The Mangnin Test Method Research Of Near-field Underwater Explosion Overpressure

Underwater explosio n experiment is ofen used in the evaluation about thepower of explosive and underwater weapon, and the protection of warships.Andpressure is an important measured parameter of underwater exp los ionexperime nt.Moreover the pressure measureme nt in near fie ld is more difficult tha nother measurement.This paper analyzes the advantages and disadvanta ges of curr ent underwaterexplos ion shock wave pressure measure ment method s in detail, and in viewmeasuring range shortco mings o f the p ie zoelectric method and s ma ll res istancema nga nese copper and temperature coeffic ient shortcomings of PVDF method.Anidea of measur ing method and measuring syste m that based on a large resistancema nga nin pressure sensor whic h used in underwater explos ion shock wave pressuremeasure me nt is put forword. This method using50ohm ma nga nin pressureresistance sensor and Wheatstone bridge, comb ining with the vo ltage a mp lificationcircuit, it so lves many proble ms about sensors whic h ha ve short rang, high cost,sma ll res istance and easy to dama ge. This meas uring method is s uitable formeasuring a few hundred MPa to1GPa underwater explosio n shock wave pressure,and combining with the improve me nt of measure ment syste m, it gets stronganti-interfere nce ability, low te mperature coeffic ie nt, the advantages of s imp lestructure and low cost of experiment.And it has the very high developme ntpotential.Further, this syste m is used to measure the underwater near-fie ld shock wavepressure distributio n of50g cylindrical TNT charges, and the results are comparedwith AUTODYN simulatio n calculation results. And find that the experime nta lmeasure me nt results are in good agreement with the simulatio n results, and itva lidates the reliab ility of the measure ment syste m and the accuracy of simulatio nresults. And the wave peak distribution and attenuation features are as follows: 1、 In the direction that relatived to blasting face, as its column a xis Angleincreases, the initia l peak pressure of sho ck wave is reduced ceaselessly. In otherwords, along the axis directio n, the maximum o f the initia l s hock wave peakpressure, initia l shock wave peak pressure along the radia l directio n of theminimum; Outs ide the150mm range fro m the detonatio n point, the radial d irectionof the s hock wave peak pressure of shock wave peak pressure slightly larger tha nthe axial direction.2、 As medic ine column axis Angle increases, the attenuation speed graduallyslow down. In other words: the fastest attenuation is along the axis of the column,and the slowest attenuatio n is a long the column o f the radia l. Outside the150mmrange fro m the detonation po int, peak pressure attenuation speeds are basicallyidentical in all directions.3、 Except that the veloc ity o f shock wave affected by the grain shape near thecylindrica l TNT charges, in the d istance that further than the largest size ofcylindrical TNT charges, the velocity of shock wave is basically no difference.