Effects of Loading Paths on Hydrodynamic Deep Drawing with Independent Radial Hydraulic Pressure of Aluminum Alloy Based on Numerical Simulation

In order to meet the forming demands for low plasticity materials and large height-diameter ratio parts, a new process of hydrodynamic deep drawing （HDD） with independent radial hydraulic pressure is proposed. To investigate the effects of loading paths on the HDD with independent radial hydraulic pressure, the forming process of 5A06 aluminum alloy cylindrical cup with a hemispherical bottom was studied by numerical simulation. By employing the dynamic explicit analytical software ETA/Dynaform based on LS-DYNA3D, the effects of loading paths on the sheet-thickness distribution and surface quality were analyzed. The corresponding relations of the radial hydraulic pressure loading paths and the part＇s strain status on the forming limit diagram （FLD） were also discussed. The results indicated that a sound match between liquid chamber pressure and independent radial hydraulic pressure could restrain the serious thinning at the hemisphere bottom and that through adjusting radial hydraulic pressure could reduce the radial tensile strain and change the strain paths. Therefore, the drawing limit of the aluminum cylindrical cup with a hemispherical bottom could be increased significantly.     

联轴器找正浅议

以实际检修过程中出现的情况入手,对联轴器可能遇到的偏移情况;找正时的测量方法;联轴器的找正步骤;联轴器找正时的计算和调整量;联轴器找正时的注意事项等五个方面进行了详细的阐述.     

基于RBF神经网络算法的连拱隧道围岩变形预测方法研究

利用径向基函数前馈式神经网络的特性,构建了连拱隧洞围岩变形的预测模型,并利用Matlab工具对模型进行求解。最后的工程实例对文章的方法进行了检验,其结果表明,此方法具有求解速度快,结果更为优化：预测效果更好等优点。     

Scrap tire ring as a low-cost post-tensioning material for masonry strengthening

Load bearing walls of masonry type construction are weak in tension and wall failure in out-of-plane bending direction is one of the common failure mechanisms. Out-of-plane bending capacity and behavior can be greatly enhanced by post-tensioning. Developing countries commonly have poor and under educated population living in self-constructed masonry houses, which are at high risk if they are located on seismically active regions. Vast amounts of used tires, which contain steel-mesh and wires vulcanized with rubber coating, can be recycled as a structural strengthening material for post-tensioning masonry house walls. This study presents the behavior and capacity of scrap tire tread-rings (STRs) and rim-rings under direct tension. STR usage for post-tensioning is demonstrated on two full-scale strip wall test specimens made from hollow concrete bricks. STRs provided average of 133 kN force and 35 MPa stress capacities in tension which can be used for masonry wall post tensioning. The out-of-plane bending capacity of the two test walls increased about 5 times. STR usage with custom design connectors is a very promising alternative for low-cost masonry wall post-tensioning.      

单晶硅（111）晶面纳米压痕过程分子动力学仿真及实验

为了研究脆性单晶材料单晶硅（111）晶面微观机械特征,应用分子动力学,对压痕过程进行仿真分析．本文应用平均势能和径向分布函数相结合方法对压痕过程进行考察．仿真结果表明,工件在压头附近的晶格结构发生变化．在仿真过程中通过确定工件内部的分界线来表明住错传播运动;在压痕结束后工件自身弛豫过程变形区域弹性恢复大约27％．应用Hysitron公司的Triboindenter纳米原位压痕仪进行压痕实验,并把实验得到的材料压痕折合模量与分子动力学仿真计算结果进行比较,结果表明仿真的误差率小于31％．     

汽车综合性能评价专家系统设计

根据汽车总体性能评价指标体系,采用visual foxpro8.0编程工具,编制了汽车总体性能评价专家系统.在数据库向导的帮助下,利用向专家提问的形式,自动收集专家知识并自动生成模型库和知识库结构,具有很强的实用性和扩充性.该系统界面友好,可供各知识层次的用户使用.     

客车车身有限元强度分析载荷条件的确定

讨论了以往汽车车身有限元分析未见论及的紧急制动工况，模拟计算客车车身的静弯曲、强扭转和紧急制动工况下的车身强度，经与客车定型可靠性道路试验结果对照，两者相当一致，可见车身强度分析时，必须考虑各种载荷条件才合理。     

MPXY8020A轮胎压力传感器的SPI接口技术

介绍MPXY8020A压力／温度传感器的SPI接口技术及其在汽车轮胎检测系统中的应用。     

信息资源在汽车维修界的应用前景

信息资源对生产要素起优化作用，信息可通过优化生产素质导向生产要素的合理有效配置。物质、能源、人力和资金构成社会的基本资源，而信息的发展对这些社会的基本资源起到补充作用。现代维修企业采用电脑管理的方式不仅势在必行，而且时机也已经成熟，利用互联网对汽车故障进行快速诊断，查阅相关技术资料，可减少车辆维修时间，显著提高生产效率。     

基于径向基神经网络的声光偏转器控制模型研究

声光偏转是一种高速非机械光束方向控制技术,近年来在卫星光通信领域日益受到重视。运用径向基(RBF)神经网络模型实现声光偏转器光束方向控制,通过训练对RBF网络的权值和网络层元数等结构参数进行优化,调整得到理想模型。研究结果验证了该模型的可靠性与准确性。