桁架式门机结构系统动态优化及可靠性研究

发布时间：2018-02-22 10:02

本文关键词： 桁架式门机瞬态分析交互式决策算法动态优化可靠性　出处：《西南交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：利用有限元分析软件ANSYS建立桁架式门机的有限元模型,研究了铁木辛柯梁理论与欧拉-伯努利梁理论的差异,得到铁木辛柯梁理论与欧拉-伯努利梁理论的适用范围。本文对桁架式门机结构进行静力分析,得到应力极值和应力分布情况。对结构杆件存在应力分布不均的状况进行了分析,探讨了制约结构轻量化设计的限制条件。通过动力学分析,得出最易引起结构共振的固有频率,提出利用交互式决策算法对桁架式门机进行动态优化,验证了此优化算法的可行性。经过优化,在减轻结构质量(10.9%)的同时提高了系统的动态性能(5.98%),同时结构杆件应力分布不均的状况有所改善。研究了冲击载荷作用下由于冲击振动等原因对结构产生的附加影响。通过对结构系统进行瞬态动力学分析,得出起重机在起吊货物瞬间产生的冲击振动对结构应力的影响程度,并验证了传统算法中以起升冲击系数的形式补偿这种动力效应的精度,同时提取等效载荷。基于强度失效理论的可靠性计算方法,探讨了不同载荷作用次数与结构系统的可靠度之间的函数关系。建立桁架式门机结构系统可靠性模型,利用等效载荷对结构系统进行分析计算,得出冲击载荷、移动载荷等多重载荷对系统可靠性的影响。本文通过理论分析,结合APDL(ANSYS Parametric Design Language)技术,对桁架式门机结构进行了可靠性方面的探讨,并提出了一种新型的多目标优化算法,为起重机结构设计提供了一种新的途径。
[Abstract]:The finite element model of truss portal crane is established by using the finite element analysis software ANSYS. The difference between the theory of Temocco beam and that of Euler-Bernoulli beam is studied. The application range of Temocco beam theory and Euler-Bernoulli beam theory is obtained. The static analysis of truss gantry structure is carried out in this paper. The stress extremum and stress distribution are obtained. The condition of uneven stress distribution in structural members is analyzed, and the limiting conditions that restrict the lightweight design of structure are discussed. By dynamic analysis, the natural frequency of structural resonance is obtained, and the dynamic optimization of truss door crane by interactive decision algorithm is put forward, which verifies the feasibility of this optimization algorithm. At the same time, the dynamic performance of the system is improved by 5.98 and the uneven stress distribution of the structural members is improved. The additional effects of shock vibration on the structure are studied. The transient dynamic analysis of the structure system is carried out. The influence of the impact vibration of the crane on the structure stress is obtained, and the accuracy of the traditional algorithm to compensate the dynamic effect in the form of lifting impact coefficient is verified. At the same time, the equivalent load is extracted. Based on the reliability calculation method of strength failure theory, the functional relationship between the different loading times and the reliability of the structural system is discussed, and the reliability model of truss gantry crane structure system is established. The effect of multiple loads such as impact load and moving load on the reliability of the structure system is analyzed and calculated by using equivalent load. Through theoretical analysis and APDL(ANSYS Parametric Design language technology, this paper discusses the reliability of truss gantry structure, and puts forward a new multi-objective optimization algorithm, which provides a new way for crane structure design.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH21;TB114.3

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