应用简化的软化桁架模型设计钢筋混凝土短牛腿

阐述了简化的软化桁架模型的传力途径、设计步骤.用简化的软化桁架模型对钢筋混凝土短牛腿进行抗剪强度分析和设计,考虑的参数包括混凝土强度、剪跨比和水平箍筋的数量.通过对一个钢筋混凝土短牛腿的实例进行了验算,与混凝土结构设计规范(GB50010-2002)规定方法的计算结果是一致的,证明了所提出的简化的软化桁架模型的有效性、实用性.     

基于带通采样定理的高效ADC系统研究

目前对射频信号进行A/D转换存在很大难度,主要采用多片A/D器件并行使用,实现高速数据采集。带通采样技术含有同时调制信号和降低信号速率两种作用,鉴于此前端设计一种基于带通采样定理的SHA抽取器,后端加入表决系统,提出一种基于带通采样定理的高效ADC系统,经理论分析该结构切实可行,对于降低数据采样率和提高数据转换效率有一定的借鉴意义。     

脉冲干扰对超宽带通信干扰效果分析

从通信干扰角度,针对TH-PPM-UWB体制,通过分析不同参数脉冲干扰信号对该通信体制的影响,运用Matlab进行仿真,给出了与理论相一致的仿真结果。     

槽道式冷却通道壁面二维温度场的计算

本文建立了燃气发生器槽道式再生冷却通道壁面二维温度场的计算模型,并用有限差分法进行了求解,所得结果与文献结果一致,验证了模型的正确性。利用该模型对某燃气发生器槽道式冷却通道壁面的二维温度场进行了计算,结果表明该燃气发生器的热防护设计合理。该模型实现了对燃气发生器传热的快速预测和分析,对燃气发生器的热防护设计具有一定的实际意义和参考价值。     

水平旋喷在饱和粉细砂围岩中的应用

水平旋喷利用高压射流浆液破碎围岩并通过旋转搅拌将水泥浆与围岩充分混合搅拌,形成柱状固结体,解决注浆无法达到充分渗透处改善围岩的目的.文章通过分析水平旋喷桩施工难点及适用地质条件,并介绍孔口止水装置在旋喷施工中的应用,以及解决跑浆塌孔断桩现象,为软流塑饱和粉细砂围岩提供有效的施工参考.     

影响钢丝绳芯输送机接头质量因素的探讨

随着钢丝绳芯输送带的使用范围越发广泛,提高接头胶接质量,确保输送带的长寿命运行成为一个关键环节.对于影响皮带机接头胶接质量的各个因素进行了探讨,提出相应对策.     

A reliability‐based traffic assignment model for multi‐modal transport network under demand uncertainty

In densely populated and congested urban areas, the travel times in congested multi‐modal transport networks are generally varied and stochastic in practice. These stochastic travel times may be raised from day‐to‐day demand fluctuations and would affect travelers' route and mode choice behaviors according to their different expectations of on‐time arrival. In view of these, this paper presents a reliability‐based user equilibrium traffic assignment model for congested multi‐modal transport networks under demand uncertainty. The stochastic bus frequency due to the unstable travel time of bus route is explicitly considered. By the proposed model, travelers' route and mode choice behaviors are intensively explored. In addition, a stochastic state‐augmented multi‐modal transport network is adopted in this paper to effectively model probable transfers and non‐linear fare structures. A numerical example is given to illustrate the merits of the proposed model. Copyright © 2012 John Wiley & Sons, Ltd.     

车轮在动态弯曲载荷作用下的应力分析

应用Abaqus软件对某钢制车轮在动态弯曲载荷作用下的应力分布进行了仿真计算,并研究了不同加载方式对车轮应力计算结果的影响。将不同加载方式下所得车轮应力危险点应力变化情况与试验结果进行对比。结果表明,动态加载方式所得应力结果与测试结果较为接近,说明在对弯曲载荷作用下钢制车轮应力进行仿真时宜采用动态加载方法。     

低应变反射波法在路基CFG桩检测中的应用

通过对某路基CFG桩的测试与波形采集处理,与桩身缺陷情况进行了对比、分析,总结了典型缺陷类型与波形的对应关系,提出了在低应变反射波法检测CFG桩过程中,应注意桩头处理方法、激发波频谱的选择对波形采集的影响,为低应变反射波法在检测CFG桩中的应用提供参考。     

Reliable Shortest Path Problems in Stochastic Time-Dependent Networks

This study investigates the time-dependent reliable shortest path problem (TD-RSPP), which is commonly encountered in congested urban road networks. Two variants of TD-RSPP are considered in this study. The first variant is to determine the earliest arrival time and associated reliable shortest path for a given departure time, referred to as the “forward” TD-RSPP. The second problem is to determine the latest departure time and associated reliable shortest path for a given preferred arrival time, referred as the “backward” TD-RSPP. It is shown in this article that TD-RSPP is not reversible. The backward TD-RSPP cannot be solved by the algorithms designed for the forward problem using the reverse search from destination to origin. In this study, two efficient solution algorithms are proposed to solve the forward and backward TD-RSPP exactly and the optimality of proposed algorithms is rigorously proved. The proposed solution algorithms have potential applications in both advanced traveler information systems and stochastic dynamic traffic assignment models.