混凝土泵车臂架结构分析及拓扑优化

发布时间：2018-01-31 12:58

本文关键词： 混凝土泵车臂架有限元分析多体动力学分析模态分析结构应力试验拓扑优化　出处：《湖南大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着房地产与建筑行业的繁荣进步，混凝土泵车应用愈加广泛，市场发展空间进一步扩大。因此，对混凝土泵车关键部件尤其臂架系统的性能和质量要求越来越高。近年来，混凝土泵车臂架有两大发展趋势：首先是臂架越来越长，市场所主要需求的泵车也日趋向长臂架品种方向发展。其次是臂架越来越轻，在设计方面，新构造的大胆应用使得轻量化设计水平不断提高。然而一般来说，泵车臂架向大跨径及轻量化方向发展的同时，臂架固有频率趋于降低，更容易引起臂架的振动。高强钢和碳纤维增强复合材料(CFK)等材料对于应力集中和缺陷十分敏感，在振动引起的大应力幅值下，对设计和工艺的要求更为严格，处理稍有不周即会带来严重的后果。针对新的泵车臂架结构形式，其作业精度与动态可靠性如何是目前面临的现实问题，而如何在臂架向大跨径、轻量化发展的同时保证臂架优良的动静态特性，利用先进的动态优化设计方法提升臂架设计水平是长期关注的方向。本文拟针对中联-CIFA双品牌47米混凝土泵车臂架，研究新的结构形式下大跨径臂架的动态可靠性，并提出相应的设计建议；进而，基于动态优化设计理论，探索在保证臂架动静态性能的前提下，进一步进行轻量化设计研究，论文主要研究内容如下：（1）建立有限元分析模型，并基于传统的等效静载方法进行强度、刚度和稳定性的校核，以了解臂架的静力特性，然后根据混凝土泵车行业标准中对应力测试所规定的内容对臂架进行应力测试，以此验证仿真与计算分析结果的准确度。（2）建立柔性多体动力学模型遍历臂架可能的各种姿态，基于各节臂上不同区域的应力变化确定臂架的危险工况，及对危险工况下的臂架可靠性进行评估。（3）进行模态分析，以探索臂架的动态特性，，并寻找最有可能与泵送频率合拍的臂架姿态；然后对多种泵送工况、多种臂架姿态下臂架端部运动幅值和危险区域动应力进行预测，并据此评估臂架结构的动态可靠性。（4）最后综合运用拓扑、形状和尺寸优化设计技术，在保证结构件工作性能和安全性的前提下减轻其重量，探索极限轻量化要求下的泵车臂架结构形式。
[Abstract]:With the prosperity and progress of the real estate and construction industry, the application of concrete pump vehicles is becoming more and more extensive, and the market development space is further expanded. The performance and quality of the key parts of concrete pump vehicle, especially the boom system, are becoming more and more high. In recent years, there are two major trends in the development of concrete pump truck boom: first, the boom is getting longer and longer. The main demand of the market for pump cars is also increasingly toward the direction of long boom varieties. Secondly, the boom is getting lighter and lighter. In design, the bold application of the new structure makes the level of lightweight design continuously improved. However, generally speaking. At the same time, the natural frequency of the boom tends to decrease as the boom develops towards the direction of long span and light weight. Materials such as high strength steel and carbon fiber reinforced composites (CFK) are sensitive to stress concentration and defects under the high stress amplitude caused by vibration. The requirements of the design and process are more stringent, which will bring serious consequences if the treatment is not well done. In view of the new structure form of boom of pump car, how to operate precision and dynamic reliability is a realistic problem. However, how to ensure the excellent dynamic and static characteristics of the boom while developing to a large span and lightweight, and how to improve the design level of the boom by using the advanced dynamic optimization design method is a long-term concern. In this paper, the dynamic reliability of the long-span boom under the new structure is studied, and the corresponding design suggestions are put forward for the 47 m concrete pump boom of Zhonglian CIFA double brand. Then, based on the theory of dynamic optimal design, this paper explores the further research on lightweight design under the premise of ensuring the dynamic and static performance of the boom. The main contents of this paper are as follows: 1) the finite element analysis model is established, and the strength, stiffness and stability are checked based on the traditional equivalent static load method to understand the static characteristics of the boom. Then according to the content of stress test in the industry standard of concrete pump car, the stress of the boom is tested, and the accuracy of the simulation and calculation results is verified. (2) the flexible multi-body dynamic model is established to traverse the various possible positions of the boom, and the dangerous conditions of the boom are determined based on the stress changes in different regions of each arm. And to evaluate the reliability of the boom under dangerous working conditions. (3) Modal analysis is carried out to explore the dynamic characteristics of the boom and to find out the most likely attitude of the boom in keeping with the pumping frequency. Then the amplitude of the end motion and the dynamic stress of the dangerous region are predicted under various pumping conditions and various boom positions, and the dynamic reliability of the boom structure is evaluated accordingly. Finally, the optimum design technology of topology, shape and size is used to reduce the weight of the structure under the premise of ensuring the working performance and safety of the structure, and to explore the structure form of the boom of the pump vehicle under the requirement of extreme lightweight.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU646

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