氧化聚丙烯腈纤维径向异质光学显微分析

为检测整束氧化聚丙烯腈纤维径向异质结构发育情况,迫切需要开发一种评价聚丙烯腈纤维是否均质氧化的检测方法。本文通过树脂包埋和研磨抛光制备用于光学分析的纤维试样,应用光学显微方法对比分析了两种类型氧化聚丙烯腈纤维径向异质结构演变过程,提出了氧化聚丙烯腈纤维径向异质结构演变模型。结果表明,TG300氧化聚丙烯腈纤维呈典型的径向异质结构,TG800氧化聚丙烯腈纤维径向异质结构不明显。随着氧化反应进行,纤维直径和碳含量逐渐降低,而氧含量逐渐上升。这说明光学显微分析可以用于氧化聚丙烯腈纤维是否均质氧化评价,可为得到均质氧化聚丙烯腈纤维提供分析检测手段。     

不等径纤维混杂复合材料混杂原理

对碳化硅-碳(SiCF-CF)/环氧和硼-碳(BF-CF)/环氧2种不等径纤维混杂复合材料的混杂模型和机理进行了初步研究.建立了三角形和四边形阵列的混杂模型;分析了材料制备工艺对混杂阵列、纤维体积含量的影响.      

光栅光纤组合探头在油料液位检测中的应用

提出了一种利用光栅光纤组合探头技术对航空油料液位进行检测的方法。该方法是将钢带浮子式液位计检测到了液位信息转换为光栅位移量,通过光纤探头探测,由光缆远距离传送至中央控制室,利用微处理机对信号进行实时处理,实现对液位的自动采集和监测,具有体积小、重量轻、精度高、可靠性好、本安防爆等优点。     

异型(三叶形)截面碳化硅纤维的异形度控制

以聚碳硅烷（ＰＣＳ）为原料,采用熔融纺丝制备三叶形ＰＣＳ纤维后,经不熔化和烧成制得异形度为０．６５～０．８５的三叶形碳化硅纤维。研究了纺丝温度、压力、收丝速度等对纤维异形度的影响,并对预氧化和烧成工艺进行了研究,研究表明,氏的纺丝温度、适当主的纺丝压力和较低的转率有效于提高纤维的异形度,聚碳硅烷原丝经预氧化和烧结后,纤维异形度基本保持不变。     

H3PO4溶液中碳纤维表面电化学改性机理研究

以H3PO4溶液为电解液对碳纤维进行电化学改性处理,通过循环伏安测试,XPS、SEM和XRD分析探讨了H3PO4溶液体系中碳纤维表面电化学改性机理。结果表明:在改性处理初期,纤维表面已有电活性物质发生电化学反应产生新的活性碳原子,此后伴随着水的电解析氧反应纤维表面进一步受到氧化和刻蚀,表面氧元素含量增加,而且各种含氧官能团含量随着改性处理得进行不断变化,其中羧基和酸酐含量明显增加。纤维表面粗糙度增加,沟槽加深加宽,但其本体结构并没有改变,只是表面层微晶尺寸有所减小,晶面间距有所增大。     

聚碳硅烷纤维的不熔化处理研究(Ⅱ)─-放大工艺的研究

采用熔融纺丝法纺出连续PCS纤维束,研究了升温制度、纤维装填量以及过热现象等因素对PCS纤维不熔化结果的影响,探讨了不熔化工艺的优化。结果表明,低温段慢速升温,中温段延长保温时间,高温段进一步强化的升温制度是比较合理的。纤维装填质量及密度增大到一定程度后,会因散热不利而引起急剧高温,导致纤维的熔并。急剧放热引起纤维结构的变化较大,而且内部纤维与表层纤维的反应程度不同。     

自愈合聚合物复合材料的研究进展

介绍了模仿人体自愈合生理机能的聚合物复合材料的研究进程,探讨了自愈合聚合物复合材料应用比较多的微胶囊、液芯纤维、仿人体毛细血管丛的自愈合模型与原理,展望了自愈合聚合物材料的应用前景。     

纤维/树脂浸润测试仪的研制与应用

针对复合材料成型工艺的特点,依据毛细原理,研制了浸润性能测试仪.该测试仪包括浸润质量测试系统与温度控制系统,能够定量测试在较宽的温度范围内发生浸润的速率和浸润程度.对该测试仪的准确性与稳定性进行了校准与标定,并运用该仪器研究了纤维种类、树脂粘度和纤维体积含量对树脂/纤维浸润性能的影响规律.研究结果表明该设备为研究各类复合材料中增强材料与基体间的浸润性能提供了方便的测试手段,对指导复合材料制备工艺具有较高的参考价值.     

Research of Optical Fiber Coil Winding Model Based on Large-deformation Theory of Elasticity and Its Application

Optical fiber coil winding model is used to guide proper and high precision coil winding for fiber optic gyroscope (FOG) application. Based on the large-deformation theory of elasticity, stress analysis of optical fiber free end has been made and balance equation of infinitesimal fiber is deduced, then deformation equation is derived by substituting terminal conditions. On condition that only axial tensile force exists, approximate curve equation has been built in small angle deformation scope. The comparison of tangent point longitudinal coordinate result between theory and approximation gives constant of integration, and expression with tangent point as origin of coordinate is readjusted. Analyzing the winding parameters of an example, it is clear that the horizontal distance from the highest point of wheel to fiber tangent point has millimeter order of magnitude and significant difference with fiber tension variation, and maintains invariant when wheel radius changes. The height of tension and accurate position of tangent point are defined for proper fiber guide. For application to fiber optic gyroscope, spiral-disc winding method and nonideal deformation of straddle section are analyzed, and then spiral-disc quadrupole pattern winding method has been introduced and realized by winding system. The winding results approve that the winding model is applicable.     

Multi-objective optimization of different dome reinforcement methods for composite cases

A multi-objective optimization method was proposed for different dome reinforcement methods of a filament-wound solid rocket motor composite case based on a Radial Basis Function (RBF) model. Progressive damage of the composite case was considered in a simulation based on Hashin failure criteria, and simulation results were validated by hydraulic burst tests to precisely predict the failure mode, failure position, and burst pressure. An RBF surrogate model was established and evaluated by Relative Average Absolute Error (RAAE), Relative Maximum Absolute Error (RMAE), Root Mean Squared Error (RMSE), and R² methods to improve the optimization efficient of dome reinforcement. In addition, the Non-dominated Sorting Genetic Algorithm (NSGA-II) was employed to establish multi-objective optimization models of variable-angle and variable-polar-radius dome reinforcements to investigate the coupling effect of the reinforcement angle, reinforcement layers, and reinforcement range on the case performance. Optimal reinforcement parameters were obtained and used to establish a progressive damage model of the composite case with dome reinforcement. In accordance with progressive damage analysis, the burst pressure and performance factor were obtained. Results illustrated that variable-angle dome reinforcement was the optimal reinforcement method compared with variable-polar-radius dome reinforcement as it could not only ensure the reinforcement angle’s continuous changing but also decrease the mass of composite materials. Compared with the unreinforced case, the reinforced case exhibited an increase in the burst pressure and performance factor of 36.1% and 23.5%, respectively.