门式起重机金属结构可靠性稳健优化设计研究

发布时间：2018-08-05 11:01

【摘要】：门式起重机作为一种大型起重运输设备用途十分广泛,金属结构是门式起重机的重要组成部分,一般占据整机重量的60%以上,主要作用是承受和传递作用在起重机上的各种载荷,其设计水平直接影响着起重机的工作性能及安全性能。有限元分析理论、确定性优化设计方法的应用一定程度上改善了传统设计存在的问题,但由于起重机在设计、制造、使用过程中存在诸多的不确定因素的影响,确定性优化结果并不一定符合工程实际对安全性的要求,将可靠性理论和稳健设计方法应用于起重机结构优化设计中,达到有效平衡产品使用安全性能和经济性能的设计效果。同时,为降低计算成本、提高计算效率,提出用代理模型替代有限元仿真程序的调用进行优化的方法。本文以某型号的门式起重机金属结构为研究对象,首先,编写APDL命令流程序建立满足准确性要求的参数化有限元模型,进行静力学分析;然后,运用Isight软件集成Ansys软件,通过实验设计方法获取反映起重机关键设计参数和响应关系的样本数据,运用RBF-NN代理模型技术拟合样本点构建高精度的结构性能函数和极限状态函数代理模型;最后,基于极限状态函数代理模型,采用随机摄动技术获取结构可靠度指标作为约束,并在约束条件中加入灵敏度附加项进行稳健设计,最终达到可靠性稳健优化设计目的。设计结果相比于一般优化设计方案,在达到减轻自重目的的情况下,有效提高了设计方案的可靠性和稳健性,具有一定的实践意义。
[Abstract]:Gantry crane is widely used as a kind of large crane transportation equipment. Metal structure is an important part of gantry crane, which occupies more than 60% of the weight of the whole crane. The main function is to bear and transmit all kinds of loads acting on the crane, and its design level directly affects the working performance and safety performance of the crane. The application of finite element analysis theory and deterministic optimization method improves the problems existing in traditional design to some extent, but there are many uncertain factors in the design, manufacture and use of crane. The deterministic optimization results do not necessarily meet the requirements of engineering practice for safety. The reliability theory and robust design method are applied to the optimization design of crane structure to achieve an effective balance between the safety performance and the economic performance of the product. At the same time, in order to reduce the calculation cost and improve the computational efficiency, an optimization method is proposed to replace the finite element simulation program with the agent model. In this paper, the metal structure of a certain type of gantry crane is taken as the research object. Firstly, the APDL command flow program is compiled to establish the parameterized finite element model to meet the accuracy requirements, and then the static analysis is carried out, and then the Ansys software is integrated with the Isight software. The experimental design method is used to obtain the sample data reflecting the key design parameters and response relationship of crane, and the RBF-NN agent model is used to fit the sample points to construct the high precision structural performance function and limit state function agent model. Based on the agent model of limit state function, random perturbation technique is used to obtain the structural reliability index as the constraint, and the sensitivity additional item is added to the constraint condition for robust design. Finally, the reliability robust optimization design is achieved. Compared with the general optimal design, the design results can effectively improve the reliability and robustness of the design scheme, and have a certain practical significance.
【学位授予单位】：太原科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH213.5

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