论文部分内容阅读
针对新一代重型运载火箭及大型飞机中存在的超大直径网格加筋壳结构,提出了一种快速屈曲分析方法。首先,基于渐进均匀化法的快速数值实现方法和瑞利-里兹法建立了快速屈曲分析框架,并通过与算例中等效刚度法屈曲载荷结果进行比较,验证了本文方法具有较高的预测精度。然后,对比了3种结构尺寸下网格加筋壳屈曲分析效率,结果表明本文方法不受结构尺寸影响,平均计算时间仅为6s,凸显了其用于超大直径结构分析的高效性。进而,基于本文方法对4种传统加筋构型及2种新型多级加筋构型进行屈曲载荷评估,其预测误差均在3.0%以内,表现出广泛的构型适用性。在此基础上,通过优化设计的方法对比了上述6种加筋构型的承载效率,优化结果表明本文提出的多级三角型加筋构型最具承载优势,相较于初始方案取得了82.2%的承载增幅,可作为一种新型超大直径网格加筋壳结构储备。
Aiming at the super-large-diameter grid stiffened shell structure in a new generation of heavy-duty launch vehicles and large aircraft, a fast buckling analysis method is proposed. First of all, a fast numerical method based on progressive homogenization method and Rayleigh-Ritz method are used to establish a fast buckling analysis framework. Compared with the results of buckling load of equivalent stiffness method in the example, it is verified that this method has high prediction Accuracy. Then, the buckling efficiency of the stiffened grids under three kinds of structural dimensions is compared. The results show that the proposed method is not affected by the size of the structure, and the average calculation time is only 6s, which highlights the high efficiency of the proposed method for analyzing large-diameter structures. Furthermore, based on the method proposed in this paper, the buckling loads of four kinds of traditional reinforced structures and two kinds of new multi-layer reinforced structures are estimated to be within 3.0%, showing a wide range of configuration applicability. On this basis, the optimal design method was used to compare the loading efficiencies of the six kinds of reinforced structures mentioned above. The optimized results show that the multi-grade triangular reinforced structure presented in this paper has the most advantage of bearing capacity. Compared with the initial design, % Of the load increase, can be used as a new type of large diameter grid stiffened shell structure reserve.