我国水泥装备发展概况（上）

1 前言 解放前我国水泥工业非常落后,根本没有水泥装备的设计力量,也没有水泥机械制造厂,建设水泥厂都是向国外购买水泥装备。解放初期也是由国外买成套水泥设备装配我国水泥厂。50年代初期,我国有了自己水泥工业设计队伍──北京水泥工业设计院（天津水泥工业设计研究院前身）,首先开发180t／d湿法生产水泥熟料生产线,为此设计制造出Φ2．5m×78m窑及相应配套水泥装备,投产以后一举获得成功。 60年代初我们开发600t／d湿法生产水泥熟料生产线,为此设计Φ3．5m×145m湿法窑和与之配套磨机等水泥装备,同时设计了Φ4m×54m和Φ4m×60…     

我国水泥装备发展概况（下）

（接上期）3 我国管磨机开发过程 图6表示中国磨机大型化趋势。1960年以前,是我国管磨机开发时期,设计出Φ1．83m×6．1m和Φ2．2m×6．5m管磨机,这阶段我们初步掌握了管磨机设计制造技术。60年代初随着开发600t／d湿法生产线和900～1000t／d半干法生产线,迫使管磨机开始大型化,设计了Φ3m～Φ3．4m的生料磨和水泥磨,满足了配套要求。1975年后我国开发2000t／d新型干法生产线,要求管磨机进一步大型化,研发出Φ4．6m生料磨和Φ4．2m水泥磨。1990年后,我国开发出4000t／d大型干法生产线,因此要求开发出更大直径的管磨。 在窑大型化…     

有限元法在汽车轮胎设计中的应用

阐述汽车轮胎的几种经典分析理论及其局限性,介绍有限元法在汽车轮胎设计和分析各领域中的应用状况。具体讨论在轮胎结构力学分析中的静态接触、刚度和侧偏特性以及模态等问题的分析与处理,在轮胎温度场分析中如何建立模型、确定求解策略以及在轮胎破坏机理分析中在裂纹扩展和胎面磨损等方面的应用研究成果。     

有限元法在汽车轮胎设计中的应用

阐述汽车轮胎的几种经典分析理论及其局限性,介绍有限元法在汽车轮胎设计和分析各领域中的应用状况。具体讨论在轮胎结构力学分析中的静态接触、刚度和侧偏特性以及模态等问题的分析与处理,在轮胎温度场分析中如何建立模型、确定求解策略以及在轮胎破坏机理分析中在裂纹扩展和胎面磨损等方面的应用研究成果。     

电弧焊在窑磨修理中的应用实例

在回转窑和磨机的修理中，用焊接的方法处理开裂问题是相当普遍的。根据多年的实践，作者介绍了手工电弧焊处理铸铁滚圈、铸铁轴承座开裂问题的一些经验，包括焊接材质的选取、焊接工艺的确定以及焊接操作中应注意的问题等。     

有限元法在材料力学中的应用

将有限元法应用于材料力学中的构件变形计算问题,优点是无需区分各向同性材料还是各向异性材料都可求出杆件的变形,并且易于计算机。     

水泥工业袋式除尘器的应用

水泥工业是我国一大支柱产业，为我国基本建设做出很大贡献。但其粉尘排放对环境造成的污染尤为严重，如果对粉尘不加以治理，水泥生产过程粉尘总排放量将超过总产量的５％左右（按水泥熟料产量计算），所散失的粉尘都是成品水泥和各个生产环节的中间产品，其经济损失是可观的。国家环境保护总局以环发[１９９８]３６６号文下发《关于印发全国２０００年工业污染源达标排放和环境保护重点城市环境功能区达标工作方案的通知》，“全国所有工业污染源排放污染物达到国家或地方规定的排放标准；直辖市及省会城市、经济特区城市、沿海开放城市和…     

PDM系统在建材装备制造企业中的运用

PDM（产品数据管理）是整合企业技术资源的有效工具。广东科达机电股份有限公司属于离散型制造企业,产品信息量大,迫切需要借助PDM系统进行有效管理。通过PDM项目四个阶段的实施,初步实现了对企业产品、项目、文件、零部件、工艺路线、用户和流程等业务数据的整体管理．构建起企业产品数据知识库及产品协同设计平台,有效促进了企业的生产效率及提高了市场竞争力,对行业具有较强的借鉴意义。     

有限元法在耐火材料中的应用

耐火材料损坏除了化学侵蚀以外 ,还有热机械应力。前者是指熔体、气体、灰尘对耐火材料的化学侵蚀及冲刷等 ,后者是指由于温度及某些内在的化学反应引起的膨胀及机械负荷在耐火材料内部产生的应力 ,超过其强度极限而导致耐火材料损坏 ,而热机械应力的计算主要用有限元法。本文阐述了有限元法在耐火材料中的应用以及有限元法在耐火材料中应用所要注意的问题和应用前景     

无损检测在水泥装备中的应用

0 引言无损检测(Non Destructive Testing,简称NDT),是在不损坏工件和原材料工作状态的前提下,对被检验部件的表面及内部质量进行检查的一种手段.随着水泥装备的质量要求提高和大型化,以及检测技术和仪器的进步,在2000年以后建材行业标准中,增加了NDT相关内容,越来越多的工件都需要经过无损检测.如回转窑轮带、大齿圈和托轮等大型铸钢件,由于工件体积的增大、低合金铸钢自身流动性较差和收缩性,在浇注过程中更容易出现铸造缺陷,因此NDT是保证产品质量的重要环节.     

有限元法在基坑稳定性验算中的应用

对基坑开挖前后土中应力场的变化规律进行分析，考虑了影响土稳定性多方面因素，建立了用有限单元法求算基坑抗隆起稳定性的力学模型与计算程序。通过实例计算，验证了此方法的科学性、可靠性。     

Simulation of freezing step in vial lyophilization using finite element method

Determination of heat transfer and temperature profile during freezing step is fundamental to predict the final structure of a lyophilized product. The aim of this study was to develop and optimize a dynamic model based on finite element method for simulation of freezing step in order to study final product morphology in both vertical and radial directions. Different factors have been taken into account: chamber pressure, shelf temperature, vial shape, initial solution temperature, nucleation temperature and phase changes. The dynamic axisymmetric model proposed could simulate temperature of each point in the vial and position of liquid-solid interface, without necessity of fitting parameters or questionable assumptions. In addition, the model was extended to predict the average crystal size in each element and the influence of different factors was examined.     

国产耐火材料在新型干法水泥窑上的使用

介绍了新型干法水泥回转窑用内衬材质的选择原则、施工时应注意的事项及使用过程中所取得的一些经验体会。认为按实际情况不断调整生产工艺、强化工艺管理是回转窑耐火材料使用寿命明显提高的主要措施     

Multi-scale finite element modelling using bubble function method for a convection-diffusion problem

Due to the multi-scale nature of the convection-diffusion equation the standard Galerkin method fails to predict accurate and stable results. A multi-scale finite element method based on the bubble function approach has been developed and applied to this problem. Finite element formulations based on the discontinuous weighting functions including the streamline upwind Petrov-Galerkin (SUPG) method are also evaluated. The results show that the multi-scale method provides stable and accurate results and matches very well the analytical solution.     

Simulation of adhesive joints using the superimposed finite element method and a cohesive zone model

Adhesive joints have been widely used in various fields because they are lighter than mechanical joints and show a more uniform stress distribution if compared with traditional joining techniques. Also they are appropriate to be used with composite materials. Therefore, several studies were performed for the simulation of the bonded joints mechanical behavior. In general for adhesive joints, there is a scale difference between the adhesive and the substrate in geometry. Thus, mesh generation for an analysis is difficult and a manual mesh technique is needed. This task is not efficient and sometimes some errors can be introduced. Also, element quality gets worse.In this paper, the superimposed finite element method is introduced to overcome this problem. The superimposed finite element method is one of the local mesh refinement methods. In this method, a fine mesh is generated by overlaying the patch of the local mesh on the existing mesh called the global mesh. Thus, re-meshing is not required.Elements in the substrate are generated. Then, the local refinement using the superimposed finite element method is performed near the interface between the substrate and the adhesive layer considering the shape of the element, the element size of the adhesive layer and the quality of the generated elements. After performing the local refinement, cohesive elements are generated automatically using the interface nodes. Consequently, a manual meshing process is not required and a fine mesh is generated in the adhesive layer without the need for any re-meshing process. Thus, the total mesh generation time is reduced and the element quality is improved. The proposed method is applied to several examples.     

水泥预分解窑用碱性耐火材料的技术进展

介绍了水泥预分解窑的工作条件及其对窑衬耐火材料的影响 ,论述了目前世界水泥预分解窑的技术进展及其对窑用碱性耐火材料的要求 ,以及窑用碱性耐火材料的技术进展 ,分析了我国预分解窑生产技术的发展及预分解窑用耐火材料的发展 ,指出了中国预分解窑用耐火材料近期的发展趋势     

Prediction of the effective diffusion coefficient in random porous media using the finite element method

A finite-element-based method is presented for evaluating the effective gas diffusion coefficient of porous solids. Using this method, the 3-D micro-scale geometries of the porous solids are constructed under the ANSYS platform by the parametric code; the relation between effective gas diffusivity and micro-scale features of random-distributed porous solids is established. The results show that in random-distributed pore media, there is a percolation threshold ε _p, and this percolation threshold decreases with increasing coordination number of the pore network. The relationship between the effective diffusivity and porosity is strongly nonlinear when the porosity, ε, is less than a certain value ε _L ; for ε > ε _L , the relationship becomes quasi-linear. This dividing point ε _L decreases with increasing coordination number. The larger the coordination number of the pore network, the higher the effective gas diffusivity. Based on the simulation results and observations, a formula relating the effective diffusion coefficient with porosity is proposed.     

Effect of five kinds of pores shape on thermal stress properties of thermal barrier coatings by finite element method

Thermal ablation is a very important technique to characterize the thermal properties of coating systems. On account of the concentration of thermal stress, thermal barrier coatings (TBCs) often break off from the substrate partly or completely during the thermal erosion. In this paper, the thermal erosion simulation of finite element geometric models based on the possible pore shapes were implemented, especially, the influence of pore shapes on the distribution of coating temperature, X component of stress, Y component of stress, XY-shear stress and von-Mises stress were focused on. The effects of the different porosity of square pore coatings on thermal insulation properties and thermal stresses were discussed in term of the simulation results. The simulation results indicate that different shape pores not only affect the thermal stress distribution above the contact area between the bond coating and top coating surface, but also affect the plastic deformation behavior of TBCs. The micromechanism was discussed in details in this study. The computed results verified that, the computational method can successfully predict thermal shear, crack initiation and normal failure mode of the studied TBCs. All the results are in good agreement with the corresponding experimental findings. The failure mechanism factors in this paper are of great importance to explain the failure micro-mechanism of TBCs.     

Analysis of strengthening and toughening mechanisms of bioinspired mineral bridges on hot-pressed alumina-based ceramics through finite element method

Bioinspired intergranular mineral bridges were fabricated in alumina-based ceramics through in situ synthesis of Al₂TiO₅ whiskers. The effects of mineral bridges on the mechanical properties of ceramics were investigated. Results showed that the flexural strength and fracture toughness of the alumina-based ceramics increased by 33.97% and 33.52%, respectively, after introducing the mineral bridges under hot pressing. Moreover, the effects of the mineral bridges on the crack tip stress (CTS) of models were calculated by finite element method for the first time. The mineral bridge buds and mineral bridges reduced the CTS by 15.54% and 22.22%, respectively. This finding revealed the root cause of the crack deflection mechanism of the mineral bridges and directly confirmed their strengthening and toughening effects.     

Analysis of crack initiation and propagation in Thermal Barrier Coatings using SEM-Based geometrical model with extended finite element method

Thermal Barrier Coatings (TBC) are widely used to protect the metallic components that operate at harsh conditions of elevated temperatures and oxidizing environments. Thermally grown oxide (TGO) causes cracks formation in the top coat (TC) that may lead to spallation failure of TBC. This work investigates effect of pores and TGO thickness on crack initiation and propagation due to thermal mismatch between TBC layers. Image processing is used to convert an SEM image, including pores, into a finite element (FE) model. An FE model using XFEM implemented in ABAQUS was developed to investigate crack initiation and propagation for various TGO thicknesses considering the effect of plastic deformation of BC, TGO and substrate. Results show that presence of pores changes the critical sites for crack initiation from the TC/TGO interface to be around the pores within the TC. Crack initiation temperatures and crack lengths were found to be affected with both TGO thickness and pores.