目的 针对内压与外部载荷联合失稳工况，对某型号D406A高强钢发动机壳体包装结构刚度、强度进行校核，确保构件满足服役强度要求。方法 采用有限元软件建立发动机壳体包装结构刚度、强度分析有限元模型，针对模型中不同网格疏密度以及不同结构单元类型进行数值仿真分析，确定最佳计算精度的屈曲变形模型参数。在壳体轴向载荷和外压分布载荷联合工况下开展屈曲分析和结构强度校核。结果 仿真表明采用单层实体网格的划分方式具有最佳计算精度，线性屈曲分析的最大应力值为67.2 MPa，特征值为2.322，结构剩余强度系数为1.39。结论 某型号D406A高强钢发动机壳体在服役环境下具有足够的刚度、强度和稳定性，满足发动机壳体包装结构工作的设计要求。

The work aims to verify the rigidity and strength of a certain D406A high-strength steel engine case for the combined instability condition of internal pressure and external load, and to ensure that the components meet the service strength requirements. The finite element software was used to establish an engine case stiffness finite element model, and numerical simulation analyses were carried out for different mesh densities and different structural cell types in the model to determine the parameters of the flexural deformation model with the best calculation accuracy. Under the combined working conditions of axial load and external pressure distributed load, the bending analysis and structural strength check were carried out, and the simulation showed that the single-layer solid mesh delineation had the best calculation accuracy, and the maximum stress value of the linear bending analysis was 67.2 MPa, the eigenvalue was 2.322, and the coefficient of structural residual strength was 1.39. In conclusion, the D406A high-strength steel engine case has sufficient strength, stiffness and stability under the service environment. It meets the design requirements of the engine case packaging structure.