Blast impulse variations in the NATO STANAG 4569 testing procedures for armoured vehicle protection level evaluation

The standard used in NATO countries for armoured vehicle protection level evaluation is the STANAG 4569 AEP-55. There are two options for test conditions described in the procedure. Both test conditions are equally accepted to be used in assessing the compliance of the vehicle mine protection requirements. A test condition that applies surrogate mine in a steel pot test condition requires less complicated preparation, which is opted for by many compared to the buried setup. However, characteristics of blast output from buried in-soil test setup would possibly alter the blast loading to the vehicle's undercarriage. There could be significant variations in blast intensity and other effects in both test setups. This study conducted a small-scale experimental test to measure the effects of global and localise impact caused by a buried explosive in Sandy Gravel and Steel Pot test conditions. Results showed global average energy transfer and average global peak acceleration in Sandy gravel test condition are respectively 40 % and 21 % higher than in Steel Pot. The localised effect showed that residual deformation is higher by 5% in Steel Pot compared to Sandy Gravel tests. However, average peak deformation and average local peak acceleration in Sandy gravel are 8% higher compared to steel pot.