Efficient force prediction for incremental sheet forming and experimental validation

Incremental sheet forming (ISF) has been attractive during the last decades because of its greater flexibility, increased formability and reduced forming forces. However, traditional finite element simulation used for force prediction is significantly time consuming. This study aims to provide an efficient analytical model for tangential force prediction. In the present work, forces during the cone-forming process with different wall angles and step-down sizes are recorded experimentally. Different force trends are identified and discussed with reference to different deformation mechanisms. An efficient model is proposed based on the energy method to study the deformation zone in a cone-forming process. The effects of deformation modes from shear, bending and stretching are taken into account separately by two sub-models. The final predicted tangential forces are compared with the experimental results which show an average error of 6 and 11 % in respect to the variation of step-down size and wall angle in the explored limits, respectively. The proposed model would greatly improve the prediction efficiency of forming force and benefit both the design and forming process.     

边远井作为城镇燃气储气调峰气源的可行性

以中江县政府、中石化、中江港华的边远井联合开发利用模式为例,从中江县城市发展规划、城镇燃气用气不均Q性、各种储气调峰方式的比较、经济分析等方面进行分析。研究结果表明:利用边远井作为储气调峰气源是可行的。     

几种简单的齿槽转矩测量方法

齿槽转矩是影响电动机运行平稳性的重要技术指标,为了能快速测量电动机的齿槽转矩,介绍了几种简单的齿槽转矩测量方法.     

Adaptive Trajectory Tracking of Wheeled Mobile Robots Based on a Fish-eye Camera

International Journal of Control, Automation and Systems - This paper presents a novel adaptive trajectory tracking control method, which can precisely control wheeled mobile robots only using an...     

Practical Robotic Auditory Perception and Approaching Methods Based on Small-sized Microphone Array

International Journal of Control, Automation and Systems - Robot control based on audition plays an important role in many robot applications, which is generally implemented by three steps: aural...     

基于混合粒子群优化算法的火箭弹内弹道优化设计

针对无控火箭弹的内弹道优化问题,以增加射程为目标,在发动机总冲恒定的约束条件下,分别建立了固体火箭发动机单室单推模式和单室双推模式的内弹道数学模型和优化模型,采用改进的混合粒子群优化算法,对固体火箭发动机的内弹道特性进行优化设计,求得了全局最优解。仿真结果表明,提出的混合粒子群优化算法具有较好的全局寻优能力和鲁棒性,是解决固体火箭发动机内弹道优化问题的有效方法; 设计的优化策略将某型122 mm无控火箭弹的最远射程提高了3.75%～4.45%,仿真结果对无控火箭弹的总体设计具有一定的理论指导意义。     

信息化技术在铸铁熔炼管理过程中的应用

在铸造生产过程中,铁液的熔炼质量控制是非常重要的管理项目;熔炼质量的有效管理不仅影响着产品质量,也影响着生产成本和效率。我公司基于互联网技术开发了一套炉前信息化管理系统,目前已经在多个铸造企业实施使用,获得得了良好的管理效果。     

体制变迁下的兰州城市总体规划实施效果分析

城市总体规划两项最重要的功能——预测城市人口、用地规模;对城市各项建设用地在空间上作出具体安排,为了检测这两项功能在不同时期发挥作用的效果,笔者运用GIS分析方法,结合城市现状人口数据分析,结果发现:传统计划经济时期城市规划人口预测畸形地符合规划期末现状人口,而改革开放以来人口预测与现实偏差巨大;在用地布局方面,不管是计划经济时期,还是改革开放以来,不同类型的城市建设用地在组团城市中的各个组团实施效果也差别明显,但实施效果均不如预期。最后通过回顾新中国成立以来各种与城市发展相关的制度演变发现:影响城市总体规划实施的根本原因是规划期内各种剧烈的社会动荡和深刻的政治和经济体制的转变。     

基于Internet远程测控系统的研究

本文分析了基于Internet的远程测控系统的结构、应具备的功能、及其工作流程,和实现基于Internet的远程测控系统的几个关键技术;重点论述了现场总线与以太网结合的可行性、必要性及实施方案。