Abstract: The estimate of ballistic properties of fiber composites is a very important problem to the ballistic composites research and application, especially to the structure design and process optimization. The two traditional methods to estimate ballistic properties of composites, physical model method and statistical model method, were analyzed through lots of testing. S.Tsai's physical model method was amended successfully on the basis of the error analysis. It was put forward that friction was a way composite panel absorbed energy, especially when the thermoeffect of thermoset composites was small. So energy absorption of friction drag should not be neglected. By dimensional analysis, the definition and evaluation methods of coefficient of friction drag item were set. The steps of calculating ballistic limit velocity by amended physical model method were revealed as well. The statistical model method was amended by including the influence of projectile velocity on energy absorption. Therefore, the error of the amended model was reduced. It was found that the statistical model method has more limits in practical use than the physical model method by comparison.

Key words: fiber compo sites, ballist ic compo sites, ballist ic lim it velocity