Within The Typical Obturator Explosion Experiment And Numerical Simulation

To study the propagation law of shockwave and distribution law of blasting loading due to internal explosion, internal explosion experiment and numerical simulation using Ansys/ls-dyna in the reinforced concrete are carried out in this issue.Main contents and conclusions of this paper are as follows:(1) The domestic and foreign research is listed to indicate the study of internal explosion is necessary for theory and practice.(2) Theory of explosion is introduced. And time-histories of overpressure on testing points are gained in the internal explosion experiment. The overpressure histories have many peaks, and overpressure value of first impulse is not the greatest. The periodically macro fluctuation of overpressure histories are evidently at the corner and across of two walls in the structure. Overpressure waveform and specific impulse are different near the corner.(3) Uncertainty evaluation of small sample measurement using Grey System Theory is summaried in this section. Experimental datas are analysed using this theory. The reliability of the results is higher in this experiment.(4) Simulation is carried out to dynamically simulate propagation, reflection, interaction and trap of shockwave in the concrete. And based on the datas obtained in the experiment, overpressure histories and specific impulse under different charge are analysed using Ls-dyna, corresponding mathematical equations overpressure value and impulse about scale distance are also established. And explosion in closed models with different scales are simulated to analyse effect of scales on propagation law of shockwave, distribution law of shockwave and distribution law of blasting load on the wall. Corresponding mathematical models are also established. For model300-80-80, overpressure values of first impulse of histories are not attenuated as the increase of scale distance, and the datas are irregular. For other models, overpressure values of first impulse of histories are attenuated in terms of Power Function, and its attenuation exponent is about2, which means that first impulse of Shockwave is little affected by the closed structure along its direction of length. Multiple peak values are also appeared on time-histories at different scale distance when the explosion happened in closed models with different scales. Moreover, the multiple peak values appear earlier for smaller model when the ratio of length and width is the same as biger model. Thus, the following impulse of shockwave in the closed is very important on the damage effent.