A reduced basis approach to quantifying damage dependent dynamic response of laminated composite structures

A finite element (FE) based formulation is utilized to represent the damage-dependent response of laminated composite structures. An internal-state-variable (ISV) approach provides a definition of the stiffness reduction caused by intralaminar crack propagation at the ply level. These ISVs are combined with simple stress criteria to accommodate ply property changes caused by fiber fracture, fiber microbuckling and interior delaminations. A set of orthogonal Ritz vectors are chosen as basis vectors to transform the dynamical equations of motion to a reduced coordinate space. The reduced basis form of the equations provides significant numerical efficiencies, especially for large ordered systems. Furthermore, damping and its variation with damage can be generally represented in any number of vibratory modes. The Newmark integration operator is used to solve the dynamic equations of motion, and equilibrium iterations are performed in each incremental time step to assure convergence. Results are given for laminated beam and plate geometries subjected to dynamic loads.     

Geotechnical properties of the soft soil in Guangzhou College City

The paper describes some geotechnical properties of the soft soils in Guangzhou College City, China, which are difficult to both sample and test. Laboratory and in situ tests were carried out to assess the physical and mechanical indices of the soils. The data were statistically analyzed and linear regression undertaken such that equations could be developed by which the geotechnical properties of the soft soils can be predicted. The statistical validity of the degree of correlation confirmed that using these equations, the mechanical indices can be estimated from physical indices determined by routine testing.      

激光辐照40Cr钢组织结构的穆斯堡尔谱分析

４０Ｃｒ钢试样经不同热处理后在空气中用ＣＯ２连续激光束进行辐照，以穆斯堡尔谱学研究试样在辐照后的组织结构变化。试验结果表明，调质预处理后再进行激光辐照的试样，不仅残作产奥氏体含量较低，而且其中碳的含量最低。     

STM32F103VET6和ENC28J60的嵌入式以太网接口设计

介绍了一种基于STM32F103VET6微处理器和以太网控制芯片ENC28J60的嵌入式以太网接口的设计方案。分析了基于Cortex-M3内核的微处理器STM32F103VET6的功能和特点,以及以太网控制芯片ENC28J60的主要性能和结构特性,并给出了接口的硬件和软件设计方案。本接口尺寸小、性能高,适合于便携式仪器仪表中的应用。     

TRIZ理论中物质-场的不同应用

通过对飞机发动机机罩概念设计中的物-场分析，简要概括了在实际的概念设计中应该如何应用和把握物质-场分析的侧重点。     

黑色颜料的制备及其性能的研究

利用Co-Cr-Mn-Fe四元系颜料开发出陶瓷用黑釉配方,并在生产中试用,有烧成温度低,颜料与基釉的适应性好,黑釉烧成的合格率高等特点。     

利用腈纶废丝合成絮凝剂PAN—DCD

本文以腈纶废丝为原料与双氰双胺在碱性溶液中反应，成功地制得含有多种活性基因的聚合物ＰＡＮ－ＤＣＤ，并用于染料废水脱色及炼油厂废水除油，除酚的处理研究，与常规使用的几种絮凝剂进行处理结果对照，实验结果表明：该产品单独使用处理效果明显优于其他絮凝剂，与聚铝复合使用处理效果更为理想。     

氯霉素在聚茜素红薄膜修饰电极上的伏安行为及其测定

研究了聚茜素红薄膜修饰电极(PARE)对氯霉素(Chloramphenicol,CAP)的电催化作用,并应用于对微量CAP的定量检测。实验结果表明:在0.010mol/LHCl+1.0×10-4mol/LCu2++0.10mol/LNaCl测定体系中,CAP的浓度在1.0×10-9mol/L～1.0×10-8mol/L范围内与它的氧化峰电流呈良好的线性关系,线性方程和线性相关系数分别为:ip(μA)=-0.188×10-8CCAP(mol/L)-7.62,γ=0.9997,检出限可达5.0×10-10mol/L。CAP的标准回收率为95.9%~102.9%,八次平行样品测定结果的相对标准偏差3.2%。     

Bi:YIG纳米薄膜的磁光特性

用射频磁控溅射和快速退火方法制备了纳米量级的Bi:YIG薄膜,研究了薄膜的磁光特性.当晶粒尺寸从150 nm降到80 nm时,透射率和Faraday角的值分别从75%和3.6°变成了80%和4.0°.结果表明:高的透射率和大Faraday角可以在晶粒尺寸为纳米量级的薄膜中共存.