A new free surface scheme for 1-D and 2-D numerical calculation of elastic-plastic flow is proposed to study e-beam or X-ray radiation,high velocity impact and blast.Some numerical examples given here show that the pressent free surface scheme is more suitable than Richtmyer's for solving thermal-mechanical effects of material subjected to e-beam or X-ray pulse radiation.It is proved that this scheme should give a third-order accuracy.

Using Monte-Carlo method, the electon transport and energy deposition in material are calculated. Combining with the elastic plastic hydrodynamic equations, numerical results cover the thermal mechanical effect and the blowoff impulse on Ly-12 Al induced by irradiating of the impulsive electrobeam which caused by ‘FLASH Ⅱ’-an impulsator of relativistic electron beams. these results are compared with the experimental data.

Electron transpart characteristics and energy deposition in the medium are calculated by using Monte-Carlo method. Based on the calculations thermal-mechanical effect on material bombarded by electro-beam can be investigated by solving the coupled fluid-plastic equations. Several numerical simulations of the effect in Al have been carried out as illustration of the present method. Calculated results coincide satisfactorily with the experimental data.