This paper analyses the collision resistance of the X-core structure. The analysis includes a detailed investigation of the non-linear plate and laser weld material behaviour using optical, full-field strain measurements. The resulting material relationships are implemented into the finite element model. Furthermore, the finite element model includes the influence of the ship motions to accurately predict the collision resistance. The verification of the numerical results is done by a comparison of the experimental and numerical force versus penetration curves and by a comparison of the deformed geometries. The latter is achieved through a digitised three-dimensional model of the post-experimental X-core structure. As a result, the accuracy of the collision simulations is presented and discussed.