夹芯复合材料耐压壳舱段仿真计算及临界环肋高度确定方法研究

本文基于Abaqus有限元仿真软件,针对夹芯复合材料耐压壳舱段有效支撑的临界环肋高度问题进行了计算分析.论文首先结合相关试验结果,对仿真计算方法进行了验证.然后建立了共3个系列15个有限元模型,对在不同腹板铺层方式、不同尺寸的T型截面舱段环肋结构支撑下的夹芯复合材料耐压壳长舱段进行了临界屈曲载荷的计算,并得到以下结论.通过设置环肋可以有效地增加夹芯复合材料耐压壳长舱段的稳定性.当环肋的支撑刚度增加到一定值时,长舱段的屈曲模态会从整体屈曲转变为被环肋边界限制在舱段范围内的的多段的单分段屈曲模态,该环肋高度称为环肋有效支撑的临界环肋高度.环肋有效支撑的临界高度可以通过屈曲载荷随腹板高度的增长趋势图中两段直线的交点位置来确定.当环肋高度大于临界环肋高度时,结构的分段屈曲载荷与环肋的属性关系不大,主要与夹芯圆柱壳自身的尺寸与材料属性有关.经计算,本文所分析的夹芯复合材料耐压壳结构其分段自身屈曲载荷可达7.0MPa.

A simulation study on the section rib-ring in sandwich composite pressure shell and a calculation method for the critical height

In this research, the Abaqus finite element simulation software was adopted to calculate and analyze the critical height of the section rib-ring in supporting the sandwich composite pressure shell. First, the simulation method was verified by comparing the simulated result with related experimental results. Then three series of T section rib structure models were established in different layer methods and different sizes to calculate their capability to support sandwich composite pressure shell long cabin section. The buckling loads of these models were carried out and the conclusions are drawn as follows. By setting rib-ring, the stability of the long section pressure shell can be effectively increased. When the rib-ring support stiffness increased to a certain value, the overall buckling mode of the long section would be limited by the connection section with the rib-ring as boundary and turn into several single section buckling modes. The certain value of the rib-ring height is called critical height, and the calculation method is given in this paper. When the rib-ring support stiffness is greater than the critical stiffness, the critical buckling load of the structure has little relation to the properties of the rib-ring, while it is related to the size and material properties of the sandwich cylindrical shell. This critical buckling load of the structure is called section buckling load, which can reach 7.0 MPa for the sandwich composite pressure shell structure analyzed in this paper.