圆形料场堆取料机金属结构分析及优化

发布时间：2018-05-15 08:56

本文选题：圆形堆取料机 + PRO/ENGINEER　；参考：《吉林大学》2012年硕士论文

【摘要】：堆取料机是一种自动化程度较高的大宗散料装卸设备，目前堆取料机按照其结构布局可以分为斗轮堆取料机、圆形料场堆取料机和StakRake（即欧洲耙式堆取料机）等几种类型[1]，主要用于储煤厂、发电厂、港口码头等场所的散料混匀与堆存。内蒙古热电厂空冷机组工程堆取料机是一种在圆形料场内作业的大型机械设备。与StakRake不同的是，它可以同时进行堆、取料作业。圆形料场是一种由半球形钢架穹顶封闭的储料系统，储料系统的核心是位于料场中心的圆形堆取料机。圆形料场具有占地面积小、自动化程度高、能够抵抗恶劣天气以及环保功能显著等优点。随着人们环保意识的逐渐提高，圆形料场越来越受到人们的重视，发展空间十分广阔。该圆形堆取料机的设计方案主要参考国外相关设备的布局。设计人员结合料场的具体情况，制定出初始的结构设计方案。为了确保设计方案的合理性和可靠性，需要对堆取料机进行刚度校核、强度分析及动态特性校核，以达到优化设计方案，减少设计成本的目的。 PRO/ENGINEER是美国参数技术公司开发的大型参数化设计软件，该软件以模块的形式集成了三维建模、结构分析、CAD出图等功能[2]。PRO/ENGINEER中的子模块MECHANICA是一个集线性静力分析、几何非线性分析、动态特性分析、疲劳分析等多种分析功能于一体的有限元计算模块。MECHANICA采用更为智能的P-method技术，可以精确的计算大应力梯度区域的应力分布，并且可以自动进行收敛求解。本次分析主要以PRO/ENGINEER软件为平台，根据初始设计方案的图纸建立堆取料机的三维模型，并针对组合工况的计算要求对模型进行参数化驱动。有限元模型的主体结构采用板单元建模，拉杆、斜撑、围板以及型钢桁架采用梁单元建模。铰接位置、回转支承以及钢丝绳卷扬机构采用杆梁组合单元进行简化模拟，以降低计算规模。组合工况的计算以批处理的形式进行，共完成了自重、正常堆取、超载堆取三个工况下的线性静力分析。每种工况又分别计算了刮板臂变幅（水平、上仰41°和下俯7.38°）与堆料机回转（夹角180°和135°）的六种组合姿态。对设备进行了18种组合工况下的静强度分析、刚度校核以及稳定性分析，并结合静力分析的结果给出了堆取料机结构的初步改进建议。堆取料机在工作过程中除了受到静载荷作用以外，还受到很多冲击载荷以及其他外部激励的影响。本文对斗轮机的金属结构进行了动态特性分析，提取出结构前若干阶的振型，并将堆取料机的固有频率与有可能使设备产生共振的震源频率进行了对比分析，为设计人员合理改进设计方案提供依据。为了进一步提高材料的利用率，结合第二章结构静力分析的结果，对应力盈余较大的部位进行了堆料机配重臂架进行了轻量化设计，给出了优化建议，进一步挖掘材料性能，使其得到更好的发挥。从堆取料机的线性静力分析结果可以看出，堆取料机主结构应力都在180MPa以下。其中堆料配重臂架主结构应力在120MPa以下，应力盈余较大。个别尖点位置以及搭接位置存在大应力区域，但区域范围不大，不会对结构造成破坏。刮板臂最大挠度为-13.6mm，挠度最大值符合设计标准。堆取料机的模态分析主要通过PRO/MECHANICA模块的FEM模式借助ANSYS求解器来完成。模态分析采用分块兰索斯法提取了结构前十个阶次的模态振型和相应的固有频率，，结合堆取料机的外部激励分析可以看出外部激励的频率与结构固有频率相差较大，不会对结构造成共振破坏，进一步确保了设计方案的安全性。结合静力分析的结果，对应力裕度较大的堆料配重臂进行了减重优化，共节省材料3.4t。优化后的取料配重架主结构应力提高到140MPa，但仍在许用范围之内。对该圆形料场堆取料机进行CAE分析，可以及时的发现设计方案中的缺陷并对初始方案的改进提出改进建议，缩短产品开发周期，降低了开发成本。
[Abstract]:The invention relates to a bulk material loading and unloading device with high automation degree , which can be divided into a bucket wheel stacker , a circular material yard stacking machine and a StakRake ( i.e . , a European rake stacker ) , and the like .

PRO / ENGINEER is a large - scale parametric design software developed by U . S . parameter technology company . The software integrates three - dimensional modeling , structural analysis , CAD drawing and so on in the form of modules . This paper mainly takes PRO / ENGINEER software as the platform , sets up the three - dimensional model of pile - taking machine according to the drawing of the initial design scheme , and makes parametric drive to the model . The main structure of the finite element model is modeled by the plate unit , the pull rod , the diagonal brace , the surrounding plate and the steel truss are modeled by the beam unit . The articulated position , the slewing bearing and the steel wire rope hoisting mechanism adopt the bar beam combination unit to simplify the simulation to reduce the calculation scale .

The calculation of the combined working condition is carried out in batch mode , and the linear static analysis of dead weight , normal heap and overload is carried out . Six kinds of combined postures of scraper arm amplitude variation ( horizontal , up to 41 掳 and down - down 7.38 掳 ) and pile turning ( included angle : 180 掳 and 135 掳 ) are calculated respectively . The static strength analysis , stiffness check and stability analysis are carried out on the equipment under 18 combined conditions , and the preliminary improvement suggestions for the structure of stacker are given in combination with the results of static analysis .

In this paper , the dynamic characteristic analysis of the metal structure of the bucket turbine is carried out , the vibration modes of several orders before the structure are extracted , and the natural frequency of the stacker is compared with that of the source frequency which can make the equipment resonate , so as to provide the basis for the reasonable design of the design personnel .

In order to further improve the utilization ratio of materials , combined with the results of the second - chapter structure static analysis , a lightweight design of the counterweight arm of the stacker was carried out on the parts with large stress surplus , and the optimization suggestion was given , and the material properties were further excavated to better play .

The results show that the stress of the main structure of stacker is less than 180 MPa . The stress of the main structure is less than 120MPa , and the stress surplus is large . The maximum deflection of the scraper arm is - 13.6mm . The maximum deflection maximum meets the design standard .

CAE analysis is carried out on the material taking machine of the circular material yard , the defects in the design scheme can be found in time and the improvement of the initial scheme is proposed , the product development cycle is shortened , and the development cost is reduced .

【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH246

【参考文献】