Comparison of blast pressure mitigation in rubber foam in a blast wave generator and field test setups

The blast wave mitigation efficiency of open-cell natural rubber foam is compared in laboratory and field test setups. Blast wave mitigation is evaluated in terms of the peak overpressure and positive phase impulse. Piezoelectric pressure sensors are flush-mounted with the top surface of the base plate of the composite material in field tests and at the end plate of the blast wave generator (BWG) in laboratory tests to measure the incident pressure and pressure transmitted through the foam. The blast wave is generated by means of detonating high explosives in field tests and by bursting the diaphragm in the BWG in laboratory tests. It is observed from the test results that the pressure transmitted through foam and the corresponding impulse values depend on the shape of the loading wave and also on the test configuration used in the laboratory method. Therefore, it can be concluded that laboratory tests using the BWG only give a trend of the transmitted pressure and so can be used, at the best, for comparative evaluation of mitigation of the blast wave passing through different materials. However, actual values of the transmitted pressure and impulse can only be obtained in field tests with blast loads generated by using explosives.