Multiscale study on the properties and crack propagation of 2D woven SiCf/SiC with pores using elastoplastic phase field

To understand the effect of processing and prefabricated pores on 2D woven SiCf/SiC composites (2DW-SiCf/SiC), their crack propagation and mechanical response under tension load at meso- and macro- scale are investigated by a promising elastoplastic phase field method (EPPFM). Of much interest, the computational results are well consistent with the available experimental results, verifying the reliability of EPPFM. A significant dependence on pores is observed in the relationship between the strength, Young's modulus, work of fracture of 2DW-SiCf/SiC and porosity when pores exist solely in the matrix out of yarns, and both in the matrix and yarns, respectively. Moreover, the more dangerous processing pores at mesoscale near yarn are attributed to the inconsistent deformation of the yarn and matrix. Finally, the EPPFM is used for the effect of geometry size on the joint failure mode of 2DW-SiCf/SiC plate with prefabricated open holes under pin-loading. Of importance, the more safe bearing failure mode occurs in 2DW-SiCf/SiC plate when edge distance-to-hole diameter ratio and width-to-hole diameter ratio are greater than 1.5 and 3, respectively.