从提高结构稳定性的基本理论出发, 给出了神光Ⅱ升级惯性约束聚变(ICF)靶室系统的初始结构方案, 并利用有限元方法(FMM)对其进行模态分析, 找出靶室系统初始结构的薄弱环节, 进而对初始方案进行结构稳定性优化, 最后对优化方案进行稳定性分析。优化与分析结果表明, 当靶室的壁厚T为50 mm, 靶室支脚与垂直方向夹角θ为27.2°, 支脚之间布置厚度B为20 mm筋板, 筋板空间距离H为120 mm时, 靶室系统可以获得很好的稳定性, 随机激励作用下的平移均方根值为1.425 μm, 满足神光Ⅱ升级装置对靶室系统的稳定性指标。

Based on the fundamental theory of improving structure stability, an initial structure of target chamber system was designed. With finite-element method (FEM), modal analysis was proceeded for the target chamber system, thus the weak links were found. Based on the weak links of initial structure, the initial structure of target chamber system was optimized. At last, the stability analysis was proceeded for the target chamber system. The results of analysis indicates that the target chamber system can obtain good stability, when the thickness of target chamber (T) is 50 mm, the angle of support leg to vertical direction (θ) is 27.2°, the rib with thickness B of 20 mm is added between the support legs, and the space distance of the rib is 120 mm. The translational displacement root-mean square (RMS) is 1.425 μm which satisfies the stability requirement of target chamber system in SGⅡ upgrade facility.