大型航空结构有限元数值模拟方法研究
Study on Finite Element Modeling for Large Aircraft Structures

利用试验数据，针对大型航空结构，系统地研究了"自然网格"模型和细节模型对结构分析的影响。采用"自然网格"方法建立翼身组合体有限元模型，计算得到机翼外端部变形误差7.46%（与试验比较），外翼上壁板试验与分析一致性评估误差带10%以内的应变片约占总数的80%，中央翼上壁板约占70%。采用以壳元模拟为主细化网格建模方法建立全机结构有限元模型，计算得到机翼外端部变形误差为1.87%，外翼和中央翼上壁板试验与分析一致性评估误差带10%以内的应变片均占总数80%以上，这表明细化模型能更精确地模拟结构的刚度和预估结构的传载分配和应力/应变响应，预判危险部位，为进一步有限元细节分析或破坏分析提供准确的边界。
The method of natural mesh and refined model for structural analysis is considered based on experimental data. Natural mesh method is employed to build a wing-body FEM model, which results in a relative error 7.46% of wing-tip displacement. The relative error between analysis and test results which are within 10% takes up about 80% of whole points on upper panel of outer wing; whereas, it takes up about 70% on upper panel of central wing. Shell elements are mainly used to establish a refined model for a full-scale aircraft, which obtains the relative error 1.87% of wing-tip displacement. The relative error between analysis and test results which are with 10% takes up over 80% on upper panels of central and outer wing. The results show that the refined model can accurately simulate the stiffness, load distribution and global stress/strain response. Therefore, the refined model could also be used to predict zones of interest for more detailed analysis, and provide the failure boundarys