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Magnesium alloys have a high potential for reducing mass in automotive and aerospace applications due to their extraordinary low density. However, their utilization is often restricted since magnesium suffers from several material inherent deficiencies like low stiffness, poor high temperature strength, low wear and creep resistance as well as a high thermal expansion coefficient. Certain remedies have been developed in the past, e.g., extremely high in‐axis strength and stiffness values can be reached by the reinforcement of magnesium with carbon long fibers. This paper reviews the investigations at the University of Erlangen on carbon long‐fibers introduced into magnesium by a gas pressure melt infiltration technique. 相似文献
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碳纤维对工程结构加固的试验研究 总被引:1,自引:0,他引:1
碳纤维及其复合材料是伴随着军工事业的发展而成长起来的新型材料,碳纤维布由于其高强、轻质、耐腐蚀等优点而广泛用于结构加固中,与其它加固方法相比,碳纤维布加固具有易于施工、工效高、造价低且耐腐蚀等优点.本文在总结前人工作基础上,研制了用于碳纤维布加固的GF结构胶,并测试了其物理力学性能;通过试验研究了碳纤维布加固梁在荷载作用下的挠度、强度、裂缝展开情况及破坏模式.试验结果表明,经过碳纤维布加固的梁,其承载能力和刚度均较未加固梁有较大幅度的增加,采用碳纤维布加固对裂缝的开展有明显的约束效果. 相似文献
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对碳纤维复合材料保险杠碰撞性能进行研究,并进行铺层优化设计。先在HyperStudy中进行试验设计获得大量试验数据,然后采用HyperKriging方法构建近似模型,随后采用遗传算法进行铺层优化,最后将最优解重新代入原模型,进行运算验证。相对于原钢制保险杠,优化后的碳纤维复合材料保险杠有更佳的安全性能,且质量显著减轻,减轻63.3%。碳纤维复合材料对于汽车碰撞安全性及轻量化具有重要的研究意义。 相似文献
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改善磷酸镁水泥砂浆(MPCM)的韧性有利于促进其在混凝土结构加固和修复领域的应用。为了增强MPCM的韧性,对比研究了未处理和硝酸预处理碳纤维对MPCM力学性能的影响,分析了碳纤维增韧MPCM的机制。结果表明,当碳纤维质量掺量为0.4%时,MPCM 7d抗折强度增大44.5%;3~6mm碳纤维有利于提高MPCM的抗压强度,而6~10mm碳纤维更有利于提高MPCM的抗折强度;未处理碳纤维与磷酸镁水泥(MPC)水化产物之间为物理作用,碳纤维未能充分发挥增韧效果;在40~60℃、浓度68%的硝酸中浸泡30~60min有利于改善碳纤维与MPC水化产物的界面粘结,使预处理后的碳纤维和MPC水化产物产生嵌合作用,显著增强了MPCM的力学性能和韧性。 相似文献
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The simulation of acoustic emission waveforms resulting from failure during mechanical loading of carbon fiber reinforced
plastic structures is investigated using a finite element simulation approach. For this investigation we focus on the dominant
failure mechanisms in fiber reinforced structures consisting of matrix cracking, fiber breakage and fiber-matrix interface
failure. To simulate the failure process accurately, we present a new acoustic emission source model that is based on the
microscopic source geometry and micromechanical properties of fiber and resin. We demonstrate that based on this microscopic
source model these failure mechanisms result in excitation of macroscopic plate waves. The propagation of these plate waves
is described using a macroscopic three-dimensional model geometry which includes contributions of reflections from the specimen
boundaries. We further present a model of the acoustic emission sensors used in experiments to simulate the influence of aperture
effects. To enhance the understanding of correlation between macroscopically detectable acoustic emission signals and microscopic
failure mechanisms we simulate the response to different source excitation times, crack surface displacements and displacement
directions. The results obtained show good agreement with fundamental assumptions about the crack process reported by various
other authors. The simulated acoustic emission signals obtained are compared to experimentally measured waveforms during four-point
bending experiments of carbon fiber reinforced plastic structures. The simulated signals of fiber-breakage, matrix-cracking
and fiber-matrix interface failure show systematic agreement with the respective experimental signals. 相似文献
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T-700碳纤维增强复合材料的激光辐照性能研究 总被引:1,自引:1,他引:0
采用Rofin-Sinar 850型CO_2激光器研究了T-700碳纤维/g氧树脂及T-700织物/酚醛树脂2种复合材料体系的激光辐照特性.研究表明,T-700碳纤维增强树脂基复合材料在激光辐照时均首先产生燃烧现象.在032激光器的输出功率2355(士3%)w、光斑直径10mm、光斑功率密度3kW/cm~2、辐照时间3s条件下,T-700碳纤维/环氧树脂与碳布/酚醛树脂复合材料的质量损失相当,质量损失最大为0.1666g.在激光辐照下,增加T-700碳纤维/环氧树脂复合材料厚度可以起到明显的隔热作用,在碳布/酚醛树脂复合材料表面粘贴DQ绝热层可有效提高激光辐照隔热性能. 相似文献
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Anatomical properties of bamboo fiber, like chemical constituents and ultra structure establish bamboo as superior to other known natural ligno-cellulosic fibers. Bamboo fibers have been separated and sized in the form of fibers and strips. These fibers and strips mat (in the form of orthogonal mat) have been used to reinforce epoxy and unsaturated polyester (USP) resins. A process has been developed to cast bamboo fiber reinforced plastic (BFRP) unidirectional, bidirectional and multidirectional composites. The resulting material combine the strength and resilience of bamboo fiber with dimensional stability and moisture resistance of thermosetting resin. 相似文献
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应用Abaqus有限元仿真软件,建立了CFRP/Al钻削有限元仿真模型,对CFRP/Al钻孔过程中碳纤维复合材料的撕裂、分层损伤及毛刺的特征和形成机理进行了仿真研究,并进一步分析了切削速度、进给量对CFRP/Al叠层结构制孔缺陷的影响规律。结果表明:麻花钻横刃对碳纤维的拉伸作用是造成撕裂的主要原因;毛刺主要产生在纤维被切削时处于拉伸状态的区域,铝合金切屑对CFRP的划伤也是毛刺形成的原因之一;在CFRP/Al叠层结构制孔缺陷中分层损伤最显著,进给量和切削速度对出入口分层损伤成正相关且对入口处分层影响更大;在这种叠层结构中,铝合金板的支撑作用有效减小了碳纤维复合材料层出口的分层损伤。 相似文献
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为探究环氧玻璃钢材料在不同温度下的放气特性,以扩散放气模型为基础,建立了环氧玻璃钢材料放气速率随抽空时间变化关系的数学表达式,并结合实验数据拟合获得了其经验模型。同时,采用静态升压法对不同温度下环氧玻璃钢材料放气速率随抽空时间的变化关系进行了研究。结果表明,温度一定时,环氧玻璃钢材料的放气速率随着抽真空时间逐渐减小;温度升高,环氧玻璃钢材料放气速率增大,且放气速率随着抽真空时间呈现出指数衰减规律。此外,采用四极杆质谱仪分析了不同温度下环氧玻璃钢材料的放气成分,放气成分以H2O为主,并含有微量的H2、CO、N2及O2等。温度升高,玻璃钢材料放气各组分的占比无明显变化,表明温度对玻璃钢材料放气组分的占比几乎没有影响。 相似文献
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碳纤维复合材料的雷达透射性研究 总被引:4,自引:0,他引:4
研究发不同铺层对碳纤维复合材料雷达波透射系数的影响。结果表明,在单向纤维铺层中,随着铺层层数的增加,材料的透射系数降低,随着纤维与电场方向夹角│θ│增大。材料的透射系数升高。 相似文献
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Yao Yuanheng Cui Junjia Wang Shaoluo Xu Liwang Li Guangyao Pan Hao Bai Xinna 《Applied Composite Materials》2022,29(3):1147-1165
Applied Composite Materials - Carbon fiber reinforced epoxy (CFRE) and basalt fiber reinforced epoxy (BFRE) are used widely in automotive, navy due to their excellent mechanical performance. In... 相似文献
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选用国产的连续炭纤维长丝与ABS树脂分别采用常规共混法、薄膜层叠法、溶液浸渍法三种工艺制备了连续炭纤维增强ABS热塑性树脂复合材料。通过对复合材料的力学性能、热性能、动态黏弹性及微观形貌的研究,分析了ABS热塑性树脂基复合材料的制备工艺对界面性能的影响。结果表明:不同制备工艺中复合材料随炭纤维含量的增加其各项力学性能都不断提高,当炭纤维含量为60%(质量分数)时力学性能达到最高,但不同制备工艺导致复合材料界面性能差异较大,影响其力学性能的增幅。溶液浸渍法制备的复合材料树脂对炭纤维的浸润性良好,其最大拉伸强度和层间剪切强度分别达到1100MPa和71MPa,较常规共混法复合材料性能提高约80%;其损耗角正切仅为常规共混法复合材料的40%;界面性能提高使复合材料的耐热性能提高。 相似文献