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在100W功率条件下,用氧等离子体对国产T800级碳纤维进行处理,通过扫描电子显微镜、原子力显微镜、X射线光电子能谱、单丝拉伸强度测试等方法对处理前后碳纤维表面物理化学特性进行表征,采用微脱粘方式研究了等离子体处理前后碳纤维环氧树脂复合材料界面的结合性能。结果表明:等离子体处理使碳纤维表面发生明显刻蚀,显著地提高了其表面化学活性;处理时间为3min时,碳纤维力学性能未发生降低,而其复合材料界面剪切强度值(IFSS)可达最高的88.61MPa,相比于未处理碳纤维复合材料而言,IFSS增幅为97.39%。 相似文献
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SiC纤维/LAS复合材料的TG-DTA-MS研究 总被引:1,自引:0,他引:1
本文首次用TG-DTA-MS联用技术对SiC纤维/LAS微晶玻璃复合材料的热分解过程、机制及其与晶化的关系进行了研究。提出了该复合材料界面形成碳层的热力学和质谱分析判别依据,并对晶化前后的复合材料的热分解行为作了实验对比和理论分析。 相似文献
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多频动态热机械分析法研究碳纤维复合材料湿热老化 总被引:2,自引:0,他引:2
采用多频温度扫描动态热机械(DMTA)方法研究了环氧树脂基碳纤维复合材料于65,95℃蒸馏水中的湿热老化性能,通过Arrhenius方程计算得到复合材料湿热老化前后的玻璃化转变表观活化能△Ea,分析了复合材料于两种温度下的吸湿性和静态力学性能变化.结果表明,不同树脂基复合材料湿热老化前后△Ea不同,随着湿热老化温度的升高,△Ea增加;湿热环境中复合材料的平衡吸湿率越低,△Ea越小;湿热老化后复合材料的力学性能保留率越低则△Ea越大.表观活化能可以用来表征树脂基复合材料的耐湿热性能. 相似文献
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苎麻纬编针织复合材料的研制 总被引:3,自引:0,他引:3
用RTM成型工艺对用苎麻和玻璃纤维设计、织造的米拉诺罗纹加衬纬和变化畦编加衬纬纬编针织物与树脂进行复合,并测试和分析了织物复合前后的拉伸性能。结果发现,纬编针织复合材料的拉伸性能主要取决于衬纬纱;变化畦编加衬纬复合材料的强度比米拉诺加衬纬的高;苎麻纤维织物的刚度影响复合材料的增强效果。 相似文献
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玻璃鳞片/环氧树脂复合材料的界面优化研究 总被引:2,自引:0,他引:2
采用ESCA,IR等研究了玻璃鳞片表面改性前后表面的变化,分别用SEM,盐水浸泡实验和电子万能测试机研究了复合材料的界面,抗渗透性和力学性能。结果表明;玻璃鳞片表面经改性后形成了一层有机物分子层,优化了玻璃鳞片与环氧树脂的界面结合提高敢复合材料的抗渗透性和力学性能。 相似文献
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颗粒增强2024Al复合材料的微屈服性能研究 总被引:2,自引:0,他引:2
为了明确亚微米颗粒增强铝基复合材料微塑性变形行为的规律和机制,利用微屈服强度测试和透射电镜分析,研究了亚微米级Al2O3颗粒增强2024Al复合材料的微屈服性能及尺寸稳定化热处理工艺对微屈服性能的影响。研究结果表明:复合材料的显微组织在稳定化热处理前后均呈现位错稀少的特点,有助于材料微屈服强度的提高;复合材料中尺寸细小,密集分布的S′相和亚微米颗粒本身对位错运动的有效阻碍也能改善材料的微屈服强度;时效后采用不同的冷热循环处理工艺,使得复合材料基体中S′相的尺寸和分布都发生一定的改变,进而呈现出不同的微屈服性能。 相似文献
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复合材料修补件的强度和疲劳性能 总被引:7,自引:1,他引:6
复合材料贴片修补损伤金属结构件已被证明是一种可靠的低成本高效益结构补强延寿方法,对复合材料贴片修补前后的含裂纹7075-T6铝合金薄板进行了拉伸和疲劳性能研究,结果表明,修补后构件的强度和疲劳寿命都明显提高,随着硼-环氧复合材料补片层的增加,修补铝合金板的疲劳扩展速率显著下降,疲劳寿命可获得10倍以上的改善,基于Rose分析解发展了一个简单的疲劳寿命预测模型,通过与试验结果比较证明了该模型的简单有效。 相似文献
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以麦秸秆纤维(WF)和高密度聚乙烯(HDPE)为原料,利用混炼和注塑成型的方法制备WF/HDPE复合材料。考察了木聚糖酶、漆酶、脂肪酶、木聚糖酶与脂肪酶复合处理对WF/HDPE复合材料力学性能、热稳定性、吸水率的影响,通过FTIR分析了酶处理前后的WF化学官能团变化,利用SEM观察了酶处理前后的WF表面形貌和WF/HDPE复合材料拉伸断裂面。结果表明:当WF/HDPE复合材料经木聚糖酶与脂肪酶复合处理后,吸水率最低且WF/HDPE复合材料的力学性能最好,其拉伸强度、弯曲强度、弯曲模量分别达到23.4 MPa、34.0 MPa、1 944.6 MPa;TG结果表明WF/HDPE的热分解过程分两个部分:WF的分解过程和HDPE的分解过程,酶能有效提高WF/HDPE的热稳定性;FTIR显示经酶处理后,WF的羟基振动峰微弱减小,在1 706~1 290 cm?1处光谱上出现部分小峰,SiO2的振动峰变得平缓;SEM显示经酶处理后,WF表面变粗糙,WF与HDPE结合紧密,其中经木聚糖酶和脂肪酶共同处理后两者界面结合性能最好。 相似文献
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In this research pull-out specimens were tested to investigate the bond behavior of superelastic NiTi (Nitinol) SMA wires to carbon fiber reinforced polymers (CFRP). A total of 45 pull-out specimens were tested monotonically up to failure. The test parameters considered include the wire diameter and embedment length. A digital image correlation (DIC) system was used to identify the onset and propagation of debonding. Based on the experimental observations two debonding mechanisms were observed: complete debonding after the onset of martensitic transformation of SMA wire, and complete debonding before the onset of wire transformation. The former mechanism predominated, while the latter mechanism governed for larger diameter wires with shorter embedment lengths. A 3-D non-linear finite element model (FEM) was developed to predict the pull-out behavior. A cohesive zone model (CZM) was used to model the interface. A parametric study was conducted using the FEM to quantify the parameters of the cohesive zone model. The results demonstrate that the proposed modeling approach can be used to characterize the bond behavior of superelastic SMA wires embedded in FRP composites. 相似文献
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Stiffness and vibration characteristics of SMA/ER3 composites with shape memory alloy short fibers 总被引:1,自引:0,他引:1
Qing-Qing Ni Run-xin Zhang Toshiaki Natsuki Masaharu Iwamoto 《Composite Structures》2007,79(4):501-507
Shape memory alloys (SMAs) possess both sensing and actuating functions due to their shape memory effect, pseudo-elasticity, high damping capability and other remarkable characteristics. Combining the unique properties of SMAs with other materials can create intelligent or smart composites. In this paper, epoxy resin composites filled with Ni–Ti alloy short fibers were developed. Microstructure was observed using digital HF microscope. The dynamic mechanical properties were investigated by measuring the first vibration mode of clamped cantilever beams and by dynamic mechanical analysis (DMA). Moreover, the natural frequency of SMA composites was predicted theoretically. As a result, the temperature dependency of vibration property and DMA characteristics is affected largely due to the addition of SMA short fibers. The vibrational characteristics of SMA composites can be improved by the addition of small amounts of SMA short fibers. The addition of 3.5 wt.% of SMA short fiber content to epoxy resin resulted in the maximum increment in both natural frequency and storage modulus. This suggested that there exists an optimum SMA fiber content for vibration characteristics. 相似文献
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Vibration characteristics of laminated composite plates with embedded shape memory alloys 总被引:1,自引:0,他引:1
Run-xin Zhang Qing-Qing Ni Arata Masuda TakahikoYamamura Masuharu Iwamoto 《Composite Structures》2006,74(4):389-398
Shape memory alloy (SMA) is commercially available for a variety of actuator and damping materials. Recently, SMA wires have also become commercially available for the design of smart composite structures because SMA wires with a small diameter can be easily produced. In this work, two types of SMA-based composites are presented for investigating the vibration characteristics. First, laminated composite plates containing unidirectional fine SMA wires are fabricated. By measuring the vibration mode of a clamped cantilever, the influence of both SMA arrangement and temperature on the vibration characteristics is made clear. Next, laminated composite plates with embedded woven SMA layer are fabricated. The stiffness tuning capability is evaluated by impact vibration tests with different temperatures. It is found that the stiffness tuning capability may be improved by increasing the volume fraction of SMAs and by controlling accurately the internal stress according to the phase transformation temperature of SMAs from martensite to austenite. The theoretical prediction on the natural frequency considering the SMAs behavior and laminated structures is proposed and their results agree reasonably with experimental ones. 相似文献
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设计了一种超弹性形状记忆合金(Shape Memory Alloy, SMA)阻尼器。在SMA丝的Graesser本构模型基础上, 建立了SMA阻尼器的常规力学模型, 进而提出了其简化力学模型。采用随机等价线性化法建立了单自由度SMA阻尼结构在高斯白噪声激励下的平稳随机振动分析公式。算例比较了随机等价线性化法和蒙特卡罗(Monte Carlo)模拟法计算的结构振动响应, 证明了随机等价线性化法的有效性;比较了无控结构和SMA阻尼结构的动力特性和振动响应, 说明了SMA阻尼器能增加结构的刚度和阻尼比, 因而可有效抑制结构的振动。 相似文献
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研究了形状记忆合金(SMA)纤维混杂复合材料大挠度层合板的非线性自由与受迫振动特性。基于描述SMA力学行为的Brinson理论以及层合板材料性能预测的混合率, 建立了SMA纤维混杂复合材料大挠度层合板的本构方程, 基于对称层合各向异性弹性板的非线性理论, 建立了以横向挠度和应力函数表示的板的横向振动方程和相容方程。采用Galerkin近似解法将振动方程化为时间变量的含有三次非线性项的Duffing型常微分方程, 采用谐波平衡法(HBM)获得系统的固有频率方程和强迫振动稳态频率响应方程。数值计算表明: 非线性板自由振动频率比与激励温度的关系具有与线性板相同的特征, 马氏体相向奥氏体相转变阶段温度对板的振动频响特性曲线的影响最显著, 同时也讨论了SMA纤维含量、 板的纵横比以及自由振动幅值对板的非线性频率比的影响。 相似文献
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SMA纤维混杂层合梁的振动分析 总被引:6,自引:0,他引:6
提出一类形状记忆合金(SMA)纤维混杂层合梁的数学模型。采用多胞模型、形状记忆合金一维本构关系分析方法,同时考虑铁木辛柯剪切和马氏体相变的影响。目的是为了更进一步了解层合梁的振动控制。SMA纤维用来作为驱动器,它能够改变弹性模量和回复力,以此改变梁的频率。分析了SMA纤维含量、铺设角度和横向剪切变形的影响。结果表明,通过激活形状记忆合金纤维及改变初始变形,对层合梁的自振频率有很强的控制和调节能力。 相似文献