HighlightsAutonomous damage detection of polymer composites using vision transformer based deep learning model.Explainable artificial intelligence by highlighting region of interest using patch attention.Comparison with the existing state of the art structural health monitoring methods.
人工智能（AI）技术越来越多地用于聚合物复合结构的结构健康监测（SHM）。然而，要对人工智能模型的可信度充满信心，模型必须是可靠、可解释和可解释的。可解释人工智能（XAI）的使用对于确保人工智能模型在决策过程中的透明性以及其提供的预测结果可以被用户信任和理解至关重要。然而，现有的聚合物复合结构 SHM 方法缺乏可解释性和透明度，因此无法进行可靠的损伤检测。因此，我们提出了一种基于可解释视觉变换器（X-ViT）的可解释深度学习模型，用于复合材料的 SHM，从而改进维修规划、维护和性能。所提出的方法已在具有多种健康状态的碳纤维增强聚合物（CFRP）复合材料上进行了验证。与现有的流行方法相比，X-ViT 模型具有更好的损伤检测性能。此外，X-ViT 方法通过斑块关注聚集过程，有效地突出了与复合材料中每种健康状况预测相关的关注区域，强调了它们对决策过程的影响。因此，将基于 ViT 的可解释深度学习模型集成到聚合物复合材料的 SHM 中，不仅提高了诊断效率，还增加了透明度和可靠性。利用补丁关注突出感兴趣区域，实现可解释的人工智能。与现有的先进结构健康监测方法进行比较。
{"title":"An explainable artificial intelligence‐based approach for reliable damage detection in polymer composite structures using deep learning","authors":"Muhammad Muzammil Azad, Heung Soo Kim","doi":"10.1002/pc.29055","DOIUrl":"https://doi.org/10.1002/pc.29055","url":null,"abstract":"<jats:label/>Artificial intelligence (AI) techniques are increasingly used for structural health monitoring (SHM) of polymer composite structures. However, to be confident in the trustworthiness of AI models, the models must be reliable, interpretable, and explainable. The use of explainable artificial intelligence (XAI) is critical to ensure that the AI model is transparent in the decision‐making process and that the predictions it provides can be trusted and understood by users. However, existing SHM methods for polymer composite structures lack explainability and transparency, and therefore reliable damage detection. Therefore, an interpretable deep learning model based on an explainable vision transformer (X‐ViT) is proposed for the SHM of composites, leading to improved repair planning, maintenance, and performance. The proposed approach has been validated on carbon fiber reinforced polymers (CFRP) composites with multiple health states. The X‐ViT model exhibited better damage detection performance compared to existing popular methods. Moreover, the X‐ViT approach effectively highlighted the area of interest related to the prediction of each health condition in composites through the patch attention aggregation process, emphasizing their influence on the decision‐making process. Consequently, integrating the ViT‐based explainable deep‐learning model into the SHM of polymer composites provided improved diagnostics along with increased transparency and reliability.Highlights<jats:list list-type=\"bullet\"> <jats:list-item>Autonomous damage detection of polymer composites using vision transformer based deep learning model.</jats:list-item> <jats:list-item>Explainable artificial intelligence by highlighting region of interest using patch attention.</jats:list-item> <jats:list-item>Comparison with the existing state of the art structural health monitoring methods.</jats:list-item> </jats:list>","PeriodicalId":20375,"journal":{"name":"Polymer Composites","volume":"13 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. C. P. Diby, N. Belkhiri, B. Nohair, M. Kazeruni, E. Ruiz, S. Kaliaguine
In order to predict the mechanical behavior of particle reinforced polymer composites, it is crucial to study changes in polymer phase distribution upon interaction with the load in the undeformed state. In this work, HDPE composites reinforced with pyrolytic carbon black (rCBNF) particles, including some rCB modified by mild air oxidation (rCBF), which enabled the aggregation of residual chemisorbed rubber at the surface, examined in a previous work. The development of lamellar morphology induces conformational behaviors resulting from interactions fillers/polymer chains. These interactions cannot be determined by DSC alone but involve short‐range FTIR and Raman and long‐range XRD models. The Raman crystalline content of HDPE was significantly reduced by the presence rCBFs and N330, which varied with lamellar morphology. This process involves the displacement of crystalline lamellae into sublayers by nucleation and crystal growth, resulting in the release of linker molecules, limiting entanglement and improving the elastic properties of the amorphous phase. A significant amount of amorphous phase was produced with N330 and oxidized rCBFs, in which the carbon surface was free of residual rubber. Mechanical tensile tests showed an improvement in the elastic modulus of composites containing these fillers.HighlightsN330 and oxidized rCBFs have surface free of the residual rubber contained in rCBNF.Significant reduction in the Raman crystallinity of HDPE with rCBF and N330.Reduction varies with lamellar size through nucleation and crystal growth.Strong release of the tie molecule improves the elastic modulus of HDPE/rCBF.Improved mechanical tensile properties of HDPE/rCBF and HDPE/N330.
{"title":"HDPE crystalline lamellae in composites involving pyrolytic carbon black: Effect on elastic modulus","authors":"I. C. P. Diby, N. Belkhiri, B. Nohair, M. Kazeruni, E. Ruiz, S. Kaliaguine","doi":"10.1002/pc.28986","DOIUrl":"https://doi.org/10.1002/pc.28986","url":null,"abstract":"<jats:label/>In order to predict the mechanical behavior of particle reinforced polymer composites, it is crucial to study changes in polymer phase distribution upon interaction with the load in the undeformed state. In this work, HDPE composites reinforced with pyrolytic carbon black (rCBNF) particles, including some rCB modified by mild air oxidation (rCBF), which enabled the aggregation of residual chemisorbed rubber at the surface, examined in a previous work. The development of lamellar morphology induces conformational behaviors resulting from interactions fillers/polymer chains. These interactions cannot be determined by DSC alone but involve short‐range FTIR and Raman and long‐range XRD models. The Raman crystalline content of HDPE was significantly reduced by the presence rCBFs and N330, which varied with lamellar morphology. This process involves the displacement of crystalline lamellae into sublayers by nucleation and crystal growth, resulting in the release of linker molecules, limiting entanglement and improving the elastic properties of the amorphous phase. A significant amount of amorphous phase was produced with N330 and oxidized rCBFs, in which the carbon surface was free of residual rubber. Mechanical tensile tests showed an improvement in the elastic modulus of composites containing these fillers.Highlights<jats:list list-type=\"bullet\"> <jats:list-item>N330 and oxidized rCBFs have surface free of the residual rubber contained in rCBNF.</jats:list-item> <jats:list-item>Significant reduction in the Raman crystallinity of HDPE with rCBF and N330.</jats:list-item> <jats:list-item>Reduction varies with lamellar size through nucleation and crystal growth.</jats:list-item> <jats:list-item>Strong release of the tie molecule improves the elastic modulus of HDPE/rCBF.</jats:list-item> <jats:list-item>Improved mechanical tensile properties of HDPE/rCBF and HDPE/N330.</jats:list-item> </jats:list>","PeriodicalId":20375,"journal":{"name":"Polymer Composites","volume":"1 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study discussed the effects of different contents of Nickel‐titanium alloy particles (NiTip) on the vibration properties of carbon fiber reinforced polymers (CFRP) and further verified the test results by dynamic mechanical analysis tests while analyzing the effects of NiTip on the thermal stability of CFRP. The test results showed that 1.0 vol% of NiTip was the most effective in reducing the vibration transmission rate of the CFRP while improving its thermal stability. The modal of the CFRP composite cantilever beam is analyzed using the finite element method. In addition, the mechanical properties of CFRP with different NiTip contents were tested, including tensile, flexural, interlaminar shear and impact properties. The test results showed that 1.0 vol% of NiTip was most effective in improving the flexural properties, tensile properties and interlayer shear properties of CFRP. At the same time, 3.0 vol% of NiTip was most effective in improving the impact properties of CFRP. In addition, the fracture surfaces of CFRP reinforced with different NiTip contents were microanalysed to elucidate the enhancement mechanism. This study developed a multifunctional composite material with both vibration damping and high performance. These results provide essential guidelines for the optimal design and application of NiTip reinforced composites in vibration control, structural and aerospace applications.HighlightsThe effects of different Nickel‐titanium alloy particles (NiTip) levels on the vibration and mechanical properties of carbon fiber reinforced polymers (CFRP) were investigated.The influence of NiTip addition on the loss factor and thermal stability of CFRP was evaluated.SEM images were used to analyze the influence mechanism of uniform dispersion of NiTip on the reduction of vibration transmission rate of CFRP and the improvement of mechanical properties of CFRP.
{"title":"The effect of nickel‐titanium alloy particles on the vibration response and the mechanical properties of carbon fiber laminates","authors":"Meng Cao, Jian Zang, Shuo Wang, Xuyuan Song, Zhijian Wang, Yewei Zhang","doi":"10.1002/pc.29056","DOIUrl":"https://doi.org/10.1002/pc.29056","url":null,"abstract":"<jats:label/>This study discussed the effects of different contents of Nickel‐titanium alloy particles (NiTip) on the vibration properties of carbon fiber reinforced polymers (CFRP) and further verified the test results by dynamic mechanical analysis tests while analyzing the effects of NiTip on the thermal stability of CFRP. The test results showed that 1.0 vol% of NiTip was the most effective in reducing the vibration transmission rate of the CFRP while improving its thermal stability. The modal of the CFRP composite cantilever beam is analyzed using the finite element method. In addition, the mechanical properties of CFRP with different NiTip contents were tested, including tensile, flexural, interlaminar shear and impact properties. The test results showed that 1.0 vol% of NiTip was most effective in improving the flexural properties, tensile properties and interlayer shear properties of CFRP. At the same time, 3.0 vol% of NiTip was most effective in improving the impact properties of CFRP. In addition, the fracture surfaces of CFRP reinforced with different NiTip contents were microanalysed to elucidate the enhancement mechanism. This study developed a multifunctional composite material with both vibration damping and high performance. These results provide essential guidelines for the optimal design and application of NiTip reinforced composites in vibration control, structural and aerospace applications.Highlights<jats:list list-type=\"bullet\"> <jats:list-item>The effects of different Nickel‐titanium alloy particles (NiTip) levels on the vibration and mechanical properties of carbon fiber reinforced polymers (CFRP) were investigated.</jats:list-item> <jats:list-item>The influence of NiTip addition on the loss factor and thermal stability of CFRP was evaluated.</jats:list-item> <jats:list-item>SEM images were used to analyze the influence mechanism of uniform dispersion of NiTip on the reduction of vibration transmission rate of CFRP and the improvement of mechanical properties of CFRP.</jats:list-item> </jats:list>","PeriodicalId":20375,"journal":{"name":"Polymer Composites","volume":"5 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ramasamy Nallamuthu, Arunkumar Thirugnanasamabandam, Kumaran Kadirgama, William Chong, Geethapriyan Thangamani, Abdullah Alarifi
This study intends to investigate the mechanical, thermal, and aging behaviors of 3D‐printed PLA (polylactic acid)‐blend with 10% polymethyl methacrylate (PMMA) and 10% alumina polymer composites for biomedical applications using compressive, DSC, and DMA analysis. The experimental results revealed that aged PLA blend with alumina samples increased compressive strength by 60.1% and 37.8% during hydrolytic and enzymatic degradation, respectively, compared to aged PLA samples. Also, it was reported that the PLA blend with PMMA samples increased compressive strength by 51.1% and 24% after hydrolytic and enzymatic degradation, respectively, as compared to aged PLA samples. Furthermore, DSC analysis revealed that alumina blended samples had a higher Tg than pure PLA and PMMA blended samples. In addition, DMA investigation revealed that the Tg of aged neat PLA, PLA/PMMA, and PLA/alumina increased by 4.38%, 4.8%, and 4.6%, respectively, compared to unaged polymer composites. Additionally, PLA/alumina‐aged samples exhibited stronger aging properties than neat PLA and PLA/PMMA blended‐aged samples. It was reported that the weight loss of PLA/Alumina was lowered by 10.7% and 15.6% compared to aged PLA/PMMA samples, for hydrolytic and enzymatic aging respectively. It was found that PLA alumina has better mechanical, thermal, and degradation resistance than PLA materials.HighlightsAlumina and PMMA materials were blended with PLA.Examined the aging and mechanical properties of PLA blended composites.Utilized hydrolytic and enzymatic aging for biomedical applications.Evaluated mechanical strength performance of aged and unaged samples.DSC and DMA were utlised for this research.
{"title":"Influence of alumina and PMMA on mechanical properties and aging behavior of 3D printed PLA composites: A comparative study","authors":"Ramasamy Nallamuthu, Arunkumar Thirugnanasamabandam, Kumaran Kadirgama, William Chong, Geethapriyan Thangamani, Abdullah Alarifi","doi":"10.1002/pc.29000","DOIUrl":"https://doi.org/10.1002/pc.29000","url":null,"abstract":"<jats:label/>This study intends to investigate the mechanical, thermal, and aging behaviors of 3D‐printed PLA (polylactic acid)‐blend with 10% polymethyl methacrylate (PMMA) and 10% alumina polymer composites for biomedical applications using compressive, DSC, and DMA analysis. The experimental results revealed that aged PLA blend with alumina samples increased compressive strength by 60.1% and 37.8% during hydrolytic and enzymatic degradation, respectively, compared to aged PLA samples. Also, it was reported that the PLA blend with PMMA samples increased compressive strength by 51.1% and 24% after hydrolytic and enzymatic degradation, respectively, as compared to aged PLA samples. Furthermore, DSC analysis revealed that alumina blended samples had a higher Tg than pure PLA and PMMA blended samples. In addition, DMA investigation revealed that the Tg of aged neat PLA, PLA/PMMA, and PLA/alumina increased by 4.38%, 4.8%, and 4.6%, respectively, compared to unaged polymer composites. Additionally, PLA/alumina‐aged samples exhibited stronger aging properties than neat PLA and PLA/PMMA blended‐aged samples. It was reported that the weight loss of PLA/Alumina was lowered by 10.7% and 15.6% compared to aged PLA/PMMA samples, for hydrolytic and enzymatic aging respectively. It was found that PLA alumina has better mechanical, thermal, and degradation resistance than PLA materials.Highlights<jats:list list-type=\"bullet\"> <jats:list-item>Alumina and PMMA materials were blended with PLA.</jats:list-item> <jats:list-item>Examined the aging and mechanical properties of PLA blended composites.</jats:list-item> <jats:list-item>Utilized hydrolytic and enzymatic aging for biomedical applications.</jats:list-item> <jats:list-item>Evaluated mechanical strength performance of aged and unaged samples.</jats:list-item> <jats:list-item>DSC and DMA were utlised for this research.</jats:list-item> </jats:list>","PeriodicalId":20375,"journal":{"name":"Polymer Composites","volume":"6 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Luanna V. Cesario, Edson A. dos Santos Filho, Gabriel Matheus Pinto, Karina L. F. Cardoso, Natália F. Braga, Guilhermino J. M. Fechine, Laura H. de Carvalho
In recent years, the demand for environmentally sustainable materials has led to the exploration of biodegradable composites as alternatives to fossil‐based polymeric matrices. Among these, poly‐ε‐caprolactone (PCL) has emerged for its versatility and broad applicability. However, challenges such as limited mechanical strength and thermal stability demand innovative approaches for enhancement. This study focuses on the development and characterization of hierarchical composites of PCL, ramie fibers, and graphene oxide (GO) to address these challenges. Differential scanning calorimetry (DSC), x‐ray diffraction (XRD), contact angle, surface energy, mechanical properties (impact and tensile), scanning electron microscopy (SEM), and ecotoxicity assays were employed for evaluation. Results indicate that the inclusion of GO and ramie fibers alters the thermal properties, increasing melting enthalpy and crystallinity due to GO's nucleating effect and fiber‐induced steric hindrance. Increased hydrophilicity and surface free energy suggest enhanced biodegradation potential. Ecotoxicity tests confirm non‐toxicity, while SEM reveals low interfacial adhesion between the fiber and matrix. Tensile tests reveal no synergistic effects, although GO enhances biodegradation without compromising mechanical integrity. The presence of GO and ramie fibers does not induce toxicity, as evidenced by normal seedling growth. While hybridization does not significantly impact mechanical properties, GO offers avenues for enhancing biodegradability and expanding ramie fiber applications. This study highlights the impacts of filler integration on the properties of PCL, indicating pathways for tailored material design aimed at sustainable solutions.
近年来，由于对环境可持续材料的需求，人们开始探索生物可降解复合材料，以替代化石基聚合物基材。其中，聚ε-己内酯（PCL）因其多功能性和广泛适用性而崭露头角。然而，由于其机械强度和热稳定性有限，因此需要采用创新方法来提高其性能。本研究侧重于 PCL、苎麻纤维和氧化石墨烯（GO）分层复合材料的开发和表征，以应对这些挑战。研究采用了差示扫描量热法 (DSC)、X 射线衍射 (XRD)、接触角、表面能、机械性能（冲击和拉伸）、扫描电子显微镜 (SEM) 和生态毒性检测等方法进行评估。结果表明，由于 GO 的成核效应和纤维引起的立体阻碍，GO 和苎麻纤维的加入改变了热性能，提高了熔化焓和结晶度。亲水性和表面自由能的增加表明生物降解潜力增强。生态毒性测试证实其无毒性，而扫描电子显微镜则显示纤维与基质之间的界面粘附力较低。拉伸测试表明，尽管 GO 增强了生物降解性，但并没有影响机械完整性，因此没有协同效应。从幼苗的正常生长情况来看，GO 和苎麻纤维的存在不会产生毒性。虽然杂化不会对机械性能产生重大影响，但 GO 为提高生物降解性和扩大苎麻纤维的应用范围提供了途径。本研究强调了填料整合对 PCL 性能的影响，为旨在实现可持续解决方案的定制材料设计指明了道路。
{"title":"Effect of ramie fiber and graphene oxide on the development of PCL‐based materials: Micro‐composites, nanocomposites and hierarchical","authors":"Luanna V. Cesario, Edson A. dos Santos Filho, Gabriel Matheus Pinto, Karina L. F. Cardoso, Natália F. Braga, Guilhermino J. M. Fechine, Laura H. de Carvalho","doi":"10.1002/pc.28989","DOIUrl":"https://doi.org/10.1002/pc.28989","url":null,"abstract":"In recent years, the demand for environmentally sustainable materials has led to the exploration of biodegradable composites as alternatives to fossil‐based polymeric matrices. Among these, poly‐ε‐caprolactone (PCL) has emerged for its versatility and broad applicability. However, challenges such as limited mechanical strength and thermal stability demand innovative approaches for enhancement. This study focuses on the development and characterization of hierarchical composites of PCL, ramie fibers, and graphene oxide (GO) to address these challenges. Differential scanning calorimetry (DSC), x‐ray diffraction (XRD), contact angle, surface energy, mechanical properties (impact and tensile), scanning electron microscopy (SEM), and ecotoxicity assays were employed for evaluation. Results indicate that the inclusion of GO and ramie fibers alters the thermal properties, increasing melting enthalpy and crystallinity due to GO's nucleating effect and fiber‐induced steric hindrance. Increased hydrophilicity and surface free energy suggest enhanced biodegradation potential. Ecotoxicity tests confirm non‐toxicity, while SEM reveals low interfacial adhesion between the fiber and matrix. Tensile tests reveal no synergistic effects, although GO enhances biodegradation without compromising mechanical integrity. The presence of GO and ramie fibers does not induce toxicity, as evidenced by normal seedling growth. While hybridization does not significantly impact mechanical properties, GO offers avenues for enhancing biodegradability and expanding ramie fiber applications. This study highlights the impacts of filler integration on the properties of PCL, indicating pathways for tailored material design aimed at sustainable solutions.","PeriodicalId":20375,"journal":{"name":"Polymer Composites","volume":"207 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Weiji Li, Xinrui Yan, Lu Ye, Changning Ran, Yue Zhang, Ruiqi He, Bixuan Zhu, Yu He, Jiacheng Guo, Hongwei Li, Jianjun Zhang, Sude Ma
In this paper, the carboxylic acid modifier 2,3,4,5‐tetrafluorobenzoic acid (F4C) was used to modify the BaTiO3 (BT) nanoparticles, which acted as a coupling agent. The modified BT(F4CBT) nanoparticles, polyvinylidene fluoride (PVDF), and polymethylmethacrylate (PMMA) were used to make the modified nanocomposite films: PVDF/PMMA‐F4C‐BaTiO3 nanocomposite films. The unmodified BT nanoparticles were used to make the unmodified nanocomposite films: PVDF/PMMA‐BaTiO3 nanocomposite films. The modification effect of the F4C resulted in an increase in the amount of β‐phase and γ‐phase, a decrease in the amount of α‐phase, and a decrease in the overall crystallinity of the PVDF‐based nanocomposite films. The dielectric constant of the PVDF/PMMA‐F4C‐BaTiO3 nanocomposite films reached a maximum value of 16.7 at a frequency of 100 Hz at 4 wt% F4C, which was 40.3% higher than that of the unmodified PVDF/PMMA‐BaTiO3 films. The F4C content of 2 wt% PVDF/PMMA‐F4C‐BaTiO3 nanocomposite films showed the lowest dielectric loss of 0.055, which was 56.7% lower than the unmodified PVDF/PMMA‐BaTiO3 films. The breakdown strength of the PVDF/PMMA‐F4C‐BaTiO3 nanocomposite films increased and then decreased with the increase of the F4C content, and the highest breakdown strength was 2800 kV/cm at 4 wt% F4C, which was 55.6% higher than the unmodified PVDF/PMMA‐BaTiO3 films. The charging density of the PVDF/PMMA‐F4C‐BaTiO3 nanocomposite films reached a maximum value of 20.65 J/cm3 at 4 wt% F4C content, which was 394% higher than the unmodified PVDF/PMMA‐BaTiO3 films.HighlightsModification of ceramic nanoparticles with carboxylic acid coupling agent.The dielectric properties of the modified nanocomposite film were significantly improved.Maximum polarization and charge/discharge density were greatly improved by coupling agent modification.
{"title":"Effect of coupling agent 2,3,4,5‐tetrafluorobenzoic acid modification on dielectric energy storage properties of PVDF/PMMA‐BaTiO3 nanocomposite films","authors":"Weiji Li, Xinrui Yan, Lu Ye, Changning Ran, Yue Zhang, Ruiqi He, Bixuan Zhu, Yu He, Jiacheng Guo, Hongwei Li, Jianjun Zhang, Sude Ma","doi":"10.1002/pc.29058","DOIUrl":"https://doi.org/10.1002/pc.29058","url":null,"abstract":"<jats:label/>In this paper, the carboxylic acid modifier 2,3,4,5‐tetrafluorobenzoic acid (F4C) was used to modify the BaTiO<jats:sub>3</jats:sub> (BT) nanoparticles, which acted as a coupling agent. The modified BT(F4CBT) nanoparticles, polyvinylidene fluoride (PVDF), and polymethylmethacrylate (PMMA) were used to make the modified nanocomposite films: PVDF/PMMA‐F4C‐BaTiO<jats:sub>3</jats:sub> nanocomposite films. The unmodified BT nanoparticles were used to make the unmodified nanocomposite films: PVDF/PMMA‐BaTiO<jats:sub>3</jats:sub> nanocomposite films. The modification effect of the F4C resulted in an increase in the amount of β‐phase and γ‐phase, a decrease in the amount of α‐phase, and a decrease in the overall crystallinity of the PVDF‐based nanocomposite films. The dielectric constant of the PVDF/PMMA‐F4C‐BaTiO<jats:sub>3</jats:sub> nanocomposite films reached a maximum value of 16.7 at a frequency of 100 Hz at 4 wt% F4C, which was 40.3% higher than that of the unmodified PVDF/PMMA‐BaTiO<jats:sub>3</jats:sub> films. The F4C content of 2 wt% PVDF/PMMA‐F4C‐BaTiO<jats:sub>3</jats:sub> nanocomposite films showed the lowest dielectric loss of 0.055, which was 56.7% lower than the unmodified PVDF/PMMA‐BaTiO<jats:sub>3</jats:sub> films. The breakdown strength of the PVDF/PMMA‐F4C‐BaTiO<jats:sub>3</jats:sub> nanocomposite films increased and then decreased with the increase of the F4C content, and the highest breakdown strength was 2800 kV/cm at 4 wt% F4C, which was 55.6% higher than the unmodified PVDF/PMMA‐BaTiO<jats:sub>3</jats:sub> films. The charging density of the PVDF/PMMA‐F4C‐BaTiO<jats:sub>3</jats:sub> nanocomposite films reached a maximum value of 20.65 J/cm<jats:sup>3</jats:sup> at 4 wt% F4C content, which was 394% higher than the unmodified PVDF/PMMA‐BaTiO<jats:sub>3</jats:sub> films.Highlights<jats:list list-type=\"bullet\"> <jats:list-item>Modification of ceramic nanoparticles with carboxylic acid coupling agent.</jats:list-item> <jats:list-item>The dielectric properties of the modified nanocomposite film were significantly improved.</jats:list-item> <jats:list-item>Maximum polarization and charge/discharge density were greatly improved by coupling agent modification.</jats:list-item> </jats:list>","PeriodicalId":20375,"journal":{"name":"Polymer Composites","volume":"64 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study delved into the Mode I fracture behavior of laser‐assisted automated fiber placement (AFP) in situ consolidated thermoplastic composite laminates under different curing pressures. In compliance with ASTM D5528 standards, T700 carbon fiber reinforced polyether ether ketone (T700‐CF/PEEK) double cantilever beam (DCB) specimens were fabricated and segregated into three test groups subjected to distinct roller pressures: DCB‐100N, DCB‐500N, and DCB‐1500N. The fracture toughness of these specimens was then inversely characterized by employing an optimized ASTM‐based data reduction methodology. A kind of tri‐linear cohesive zone model (CZM) incorporating the fracture process zone (FPZ) length was developed to simulate delamination behavior, showing good agreement between experimental results and simulation predictions. Compared with the other two test groups, DCB‐1500N specimens have more inter‐laminar bridging fibers and higher propagated toughness. Although the length of fiber bridging area is shorter, the fiber bridging density is higher, so the influence of fiber bridging on toughness is more pronounced in the DCB‐1500N specimens. This study provides theoretical guidance for the impact resistance design of thermoplastic composites (TPCs), offering valuable insights into the intrinsic relationship between material processing and fracture damage mechanisms.HighlightsExplore the characteristic interlaminar fracture behavior of thermoplastic laminates made by AFP under different curing pressures.Develop a more accurate tri‐linear CZM model to describe the plastic deformation at crack tips and fiber bridging during the delamination process.Unveil the intrinsic relationship between AFP curing pressure and ductile fracture mechanism of thermoplastic composites.
{"title":"Study on Mode I interlaminar fracture behavior of automated fiber placement in situ consolidation thermoplastic composite considering the influence of roller compaction pressure","authors":"Chen Liu, Chen He, Zhongfeng Zou, Yong Li","doi":"10.1002/pc.29050","DOIUrl":"https://doi.org/10.1002/pc.29050","url":null,"abstract":"<jats:label/>This study delved into the Mode I fracture behavior of laser‐assisted automated fiber placement (AFP) in situ consolidated thermoplastic composite laminates under different curing pressures. In compliance with ASTM D5528 standards, T700 carbon fiber reinforced polyether ether ketone (T700‐CF/PEEK) double cantilever beam (DCB) specimens were fabricated and segregated into three test groups subjected to distinct roller pressures: DCB‐100N, DCB‐500N, and DCB‐1500N. The fracture toughness of these specimens was then inversely characterized by employing an optimized ASTM‐based data reduction methodology. A kind of tri‐linear cohesive zone model (CZM) incorporating the fracture process zone (FPZ) length was developed to simulate delamination behavior, showing good agreement between experimental results and simulation predictions. Compared with the other two test groups, DCB‐1500N specimens have more inter‐laminar bridging fibers and higher propagated toughness. Although the length of fiber bridging area is shorter, the fiber bridging density is higher, so the influence of fiber bridging on toughness is more pronounced in the DCB‐1500N specimens. This study provides theoretical guidance for the impact resistance design of thermoplastic composites (TPCs), offering valuable insights into the intrinsic relationship between material processing and fracture damage mechanisms.Highlights<jats:list list-type=\"bullet\"> <jats:list-item>Explore the characteristic interlaminar fracture behavior of thermoplastic laminates made by AFP under different curing pressures.</jats:list-item> <jats:list-item>Develop a more accurate tri‐linear CZM model to describe the plastic deformation at crack tips and fiber bridging during the delamination process.</jats:list-item> <jats:list-item>Unveil the intrinsic relationship between AFP curing pressure and ductile fracture mechanism of thermoplastic composites.</jats:list-item> </jats:list>","PeriodicalId":20375,"journal":{"name":"Polymer Composites","volume":"30 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amir Reza Fatolahi, Yousef Ghanbari, Hadi Khoramishad, L. F. M. da Silva
A comparative analysis was conducted among nanocomposites fabricated using pristine multi‐walled carbon nanotubes (MWCNTs), iron oxide nanoparticles (Fe3O4), MWCNT/Fe3O4 hybrid nanofillers, and a mixture of MWCNTs and Fe3O4 nanoparticles with varying nanofiller contents. MWCNT/Fe3O4 hybrid nanofillers with significant magnetic properties were synthesized using a chemical coating method to reinforce the epoxy polymer. Characterization techniques, including transmission electron microscopy, energy‐dispersive x‐ray spectroscopy, and Fourier transform infrared spectroscopy, confirmed the successful attachment of Fe3O4 nanoparticles onto MWCNTs. Various solvents and sonication parameters were employed to improve the dispersion quality of nanofillers within the epoxy matrix, and their collective impact on the thermomechanical properties of nanocomposites was investigated. The results showed that nanocomposites containing MWCNT/Fe3O4 hybrid nanofillers dispersed using chloroform and optimized sonication parameters exhibited 5%, 9%, 32%, and 46% improvements in tensile strength and 11%, 20%, 38%, and 50% improvements in elastic modulus compared to those fabricated with mixed nanofillers, pristine MWCNTs, Fe3O4 nanoparticles, and the neat epoxy, respectively. These nanocomposites also experienced considerable enhancements in thermal stability parameters. Field‐emission scanning electron microscopy was also used to evaluate the dispersion quality and failure mechanisms. The results of this study can be applied in industries that require controllable magnetic properties.HighlightsConfirmed successful attachment of Fe3O4 nanoparticles onto MWCNTs.Sonication parameters considerably affected thermomechanical properties.Chloroform showed the highest improvement in thermomechanical properties.The improvements were due to the high dispersion quality assessed by FESEM.Hybrid nanofillers showed superior properties than single and mixed fillers.
{"title":"A comparative study on the thermomechanical properties of polymeric nanocomposites incorporating single, mixed, and hybrid nanofillers","authors":"Amir Reza Fatolahi, Yousef Ghanbari, Hadi Khoramishad, L. F. M. da Silva","doi":"10.1002/pc.29003","DOIUrl":"https://doi.org/10.1002/pc.29003","url":null,"abstract":"<jats:label/>A comparative analysis was conducted among nanocomposites fabricated using pristine multi‐walled carbon nanotubes (MWCNTs), iron oxide nanoparticles (Fe<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub>), MWCNT/Fe<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> hybrid nanofillers, and a mixture of MWCNTs and Fe<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> nanoparticles with varying nanofiller contents. MWCNT/Fe<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> hybrid nanofillers with significant magnetic properties were synthesized using a chemical coating method to reinforce the epoxy polymer. Characterization techniques, including transmission electron microscopy, energy‐dispersive x‐ray spectroscopy, and Fourier transform infrared spectroscopy, confirmed the successful attachment of Fe<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> nanoparticles onto MWCNTs. Various solvents and sonication parameters were employed to improve the dispersion quality of nanofillers within the epoxy matrix, and their collective impact on the thermomechanical properties of nanocomposites was investigated. The results showed that nanocomposites containing MWCNT/Fe<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> hybrid nanofillers dispersed using chloroform and optimized sonication parameters exhibited 5%, 9%, 32%, and 46% improvements in tensile strength and 11%, 20%, 38%, and 50% improvements in elastic modulus compared to those fabricated with mixed nanofillers, pristine MWCNTs, Fe<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> nanoparticles, and the neat epoxy, respectively. These nanocomposites also experienced considerable enhancements in thermal stability parameters. Field‐emission scanning electron microscopy was also used to evaluate the dispersion quality and failure mechanisms. The results of this study can be applied in industries that require controllable magnetic properties.Highlights<jats:list list-type=\"bullet\"> <jats:list-item>Confirmed successful attachment of Fe<jats:sub>3</jats:sub>O<jats:sub>4</jats:sub> nanoparticles onto MWCNTs.</jats:list-item> <jats:list-item>Sonication parameters considerably affected thermomechanical properties.</jats:list-item> <jats:list-item>Chloroform showed the highest improvement in thermomechanical properties.</jats:list-item> <jats:list-item>The improvements were due to the high dispersion quality assessed by FESEM.</jats:list-item> <jats:list-item>Hybrid nanofillers showed superior properties than single and mixed fillers.</jats:list-item> </jats:list>","PeriodicalId":20375,"journal":{"name":"Polymer Composites","volume":"9 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. Kavitha, J. Manoj Dhivakar, N. P. G. Bhavani, Ramanujam Sarathi, Stefan Kornhuber
In the present work, the impact of corona aging on the dielectric, thermal, and surface properties of silicone rubber filled with different nanofillers such as alumina (Al2O3), aluminum trihydrate (ATH), boron nitride (BN), and titania (TiO2) are studied. The surface degradation of the silicone rubber nanocomposites after corona aging is evaluated through contact angle measurement, atomic force microscopy (AFM) studies, and by water droplet‐initiated corona inception voltage studies. Alumina filled silicone rubber shows less reduction in surface and hydrophobic properties after corona aging. Water droplet initiated corona inception voltage (CIV) under negative DC voltage is much higher than under positive DC and AC voltages. Al2O3/TiO2‐ filled silicone rubber samples show better CIV performance. The Dielectric Response Spectroscopy (DRS) indicates that TiO2 filled silicone rubber insulating material possesses higher permittivity at lower frequencies. Boron nitride added composites have high thermal conductivity whereas ATH filled silicone rubber composites shows higher decay rate, as observed through laser‐induced thermography studies. A significantly high surface leakage current is observed in all samples after corona aging. The Space Charge Limited Current (SCLC) studies clearly indicate that inclusion of nano‐fillers resulted in an increase in crossover voltage and trap density values compared to base silicone rubber.HighlightsAl2O3 filled silicone rubber exhibits lower surface roughness even after corona aging.High thermal conductive composites show better performance even after corona aging.ATH, and BN filled silicone rubber have improved thermal conductivity by 35.2% and 76.3%.TiO2 filler added silicone rubber exhibits high permittivity with low tan δ.Al2O3 filled silicone rubber has minimal surface and volume leakage currentCrossover voltage and the trap density get enhanced on addition of fillers to the base polymer.
{"title":"Understanding the impact of different nanofillers on electrical, thermal, and surface properties of corona‐aged silicone rubber nanocomposites","authors":"N. Kavitha, J. Manoj Dhivakar, N. P. G. Bhavani, Ramanujam Sarathi, Stefan Kornhuber","doi":"10.1002/pc.29065","DOIUrl":"https://doi.org/10.1002/pc.29065","url":null,"abstract":"<jats:label/>In the present work, the impact of corona aging on the dielectric, thermal, and surface properties of silicone rubber filled with different nanofillers such as alumina (Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>), aluminum trihydrate (ATH), boron nitride (BN), and titania (TiO<jats:sub>2</jats:sub>) are studied. The surface degradation of the silicone rubber nanocomposites after corona aging is evaluated through contact angle measurement, atomic force microscopy (AFM) studies, and by water droplet‐initiated corona inception voltage studies. Alumina filled silicone rubber shows less reduction in surface and hydrophobic properties after corona aging. Water droplet initiated corona inception voltage (CIV) under negative DC voltage is much higher than under positive DC and AC voltages. Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>/TiO<jats:sub>2</jats:sub>‐ filled silicone rubber samples show better CIV performance. The Dielectric Response Spectroscopy (DRS) indicates that TiO<jats:sub>2</jats:sub> filled silicone rubber insulating material possesses higher permittivity at lower frequencies. Boron nitride added composites have high thermal conductivity whereas ATH filled silicone rubber composites shows higher decay rate, as observed through laser‐induced thermography studies. A significantly high surface leakage current is observed in all samples after corona aging. The Space Charge Limited Current (SCLC) studies clearly indicate that inclusion of nano‐fillers resulted in an increase in crossover voltage and trap density values compared to base silicone rubber.Highlights<jats:list list-type=\"bullet\"> <jats:list-item>Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> filled silicone rubber exhibits lower surface roughness even after corona aging.</jats:list-item> <jats:list-item>High thermal conductive composites show better performance even after corona aging.</jats:list-item> <jats:list-item>ATH, and BN filled silicone rubber have improved thermal conductivity by 35.2% and 76.3%.</jats:list-item> <jats:list-item>TiO<jats:sub>2</jats:sub> filler added silicone rubber exhibits high permittivity with low tan δ.</jats:list-item> <jats:list-item>Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> filled silicone rubber has minimal surface and volume leakage current</jats:list-item> <jats:list-item>Crossover voltage and the trap density get enhanced on addition of fillers to the base polymer.</jats:list-item> </jats:list>","PeriodicalId":20375,"journal":{"name":"Polymer Composites","volume":"66 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142254033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The objective of this paper is to analyze the mechanical properties and damage mechanisms of carbon fiber‐reinforced polyamide thermoplastic composite laminates. Four specimens with different ply orientations were designed for open‐hole tensile experiments, and interlaminar toughness experiments including double cantilever beam and end‐notched flexural were carried out. The experimental process was monitored synchronously using acoustic emission, and the strain field changes of the tensile specimens were captured using digital image correlation technology. The unsupervised clustering of the peak frequencies of the acoustic emission signals based on the K‐means++ algorithm was employed to ascertain the peak frequency ranges corresponding to the various damage modes. Typical signals from different specimens were selected, and the gray wolf algorithm was used to optimize the variational modal parameters to decompose the signals. The waveform characteristics, frequency components, and Hilbert spectra of each damage mode were given. The correlation analysis of the intrinsic mode function (IMF) components of the same damage in different specimens demonstrated that the IMF components exhibited high similarity. By analyzing the time series changes in the energy of each damage mode in different specimens, the contribution of different damage modes to the evolution of laminated plate damage was evaluated.HighlightsThe mechanical properties of CF/PA6 laminates were investigated based on open‐hole tensile specimens and pre‐cracked delamination specimens.Unsupervised clustering of AE peak frequencies using K‐means++ to establish the relationship between peak frequencies and damage patterns.AE counts and cumulative energy were used to assess damage evolution.By identifying a single damage signal and providing a more intuitive treatment of the damage energy evolution.
{"title":"Investigation on damage behaviors of carbon fiber‐reinforced nylon 6 thermoplastic composite laminates using acoustic emission and digital image correlation techniques","authors":"Jixin Zhu, Kejun Hu, Wenqin Han, Qinghe Shi, Yingming Wang, Fengling Zhao, Fuxian Zhu","doi":"10.1002/pc.29063","DOIUrl":"https://doi.org/10.1002/pc.29063","url":null,"abstract":"<jats:label/>The objective of this paper is to analyze the mechanical properties and damage mechanisms of carbon fiber‐reinforced polyamide thermoplastic composite laminates. Four specimens with different ply orientations were designed for open‐hole tensile experiments, and interlaminar toughness experiments including double cantilever beam and end‐notched flexural were carried out. The experimental process was monitored synchronously using acoustic emission, and the strain field changes of the tensile specimens were captured using digital image correlation technology. The unsupervised clustering of the peak frequencies of the acoustic emission signals based on the K‐means++ algorithm was employed to ascertain the peak frequency ranges corresponding to the various damage modes. Typical signals from different specimens were selected, and the gray wolf algorithm was used to optimize the variational modal parameters to decompose the signals. The waveform characteristics, frequency components, and Hilbert spectra of each damage mode were given. The correlation analysis of the intrinsic mode function (IMF) components of the same damage in different specimens demonstrated that the IMF components exhibited high similarity. By analyzing the time series changes in the energy of each damage mode in different specimens, the contribution of different damage modes to the evolution of laminated plate damage was evaluated.Highlights<jats:list list-type=\"bullet\"> <jats:list-item>The mechanical properties of CF/PA6 laminates were investigated based on open‐hole tensile specimens and pre‐cracked delamination specimens.</jats:list-item> <jats:list-item>Unsupervised clustering of AE peak frequencies using K‐means++ to establish the relationship between peak frequencies and damage patterns.</jats:list-item> <jats:list-item>AE counts and cumulative energy were used to assess damage evolution.</jats:list-item> <jats:list-item>By identifying a single damage signal and providing a more intuitive treatment of the damage energy evolution.</jats:list-item> </jats:list>","PeriodicalId":20375,"journal":{"name":"Polymer Composites","volume":"66 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142253710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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