Pub Date : 2025-02-17DOI: 10.1016/j.compositesb.2025.112317
Lucas Schraa , Carol Rodricks , Gerhard Kalinka , Karl Roetsch , Christina Scheffler , Anna Sambale , Kai Uhlig , Markus Stommel , Volker Trappe
This study investigates the suitability of the single fibre push-out (SFPO) test for the determination of the interfacial shear strength (IFSS) of injection moulded short fibre reinforced thermoplastics. It includes a detailed description of the required sample preparation steps and the boundary conditions of the SFPO setup. Experimental SFPO tests were carried out on PA66 GF, PPA GF35 and PA6 GF50 materials. Furthermore, a finite element model was set up to simulate the behaviour of these materials during this test. The numerical results showed that the inhomogeneous stress distribution in the fibre-matrix interphase during the test causes the measured apparent IFSS to underestimate the true strength of the interphase. The simulations put the experimental results into perspective and provide valuable information for the further development of the test setup. This study therefore not only provides new insights into the interphase strength of injection moulded short fibre reinforced thermoplastics, but also an insight into local load conditions during testing and thus an indication of the true IFSS.
{"title":"Characterisation and modelling of the fibre-matrix interface of short fibre reinforced thermoplastics using the push-out technique","authors":"Lucas Schraa , Carol Rodricks , Gerhard Kalinka , Karl Roetsch , Christina Scheffler , Anna Sambale , Kai Uhlig , Markus Stommel , Volker Trappe","doi":"10.1016/j.compositesb.2025.112317","DOIUrl":"10.1016/j.compositesb.2025.112317","url":null,"abstract":"<div><div>This study investigates the suitability of the single fibre push-out (SFPO) test for the determination of the interfacial shear strength (IFSS) of injection moulded short fibre reinforced thermoplastics. It includes a detailed description of the required sample preparation steps and the boundary conditions of the SFPO setup. Experimental SFPO tests were carried out on PA66 GF, PPA GF35 and PA6 GF50 materials. Furthermore, a finite element model was set up to simulate the behaviour of these materials during this test. The numerical results showed that the inhomogeneous stress distribution in the fibre-matrix interphase during the test causes the measured apparent IFSS to underestimate the true strength of the interphase. The simulations put the experimental results into perspective and provide valuable information for the further development of the test setup. This study therefore not only provides new insights into the interphase strength of injection moulded short fibre reinforced thermoplastics, but also an insight into local load conditions during testing and thus an indication of the true IFSS.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"297 ","pages":"Article 112317"},"PeriodicalIF":12.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-17DOI: 10.1016/j.compositesb.2025.112300
Peijin Yang , Yugen Shi , Hesheng Hu , Yu Wang , Ye Wang , Xinran Li , Lu Zhang , Yiping Wang , Lei Yu , Huitang Xia , Yan Li , Jie Yin
Inflammation-dominated sympathetic innervation adjacent to the infarcted region plays a pivotal role in the pathogenesis of severe ventricular arrhythmias (VAs) following myocardial infarction (MI). Thus, targeting inflammation process and sympathetic innervation represents a promising therapeutic approach to prevent VAs in clinical settings. Herein, we developed intelligent injectable hydrogels using boronic ester dynamic crosslinking as a pH- and reactive oxygen species (ROS)-responsive mechanism. We synthesized fluorophenylboronic acid-modified gelatin (GelPB) and combined it with polyvinyl alcohol (PVA) to create GelPB/PVA hydrogels (GP-gel) loaded with c-type natriuretic peptide (CNP) and Sema3A. The efficacy of this smart hydrogel was evaluated in an MI model induced by left anterior descending coronary artery ligation. The drug-loaded hydrogel demonstrated the excellent anti-inflammatory, pro-angiogenic, and anti-nerve sprouting effects. Specifically, it reduced macrophages infiltration, promoted M2 macrophage polarization in the early post-MI phase, and enhanced the expression of CD31 and a-SMA. As a result, sympathetic hyperinnervation was suppressed, arrhythmia susceptibility was reduced, and electrical conduction velocity was improved. Additionally, a notable improvement in cardiac function was observed. In conclusion, hydrogel co-loaded with CNP and Sema3A offers a promising therapeutic strategy for addressing both malignant arrhythmia and heart failure post-MI.
{"title":"Inhibition of neuron and cardiac remodeling by microenvironment-responsive injectable hydrogels with sympatho-immune regulation properties for myocardial infarction therapy","authors":"Peijin Yang , Yugen Shi , Hesheng Hu , Yu Wang , Ye Wang , Xinran Li , Lu Zhang , Yiping Wang , Lei Yu , Huitang Xia , Yan Li , Jie Yin","doi":"10.1016/j.compositesb.2025.112300","DOIUrl":"10.1016/j.compositesb.2025.112300","url":null,"abstract":"<div><div>Inflammation-dominated sympathetic innervation adjacent to the infarcted region plays a pivotal role in the pathogenesis of severe ventricular arrhythmias (VAs) following myocardial infarction (MI). Thus, targeting inflammation process and sympathetic innervation represents a promising therapeutic approach to prevent VAs in clinical settings. Herein, we developed intelligent injectable hydrogels using boronic ester dynamic crosslinking as a pH- and reactive oxygen species (ROS)-responsive mechanism. We synthesized fluorophenylboronic acid-modified gelatin (GelPB) and combined it with polyvinyl alcohol (PVA) to create GelPB/PVA hydrogels (GP-gel) loaded with c-type natriuretic peptide (CNP) and Sema3A. The efficacy of this smart hydrogel was evaluated in an MI model induced by left anterior descending coronary artery ligation. The drug-loaded hydrogel demonstrated the excellent anti-inflammatory, pro-angiogenic, and anti-nerve sprouting effects. Specifically, it reduced macrophages infiltration, promoted M2 macrophage polarization in the early post-MI phase, and enhanced the expression of CD31 and a-SMA. As a result, sympathetic hyperinnervation was suppressed, arrhythmia susceptibility was reduced, and electrical conduction velocity was improved. Additionally, a notable improvement in cardiac function was observed. In conclusion, hydrogel co-loaded with CNP and Sema3A offers a promising therapeutic strategy for addressing both malignant arrhythmia and heart failure post-MI.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"297 ","pages":"Article 112300"},"PeriodicalIF":12.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143508203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-17DOI: 10.1016/j.compositesb.2025.112294
Laiming Song , Yize Wu , Jinlong Xue , Jinmei He , Chao Wang
The development of advanced thermal protection systems for hypersonic vehicles necessitates materials that can withstand extreme conditions. Traditional phenolic foams, while providing good fireproofing and insulation, often suffer from brittleness, low mechanical strength, and insufficient high-temperature stability, limiting their application in critical environments. This study introduces a novel phosphate-modified phenolic foam (PF/NBR/P), enhanced by the incorporation of nitrile rubber (NBR) and phosphate to address these shortcomings. Through a series of experiments, including ablation tests and characterization techniques such as XRD and XPS, the performance of the composite foam was thoroughly evaluated. Key results reveal that PF/NBR/P foam exhibits a compressive strength of 0.41 MPa, a modulus of 6.58 MPa, thermal stability up to 400 °C, and a notably low peak heat release rate (PHRR) of 6.21 kW/m2, with minimal toxic emissions upon combustion. The phosphate-modified phenolic foam developed in this study demonstrates enhanced thermal stability, flame retardancy, and mechanical strength, providing valuable insights into optimizing phenolic foams for advanced aerospace applications.
{"title":"A high-temperature resistant phosphate-phenolic composite foam with low density, high strength, flame retardant and thermal insulating properties","authors":"Laiming Song , Yize Wu , Jinlong Xue , Jinmei He , Chao Wang","doi":"10.1016/j.compositesb.2025.112294","DOIUrl":"10.1016/j.compositesb.2025.112294","url":null,"abstract":"<div><div>The development of advanced thermal protection systems for hypersonic vehicles necessitates materials that can withstand extreme conditions. Traditional phenolic foams, while providing good fireproofing and insulation, often suffer from brittleness, low mechanical strength, and insufficient high-temperature stability, limiting their application in critical environments. This study introduces a novel phosphate-modified phenolic foam (PF/NBR/P), enhanced by the incorporation of nitrile rubber (NBR) and phosphate to address these shortcomings. Through a series of experiments, including ablation tests and characterization techniques such as XRD and XPS, the performance of the composite foam was thoroughly evaluated. Key results reveal that PF/NBR/P foam exhibits a compressive strength of 0.41 MPa, a modulus of 6.58 MPa, thermal stability up to 400 °C, and a notably low peak heat release rate (PHRR) of 6.21 kW/m<sup>2</sup>, with minimal toxic emissions upon combustion. The phosphate-modified phenolic foam developed in this study demonstrates enhanced thermal stability, flame retardancy, and mechanical strength, providing valuable insights into optimizing phenolic foams for advanced aerospace applications.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"297 ","pages":"Article 112294"},"PeriodicalIF":12.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-17DOI: 10.1016/j.compositesb.2025.112316
Hua Liu , Xiaohui Liu , Lingzhi Wang , Birong Zeng , Qingyun Zhao , Weiang Luo , Yiting Xu , Conghui Yuan , Lizong Dai
Despite being the earliest and most extensively studied class of vitrimers, transesterification epoxy (EP) vitrimers still face some large limitations in thermomechanical stability and flammability. Unlike the preparation of functional composite materials using ordinary curing agent compounds and nano fillers, this paper proposed a new strategy of using carbon dots to design nano-curing agents and dynamically crosslink active sites for constructing epoxy vitrimers with excellent thermomechanical stability and flame retardancy. Herein carboxylic acid type carbon dots (C-CDs) was synthesized via glutamate pyrolysis, subsequently grafting with organophosphorus compounds via the Kabachnik-Fields reaction to achieve the phosphorus doping (P-CDs). It is interesting that the synthesized P-CDs played a quadruple role as flame retardants, curing agents, dynamically exchangeable bonds, and nano-reinforcement effect. The results showed that this new kind of organic-inorganic hybrid flame-retardant EP/CDs vitrimers was firstly reported, which exhibited good thermomechanical stability, flame retardancy and fast stress relaxation time. When the molar ratio of P-CDs to epoxy was about 1:1, the peak heat release rate (PHRR) and CO2 production (CO2P) of the EP/P-CDs could be reduced by 53.4 %, and 65.1 %. The limiting oxygen index (LOI) was 31.3 % and the UL-94 grade reached V-0 rating, which benefitted from the dual-phase flame-retardant mechanisms. Furthermore, the stress relaxation time of EP/P-CDs was significantly shortened to be 90 s, which was important for the reprocessing of epoxy thermosets. Notably, EP/P-CDs maintained up to 98 % of its thermo-mechanical properties even after twice reprocessing. This kind of organic-inorganic hybrid flame-retardant EP/CDs vitrimers will have imposing potential applications in many fields.
{"title":"Organic-inorganic hybrid epoxy vitrimers with excellent thermal-mechanical stability based on carboxylic-acid type carbon dots as curing agent: Flame retardancy and reprocessing","authors":"Hua Liu , Xiaohui Liu , Lingzhi Wang , Birong Zeng , Qingyun Zhao , Weiang Luo , Yiting Xu , Conghui Yuan , Lizong Dai","doi":"10.1016/j.compositesb.2025.112316","DOIUrl":"10.1016/j.compositesb.2025.112316","url":null,"abstract":"<div><div>Despite being the earliest and most extensively studied class of vitrimers, transesterification epoxy (EP) vitrimers still face some large limitations in thermomechanical stability and flammability. Unlike the preparation of functional composite materials using ordinary curing agent compounds and nano fillers, this paper proposed a new strategy of using carbon dots to design nano-curing agents and dynamically crosslink active sites for constructing epoxy vitrimers with excellent thermomechanical stability and flame retardancy. Herein carboxylic acid type carbon dots (C-CDs) was synthesized via glutamate pyrolysis, subsequently grafting with organophosphorus compounds via the Kabachnik-Fields reaction to achieve the phosphorus doping (P-CDs). It is interesting that the synthesized P-CDs played a quadruple role as flame retardants, curing agents, dynamically exchangeable bonds, and nano-reinforcement effect. The results showed that this new kind of organic-inorganic hybrid flame-retardant EP/CDs vitrimers was firstly reported, which exhibited good thermomechanical stability, flame retardancy and fast stress relaxation time. When the molar ratio of P-CDs to epoxy was about 1:1, the peak heat release rate (PHRR) and CO2 production (CO2P) of the EP/P-CDs could be reduced by 53.4 %, and 65.1 %. The limiting oxygen index (LOI) was 31.3 % and the UL-94 grade reached V-0 rating, which benefitted from the dual-phase flame-retardant mechanisms. Furthermore, the stress relaxation time of EP/P-CDs was significantly shortened to be 90 s, which was important for the reprocessing of epoxy thermosets. Notably, EP/P-CDs maintained up to 98 % of its thermo-mechanical properties even after twice reprocessing. This kind of organic-inorganic hybrid flame-retardant EP/CDs vitrimers will have imposing potential applications in many fields.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"297 ","pages":"Article 112316"},"PeriodicalIF":12.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Conventional adhesives employed in woody composites production have drawbacks such as formaldehyde-releasing or high price, with complex production processes. In this study, we developed an in-situ surface liquefaction strategy, liquefaction and re-condensation of bamboo are directly transferred to the bonding interface. the glycerol and NaOH aqueous solution were directly coated on the bamboo surface, followed by a conventional hot-pressing process, bamboo trips were tightly bonded with a maximum bonding strength of 10.61 MPa, and the performance rivals that of phenolic resin. The bonding mechanism results revealed that glycerol initiates the ether bond cleavage of lignin on the bamboo surface and makes it from solid to flowing deformation, penetrating and filling the porous structure of the bamboo. Subsequently, the lignin condensation by the C–C bond and solidifies in these pores creating a robust cross-linked interlocking. Due to the absence of formaldehyde introduction and the elimination of the complex adhesive synthesis process, we have successfully achieved an environmentally friendly, straightforward, cost-effective, and high-performance bamboo gluing solution, making this strategy great potential for industrial production.
{"title":"In-situ surface liquefaction strategy for bamboo bonding with high-performance","authors":"Lin chen , Linmin Xia , Qi Chen , Menghong Jiang , Jing Yuan , Jiulong Xie","doi":"10.1016/j.compositesb.2025.112288","DOIUrl":"10.1016/j.compositesb.2025.112288","url":null,"abstract":"<div><div>Conventional adhesives employed in woody composites production have drawbacks such as formaldehyde-releasing or high price, with complex production processes. In this study, we developed an in-situ surface liquefaction strategy, liquefaction and re-condensation of bamboo are directly transferred to the bonding interface. the glycerol and NaOH aqueous solution were directly coated on the bamboo surface, followed by a conventional hot-pressing process, bamboo trips were tightly bonded with a maximum bonding strength of 10.61 MPa, and the performance rivals that of phenolic resin. The bonding mechanism results revealed that glycerol initiates the ether bond cleavage of lignin on the bamboo surface and makes it from solid to flowing deformation, penetrating and filling the porous structure of the bamboo. Subsequently, the lignin condensation by the C–C bond and solidifies in these pores creating a robust cross-linked interlocking. Due to the absence of formaldehyde introduction and the elimination of the complex adhesive synthesis process, we have successfully achieved an environmentally friendly, straightforward, cost-effective, and high-performance bamboo gluing solution, making this strategy great potential for industrial production.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"297 ","pages":"Article 112288"},"PeriodicalIF":12.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-17DOI: 10.1016/j.compositesb.2025.112287
Huizhou Luo , Henghui Deng , Yongyin Zhu , Hebo Shi , Chaoqun Zhang , Yang Wang
Elastomers are widely used in daily life, high-performance elastomers are expected to possess high strength, high toughness, excellent reparability and recyclability. Here, synthesized through simple one-pot method, amorphous polyurethane elastomers with suitable ratio of rigid and flexible segments could exhibit mechano-responsive self-reinforcing effect, which was caused by the strain induced orientation of polymer chains. Surprisingly, BPU-HDI0.4-HMDI0.6 had 24 times and 95 times the toughness of the samples with only flexible segments (BPU-HDI) or rigid segments (BPU-HMDI), respectively. Furthermore, BPU-HDI0.4-HMDI0.6 exhibited high strength (49.5 MPa), excellent Young's modulus (554.6 MPa), outstanding toughness (256.5 MJ m−3), as well as good fracture energy (115.5 kJ m−2), while possessed recovery, puncture resistance, self-healing and recyclability properties. The high-performance polyurethane elastomers with mechano-responsive self-reinforcing effect obtained in this work verified the potential of achieving a balance between strength and toughness of amorphous polymers by regulating the ratio of rigid and flexible segments. The material regulation strategy presented in this work is expected to provide valuable ideas for the construction of high-performance elastomers.
{"title":"High-performance polyurethane elastomers with mechano-responsive self-reinforcing via rigid-flexible segments regulation","authors":"Huizhou Luo , Henghui Deng , Yongyin Zhu , Hebo Shi , Chaoqun Zhang , Yang Wang","doi":"10.1016/j.compositesb.2025.112287","DOIUrl":"10.1016/j.compositesb.2025.112287","url":null,"abstract":"<div><div>Elastomers are widely used in daily life, high-performance elastomers are expected to possess high strength, high toughness, excellent reparability and recyclability. Here, synthesized through simple one-pot method, amorphous polyurethane elastomers with suitable ratio of rigid and flexible segments could exhibit mechano-responsive self-reinforcing effect, which was caused by the strain induced orientation of polymer chains. Surprisingly, BPU-HDI<sub>0.4</sub>-HMDI<sub>0.6</sub> had 24 times and 95 times the toughness of the samples with only flexible segments (BPU-HDI) or rigid segments (BPU-HMDI), respectively. Furthermore, BPU-HDI<sub>0.4</sub>-HMDI<sub>0.6</sub> exhibited high strength (49.5 MPa), excellent Young's modulus (554.6 MPa), outstanding toughness (256.5 MJ m<sup>−3</sup>), as well as good fracture energy (115.5 kJ m<sup>−2</sup>), while possessed recovery, puncture resistance, self-healing and recyclability properties. The high-performance polyurethane elastomers with mechano-responsive self-reinforcing effect obtained in this work verified the potential of achieving a balance between strength and toughness of amorphous polymers by regulating the ratio of rigid and flexible segments. The material regulation strategy presented in this work is expected to provide valuable ideas for the construction of high-performance elastomers.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"297 ","pages":"Article 112287"},"PeriodicalIF":12.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-17DOI: 10.1016/j.compositesb.2025.112291
Wenhui Wang , Shuai Liu , Jianyu Zhou , Zimu Li , Junshuo Zhang , Guilin Mei , Jinyu Yang , Sheng Wang , Yuan Hu , Xinglong Gong
Mechanical impacts posed significant safety threats to individuals and equipment, driving the increasing demand for high-performance protective materials and structures. Here, by combining shear stiffening elastomer (SSE) with ethylene-vinyl acetate (EVA), a novel strain rate-dependent shape memory polymer composite (SEVA) was developed. The storage modulus of SEVA increased from 63.08 kPa to 0.30 MPa as the shear frequency rose from 0.1 Hz to 50 Hz. A phase-transition-viscoelastic combined constitutive model was proposed, which successfully described the shape memory and rate-dependent properties of SEVA. Furthermore, based on the UMAT subroutine, the shape memory deformation process of SEVA was accurately simulated via a commercial ABAQUS software. Based on the thermo-dependent deformation mechanism, a self-folding hinge was fabricated by assembling pre-stretch programmed SEVA with polyethylene terephthalate film tape. The maximum folding angles were influenced by heating temperatures, programmed strains and PET film tape spacing. Additionally, various 2D-to-3D self-folding structures, including W-shaped, hexagonal, spiral, and gripper configurations were further designed, which presented enhanced impact resistance against dynamic drop hammer loads. Particularly, the hexagonal structure demonstrated superior impact attenuation performance, achieving reductions of 69.2 % in the maximum impact force and 78.5 % in the maximum residual impact force. Finally, an optimal self-folding honeycomb multicell structure was developed, which effectively improved impact energy transmission and dissipation through structural deformation, offering a semi-active protection solution. This work expanded the application potential of protective materials and structures in impact resistance.
机械冲击对个人和设备的安全构成重大威胁，推动了对高性能防护材料和结构日益增长的需求。在这里，通过将剪切加硬弹性体（SSE）与乙烯-醋酸乙烯酯（EVA）相结合，开发出了一种新型应变速率依赖性形状记忆聚合物复合材料（SEVA）。当剪切频率从 0.1 Hz 上升到 50 Hz 时，SEVA 的存储模量从 63.08 kPa 上升到 0.30 MPa。提出的相变-粘弹性组合构成模型成功地描述了 SEVA 的形状记忆和随速率变化的特性。此外，基于 UMAT 子程序，通过商用 ABAQUS 软件精确模拟了 SEVA 的形状记忆变形过程。根据热依赖变形机制，通过将预拉伸编程的 SEVA 与聚对苯二甲酸乙二醇酯薄膜带组装在一起，制作出了自折叠铰链。最大折叠角受加热温度、编程应变和 PET 薄膜带间距的影响。此外，还进一步设计了各种二维到三维自折叠结构，包括 W 形、六角形、螺旋形和抓手结构，这些结构在动态落锤载荷下具有更强的抗冲击性。特别是六边形结构表现出卓越的冲击衰减性能，最大冲击力降低了 69.2%，最大残余冲击力降低了 78.5%。最后，还开发了一种最佳自折叠蜂窝多孔结构，通过结构变形有效改善了冲击能量的传递和消散，提供了一种半主动防护解决方案。这项研究拓展了防护材料和结构在抗冲击方面的应用潜力。
{"title":"A rate-dependent shape memory polymer composite for self-folding 2D-to-3D structural transition with improved impact resistance","authors":"Wenhui Wang , Shuai Liu , Jianyu Zhou , Zimu Li , Junshuo Zhang , Guilin Mei , Jinyu Yang , Sheng Wang , Yuan Hu , Xinglong Gong","doi":"10.1016/j.compositesb.2025.112291","DOIUrl":"10.1016/j.compositesb.2025.112291","url":null,"abstract":"<div><div>Mechanical impacts posed significant safety threats to individuals and equipment, driving the increasing demand for high-performance protective materials and structures. Here, by combining shear stiffening elastomer (SSE) with ethylene-vinyl acetate (EVA), a novel strain rate-dependent shape memory polymer composite (SEVA) was developed. The storage modulus of SEVA increased from 63.08 kPa to 0.30 MPa as the shear frequency rose from 0.1 Hz to 50 Hz. A phase-transition-viscoelastic combined constitutive model was proposed, which successfully described the shape memory and rate-dependent properties of SEVA. Furthermore, based on the UMAT subroutine, the shape memory deformation process of SEVA was accurately simulated via a commercial ABAQUS software. Based on the thermo-dependent deformation mechanism, a self-folding hinge was fabricated by assembling pre-stretch programmed SEVA with polyethylene terephthalate film tape. The maximum folding angles were influenced by heating temperatures, programmed strains and PET film tape spacing. Additionally, various 2D-to-3D self-folding structures, including W-shaped, hexagonal, spiral, and gripper configurations were further designed, which presented enhanced impact resistance against dynamic drop hammer loads. Particularly, the hexagonal structure demonstrated superior impact attenuation performance, achieving reductions of 69.2 % in the maximum impact force and 78.5 % in the maximum residual impact force. Finally, an optimal self-folding honeycomb multicell structure was developed, which effectively improved impact energy transmission and dissipation through structural deformation, offering a semi-active protection solution. This work expanded the application potential of protective materials and structures in impact resistance.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"297 ","pages":"Article 112291"},"PeriodicalIF":12.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-17DOI: 10.1016/j.compositesb.2025.112312
Jingru Ai, Ming Xing, Haibin Wang, Zhi Zhao, Hao Lu, Xuemei Liu, Xiaoyan Song
This work presents specific one-step additive manufacturing of crack-free WC-12Co cemented carbides by the laser powder bed fusion (LPBF) technology using the mixed ultra-coarse WC and agglomerated Co powder as feedstock. The critical role of the agglomerated Co in elimination of cracks, pores and carbon-deficient phases during the LPBF fabrication and subsequent heat-treatment process was disclosed. Moreover, the agglomerated Co led to the formation of lath-shaped WC grains containing numerous Co-rich particles with sizes ranging from a few nanometers to approximately 300 nm. These in-grain Co-rich particles could accommodate plastic deformation and hinder dislocation motion within lath-shaped WC grains, but did not cause local stress concentration, thereby contributing to enhance both the toughness and strength of the resulting cemented carbides. The proposed novel strategy of tuning the distribution state of metallic phase within the feedstock holds significant potential for applications in the direct additive manufacturing of high-performance cermet materials.
{"title":"Tuning Co distribution in powder feedstock for laser powder bed fusion of crack-free WC-Co cemented carbides","authors":"Jingru Ai, Ming Xing, Haibin Wang, Zhi Zhao, Hao Lu, Xuemei Liu, Xiaoyan Song","doi":"10.1016/j.compositesb.2025.112312","DOIUrl":"10.1016/j.compositesb.2025.112312","url":null,"abstract":"<div><div>This work presents specific one-step additive manufacturing of crack-free WC-12Co cemented carbides by the laser powder bed fusion (LPBF) technology using the mixed ultra-coarse WC and agglomerated Co powder as feedstock. The critical role of the agglomerated Co in elimination of cracks, pores and carbon-deficient phases during the LPBF fabrication and subsequent heat-treatment process was disclosed. Moreover, the agglomerated Co led to the formation of lath-shaped WC grains containing numerous Co-rich particles with sizes ranging from a few nanometers to approximately 300 nm. These in-grain Co-rich particles could accommodate plastic deformation and hinder dislocation motion within lath-shaped WC grains, but did not cause local stress concentration, thereby contributing to enhance both the toughness and strength of the resulting cemented carbides. The proposed novel strategy of tuning the distribution state of metallic phase within the feedstock holds significant potential for applications in the direct additive manufacturing of high-performance cermet materials.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"297 ","pages":"Article 112312"},"PeriodicalIF":12.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-17DOI: 10.1016/j.compositesb.2025.112314
Jiaming Liu , Dong Quan , Gennaro Scarselli , Rene Alderliesten , Hao Wang , Guoqun Zhao
Carbon fiber reinforced thermoplastic composites (TPCs) attracted significant attentions from the aerospace, transportation, and defense industries, due to their high specific stiffness and specific strength, outstanding thermal stability and good damage resistance, etc. As the demand of TPCs significantly increased for aerospace applications, the development of advanced joining technologies for TPC components becomes critical to ensure the structural integrity of aviation structures. This paper provides a comprehensive review of the historical development and recent advancements in welding technologies for TPCs, including ultrasonic welding, induction welding, resistance welding, and laser welding. Special emphasis is placed on ultrasonic welding due to its growing prominence in the field. The characteristics of various types of welding technologies for TPCs have been systematically discussed. Simultaneously, the strengths of the TPC joints manufactured by different welding technologies have been summarized and compared. The future development trend and research focuses for the welding technologies of TPC components are also proposed.
{"title":"Developments and future prospects of welding technology for carbon fiber thermoplastic composites","authors":"Jiaming Liu , Dong Quan , Gennaro Scarselli , Rene Alderliesten , Hao Wang , Guoqun Zhao","doi":"10.1016/j.compositesb.2025.112314","DOIUrl":"10.1016/j.compositesb.2025.112314","url":null,"abstract":"<div><div>Carbon fiber reinforced thermoplastic composites (TPCs) attracted significant attentions from the aerospace, transportation, and defense industries, due to their high specific stiffness and specific strength, outstanding thermal stability and good damage resistance, etc. As the demand of TPCs significantly increased for aerospace applications, the development of advanced joining technologies for TPC components becomes critical to ensure the structural integrity of aviation structures. This paper provides a comprehensive review of the historical development and recent advancements in welding technologies for TPCs, including ultrasonic welding, induction welding, resistance welding, and laser welding. Special emphasis is placed on ultrasonic welding due to its growing prominence in the field. The characteristics of various types of welding technologies for TPCs have been systematically discussed. Simultaneously, the strengths of the TPC joints manufactured by different welding technologies have been summarized and compared. The future development trend and research focuses for the welding technologies of TPC components are also proposed.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"297 ","pages":"Article 112314"},"PeriodicalIF":12.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-17DOI: 10.1016/j.compositesb.2025.112293
Yan-Fang Xiao , Song Gu , Feng-Ming He , Yi Wang , Chuan Liu , Yu-Zhong Wang , Li Chen
Epoxy resins (EP), as prototypical highly crosslinked thermosets, face challenges in balancing strength with toughness, while simultaneously incorporating multi-functionalities, such as flame retardancy, thermal properties, transparency, and ultraviolet (UV) shielding capabilities. To overcome these limitations, this study designs and synthesizes two phosphaphenanthrene-modified poly-Schiff base “all-in-one” modifiers with tailored flexible segments, yielding two binary systems named EP-PPSR and EP-PPSi. These modifiers, through subtle structural variations, effectively regulate interfacial interactions and stress responsiveness in the EP matrix, enabling a unique balance between toughness and strength. Notably, EP-PPSi, featuring a highly flexible chain, exhibits superior tensile and flexural properties, with tensile and flexural strengths increasing by up to 34.7 % and 25.4 %, respectively, compared to neat EP. However, EP-PPSR, with a larger toughening interface, shows higher impact strength and fracture toughness, achieving an impact strength of 35.4 kJ m−2, nearly 2.9 times to that of neat EP. Both systems demonstrate excellent flame retardancy, self-extinguishing properties, and ignition resistance, with limiting oxygen index (LOI) values reaching up to 35.5 % and 37.5 %, respectively. At 4 wt% addition, both systems achieve a UL-94 vertical burning V-0 rating. EP-PPSi, leveraging a P–Si synergistic effect, outperforms EP-PPSR in suppressing heat release, smoke generation, and flame propagation under intense heat. Additionally, both materials boast remarkable transparency, UV shielding capacity, dielectric and thermomechanical properties, as well as a high glass transition temperature. This work presents a novel strategy for crafting multifunctional, high-performance flame-retardant thermosets, broadening their application horizons in demanding fields.
{"title":"Towards superb toughness, strength, and flame retardancy in epoxy resins via molecular interface engineering","authors":"Yan-Fang Xiao , Song Gu , Feng-Ming He , Yi Wang , Chuan Liu , Yu-Zhong Wang , Li Chen","doi":"10.1016/j.compositesb.2025.112293","DOIUrl":"10.1016/j.compositesb.2025.112293","url":null,"abstract":"<div><div>Epoxy resins (EP), as prototypical highly crosslinked thermosets, face challenges in balancing strength with toughness, while simultaneously incorporating multi-functionalities, such as flame retardancy, thermal properties, transparency, and ultraviolet (UV) shielding capabilities. To overcome these limitations, this study designs and synthesizes two phosphaphenanthrene-modified poly-Schiff base “all-in-one” modifiers with tailored flexible segments, yielding two binary systems named EP-PPSR and EP-PPSi. These modifiers, through subtle structural variations, effectively regulate interfacial interactions and stress responsiveness in the EP matrix, enabling a unique balance between toughness and strength. Notably, EP-PPSi, featuring a highly flexible chain, exhibits superior tensile and flexural properties, with tensile and flexural strengths increasing by up to 34.7 % and 25.4 %, respectively, compared to neat EP. However, EP-PPSR, with a larger toughening interface, shows higher impact strength and fracture toughness, achieving an impact strength of 35.4 kJ m<sup>−2</sup>, nearly 2.9 times to that of neat EP. Both systems demonstrate excellent flame retardancy, self-extinguishing properties, and ignition resistance, with limiting oxygen index (LOI) values reaching up to 35.5 % and 37.5 %, respectively. At 4 wt% addition, both systems achieve a UL-94 vertical burning V-0 rating. EP-PPSi, leveraging a P–Si synergistic effect, outperforms EP-PPSR in suppressing heat release, smoke generation, and flame propagation under intense heat. Additionally, both materials boast remarkable transparency, UV shielding capacity, dielectric and thermomechanical properties, as well as a high glass transition temperature. This work presents a novel strategy for crafting multifunctional, high-performance flame-retardant thermosets, broadening their application horizons in demanding fields.</div></div>","PeriodicalId":10660,"journal":{"name":"Composites Part B: Engineering","volume":"297 ","pages":"Article 112293"},"PeriodicalIF":12.7,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号