芳烷基酚树脂及其玻璃布层压板的制备

研究用二甲苯甲醛树脂、苯酚和甲醛等合成热固性芳烷基酚树脂以及用该树脂制备玻璃布层压板的工艺方法，通过热失重(TGA)曲线研究树脂的耐热性，对所制层压板的机械性能和电性能进行检测，结果表明芳烷基酚玻璃布层压板具有H级的耐热性能，其机械性能和电性能均满足H级层压板的使用要求。     

芳烷基酚聚酰胺玻璃布层压板的研制

将二甲苯甲醛树脂、苯酚和甲醛等合成热固性芳烷基酚树脂，再与聚酰胺-酰亚胺树脂混合，得到的树脂用于制备玻璃布层压板。经对该层压板的机械性能和电性能进行检测，结果表明芳烷基酚聚酰胺玻璃布层压板具有H级的耐热性，其机械性能和电性能均满足H级层压板的要求。     

Experimental Study on Penetration and Perforation of Laminated Kevlar

The penetration behavior and perforation characteristics of Kevlar/Epoxy laminates with various thickness in quasi-static and ballistic perforation penetrated by steel projectiles with different noses are investigated. Quasi-static tests are conducted on MTS810 testing system. The results indicate that global deformation is the major mechanism of energy absorption and woven laminates exhibit larger energy dissipation than that of angleplied laminates. Therefore, the woven laminates have better quasi-static penetration resistance. Ballistic tests with velocity of 200 - 700 m/s are executed by using a powder gun with 7.62 mm barrel. Comparing ballistic experimental results with those under quasi-static condition, both the perforation performance and the failure modes are related closely to the speed of penetrator. Quite different from quasi-static tests, ballistic tests indicate that thick angle-plied laminate targets are even better than woven laminates in resisting ballistic impact. It is observed that the damage zone of the laminate is localized highly with the increasing of the impact velocity and correspondingly, the failure modes are more manifold. The shape of projectile noses affects the impact resistance of laminated Kevlar significantly in the range of velocity around the ballistic limit.     

胶合板缺陷识别方法比较研究

结合胶合板缺陷检测分类,通过对比研究了几种有效、实用的模式分类方法,讨论了该方法的优势和局限性,提出了一种基于粗糙集和神经网络的模式分类方法.利用粗糙集处理图像特征中冗余的或较差的属性特征,有效地减小了网络规模,将该特性和神经网络的非线性映射能力和很强的抗干扰性相结合,能够进一步提高分类精度和收敛速度.在胶合板缺陷识别的实际应用中,其识别精度达到了90 93%,循环次数较粗糙集预处理前平均下降了1000余次.研究结果表明粗糙集神经网络模式识别方法适于胶合板缺陷分类.     

民爆中包包装和装箱全自动生产线关键技术研究

在分析我国民爆中包包装和装箱全自动生产线的基础上,根据功能分析法原则对该生产线功能进行了分解,以此得到了生产工艺流程,同时重点探讨了民爆中包包装和装箱全自动生产线的关键技术,并得出了产品.     

受压对称迭层矩形板的自由振动分析

根据受压的对称迭层矩形板自由振动的微分方程可以求得各种解析解来求解各种边值问题。迭层板有两种,一种是正交铺设,其方向与坐标轴平行,属正交异性板,当板的四边为简支时,可用双正弦级数来求解自由振动的各阶频率及其振型以及均匀受压的各阶临界载荷及其屈型。另一种是角铺设,属各向异性板,当两相邻边为自由,另两边为简支或固支时可用复数级数来求解其最低频率及其振型以及最低临界载荷及其屈型。此时其特征方程的根为两对复根,且可表成三角级数和双曲线级数,以满足边界条件。另外用代数多项式和双正弦级数组成的解来满足角点条件。在算例中计算了若干板受压或不受压的振动频率和临界载荷,并与其他文献进行了对比。     

Si3N4/BN层状复合陶瓷抗穿甲破坏实验研究

研究了Si3N4/BN层状复合陶瓷的抗冲击破坏及抗穿甲破坏行为.研究发现:在射钉枪的作用下,处于自由状态的Si3N4/BN层状复合陶瓷比Si3N4块体陶瓷具有更好的抗冲击破坏能力.在7.62mm口径穿甲燃烧弹的作用下,Si3N4/BN层状复合陶瓷的抗穿透能力比Si3N4块体陶瓷略有下降,但仍远远高于45号钢材,而且在实弹冲击后不会像Si3N4块体陶瓷那样整体破坏.     

层状复合陶瓷增韧机理的数值模拟

基于多层梁模型，在考虑材料非均匀性的基础上，采用有限元数值模拟的方法研究了层状复合陶瓷的断裂行为．给出了复合陶瓷模型在三点弯曲的加载条件下，裂纹拐折和扩展的过程，验证了层状复合陶瓷的主要增韧机理：裂纹沿软层界面拐折耗能．在此基础上，研究了不同参数条件下，层状复合陶瓷韧性的变化规律．     

圆钢管混凝土偏压长柱屈曲承载力的FEM法分析

构造了非线性三维虚拟层合单元法,对5组圆钢管混凝土偏压柱的非线性屈曲承载力进行了三维有限元分析,计算结果与试验结果符合良好.以典型截面形式的圆钢管混凝土偏压长柱为例,对其载荷-变形全过程进行了分析,给出了非线性屈曲承载力与长细比的关系,研究结果可为圆钢管混凝土柱的承载力设计提供参考.     

Free vibration analysis of generally laminated beams via state-space-based differential quadrature

A new method of state-space-based differential quadrature is presented for free vibration of generally laminated beams. By discretizing the state space formulations along the axial direction using the technique of differential quadrature, new state equations at discrete points are established. Applying end conditions and using matrix theory, the general solution is derived. Taking account of the boundary conditions at the top and bottom planes, frequency equation governing the free vibration of generally laminated beams is then formulated. The method is validated by comparing numerical results with that available in the literature.