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1.
    
Today, various fiber reinforcements are used in automotive, aerospace and defense industries. Many of these fibers are synthetic structures, which can cause problems such as environmental pollution and high manufacturing costs. Researchers have turned to the use of more environmental-friendly and cost-effective natural materials to minimize these problems. In this study energy absorption properties of the fiber laminate-hybrid epoxy composites were investigated with dynamic loadings. Fiber type and hybridization effects were investigated under drop weight impact tests with 10, 20, 30 and 50 Joule impact energies. Besides, mechanical characteristics were examined via quasi-static bending tests. In this context, double and triple fiber reinforced natural/synthetic and synthetic/synthetic hybrid composites were manufactured as sandwich type. Furthermore, it is also aimed an evaluation of using natural fibers in ballistic activities with this study. Fiber materials consist of woven type carbon, aramid and jute fibers. Hybrid composites were manufactured with the aim of providing mechanical optimization between the fibers and enabling the fiber layers to absorb more impact energy. In addition, performance evaluation was made by comparing natural/synthetic reinforced hybrid composites with full synthetic hybrid composites. The results show that significant improvements were achieved in bending and impact resistance of the composites by using jute fibers to the inner layers.  相似文献   

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采用电子记忆式冲击试验机研究了玻璃纤维(GF)、镁离子改性聚磷酸蜜胺盐无卤阻燃剂(Mg-MPP)及改性剂马来酸酐接枝EPDM(EPDM-MA)对聚酰胺66(PA66)基复合材料冲击断裂行为的影响。结果表明:纯PA66及PA66/GF的断裂行为依赖于引发能,韧性指数分别为0.660和0.675,表现为脆性断裂;而添加Mg-MPP及EPDM-MA主要影响断裂的扩展阶段,韧性指数分别为0.833和0.883,说明阻燃剂及冲击改性剂的存在增加了材料的韧性。  相似文献   

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The aim of this study is to develop a light weight hybrid biocomposite using pineapple and Kevlar fiber with peanut husk cellulose in vinyl ester resin for applications in unmanned aerial vehicles. This study focuses on how the silane treatment on fiber and cellulose particle influences the mechanical, fatigue and low velocity impact properties of this hybrid biocomposites. Using hand lay-up technique, the biocomposite was prepared with cellulose loading ranging from 1 to 5 vol%. The results revealed that the 5 vol% of cellulose added composite had an improved tensile, impact, flexural, hardness and ILSS of 161 MPa, 224 MPa, 6.8 J, 84 shore-D and 21.4 MPa. Moreover, the biocomposite with the inclusion of 3 vol% cellulose had an improved fatigue life count of 42 697, 29 821, 22 381 and 18 164 at 25%, 50%, 75% and 90% of UTS. Similarly, the 3 vol% cellulose reinforced composite showed an improved low velocity impact toughness of 12.36 J. The obtained results clearly indicated that these mechanically strengthened and highly toughened biocomposites could be used as working material for number of applications, especially in making of UAVs for the aerospace industry, automotive components for the transportation sector and structural material in domestic infrastructure.  相似文献   

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以硅粉含量和混杂纤维含量为试验参数,将1根普通混凝土梁作为对照组,3根不同硅粉含量和2根混杂纤维不同体积含量的梁作为试验组,对改性再生混凝土梁的抗弯性能进行分析,结果表明:改性再生混凝土梁与普通再生混凝土梁的破坏过程一样都具有明显的四个阶段,而且其基本受力过程也符合平截面假定;而且随着硅粉和混杂纤维的掺入使得改性再生混凝土梁的抗弯性能增强,抗开裂和极限承载力方面优于普通再生混凝土梁;而且按照规范计算出来的正截面极限承载力与试验值基本吻合,改性再生混凝土可以按照规范进行设计,为工程实践提供了参考依据.  相似文献   

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In this article we report the transesterification of jute with n-Butylacrylate (BA) under appropriate condition using NaOH, Pyridine (Py), and a Pyridine–acetone mixture as a catalyst. The modified vinylog jute was subsequently cured with benzoylperoxide (BPO) in acetone at 50–60°C. The parent and chemically modified jute were characterized by FTIR spectra. The percent moisture regain, mechanical strength, and behavior to common chemical reagents of the parent and modified fibers have also been tested. Transesterification and curing of jute lowered the percentage of moisture regain, imparted mechanical strength, and resistance to common chemical reagents. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 575–581, 2001  相似文献   

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姚鑫  徐亚星  董晓强 《硅酸盐通报》2021,40(9):2921-2929
深层水泥土搅拌桩围护墙具有水泥基材料的特性,包括脆性破坏以及较低的拉伸强度和弯曲强度,且温度应力产生的干燥收缩可能会导致裂缝的产生并引起墙体渗漏和塌陷.本文研究了黄麻纤维和聚乙烯醇(PVA)纤维增强水泥土搅拌桩的弯曲性能和裂后性能,并对纤维改善水泥土早期干缩裂缝的效果进行了对比.结果表明,随着黄麻纤维和PVA纤维含量的...  相似文献   

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高韧性的PVA-HPFRCC具有很高的能量吸收能力,但强度通常较低。本文采用工业废料(粉煤灰、硅灰等)替代部分水泥来制备高强度的PVA-HPFRCC,并研究粉煤灰、硅灰掺量以及PVA纤维体积掺量对高强度HPFRCC的弯曲行为的影响。研究结果表明:大掺量粉煤灰替代水泥可有效改善HPFRCC的应变-硬化特性,当粉煤灰掺量达到胶凝材料重量的60%时,其应变-硬化特性发挥的最为明显;增加PVA纤维体积掺量可提高HPFRCC的抗弯承载力和达到极限荷载时的变形能力,硅灰则降低了HPFRCC的韧性。  相似文献   

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对纤维增强混凝土梁的国内外研究进展进行了归纳总结,从试验分析方面阐述了纤维对梁力学性能的影响;在理论研究方面对纤维混凝土梁的抗弯和抗剪理论及抗剪承载力计算公式进行了总结并对公式的实用性做了进一步的阐述;在数值模拟方面介绍了纤维混凝土梁数值计算使用的的软件及成果.最后,基于现有的研究成果,提出了目前存在的不足,探讨了未来纤维混凝土梁的发展方向.  相似文献   

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Coir and palm fibers from agricultural waste were investigated as reinforcement for low density polyethylene (LDPE). The effect of fiber preparation with alkaline treatment and with/without bleaching on fiber physical properties was also an objective of this study. The chemical composition and FTIR (Fourier transform infrared spectroscopy) results confirmed that palm fibers had less impurity than coir fibers. This could be the reason for a greater fiber-matrix interfacial interaction of the palm fibers as compared to that of coir fibers, which was in good agreement with the estimation of surface free energy of the dispersion component. Moreover, fiber bleaching improved the single fiber pullout stress. Composites with both alkaline treated and bleached fibers, at different fiber contents (5, 10, 15, and 20 wt.%), were manufactured using a compression molding machine. Addition of both fibers in the LDPE matrix resulted in composites with a higher Young’s modulus compared to that of homopolymer. The Young’s modulus of the composites increased with the effect of either fiber content or fiber bleaching. Differential scanning calorimetry (DSC) showed that composites reinforced with both types of fibers had a single melting temperature peak, indicating the existence of only one type of crystalline species. Moreover, there were no significant differences in the melting temperatures for the fiber reinforced composites and the homo-LDPE. The heat of fusion decreased in the case of fiber reinforced composites.  相似文献   

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In this study, the flexural tests were conducted to investigate the effects of temperature, steel fiber, nano‐SiO2, and nano‐CaCO3 on flexural behavior of concrete at high temperatures. The load‐deflection curves of fiber and nanoparticle reinforced concrete (FNRC) were measured both at room and high temperatures. Test results show that the load‐deflection curves become flatter, and the flexural strength, peak deflection, and energy absorption capacity decrease seriously with the increase of temperature. Both steel fiber and nanoparticles could significantly improve the flexural behavior of the concrete at room and high temperatures. The energy absorption capacity of FNRC before the peak point increases with the increase of steel fiber volume fraction. The improvement of nano‐SiO2 on flexural strength of FNRC at high temperature is better than that at room temperature, but the enhancement on energy absorption capacity is reverse. Nano‐SiO2 is more effective than nano‐CaCO3 in improving flexural behavior of concrete both at room and high temperatures.  相似文献   

13.
橡胶制品用芳纶纤维的疲劳性能研究   总被引:1,自引:0,他引:1  
费传军  夏涛  李静  黄欣  申明霞 《玻璃纤维》2006,(4):13-14,26
从宏观的角度研究了芳纶纤维涂覆纱增强橡胶疲劳性能,采用橡胶疲劳试验机,对用芳纶纤维涂覆纱制成的芳纶线绳增强的橡胶试样进行曲挠、拉伸交变作用下的疲劳试验,研究不同涂覆处理的芳纶纤维纱和芳纶线绳与橡胶结合后的疲劳性能之间的关系。采用疲劳后试样的拉伸性能作为评价的标准,得出了芳纶纤维涂覆纱增强橡胶的耐疲劳性能优异,但同时由于拉伸断面不理想,说明RFL浸渍剂配方需要改进。  相似文献   

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为改善普通钢筋混凝土梁易开裂的缺点,可将受拉区部分混凝土采用同体积的HPFRCC替代形成HPFRCC/混凝土复合梁。基于复合梁的正截面弯曲性能试验,主要研究PVA纤维体积掺量对复合梁受弯性能的影响,研究结果表明,受拉区HPFRCC层的存在,可有效分散裂缝且抑制裂缝的扩展,复合梁的裂缝呈"根系状"分布形态,且随着HPFRCC层内纤维掺量的增加,裂缝变得更加细密;开裂后,PVA纤维的桥接承拉作用使复合梁中受拉钢筋与压区混凝土的应变增长较为迟缓;与普通混凝土梁相比,复合梁的初裂荷载、屈服荷载与极限荷载均有不同程度的提高且开裂荷载的提高幅度最为明显。  相似文献   

15.
研究了缝合及加强筋增强方式下泡沫夹芯复合材料的三点弯曲性能.采用万能试验机分别进行了缝合与未缝合碳纤维、玻璃纤维、玻碳混杂纤维泡沫夹芯复合材料的三点弯曲实验,分别得出各自的载荷-挠度曲线,再引入加强筋的方式进一步研究缝合碳纤维泡沫夹芯复合材料的弯曲性能.结果表明,玻碳混杂纤维泡沫夹芯复合材料较玻璃纤维泡沫夹心复合材料性...  相似文献   

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黄麻纤维增强聚丙烯的力学性能   总被引:9,自引:0,他引:9  
本文讨论了注塑成型黄麻纤维增强聚丙烯的制备方法和力学性能.将纤维重量含量分别为10%、20%和30%的复合材料进行比较,分析纤维含量对复合材料拉伸、弯曲和冲击性能的影响;将纤维分别切成约3mm、5mm和10mm长制成复合材料进行比较,分析纤维长度对复合材料拉伸、弯曲和冲击性能的影响.掺入黄麻纤维能使聚丙烯的拉伸和弯曲性能提高,但使其冲击强度降低;随纤维含量的增加或纤维长度的增加,复合材料的强度和模量是递增的,而冲击强度是递减的.  相似文献   

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设计并制作了3根玄武岩纤维增强塑料筋(BFRP筋)混凝土梁,并对其进行三分点加载试验,主要测试了构件的开裂荷载、裂缝和挠度发展情况以及极限荷载等。结果表明,受BFRP筋线弹性的材料性质、较低的弹性模量等因素的影响,BFRP筋混凝土梁的受弯工作具有以下特点:(1)构件均发生脆性破坏;(2)构件的开裂荷载和开裂前的挠度受BFRP筋配筋率的影响很小;(3)构件的极限荷载随BFRP筋配筋率的增加而增大;(4)构件的荷载-挠度曲线在混凝土开裂前后均为线性,其转折点对应构件开裂。  相似文献   

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This study evaluated the effect of latex content on the pullout behavior of macro synthetic fiber in hybrid fiber‐reinforced latex‐modified cement‐based composites (HFLMCCs). A bond‐strength test which utilized dog‐bone‐shaped test specimens was used to determine the pullout behavior. Micro jute fiber was incorporated at 9.00 kg/m3 and macro synthetic fiber at 0.45 kg/m3. Latex was added at 0, 5, 10, 15, 20, and 25% of the binder weight (wt %). Pullout tests showed that latex increased the area of the debonded zone of the pullout load–displacement curve. Bond strength increased with latex content up to 15% in HFLMCCs and decreased when the latex content reached 20%. The interface toughness increased until the latex content reached 20% and decreased when the latex content was 25%. These results were confirmed by microstructural analysis of the macro synthetic fiber surface, which showed that the number of scratches increased due to friction. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci, 2013  相似文献   

19.
利用自制的新型疲劳实验装置,对玻璃纤维(GF)增强聚丙烯(PP)复合材料进行疲劳性能研究,得到PP/GF复合材料在不同初始应力、不同振幅、不同频率下疲劳性能与GF含量的关系.结果表明,初始应力、振幅、频率越大,材料疲劳拉伸性能越差.初始应力较大时,初始应力的变化对PP/GF材料疲劳性能的影响更为明显,振幅在75 ~80...  相似文献   

20.
混杂纤维丝束冲击拉伸性能实验研究   总被引:2,自引:0,他引:2  
采用自行研制的摆锤式冲击拉伸试验机对玻璃纤维、芳纶纤维、超高分子量聚乙烯纤维和PBO纤维丝束及其混杂丝束进行了冲击拉伸试验.得到混杂纤维丝束断裂吸能和断裂强度随纤维混杂比变化的规律.  相似文献   

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