Experimental and FEM study of windshield subjected to high speed bird impact

Both experimental and finite element model (FEM) results are presented for the dynamic strength behavior of windshield subjected to bird impact. The experimental data taken from a series of high speed photographs are compared with the numerical results predicted by using FEM in which the windshield was modeled entirely with solid elements and the bird body was approximately simulated by an elastic-plastic material with failure element behavior. Effective plastic strain and element pressure were adopted as the failure criteria and once the pressure or the effective plastic strain of an element reached the critical value, the element would lose the tensile resistance capability completely. The deflection and stress distribution in the windshield were obtained. It is shown that the result from the finite element analysis agrees with those from the full-scale bird impact test. The project supported by the National Natural Science Foundation of China (10272011)     

预应力钢梁体外索的张力增量分析

将预应力钢梁看作梁与索的组合结构,充分考虑了二者之间的相互作用．利用变分原理推导出在外荷载作用下,体外索张力增量的计算公式,并通过预应力钢梁模型试验对计算结果进行了验证．     

Nonlinear traveling waves in a compressible Mooney-Rivlin rod I. Long finite-amplitude waves

In literature, nonlinear traveling waves in elastic circular rods have only been studied based on single partial differential equation (pde) models, and here we consider such a problem by using a more accurate coupled-pde model. We derive the Hamiltonian from the model equations for the long finite-amplitude wave approximation, analyze how the number of singular points of the system changes with the parameters, and study the features of these singular points qualitatively. Various physically acceptable nonlinear traveling waves are also discussed, and corresponding examples are given. In particular, we find that certain waves, which cannot be counted by the single-equation model, can arise. The project supported by the Research Grants Council of the HKSAR, China (City U 1107/99P) and the National Natural Science Foundation of China (10372054 and 10171061)     

基于LabWindows/CVI的矿井提升机钢丝绳张力监测仪设计实现

针对煤炭生产企业矿井多绳摩擦式提升机存在的钢丝绳张力不平衡问题,设计和开发了基于LabWindows/CVI的钢丝绳张力不平衡监测分析仪;该仪器装置能实时同步采集箕斗钢丝绳的张力和箕斗在井筒中的位移行程数据,箕斗的位移行程数据采用直接从在工控机端建立的OPC服务器内读取的方法,节省硬件成本;该监测仪装置能将箕斗的张力和位移监测数据自动存储于MySQL数据库,能自动绘制每根钢丝绳的张力-位移历史变化趋势曲线;当钢丝绳张力不平衡度超限时发出报警信息;该仪器装置可靠分析了箕斗在井筒中上下运动时的钢丝绳张力变化规律,对进一步提高提升系统的安全高效可靠运行性能具有十分重要的意义。      

疏水缔合聚丙烯酰胺与双子表面活性剂的相互作用

制备了一种脂肪酸酯双磺酸盐型双子表面活性剂, 利用粘度法、界面张力法和原子力显微镜研究了疏水缔合聚丙烯酰胺与双子表面活性剂在溶液中的相互作用. 实验结果表明: 疏水缔合聚丙烯酰胺在溶液中能够通过自组装形成疏水微区并发展成网络结构, 疏水微区与表面活性剂在溶液中能形成混合胶束; 当一定量的表面活性剂加入时, 对疏水缔合聚丙烯酰胺的自组装起促进作用, 而过多双子表面活性剂的加入又会对聚合物分子的自组装起抑制作用, 从而显著影响疏水缔合聚丙烯酰胺的溶液性质, 随着表面活性剂浓度的增加, 聚合物溶液粘度先增加、再降低; 同时, 疏水缔合聚丙烯酰胺对双子表面活性剂的界面性能也有较大影响, 聚合物的加入使双子表面活性剂降低油/水界面张力的能力下降, 油/水界面张力达到平衡所需时间延长.     

软光缆生产线绞笼放线设备的改进

介绍了影响软光缆生产工艺的因素，提出软光缆生产线的关键控制技术，以及软光．缆生产线绞笼放线设备的创新改造。     

利用表面波测量液体的表面张力系数

本文利用表面张力在液面上产生毛细波的现象，设计了一种原理上的比较新颖，操作上简单，相对误差为０．２％，可与公认的毛细上升法相比的测量方法。     

张力桁架天线的优化设计

本文提出了一种预应力桁架结构天线的设计方法，该方法将预紧张力结构设计的基本原理同索网结构设计中有效的找形方法结合起来。首先，对给定的支撑结构做出静态稳定的张力桁架；然后，利用找形方法做出桁架的预应力几何结构。为了论证该方法的有效性，分别对三种不同支撑结构的天线进行了分析。     

桔纹化涂装探讨

对桔纹化涂装进行了探讨,提出了桔纹化涂装机理及涂层形成时的影响因素,并找出了实现桔纹化涂装的途径。特别是对普通漆桔纹化涂装的探索,很有独到之处。     

PVW—2000系列录像机的张力故障分析

ＰＶＷ－２０００系列录像机的张力故障分析张昌旭湖北电视台１概述索尼公司推出的ＢＥＴＡＣＡＭＳＰ系列录像机目前在国内各电视台中占有很大的市场，其中１９９１年推出的ＰＶＷ－２０００系列录像机（以下简称ＰＶＷ录像机）拥有的比例相对又多些。这种录像机在电路上...