机车构架翻边装置设计与应用

机车构架在制造过程中需要将其进行旋转翻边,采用传统天车翻边的方式容易造成工件损坏和安全事故.文章通过对机车构架的结构及制造工艺进行分析,设计了一种机车构架翻边装置,并应用有限元分析方法对装置主要部件进行了强度校核,应用情况表明该机车构架翻边装置安全可靠,快速方便,并且避免了工件的损坏.     

A Bayesian approach to detect pedestrian destination-sequences from WiFi signatures

In this paper, we propose a methodology to use the communication network infrastructure, in particular WiFi traces, to detect the sequence of activity episodes visited by pedestrians. Due to the poor quality of WiFi localization, a probabilistic method is proposed that infers activity-episode locations based on WiFi traces and calculates the likelihood of observing these traces in the pedestrian network, taking into account prior knowledge. The output of the method consists of candidates of activity-episodes sequences associated with the likelihood to be the true one. The methodology is validated on traces generated by a known sequence of activities, while the performance being evaluated on a set of anonymous users. Results show that it is possible to predict the number of episodes and the activity-episodes locations and durations, by merging information about the activity locations on the map, WiFi measurements and prior information about schedules and the attractivity in pedestrian infrastructure. The ambiguity of each activity episode in the sequence is explicitly measured.     

铜管路件焊缝致密度检验方法研究

铜管路件主要由铜管及三通接头焊接而成,焊接的质量对水冷系统有很大的影响。本文研究了铜管路件焊缝致密度的检验方法,介绍了铜管路件焊接方法、影响焊接质量的各种因素及焊接工艺过程。提出了铜管路件焊缝致密度检验方法,该方法首先对检验样本进行制备,接着通过由光学显微镜与计算机组成的成像系统对样本焊缝位置进行显微图像采集,对采集到的焊缝显微图像在图像软件中进行处理,获取焊缝缺陷的长度,从而计算焊缝位置的致密度。     

Modeling, identification and simulation of DC resistance spot welding process for aluminum alloy 5182

Currently the aluminum alloy resistance spot welding(AA-RSW) has been extensively used for light weight automotive body-in-white manufacturing.However the aluminum alloys such as AA5182 have inferior weldability for forming the joint due to their high reflectiveness to heat and light.Therefore it is necessary to further develop the high performance control strategy and the set-up of a new welding schedule.The welding process identification is the essential issue where the difficulty arises from the fact that the AA-RSW is a nonlinear time-varying uncertain process which couples the thermal,electrical,mechanical and metallurgical dynamics.To understand this complicated physical phenomenon a novel dual-phase M-series pseudo-random electrical pattern is adopted to excite the AA-RSW electrical-thermal process and the thermal response is recorded according to the welding power outputs.Based on the experimental information,the transfer function of an AA-RSW electrical- thermal mechanism is identified,and the optimum model order and parameters are determined.Subsequently a control-oriented DC AA-RSW model is established to explore the welding power control algorithm.The simulated results of the control model show agreement with the experimental data,which validates its feasibility for the corresponding welding control.     

大榭第二大桥钢塔节段制造工艺及焊接变形控制技术

针对大榭第二大桥钢塔节段的结构特点,从制作工艺、焊接变形控制等方面介绍了控制钢塔精度的方法,为今后钢塔节段制造提供技术参考.     

现代焊接技术在车桥桥壳焊接中的应用

根据桥壳材料的力学性能和焊接工艺性,阐述了自动焊接技术在桥壳焊接过程中的应用．并以具体实例说明了PLC技术在焊接专机上的应用;通过焊接工艺参数对焊缝质量的影响规律介绍,确定了桥壳焊接。工艺参数的选择范围。     

小口径水平固定管组合焊技术探索

文章针对小口径水平固定管组合焊,研究了其焊前清理、焊接装配、焊接方法（焊条电弧焊和TIG焊）、工艺参数、操作方法、焊接检验等方面技术,对提高焊接质量具有一定的应用价值。     

WC/Ni60A覆层抗泥沙磨损性能研究

叙述了WC/Ni60A覆层的粉末制备材料和喷焊工艺方法,测试覆层的硬度及沿厚度方向的硬度分布,对35%WC/Ni60A喷焊覆层进行泥沙磨损实验、XRD测试、金相分析和覆层样品磨损形貌观察。在实验基础上讨论该喷焊覆层的抗泥沙磨损性能,分析覆层中硬质相和基体相的成分构成、结合机理,结合泥沙磨损实验结果及其磨损形貌,探讨该覆层材料在泥沙磨损条件下的磨损机理及覆层中硬质相和基体相的作用。     

新型提速120 t长大平车4D轴焊接构架式转向架的研制

介绍了4D轴焊接构架式转向架的研制目标、主要技术特点和参数、主要结构、有限元计算结果及试验情况。     

门机门腿与上支承环焊缝开裂修复方案

阐述了门机门腿与上支承环焊缝经常性开裂的情况,分析了开裂的原因,提出了修复门机门腿与上支承环之间焊缝的建议。由此排除金属结构隐患,确保设备的安全运行。