周期对称性在叶盘结构瞬态响应求解中的应用

Application of cyclic symmetry property in transient forced vibration of bladed disks

研究了利用结构周期对称性计算叶盘结构瞬态响应的方法.首先用ANSYS得到扩充扇区的刚度和质量矩阵,通过周期对称边界上节点的对应关系得到扩充扇区到基本扇区的转换矩阵.利用叶盘结构中各扇区所受载荷的特点,得到任意时刻载荷的空间分布,并对其进行Fourier展开,以得到周期对称模型的载荷.采用Newmark法进行时域积分,利用多波前法求解线性方程组.最后以一个叶盘结构的有限元模型作为算例,验证了文中方法的正确性和有效性.

A method for transient response calculation of bladed disks was presen ted using the cyclic symmetry property of the structure.The stiffness and mass m atrices of expanded sector were generated by ANSYS.The transformation matrix fro m expanded sector to basic sector was obtained using the corresponding nodes on sector boundaries.The load vector for the cyclic symmetric model was obtained fr om the spatial Fourier transformation of the forces on every sector.The transien t responses were calculated using Newmark method,and multi-frontal method was se lected as the direct equation solver.A bladed disk with 12 sectors was applied a s the numerical example,indicating that the proposed method is effective for tra nsient analysis of bladed disks.