Abstract:The numerical manifold method (NMM) can tackle both continuous and discontinuous with high efficiency and accuracy. Due to the independence of the mathematical cover system and the physical domain, the NMM is very suitable for crack problems. At the same time, the n-sided elements (n>4) are also very attractive due to their greater flexibility in meshing and higher accuracy, compared with the frequently used triangular and quadrilateral elements. In the present paper, the NMM, combined with the regular hexagonal mathematical elements, is applied to solve linear elastic complex crack problems. Through the interaction integral, the stress intensity factors at concerned crack tips are computed in typical numerical examples, and the results agree well with the reference solutions. In addition, the accuracy on different mathematical elements is also investigated and the results show that the accuracy on hexagonal elements is higher than that on regular triangular and quadrilateral elements.