盾构机直接切削玻璃纤维筋洞门进洞技术

玻璃纤维筋是一种非常适用于NOMST工法的材料。文章介绍了玻璃纤维筋的物理力学性质。以珠江三角洲城际轨道交通广州至佛山段土建12标(西朗—鹤洞)盾构区间工程为应用背景,介绍了玻璃纤维筋围护桩的施工技术及盾构机采用NOMST工法直接切削玻璃纤维筋围护桩洞门进洞的施工技术。初步探讨了进洞过程中盾构推力对车站接收端墙的作用,采用有限元法进行了模拟分析,并在此基础上提出了NOMST工法进洞时盾构推力的确定方法。     

圆柱滚子轴承有限元分析

接触问题是一种典型的边界条件非线性问题。在分析接触问题时,使用Abaqus/standard模块,能正确模拟接触的过程,判断接触状态、输出接触压力。通过对圆柱滚子轴承在Pro/E中建立三维模型,然后导入ABAQUS软件进行接触分析,得出滚子与内、外圈之间接触应力的分布情况,和理论分析能很好地吻合,对轴承的选型具有指导意义。     

计算结构力学与有限单元法课程教学的思考

有限单元法普遍作为研究生课程中的学位课,推广到本科生教学中存在一定的难度。因此,要采用多元化教学方法和手段,增强学生软件编写能力和提高学生综合能力,使学生系统掌握该课程的理论和方法,为以后从事设计、施工或本专业进一步的学习打下良好的基础。     

Is the Dutch consumer a true ricardian?

Summary In this paper the intertemporal optimization approach is adopted in order to estimate an empirical version of Blanchard's (1985) overlapping generations model. The observed sluggishness in consumption is incorporated into the model by recognizing both durability and habit formation as relevant determinants of total consumption. The model is estimated using quarterly data for The Netherlands from 1969:I to 1990:IV. The empirical estimates suggest that the status of the Dutch consumer as a true Ricardian is unambiguously rejected. The results furthermore suggest that this rejection is due to the existence of both liquidity constraints and finite planning horizons.Comments by Peter Broer, Jeroen Kremers, Debora Molenaar, Rick van der Ploeg, Frans Spinnewyn, Casper de Vries, Ed Westerhout and two anonymous referees are very much appreciated. Elbert Dijkgraaf has provided invaluable research assistance. We also thank participants of the OCFEB workshop and the CES seminar at the K.U. Leuven for their comments.     

Clustering at the Movies

Weekly box office revenues for approximately 100 successful motion pictures are analyzed by use of a finite mixture regression technique to determine if regular sales patterns emerge. Based on an exponential decay model applied to market share data, four clusters of movies, varying in opening strength and decay rate, are found. Characteristics of the clusters and implications for future research are discussed.     

Mean squared error of the empirical best linear unbiased predictor in an orthogonal finite discrete spectrum linear regression model

The mean squared error (MSE) of the empirical best linear unbiased predictor in an orthogonal finite discrete spectrum linear regression model is derived and a comparison with the MSE of the best linear unbiased predictor in this model is made. It is shown that under weak conditions these two mean square errors are asymptotically the same.     

一种基于有限元计算的半挂车强度分析

用有限元计算方法对某型半挂车车架的强度进行了分析计算。通过有限元仿真计算,提出在进行局部加强的同时,采用细而密的横梁结构的优化方案,解决了原来结构的应力集中现象,确保半挂车的结构强度。     

Characteristic properties of multivariate survival functions in terms of residual life distributions

This paper discusses the relationships among some characteristic properties of the multivariate survival function based on the residual life distribution, and provides the conditions for their equivalence. In the meanwhile, the corrected version of Ma (1996, Theorem 1 (ii) and (iii)) is given.     

栈桥钢管桩浮冰冲击作用下的有限元分析

本文运用有限元分析软件Midas civil和ANSYS分别建立了栈桥钢管桩的整体及局部有限元模型,分析了在浮冰冲击荷载作用下钢管柱的受力情况,为栈桥检算提供理论依据,同时优化设计方案,保证了栈桥在使用中的安全可靠。     

三相12/8极高压开关磁阻电机设计及仿真

根据开关磁阻电机的工作原理及结构,简要概述了电机参数设计方法、注意事项及步骤,给出了一台12/8极高压开关磁阻电机实验样机参数,利用Ansoft/Maxwell软件对电机参数进行了二维全场域的有限元分析和计算。得出了转矩脉动、绕组电流等波形以及电机磁力线分布、磁通密度云图分布。仿真结果和实验结果验证了参数设计方法的正确性,为今后开关磁阻电机的改进和优化提供了依据。