基于缩尺模型的桥式抓斗卸船机安全评估研究

发布时间：2018-05-27 22:18

本文选题：卸船机 + 相似准则　；参考：《广东海洋大学》2014年硕士论文

【摘要】：桥式抓斗卸船机在作业过程中存在反复启动和制动，各结构件经常承受比较强烈的振动和冲击，所以，整体钢结构的强度计算和稳定性控制变得非常重要。但是，由于卸船机结构庞大、工作环境恶劣，受到人力、经济和设备能力的限制，现场试验难以组织。为了以较低的试验成本，为卸船机的设计、制造、维护和维修等提供相关理论依据和试验数据，本论文以湛江港在役的2250t/h型桥式抓斗卸船机（以下简称卸船机）为具体研究对象，对其开展静力与动力相似理论分析、缩尺模型设计与制作、三维有限元建模与仿真以及模型试验等系统研究。具体方法、结果及结论如下：通过大量收集国内外港口起重机的相关资料，系统了解港口起重机研究现状和发展趋势；实地勘查2250t/h型桥式抓斗卸船机，掌握该型号卸船机的工作原理、结构组成、主要技术参数和载荷类型等。在此基础上，根据相似原理，运用量纲分析法推导该卸船机在多种因素影响下的静力和动力相似准则，为其缩尺模型的设计、制作以及相似性判定提供理论依据。综合卸船机的静力和动力相似理论分析结果，，完成其1:40缩尺模型的设计，并用Pro/E画出整体装配图和所有零件图，最后选用合适的型材制作卸船机钢结构的实物缩尺模型，为后面的模型试验研究打下了基础。在完成卸船机钢结构缩尺模型的设计和制作基础上，用Pro/E分别建立了卸船机原型及其缩尺模型的三维实体模型，并导入Ansys Workbench建立两者的三维有限元模型。首先，对两者分别进行了结构静力分析，比较两者的应力场和应变场，验证了静力相似准则的正确性；其次，对两者分别进行了模态分析，对比两者的模态振型和模态频率，验证了动力相似准则的正确性。以上研究为卸船机的设计、制造和维护提供相关理论依据。根据卸船机原型及其缩尺模型的有限元分析结果，对制作出的卸船机钢结构缩尺模型开展了应力应变特性研究和模态试验研究：通过应力应变特性试验研究，获得了模型俯仰梁与前拉杆上5个测点在满载荷的抓斗从抓料位置运动至卸料位置过程中的应变-时间历程曲线，将试验结果与有限元结构静力分析结果对比，吻合较好，验证了卸船机缩尺模型的合理性和结构静力分析结果的正确性；通过模态试验研究，获得了模型俯仰梁端部、主梁端部和塔架最高处三个测点的三向振动幅频特性曲线，识别得出各测点在三个方向上的固有频率，与缩尺模型的有限元模态分析结果吻合较好，验证了模型的合理性和模态分析结果的正确性。综合以上研究，得出结论：本文设计制造的卸船机缩尺模型符合静力和动力相似准则；可以将该模型上的试验数据推算到原型上，为卸船机的设计制造、维护维修和安全评估等提供数据。
[Abstract]:The bridge grab ship unloader has repeated starting and braking in the process of operation, and the structural parts often bear strong vibration and shock. Therefore, the strength calculation and stability control of the whole steel structure becomes very important. However, due to the large structure of ship unloader, the poor working environment and the limitation of manpower, economy and equipment, the field test is difficult to organize. In order to provide theoretical basis and test data for the design, manufacture, maintenance and maintenance of ship unloader at lower test cost, In this paper, the 2250t/h bridge grab ship unloader (hereinafter referred to as ship unloader) in Zhanjiang Port is taken as the specific research object, the static and dynamic similarity theory analysis, the design and manufacture of scale model are carried out. Three-dimensional finite element modeling and simulation as well as model test and other system research. The specific methods, results and conclusions are as follows: Through collecting a large number of relevant information of port crane at home and abroad, the research status and development trend of port crane are systematically understood, 2250t/h bridge grab ship unloader is investigated on the spot, the working principle and structure composition of this type ship unloader are grasped, Main technical parameters and load types etc. On this basis, according to the similarity principle, the static and dynamic similarity criteria of the ship unloader under the influence of many factors are deduced by using the dimensional analysis method, which provides a theoretical basis for the design, manufacture and similarity judgment of the scale model. Based on the analysis of static and dynamic similarity theory of ship unloader, the design of its 1:40 scale model is completed, and the integral assembly drawing and all parts drawing are drawn with Pro/E. Finally, the suitable profile is selected to make the physical scale model of the steel structure of ship unloader. It lays a foundation for the later research of model test. On the basis of the design and manufacture of the steel structure scale model of ship unloader, the 3D solid model of the ship unloader prototype and its scale model is established by Pro/E, and the 3D finite element model of the two models is established by introducing Ansys Workbench. First of all, the static analysis of the two structures is carried out, and the stress and strain fields are compared to verify the correctness of the static similarity criterion. Secondly, the modal analysis is carried out, and the modal modes and frequencies of the two are compared. The correctness of the dynamic similarity criterion is verified. The above research provides theoretical basis for the design, manufacture and maintenance of ship unloader. According to the finite element analysis results of the prototype of ship unloader and its scale model, the stress-strain characteristic and modal test of the steel structure scale model of ship unloader are studied. The strain-time history curves of five measuring points on the model pitching beam and the front pull bar in the course of the full load grab moving from the position of grab to the position of unloading are obtained. The experimental results are compared with the static analysis results of the finite element structure, and the results are in good agreement with the results of the static analysis of the finite element structure. The rationality of the scale model of the ship unloader and the correctness of the structural static analysis results are verified, and the three direction vibration amplitude-frequency characteristic curves at the end of the pitch beam, the end of the main beam and the top of the tower are obtained by modal test. The natural frequencies of the measured points in three directions are identified, which are in good agreement with the finite element modal analysis results of the scale model, and verify the rationality of the model and the correctness of the modal analysis results. Synthesizing the above research, it is concluded that the scale model of the ship unloader designed and manufactured in this paper accords with the criterion of static and dynamic similarity, and the experimental data on the model can be deduced to the prototype for the design and manufacture of the ship unloader. Provide data for maintenance, maintenance and safety assessment.
【学位授予单位】：广东海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U653.928.1

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