Through the observation of photomicrographs of the resin regions around Z-pin ends in the X-cor sandwich the basic hypothesis of the elliptic configuration of resin regions were proposed.The parametric equations for describing the microscopic structures of resin regions were given.Then the geometric analysis model of X-cor sandwich integrated the structural design and the geometric analysis was established.According to the geometric analysis model the finite element software ANSYS was used to establish the finite element model of the shear modulus of X-cor sandwich and the shear modulus was calculated.The effects of changing Z-pin angle

diameter and density on the shear modulus of X-cor sandwich were analyzed.The numerical analysis results indicate that the shear modulas of X-cor sandwich increases as the Z-pin angle increases

and as the Z-pin diameter and density increase the shear modulus both increase.Via the analysis of finite element model

the influencing trends of parameters of X-cor sandwich to the shear modulus are achieved and the error range is ±10%.So the rationality of the proposed finite element model is verified and the finite element model can be used to forecast the shear modulus of X-cor sandwich.