Application of warm forming aluminum alloy parts for automotive body based on impact

Aluminum alloys are important technological materials for the application on lightweight design and development of vehicle body. The research works for characterizing warm forming behavior of aluminum alloys have generally reported. However, there were few researches focused on the flow behavior of warm forming aluminum alloy parts for the energy absorbing performance during crash. The tensile stress-strain response for warm forming AA5182 specimens tested under the strain rates of 0.0015 s^?1, 0.015 s^?1, 0.15 s^?1 and 1.5 s^?1 are presented in this paper. The data were fit to the Johnson-Cook constitutive model for the simulation of frontal impact. The energy absorbing performance of warm forming AA5182 parts were analyzed. The results show the higher flow stresses and lower fractured strain of warm forming aluminum alloy parts with the strain rate increasing. The flow stresses of warm forming aluminum alloy parts are insensitive to strain rate, while the fractured strain and elongation are sensitive to strain rate. The intrusion displacement of the warm forming aluminum alloy parts is appropriate for the satisfaction of vehicle body design avoiding the excessive deformation for the injury of passenger or the failure of frontal door opening. The feasibility of warm forming aluminum alloy parts is verified with the analysis of energy absorbing performance, stiffness and modal of vehicle body.     

中国市场SUV动力类型现状及趋势研究

<正>面对日益严峻的能源短缺和环境危机,国家对于乘用车能耗和排放的要求更加严格,2015年,企业乘用车新车平均燃料消耗量将降至每百公里6.9L。在如此形势下,作为传统油耗大户的SUV车型,其动力类型该怎样改变,关系到车企乃至整个产业的健康发展。     

一种中分自卸汽车列车控制系统的设计

本论文介绍了一种可实现多卸货次序的中分自卸汽车列车,它通过电控气、气控液的方式分别控制汽车列车两货箱侧箱板开启、底板中部突起进行卸货,前、后箱卸货次序不受限制,避免了传统自卸车对车厢长度要求高、稳定性差、对卸货场地要求严格、无法加装全挂列车等缺点,使货物堆放更到位,避免二次转运造成的资源浪费,提高了卸货效率。     

Modeling oil spills in a river—lake system

A general model shell, ROSS3, is developed for simulating oil spills in complex river systems using techniques which have not been previously exploited in oil spill models. ROSS3's new approach has several advantages over the approach to model oil spills in the past: (a) The use of a time-varying boundary-fitted coordinate system that allows accurate accounting for complex river/lake boundary as well as the river boundary changes as its water levels fluctuate; (b) The ability to confine two-dimensional hydrodynamic computations to a limited river reach; (c) The ability to interactively layout the channel networks for setting up the model, define extra cross sections to increase the accuracy if needed, in addition to the traditional data entry and visualization interfaces.ROSS3 is a two-layer two-dimensional oip spill model that can simulate the mechanism of advection, horizontal diffusion, mechanical spreading, shoreline deposition, evaporation, dissolution, vertical mixing, resurfacing and sinking. In ROSS3 spilled oil may be a surface slick or suspended oil droplets, or a combination of both. Both free surface and ice cover conditions can be simulated. The flow of conditions can be varied and the unsteady flow model can be run within ROSS3 to simulate the flow conditions in both the river and the lake. The ice conditions can be added or removed from the model input using easy interactive procedures.     

Fuzzy子群和拟Fuzzy正规子群

给出了Fuzzy子群的一种等价定义，利用这种定义讨论了Fuzzy子群的截集，强截集，水平截集之间的关系，同时讨论了Fuzzy正规子群的一些性质，并给出了拟Fuzzy正规子群的概念，在讨论中发现，在某些方面拟Fuzzy正规子群可以代替Fuzzy正规子群。     

试验数据统计建模研究

针对数据融合技术和仿真试验的难点，对试验数据的建模问题作了分析研究，简要介绍试验数据建模的成果。     

Hybrid Simulation of Dynamics for the Pantograph-Catenary System

Summary In order to examine the static and dynamic behavior of the pantograph-catenary system, a special teat facility is established and described in this paper. Since the catenary is difficult to be modeled by a hardware teat facility indoor, a mixed theoretical-experimental technique is introduced, in which the pantograph is an actual one but the catenary is just an input of a mathematical model. Bayed on setting up the hybrid simulation teat device of the pantograph-catenary system, the dynamic behavior of the system under overhead equipment with variant parameters is analyzed for different speed. The effect of the presag and the surface irregularities of contact wire on current-collection has been studied.     

桩底后压浆技术在城市地铁车站洞桩法施工中的应用

以北京地铁光华路站洞桩法灌注桩后压浆技术的成功应用为例,详细介绍了其施工方法及施工工艺。研究表明,该项技术不仅可有效地提高桩基综合承载力,且可减少工期、降低工程成本,具有良好的社会效益和经济效益。     

汽车侧面碰撞中影响假人性能指标的因素及改进

刚发布的关于汽车侧面碰撞的乘员保护标准是第二个整车碰撞的强制性国家标准,它的发布将带给车辆制造商一些新的挑战和机遇。本文分析了在碰撞中影响假人性能指标的因素并提供了一系列可行的改进措施,结合一个最终取得良好效果的侧面碰撞试验实例阐述了具体的改进方法。     

大跨度斜拉桥施工风险分析理论研究与应用

结构在施工期的平均风险远远高于使用期,开展大跨度斜拉桥施工期间的风险分析研究是十分必要的。本文在介绍风险分析基本原理的基础上,针对斜拉桥施工期风险分析中不存在显式的极限状态函数的问题,提出了基于人工神经网络-有限元-蒙特卡罗模拟的风险分析方法。运用该方法对某大跨度斜拉桥进行施工风险分析,结果表明该方法可行、有效。