Mechanical Behavior of a Glass-fiber Reinforced Composite to Steel Joint for Ships

The use of a glass-fiber reinforced composite in marine structures is becoming more common, particularly due to the potential weight savings. The mechanical response of the joint between a glass-fiber reinforced polymer （GRP） superstructure and a steel hull formed is examined and subsequently modified to improve performance through a combined program of modeling and testing. A finite-element model is developed to predict the response of the joint. The model takes into account the contact at the interface between different materials, progressive damage, large deformation theory, and a non-linear stress-strain relationship. To predict the progressive failure, the analysis combines Hashin failure criteria and maximum stress failure criteria. The results show stress response has a great influence on the strength and bearing of the joint. The Balsawood-steel interface is proved to be critical to the mechanical behavior of the joint. Good agreement between experimental results and numerical predictions is observed.

Material Properties and Mold Folded Core Based on Ultra-violet Cured Resins

Ultra-violet(UV)curing is an efficient method for composite molding.Firstly,thermophysical properties of UV cured glass-fiber reinforced plastics are conducted.Material properties are studied for various kinds of postcuring modes.Then the UV curing method is suggested in manufacturing V-crimp folded core for sandwich panels.Two kinds of processing schemes for V-crimp folded core manufacturing using UV curing are presented.Finally,the effect of post-curing on the mechanical properties of folded core sandwiches is experimentally studied,and optimum modes of post-curing are determined.The experimental results show that the ultimate compressive strength of the folded sandwiches is increased by 60% after post-curing with the optimum post-curing mode.

高强度聚甲醛复合材料的动态力学性能

采用熔体浸渍工艺制备了增强聚甲醛复合材料,利用动态热机械分析仪(DMA)对增强聚甲醛复合材料进行动态力学性能测试和表征,结果表明,增强聚甲醛复合材料中玻纤含量和扫描频率对增强聚甲醛复合材料的动态力学性能有一定程度的影响,随着玻纤含量的增加,增强聚甲醛复合材料的储能模量逐渐增加,随着扫描频率的增加,复合材料的损耗因子降低,同时采用Arrhenius方程计算增强聚甲醛复合材料在α转变时分子运动活化能。另外,还研究了玻纤含量对增强聚甲醛复合材料的力学性能的影响。

碳纤维增强聚甲醛复合材料的制备及性能研究

以碳纤维为增强体,用双螺杆挤出机共混制备了碳纤维增强聚甲醛复合材料,研究了碳纤维含量对复合材料的力学性能、热性能、熔体流动性能的影响。结果表明,碳纤维的加入大幅提高了复合材料的力学性能,改善了热稳定性能,但熔体流动速率减小;当碳纤维质量分数为25%时,复合材料的弯曲弹性模量、弯曲强度、拉伸强度、缺口冲击强度、断裂伸长率分别为19.8 GPa,187 MPa,153 MPa,16.2 kJ/m2,0.52%,综合力学性能最佳。

玻璃纤维增强聚甲醛复合材料性能与结构的研究

制备了一系列玻璃纤维增强聚甲醛(POM/GF)复合材料,采用傅立叶变换红外光谱仪、差示扫描量热仪、扫描电子显微镜及万能材料试验机等对POM/GF复合材料的结构与力学性能进行了研究,并详细考察了增容剂二苯基亚甲基二异氰酸酯(MDI)的不同添加量对复合材料性能的影响。结果表明,MDI的加入使得POM/GF复合材料的性能显著提高,并在其添加量为POM质量的0.7%时具有最佳性能。

针状填料/POM复合材料的研究进展

综述了近几年国内外碳纤维(CF)、玻璃纤维(GF)、硅灰石纤维(WF)、玄武岩纤维(BF)、聚四氟乙烯纤维(PTFE)、晶须、碳纳米管、天然纤维等不同一维针状填料在填充增强聚甲醛(POM)复合材料中的应用与研究进展,并对其重点研究方向及前景进行了展望。