多铁性磁电智能复合材料的力学研究进展

介绍了多铁性磁电智能复合材料的概念、分类及发展现状;总结了两类典型多铁性复合材料的力学问题（包括波动与振动问题、夹杂问题、断裂问题等）的研究进展;分析了层状多铁性复合材料力学行为的特殊性;基于应变介导的磁电耦合机制,阐述了界面断裂力学研究对于层状多铁性复合材料研制的重要性和必要性;最后指出了该领域下一步的研究方向。     

型钢混凝土桁架转换层的监控与分析

对贵阳市某大楼型钢混凝土桁架转换层进行了施工期间的监控,并利用有限元分析软件ANSYS建立了带有型钢混凝土桁架转换层的结构有限元分析模型.针对工程中连接、构造和施工影响等相关因素进行有限元模型的对比分析,明确各因素对桁架受力的影响.结合施工阶段的监控数据,分析此工程中桁架受力状态的成因,为准确判断工程在正常投入使用后的...     

Prediction of three-dimensional elastic behavior of filament-wound composites based on the bridging model

This work provides a method to predict the three-dimensional equivalent elastic properties of the filament-wound composites based on the multi-scale homogenization principle.In the meso-scale,a representative volume element(RVE)is defined and the bridging model is adopted to establish a theoretical predictive model for its three-dimensional equivalent elastic constants.The results obtained through this method for the previous experimental model are compared with the ones gained respec-tively by experiments and classical laminate theory to verify the reliability of this model.In addition,the effects of some winding parameters,such as winding angle,on the equivalent elastic behavior of the filament-wound composites are analyzed.The rules gained can provide a theoretical reference for the optimum design of filament-wound composites.     

聚硅氧烷先驱体转化制备2D Cf/Si-O-C材料

以二维碳纤维布和廉价的聚硅氧烷为原料,采用先驱体转化工艺制备2D Cf/Si-O-C材料,对其力学性能进行了考察,并与以聚碳硅烷为先驱体制备的2D Cf/SiC材料在价格和性能方面进行了对比。实验表明,2D Cf/Si-O-C材料力学性能较2D Cf/SiC材料有所下降,但成本大大降低。2D Cf/Si-O-C材料弯曲强度达到157.9 MPa,断裂韧性达到8.4MPa.m1/2,剪切强度达到23.4MPa,并且在1400℃下能较好保持材料的力学性能。     

Investigation of the mechanical and ballistic properties of hybrid carbon/ aramid woven laminates

High-performance ballistic fibers, such as aramid fiber and ultra-high-molecular-weight polyethylene (UHMWPE), are commonly used in anti-ballistic structures due to their low density, high tensile strength and high specific modulus. However, their low modulus in the thickness direction and insufficient shear strength limits their application in certain ballistic structure. In contrast, carbon fiber reinforced epoxy resin matrix composites (CFRP) have the characteristics of high modulus in the thickness direction and high shear resistance. However, carbon fibers are rarely used and applied for protection purposes. A hybridization with aramid fiber reinforced epoxy resin matrix composites (AFRP) and CFRP has the potential to improve the stiffness and the ballistic property of the typical ballistic fiber composites. The hybrid effects on the flexural property and ballistic performance of the hybrid CFRP/AFRP laminates were investigated. Through conducting mechanical property tests and ballistic tests, two sets of reliable simulation parameters for AFRP and CFRP were established using LS-DYNA software, respectively. The experimental results suggested that by increasing the content of CFRP that the flexural properties of hybrid CFRP/AFRP laminates were enhanced. The ballistic tests’ results and the simulation illustrated that the specific energy absorption by the perforation method of CFRP achieved 77.7% of AFRP. When CFRP was on the striking face, the shear resistance of the laminates and the resistance force to the projectiles was promoted at the initial penetration stage. The proportion of fiber tensile failures in the AFRP layers was also enhanced with the addition of CFRP during the penetration process. These improvements resulted in the ballistic performance of hybrid CFRP/AFRP laminates was better than AFRP when the CFRP content was 20 wt% and 30 wt%.     

低压电场驱动下膜分离 CO2的研究

以离子交换膜为基础,进行预处理和化学改性.研究了不同预处理条件、化学改性方法及低压电场的电压对离子交换膜的CO2分离效率的影响.结果表明,改进处理条件、施加低压电场及在膜中加入亲水物质可明显地增加离子交换膜的二氧化碳通量.     

无铬型防毒浸渍炭的发展与应用

简单回顾了防毒浸渍炭的研究历史,指出了ASC型浸渍炭中六价铬（Cr^6＋）对人体的危害作用,较详细叙述了无铬型浸渍炭的研究和发展过程,根据使用和评价结果评述了无铬型浸渍炭在国内外化学防护领域的应用前景．     

用溶胶-凝胶法制备碳纤维三维编织物增强氧化铝基复合材料的研究

本文研究了溶胶－凝胶（Ｓｏｌ－ｇｅｌ）法制备碳纤维三维编织物增强氧化铝（Ａｌ２Ｏ３）基复合材料的成型工艺及其力学性能，研究了两种主要起始物Ａｌ（ＮＯ３）３、ＡｌＣｌ３配制的氧化铝溶胶对复合材料成型工艺和力学性能的影响。分别以Ａｌ（ＮＯ３）３和ＡｌＣｌ３为起始物，制备得到Ⅰ＃、Ｉ＃复合材料。研究表明，以Ａｌ（ＮＯ３）３为起始物配制的溶胶粘度较小，利于材料的致密化。经过溶胶浸渍、凝胶、裂解１３个周期后，Ⅰ＃材料的密度和室温三点弯曲强度分别为１．８６ｇ／ｃｍ３和１４５．２ＭＰａ，而ＩＩ＃材料的密度和室温三点弯曲强度分别为１．６３ｇ／ｃｍ３和１０４．１ＭＰａ，材料均呈典型的韧性断裂模式。用扫描电子显微镜（ＳＥＭ）观察试样的断口形貌，发现断口表面有大量的纤维拔出，纤维表现了较好的增韧效果。     

渗碳气氛的热力学及动力学分析

本文对渗碳气氛进行热力学及动力学分析,给出炉气各组分间反应速率的测试方法及测试数据。结果表明,渗碳气氛的独立反应数为4,自由度为3,甲烷的渗碳作用不可忽略,控制甲烷这一碳源有利于提高碳势控制精度.     

长杆射弹对钢纤维混凝土靶开坑特性的实验研究

为考察射弹对钢纤维混凝土靶的侵彻特性,采用57mm轻气炮,进行了小尺寸模拟射弹对钢纤维混凝土靶(钢纤维的体积分数为2%)的侵彻实验。实验中观察了钢纤维混凝土靶的开坑形状,测量了射弹的击靶速度,并且采用注沙法测出靶体的开坑体积,计算出射弹对靶体的侵彻体积,得到了长杆射弹的动能与侵彻体积的关系。引入射弹单位面积的冲击动能和靶体单位侵彻体积的冲击动能,结合钢纤维混凝土靶的实验数据,考察了两者之间的关系。