The design of an impulse meter to characterise vertical blast loads

[摘要] ENGLISH ABSTRACT: This report covers the development of an impulse meter for the characterization ofvertically applied blast loads in terms of total impulse transferred to a test structure. TheSpring-Mass Impulse Meter (SMI) was developed for the Blast Impact andSurvivability Research Unit (BISRU) based at the University of Cape Town (UCT). TheSMI was developed specifically for the measurement of impulses due to the momentumtransfer between blasts from soil buried charges and thin plates or small structures forlandmine related research. Several impulse measurement methods and concepts wereinvestigated and compared; the SMI was shown by qualitative comparisons to be theconcept that is most likely to satisfy BISRU's needs. The resulting SMI structure wasanalysed using Finite Element Analysis to confirm its structural integrity and acceptabledynamic response. The system dynamics and impulse response were analysed andoptimised using single degree of freedom spring-mass models. The SMI wasmanufactured, installed at UCT and also calibrated against a horizontal ballisticpendulum with a series of bulge tests. The calibration tests were done on plates withthicknesses ranging from 1.6 mm to 4 mm using PE4 plastic explosive as the impulsesource. Tests results showed the SMI to be capable of measuring impulses between10 N·s and 75 N·s with accuracy and repeatability similar to that of a ballisticpendulum.

[发布机构] Stellenbosch University