Development of the large increment method in analysis for thin and moderately thick plates

Many displacement-based quadrilateral plate elements based on Mindlin-Reissner plate theory have been proposed to analyze the thin and moderately thick plate problems. However, numerical inaccuracies of some elements appear since the presence of shear locking and spurious zero energy modes for thin plate problems. To overcome these shortcomings, we employ the large increment method （LIM） for the analyses of the plate bending problems, and propose a force-based 8-node quadrilateral plate （8NQP） element which is based on Mindlin- Reissner plate theory and has no extra spurious zero energy mode. Several benchmark plate bending problems are presented to illustrate the accuracy and convergence of the plate element by comparing with the analytical solutions and displacement-based plate elements. The results show that the 8-node plate element produces fast convergence and accurate stress distributions in both the moderately thick and thin plate bending problems. The plate element is insensitive to mesh distortion and it can avoid the shear locking for thin plate analysis.     

基于事故树分析的货运驾驶员失误研究

以从事公路运输的货运驾驶员为研究对象,基于对4家货运企业的实际调研,在总结前人研究成果的基础上,建立货运驾驶员失误引发道路交通事故的事故树模型,并对事故树进行了分析,最后提出预防驾驶员失误的措施和建议。研究表明,货运驾驶员失误及其由此引发的交通事故极易发生,危险性很大,且控制事故的途径较少;紧张、饮酒、疲劳、药物与疾病对货运驾驶员失误影响最大。     

化学氧化法合成聚吡咯工艺条件优化及电化学性能

采用化学氧化法合成粉末状导电高分子材料聚吡咯(PPy),研究氧化剂浓度、氧化剂种类、反应温度及反应时间对PPy电导率的影响,通过正交设计思路,优化合成工艺条件,并研究其电化学活性.结果表明,合成导电高分子材料PPy的影响因素顺序依次为:氧化剂种类、反应温度、氧化剂用量、反应时间;PPy的最佳合成条件为:以FeC l3为氧化剂,PPy与FeC l3用量摩尔比为1∶1,在0℃冰水浴条件下反应6 h;聚吡咯的电导率随氧化剂用量的增加呈现先增大后减小的趋势,合成聚吡咯的氧化剂为FeC l3时电导率较高,随着反应时间的增加,聚吡咯的电导率有显著地增加,在低温下有利于提高聚吡咯的电导率;循环伏安表明,PPy具有良好的电化学活性.     

Development of 2D hybrid equilibrium elements in large increment method

As a force-based finite element method (FEM), large increment method (LIM) has been developed in recent years. It has been shown that LIM provided prominent advantage of parallel computation with high efficiency and low time consumption for member structural system. To fully utilize its advantage in parallel computation, it is the time to extend LIM to 2D and 3D continua analysis. In this paper, a 2D finite element library with the capability of modeling arbitrary configurations is developed. Some illustrative numerical examples are solved by using the proposed library; the obtained results are compared with those obtained from both traditional displacement-based FEM and analytical solutions, which has clearly shown the advantages of LIM.     

品管圈活动对提高雾化吸入治疗患者吸入方式正确率的影响

目的:探讨品管圈(QCC)活动对提高雾化吸入治疗患者吸入方式正确率的影响。方法:开展QCC活动,包括确立活动主题、进行要因分析、设定目标、制订对策并实施,比较QCC活动前后患者雾化吸入治疗吸入方式的正确率和残余药量的差异。结果:QCC活动后患者雾化吸入治疗吸入方式的正确率(80.0%)较活动前(38.0%)提高,残余药量活动前后比较差异具有统计学意义(P<0.01)。结论:QCC活动可提高雾化吸入患者吸入方式的正确率,促进护理质量持续性改进,值得临床推广。