Abstract：In this work, a cohesive zone model (CZM) is developed by means of embedding cohesive elements into FEM continuum elements, so that the energy dissipated in the separation of the fracture surfaces during spalling can be taken into account. The proposed numerical model is used to predict the rear free surface velocity profiles in flyer plate impact tests for steel samples under different impact velocities. The influences of the characteristic parameters of CZM on the computed free surface velocity profiles are discussed in detail. The simulation results indicate that the exponential damage evolution of cohesive elements is satisfied to describe the energy dissipated behavior during spalling. Once the characteristic parameters are calibrated by a reference test, the same parameters of CZM can be used to successfully predicte other free surface velocity profiles under different impact velocities. A satisfied agreement between the predictions and the experimental data , especially the oscillation frequency and decay of the free surface velocity profiles in the later phases of spalling. The results thus demonstrate that the proposed cohesive law is appropriated to characterize the energy dissipated behavior during spallation.
2012, Vol. 33 
