低温卷取钢坯头部和尾部跟踪智能控制技术的研究

随着现代热连轧生产工艺的不断提高,对热轧卷取机的控制系统也提出了更高要求。基于改进卷取带钢低温跟踪检测技术和减小咬钢时的头部打滑的目的,采用了智能控制方案能够动态调整控制器参数的方法,通过MAT-LAB/SIMULINK系统仿真的试验,实现了带钢在200~300℃可以正常卷取,批量生产出热轧双相钢。     

基于OpenCV的集成芯片基板定位技术

针对集成芯片制造中对定位、校准的高精度、实时性要求,提出了用机器视觉技术解决芯片基板定位的方法,通过对几种模板匹配算法的研究,采用基于OpenCV的图像分析技术实现了对集成芯片基板的准确定位,解决了传统机械定位精度低、速度慢的问题。     

一种具有高正向阻断电压及优良开关特性的新型静电感应晶闸管

设计并构造了一种具有条状阳极P-缓冲层结构（SAP-B）的新型静电感应晶闸管。该结构以具有p- 缓冲层和嵌入p+发射区（条状阳极区）的弱掺杂n-发射区（泄漏阳极区）为特点。与传统扩散源区埋栅结构相比,SAP-B结构可进一步简化工艺,并将扩散源区埋栅结构静电感应晶闸管的正向阻断电压从1000V提高至1600V,阻断增益从40提高至70,同时将关断时间从0.8μs降低至0.4μs。     

金属磁性衬板在鲁中选矿厂的应用与分析

通过对金属磁性衬板的实际应用和生产考查，初步表明了金属磁性衬板替代锰钢衬板的优越性。文中还对存在的问题提出了改进的意见。     

DTM287/410型球磨机"烧大瓦"事故的分析与处理

球磨机主要应用于发电、水泥生产等行业,球磨机烧大瓦事故时有发生,曾一度威胁着锅炉的安全经济运行.文章概述了球磨机烧大瓦事故的发生原因、消除方法及预防措施,特别是针对DTM287/410型球磨机详细分析了其烧大瓦的原因及处理方法.     

A Conservative Integral for Determining Stress Intensity Factors of a Bimaterial Strip

Both conservative line and area integrals are derived from the Betti reciprocal principle to determine the stress intensity factor for a bimaterial strip. Numerical results are presented to demonstrate the accuracy of the methods. Several mesh types have been exploited to examine the effect of meshing on the results. Stress intensity factors obtained by means of the line integral vary somewhat between paths. Those found by means of the area integral have the same value on different paths. This revised version was published online in August 2006 with corrections to the Cover Date.     

Stress and failure analysis of laminated composites based on layerwise B-spline finite strip method

A layerwise B_k,k−1-spline finite strip method is developed for stress and failure analysis in fibre reinforced composite laminates. The composite laminates are divided into a number of numerical layers in the thickness direction. A linear variation of in-plane displacements are assumed across the thickness of each numerical layer to represent the sectional warping which can have significant effects on through thickness shear stresses. The development of B_k,k−1-spline finite strip method is presented. Material failure criteria and material degradation models for progressive failure are discussed and integrated in a progressive failure analysis for composite laminates. Numerical applications include a progressive failure analysis example are presented to verify the layerwise B-spline finite strip method developed for stress and failure analysis in composite laminates. Whenever possible the present predictions are compared with the existing analytical and numerical results.     

Production of Submicron Particles by Mechanical Treatment: Width of Particle Size Distribution and Fineness of Product

Calcium carbonate (CaCO₃) powders commonly used as a functional filler in paints, inks, papers, plastics, cosmetics, and so on, are generally produced by mechanical treatment (milling). This research was aimed to produce calcium carbonate submicron particles by stirred milling in wet conditions. The experiments were carried out by a batch operation, and determined the change in particle size distribution (PSD) of calcium carbonate. The product size (fineness) and PSD were used in the evaluation of the test results. The results showed that wet grinding in a stirred bead mill using the smaller grinding media (500 µm) is an effective method for reduction of product size (～500 nm) of the CaCO₃ powder.     

Three dimensional modeling and finite element simulation of a generic end mill

The geometry of cutting flutes and the surfaces of end mills is one of the crucial parameters affecting the quality of the machining in the case of end milling. These are usually represented by two-dimensional models. This paper describes in detail the methodology to model the geometry of a flat end mill in terms of three-dimensional parameters. The geometric definition of the end mill is developed in terms of surface patches; flutes as helicoidal surfaces, the shank as a surface of revolution and the blending surfaces as bicubic Bezier and biparametric sweep surfaces. The proposed model defines the end mill in terms of three-dimensional rotational angles rather than the conventional two dimensional angles. To validate the methodology, the flat end milling cutter is directly rendered in OpenGL environment in terms of three-dimensional parameters. Further, an interface is developed that directly pulls the proposed three-dimensional model defined with the help of parametric equations into a commercial CAD modeling environment. This facilitates a wide range of downstream technological applications. The modeled tool is used for finite element simulations to study the cutting flutes under static and transient dynamic load conditions. The results of stress distribution (von mises stress), translational displacement and deformation are presented for static and transient dynamic analysis for the end mill cutter flute and its body. The method described in this paper offers a simple and intuitive way of generating high-quality end mill models for use in machining process simulations. It can be easily extended to generate other tools without relying on analytical or numerical formulations.     

提高热连轧板板形质量的方法与措施

通过分析楔形、凸度、平直度等板形控制机理,结合莱钢热连轧工艺装备和板形质量特点,优化原始辊型、换辊周期、负荷分配等工艺,制定出与产品质量相关联的换辊制度、换辊模式、轧制计划安排等控制策略,改善了产品断面形状,板凸度由-20～250μm改善到30～70μm,板形异常卷控制在0.25%以下,薄规格比重提高到总产量的30%～40%。