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。     

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)     

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.     

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。     

地铁隧道混凝土管片的孔洞和裂缝控制

介绍了地铁隧道衬砌管片制作过程中出现孔洞和裂缝的原因。结合深圳地铁一期工程的实际情况,从材料、设备、工艺几个方面讨论了防止混凝土孔洞裂缝产生的措施:严格控制原材料的质量,重视混凝土的配制过程,改进施工和养护工艺,降低环境因素的影响,对存在的裂缝及时处理等。     

港口腹地划分的两种新方法探讨--以大连国际航运中心为例

引入经济地理学的新理论成果———圈层结构法和点轴法,提出了圈层结构划分法和点轴结构划分法两种新的港口腹地划分方法,并应用这两种新方法对大连国际航运中心港口腹地范围的界定与划分进行实例分析。与以往的行政区划法、经济区域法等港口腹地划分方法相比,这两种方法更加注重对港口原有腹地的细分,更接近于港口腹地的实际状况,进而有利于港口企业的经营发展。     

组合结构力法分析

本文应用集合概念，对组合结构作了形式化描述。通过矩阵分析，导出了力法方程的统一列式。给出了算法实施的流程框图和具体算例。     

开关磁阻电机最优化设计的研究

ＳＲＭ优化设计问题属于带多个约束条件的非线性规划问题，除变量的离散性外，约束条件众多且非线性程度高，目标函数是离散跳跃的，本文着重对ＳＲＭ最优化方法进行了研究，提出了一种改进的增广Ｌａｒｇｒａｎｇｅ乘子法，与罚函数法相比，对复杂数学模型的优化具有明显的优越性。