复合材料盒段结构屈曲稳定性分析及优化技术

随着计算机科学和有限元技术的发展,屈曲稳定性问题有限元数值求解技术已经比较成熟,但是在大型飞机结构工程应用中还是由于计算量大、收敛困难而受到限制.特别是在需要反复迭代计算的优化过程中,更是受到该问题的困扰.针对飞机机翼结构中的典型盒段结构,本文研究了基于ANSYS子模型的考虑线性屈曲稳定性约束的优化方法,以及非线性数值计算技术.研究表明,在相同精度要求的条件下,位移求解模型所需网格尺寸可远大于屈曲稳定性模型.本文利用验证结论,采用网格尺寸100mm建立粗模型进行位移求解并确定危险部位,采用网格尺寸10mm建立子模型进行屈曲稳定性求解,从而完成全结构的优化设计.此方法计算效率高,在非线性屈曲稳定性求解以及优化迭代计算中优势明显.

Analysis and Optimal Design of the Buckling Stability of a Composite Box

With the development of computer science and finite element method,the finite element solution to buckling stability has becoming mature.But it is still restricted to the large and complex structures,because of the computation spending and convergence.In the process of iterative computation for optimal design,this disadvantage is especially severe.In the optimal design of large composite wing subject to buckling stability constraint,the typical box structure of the wing is built to research the grid size requirement of computation precision and efficiency,showing that the grid size for displacement solution can be larger more than for buckling solution with the same requirement of precision.In this paper,the coarse model is meshed with the element size of 100mm to obtain the displacement solution,which is used to decide where the sub-model with the element size of 10mm is built to gain the buckling solution.By this method,the optimal design of the wing is finished efficiently and accurately.