Estimation of road profile variability from measured vehicle responses

When assessing the statistical variability of fatigue loads acting throughout the life of a vehicle, the question of the variability of road roughness naturally arises, as both quantities are strongly related. For car manufacturers, gathering information on the environment in which vehicles evolve is a long and costly but necessary process to adapt their products to durability requirements. In the present paper, a data processing algorithm is proposed in order to estimate the road profiles covered by a given vehicle, from the dynamic responses measured on this vehicle. The algorithm based on Kalman filtering theory aims at solving a so-called inverse problem, in a stochastic framework. It is validated using experimental data obtained from simulations and real measurements. The proposed method is subsequently applied to extract valuable statistical information on road roughness from an existing load characterisation campaign carried out by Renault within one of its markets.     

提高标准件模具寿命的有效途径

在汽车标准件的生产过程中,模具起着主导作用,只有提高模具寿命,才能起到事半功倍的效果。有效提高标准件模具的寿命,除了需要合理选用模具的材料,合理设计模具的结构,做好模具的热处理以及加工与抛光外,还要选用恰当的润滑剂和精度高的设备,同时要加强管理,提高操作者的素质。     

The train platforming problem: The infrastructure management company perspective

If railway companies ask for station capacity numbers, their underlying question is in fact one about the platformability of extra trains. Train platformability depends not only on the infrastructure, buffer times, and the desired departure and arrival times of the trains, but also on route durations, which depend on train speeds and lengths, as well as on conflicts between routes at any given time. We consider all these factors in this paper. We assume a current train set and a future one, where the second is based on the expected traffic increase through the station considered. The platforming problem is about assigning a platform to each train, together with suitable in- and out-routes. Route choices lead to different route durations and imply different in-route-begin and out-route-end times. Our module platforms the maximum possible weighted sum of trains in the current and future train set. The resulting number of trains can be seen as the realistic capacity consumption of the schedule. Our goal function allows for current trains to be preferably allocated to their current platforms.Our module is able to deal with real stations and train sets in a few seconds and has been fully integrated by Infrabel, the Belgian Infrastructure Management Company, in their application called Ocapi, which is now used to platform existing and projected train sets and to determine the capacity consumption.     

双螺旋折流板换热器最佳螺旋角的研究

为了研究换热器的传热性能与双螺旋折流板换热器的螺旋角的关系，通过建立多个不同螺旋角的管壳式换热器模型，运用数值计算的技术手段对其进行模拟，并对其数值模拟结果进行对比分析。结果表明：双螺旋折流板换热器存在最佳螺旋角使得换热器的换热性能最优。相同换热器结构的条件下，壳程进口流量对双螺旋折流板换热器的最佳螺旋角没有影响。随着壳径的增大，双螺旋折流板式换热器的最佳螺旋角有下降趋势。     

Flexible feeder transit route design to enhance service accessibility in urban area

To improve the accessibility of transit system in urban areas, this paper presents a flexible feeder transit routing model that can serve irregular‐shaped networks. By integrating the cost efficiency of fixed‐route transit system and the flexibility of demand responsive transit system, the proposed model is capable of letting operating feeder busses temporarily deviate from their current route so as to serve the reported demand locations. With an objective of minimizing total bus travel time, a new operational mode is then proposed to allow busses to serve passengers on both street sides. In addition, when multiple feeder busses are operating in the target service area, the proposed model can provide an optimal plan to locate the nearest one to response to the demands. A three‐stage solution algorithm is also developed to yield meta‐optimal solutions to the problem in a reasonable amount of time by transforming the problem into a traveling salesman problem. Numerical studies have demonstrated the effectiveness of the proposed model as well as the heuristic solution approach. Copyright © 2015 John Wiley & Sons, Ltd.     

公路桥梁技术状况评定方法分析

根据实际工作经验详细分析了桥梁的技术状况评定方法,对计算过程进行了详细说明,并列举了在评定过程中需要注意的问题,提出了公路桥梁技术状况评定的建议。     

An inverse finite element method for the analysis of VIV data

This paper presents an algorithm for the frequency domain solution of dynamic linear “inverse” problems, that is for the processing of measurement data (strain, acceleration etc.) acquired on a mechanical structure, in order to estimate the loads acting on the structure and its corresponding response. The problem is formulated as a constrained (force equilibrium) optimization (small deviations from measurements, small loads) problem, which is transformed into an unconstrained problem, then into differential equations. The algorithm is applied to the estimation of hydrodynamic forces induced by the shedding of vortices from an offshore oil riser.     

关于一类二阶共轭矩阵方程的解

考虑一类二阶共轭矩阵方程 B*X*AXB+B*X*C+C*XB+D=O 其中，B∈Cp×m，A∈n×n，C∈Cn×m，D∈Cm×m，在A＞O及A≥O，C或B为列满秩阵两种情况 下，此方程可解的充分必要条件，并在有解的情况下，给出了通解的显式表示。     

奇摄动三阶非线性边值问题

利用微分不等式技巧和Volterra型积分算子，研究了三阶非线性奇摄动边值问题εx^(3)=f(t,x,x′,w(ε）x^(3)，ε），g（x′（0），x″（0）=0，x（1）=A，x′（1）=B的存在性及渐近估计。     

加快工程建设规范化、法制化,促进防洪、排涝工程监理的健康发展

本文主要介绍了日前福州市防洪、排涝工程监理存在的问题 ,面对二十一世纪 ,针对防洪、排涝工程监理事业的发展战略谈了看法。