Experimental Study On The Explosion Of A Cylindrical Drug Pack

Based on the similarity theory and the funnel theory,the velocity field of the free surface of the funnel and the regularities of distribution of the model stress field are studied in this paper.Based on the similarity theory and blasting theory,with the dimensional analysis method,the similarity criterion that column charge blasting funnel model test should follow is derived as well as the proper similar material proportion is selected for on-site model pouring through proportioning test of similar materials.A single-hole blasting funnel test on the testing field model is studied to analyze the effect of draw ratio and filling height on blasting effect.The result shows that the volume of blasting funnel with same draw ratio largens gradually by 45%?250%and the per explosive consumption gradually decreases by30%?71%with the increase of filling height,the volume of blasting funnel with same filling height largens by 14%?97%and the per explosive consumption gradually increases by 13%?75%with the increase of draw ratio.With the use of high-speed photography system on the free surface of column charge blasting funnel model and the collection of the initial blasting process of blasting funnel,the bulging movement contour curve and the change law of the kinematic velocity of the bulging free surface center is obtained.The results of high-speed photography show that the motion morphology of the bulging surface has a similar change rule to the kinematic velocity of the bulging free surface center.The motion morphology of bulging surface is approximately expressed as curve outwards in the middle with the protrusion around decreasing gradually;the bulging height of bulging movement is in direct proportion to explosive payload and is in inversely proportion to the minimum resistance line;the kinematic velocity of the bulging free surface center is characterized by "acceleration--uniform velocity—acceleration again--deceleration".The stress field around the cartridge was measured by using the super dynamic strain system and the propagation law of strain field is obtained through collecting strain waveform in different locations.Super dynamic strain test results show that the pressure wave firstly generates near the explosion source,the strain at each test point changes greatly with large negative strain added to radial strain,the maximum negative strain increases with the increase of explosive payload of cannon,the maximum negative strain decreases with the increase of the distance between the model boundary and explosion center and the actual stress waveform is closer to the theoretical propagation law of stress wave with the increase of the diameter of model with same draw ratio.