Abstract: Nowadays there is a need to develop special techniques to protect the critical infrastructures from exposing events. The use of real explosive material on the experiments is very expensive and a lot of security measures should be taken. Especially in the case that the test should be repeated many times in order to obtain accurate results is almost impossible to perform the real explosive experiments. That for came up the idea of a blast simulator that can reproduce an explosive charge in a most economic and controllable way. The setup of such an apparatus is a very difficult task where many details should be studied. The most appropriate way to study the several parameters that influence the performance of the blast actuator is to use numerical simulation techniques. This report performs numerous numerical investigations and gives answers to many questions concerning the performance of the impacting mass of the blast actuator on the specimen. The numerical results have been generated with the fast explicit transient dynamic finite element code EUROPLEXUS.