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William C. Webster 《船舶与海洋工程学报》2011,10(3):253-258
In this work,Green-Naghdi (GN) equations with general weight functions were derived in a simple way. A wave-absorbing beach was also considered in the general GN equations. A numerical solution for a level higher than 4 was not feasible in the past with the original GN equations. The GN equations for shallow water waves were simplified here, which make the application of high level (higher than 4) equations feasible. The linear dispersion relationships of the first seven levels were presented. The accuracy of dispersion relationships increased as the level increased. Level 7 GN equations are capable of simulating waves out to wave number times depth . Numerical simulation of nonlinear water waves was performed by use of Level 5 and 7 GN equations, which will be presented in the next paper. 相似文献
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在高速公路施工路段缺少合适的填筑材料的条件下,可选择土包砂作为路基结构形式。经试验研究发现,路基的各项指标均满足规范要求.可供类似工程参考借鉴。 相似文献
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A macroscopic taxi model for passenger demand,taxi utilization and level of services 总被引:1,自引:0,他引:1
In most urban areas taxi services are subject to various types of regulation such as entry restriction and price control.
However, effective intervention depends on generating and using suitable information on the demand-supply equilibrium of the
taxi market. This paper develops a simultaneous equation system of passenger demand, taxi utilization and level of services
based on a taxi service situation found in the urban area of Hong Kong over the last ten years. A set of variables is introduced
including number of licensed taxis, taxi fare, disposable income, occupied taxi journey time as exogenous variables and daily
taxi passenger demand, passenger waiting time, taxi availability, taxi utilization and average taxi waiting time as endogenous
variables. These variables are coupled together through a system of nonlinear simultaneous equations whose parameters are
estimated from survey data. The simultaneous equation system can be used to obtain useful regulatory information to assist
with the decisions concerning the restriction over the number of taxi licenses and the fixing of the taxi fare structure as
well as a range of service quality control.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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预应力混凝土梁开裂后的受力性能分析 总被引:6,自引:0,他引:6
基于实体退化壳单元,采用层状模型模拟钢筋混凝土结构,选取恰当的混凝土和钢筋的本构关系,采用弥散裂缝模式,考虑材料非线性效应有效地模拟了预应力混凝土T梁的开裂、屈服和失效全过程,并与试验结果进行比较。分析了T梁在开裂后的刚度及裂缝的位置和发展情况。探讨了混凝土和预应力钢筋在T梁开裂后的应力发展规律。结果表明退化分层壳单元模型对于预应力混凝土T梁的非线性分析有良好的适应性。 相似文献
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考虑了比例延迟微分方程的数值方法的散逸性,把一类线性多步法应用到以上问题中,得到了该数值方法的散逸性结果。 相似文献
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在对三维体元任一点移动和转动分析的基础上,导出了体元和梁元恰当连接应满足的多点约束方程,通过直接代入梁元的单元分析进行自由度替换实现了体梁的良好连接.本文方法对体元和梁元的连接形式具有较强的适应能力,应用方便,算例表明具有较高的数值精度. 相似文献
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