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提出了一种基于混合边界模态综合的复杂结构有限元模型修正方法。其主要步骤包括:(1)子结构划分,根据结构形式划分待修正区域,得到子结构和残余结构;(2)缩聚和装配,利用混合边界模态综合法,将子结构内部自由度集缩聚至混合边界自由度集,得到子结构缩聚矩阵,并与残余结构的系统矩阵进行装配;(3)修正,基于灵敏度分析方法,对装配后的残余结构进行参数修正。将该方法应用于航空发动机外机匣的精细化有限元建模及模型修正研究,针对局部连接结构参数修正,子结构模型修正方法的参数收敛后最大误差为0.64%,其计算效率提高了5.15倍。算例结果表明,该方法在保证修正精确度的同时,能提高大规模复杂结构有限元模型修正的计算效率。
A new method to correct the complex structure finite element model based on mixed boundary modal synthesis is proposed. The main steps are as follows: (1) Sub-structure division, sub-structure and residual structure are divided according to structure form; (2) Polycondensation and assembly, the mixed boundary modal synthesis method To the mixed boundary degree of freedom set, the substructure polycondensation matrix is obtained and assembled with the system matrix of the residual structure; (3) The correction is performed on the residual structure after assembly based on the sensitivity analysis method. The method was applied to the finite element modeling and model revision of aeroengine case. Aiming at the modification of the parameters of the local connection structure, the maximum error of the parameters of the substructure model after convergence was 0.64%, and the computational efficiency was improved by 5.15 Times The experimental results show that this method can improve the computational efficiency of the finite element model of large-scale complex structures while ensuring the accuracy of the correction.