基于全隐式紧耦合算法的气动弹性数值仿真

为进行气动弹性问题的计算,提出了一种全隐式紧耦合算法,在子迭代过程中分别采用LU\|SGS隐格式和隐式线性多步法交替求解气动和结构方程,以获得物理时间域的高精度解。一种径向基函数和超限插值结合的方法被用来进行气动网格的快速变形。运用该算法,进行了Isogai wing和AGARD 445.6 wing的颤振分析,颤振边界的计算结果与文献值和实验值较符合,表明该全隐式紧耦合算法能够有效地计算气动弹性问题。
     

A partition of unity level set method with moving knot CS-RBFs for optimizing variable stiffness composites

A partition of unity level set method with moving knot Compactly Supported Radial Basis Functions (CS-RBFs) is proposed for optimizing variable stiffness composite structures. The iso-contours of a level set function are utilized to represent the curved fiber paths, and the tangent vector of the iso-contour defines the orientation of fiber. The level set function of the full design domain is constructed according to the Partition of Unity (POU) method by a set of local level set functions defined on an array of overlapping subdomains, and they are constructed by using the CS-RBFs. The positions of knots are iteratively changed during the optimization to improve the performance of composite structures. Several examples of compliance minimization are presented.