Determination of Critical Slip Surface of Soil Slope

A new complex method is presented considering not only the improvement upon the ＂bad ＂design point, but also the diversity of the newly generated complex, which is obtained by replacing the ＂bad ＂design point with the better design point located at the line between the ＂bad ＂design point and the ceotroid of the remaining design points of the old complex. The new complex method is applied to searching for the critical slip surface of two non-homogeneous soil slopes. The comparison of the results obtained by the new complex method with that by the basic complex method shows that the new complex method is much more likely to find the true critical surface for the randomly generated initial complex.     

基于ANN星识别算法的仿真平台

星敏感器是一种高精确度的姿态测量仪器，它通过对观测到的星点进行识别来计算姿态。为了能够较好地测试和验证星识别系统的性能，设计了一个基于ANN算法的星识别仿真平台。通过对该星识别仿真平台性能的测试，表明该仿真平台能够方便，实时地测试星识别算法的性能与正确性，因此说它是一种具有较好实用价值的星识别仿真平台。     

三峡左岸电站500kV输电线路杆塔桩基础静载试验

以三峡左岸电站500kV输电线路杆塔桩基础静载试验工程为实例，介绍单桩垂直静载抗压试验、单桩垂直静载抗拔试验、单桩水平静载抗推试验，供同类工程参考。     

杭州湾跨海大桥70 m预应力混凝土箱梁用海工耐久混凝土的试验研究

通过平板抗裂试验,研究了海工耐久混凝土的早期抗裂性,采用RCM法研究了海工耐久混凝土抗氯离子渗透的能力。结果表明,使用P.Ⅱ42.5(R)硅酸盐水泥、Ⅱ区中砂、5~25 mm碎石、Ⅰ级或Ⅱ级低钙粉煤灰、粒化高炉矿渣粉及新一代高性能高效减水剂,可以配制出C 50~C 60海工耐久混凝土。     

Mixed analysis of shell and solid elements using the overlaying mesh method

 This article presents a mixed method of analyzing shell elements and solid elements using the overlaying mesh method. In the structural design of a ship's hull, the shell elements are used for the global model. However, the solid elements are necessary to analyze the stress concentration zones or the vicinity of a crack. In such cases, the models are analyzed using zooming analysis, in which the results of a global model analysis are transferred to a local model analysis by imposing boundary conditions. This method is more advantageous than zooming analysis in terms of the accuracy of the solution and the modeling flexibility. Some examples of a plate model with a cracked surface or with a projection are shown in order to demonstrate the effectiveness of the method. Received: August 6, 2002 / Accepted: November 25, 2002 Address correspondence to: S. Nakasumi (sumi@nasl.t.u-tokyo.ac.jp) Updated from the Japanese original, which won the 2002 SNAJ prize (J Soc Nav Archit Jpn 2001;189:219–224; and 190:655–662)     

京秦线提速路涵过渡段动力仿真与试验对比

结合京秦线提速改造工程进行了列车 路基动力仿真计算。在不同速度条件下,通过对路涵过渡段加固前后状态下机车车辆运行安全舒适性指标、轨道及路基主要动力性能指标的分析计算,对京秦既有线路涵过渡段提速到200km/h的适应性及加固方案的可行性提出了相应评价意见与建议,并与随后的实车试验进行了对比。试验测试结果验证了仿真分析的可靠性。     

Numerical simulation of the flow about self-propelling tanker models

A time-marching CFD simulation is performed for self-propelling ships. The flow about the hull is simulated by the finite-volume method, and the propeller action is approximated as a propeller disk for which the solution is given by a simplified propeller model. The interaction of two flow models is treated in a time-marching procedure converging towards the steady self-propelling condition. This method is applied to five tanker models, and detailed comparisons are made between the simulated results and corresponding experimental results. It is shown that the flow field in the self-propelling condition is qualitatively well reproduced in the simulation, and the estimated thrust deduction factors for the five hull forms agree well with measured ones. However, the effective wake factors are underestimated, since the Reynolds number in the simulations differs from that in the experiment.     

柴油闪急沸腾喷雾的试验研究

通过对柴油机高压油管进行外加热源加热热，在Ｅ１５０柴油机上实现柴油的闪急沸腾喷雾，并对柴油机的性能及排放进行了试验研究。结果表明，采用闪急沸腾喷雾，柴油机油耗可降低８ｇ／ｋＷ．Ｈ，烟度下降０．４ＢＳＵ，ＮＯＸ排放略有升高，ＣＯ，ＨＣ排放均降低。     

装配式公路钢桥承载力的有限元分析

指出装配式公路钢桥设计中所采用的简化计算方法的不足,使用大型有限元软件ANSYS对其受力情况和承载力进行了分析,并与简化计算方法作了对比,得出了一些规律性的结论,对实际应用具有指导意义。     

同步发电机参数辨识的相关方法探讨

随着电网安全及稳定运行问题的重要性日益突出,基于获得准确的系统模型和参数辨识方法,优化同步发电机相关参数将是十分有意义的。本文针对当今几种比较典型的参数辨识方法做了系统的介绍,通过比较得出何种方法对于同步电机的参数辨识是最适合的。