We propose a concurrent multiscale method for fracture coupling two three-dimensional continuum domains. Fracture in both domains is treated by the extended finite element method. The coupling is based on the Arlequin method which blends the energies of different scales in a so called "handshake domain". To our knowledge, it is the first time that a three dimensional extended Arlequin method for fracture is reported for dynamic applications. To show the suitability of the proposed method, two crack problems with a very fine region around the crack front are solved. The results show that the method is capable of effectively coupling the two regions while having the same accuracy of the full scale model based on a very fine mesh.DFG, Qatar Na...