Study On Dynamic Mechanical Response And Explosion Harmful Effects Control Of Explosive Vessel

Explosive vessel is a type of special internal high-pressure antiknock container,which can effectively restrain explosion shock wave and limit the action range of detonation products and fragments,and provide safer protection for personnel and the surrounding experimental instruments.Therefore,it is widely used in the fields of scientific research,industry and national defense,such as explosive material performance test,explosion effect test,explosive processing and explosion destruction.Explosive vessel is subjected to large impact load and the reflection superposition of the shock wave.Thus,its dynamic response study has important significance for safety analysis.In this paper,we focus on the 1 kg TNT equivalent ellipsoidal head cylindrical explosive vessel in the Anhui University of Science and Technology to spread relevant researches,which mainly include calculation and verification of explosive vessel design parameters,internal explosion shock wave overpressure measurement,ground vibration effect measurement and cylinder vibration effect measurement.The specific research work and related conclusions are as follows:(1)For the explosive container,the design parameters calculation and verification were carried out.The reflected wave overpressure was calculated by incident wave overpressure,and dynamic load was converted to equivalent static load by dynamic coefficient method.Then,wall thickness,maximum allowable working pressure and stress checking were carried out by strength checking theory.Considering the fatigue damage and corrosion margin during the long-term use of the explosive container,and the calculation results show that:The calculated wall thickness values of the elliptical head and cylinder were far less than the design wall thickness values.Meanwhile,the maximum allowable working pressure was far greater than the transformation static load pressure of 1 kg TNT equivalent explosive explosion.Therefore,the explosion vessel design safety is high.(2)The pressure time history curves of explosion shock wave at different points were collected through the shock wave overpressure test system,the shock wave propagation law was analyzed.Then,the shock wave overpressure peak values were calculated by W.E.Baker and K-G formulas.The results of experimental measurement and theoretical calculation show that:The error between the K-G formula calculated values and the experimental test values was very large,and the error range was 70%?80%,while the calculation error of the W.E.Baker formula was 75%?85%.According to the explosion similarity principle,the overpressure calculation formula suitable for the explosion environment was obtained,that is (?).The calculation error is reduced to 0.5%?15%by this formula.(3)The ground vibration effect caused by the air and ground explosion in the explosive vessel was tested.Firstly,the influences of charge and measurement point distance on the ground vibration effect were analyzed.Then,the frequency distribution of ground vibration was obtained by HHT method.The study results show that:The vibration speed was closely related to the charge and measurement point distance.The relationship between the three variables was obtained by least square fitting,that is,(?).The explosive charge increase has a great influence on the low-order frequency distribution of ground explosion in explosion vessel.That is,the vibration amplitude and time of the 5?10 Hz lower-order frequency band will increase gradually with the charge increase.Furthermore,with the increase of measuring point distance,the energy amplitude and vibration time of the low-frequency band will decrease.(4)Acceleration sensors were adopted to collect the vibration acceleration signals of explosion vessel cylinder.Then,effective time-velocity curve can be obtained by eliminating the integral trend terms.Thereafter,the HHT method was applied to analyze the vibration signal time-frequency distribution;the influence of vibration effect on the explosive vessel safety was analyzed combining the natural vibration frequency of explosion vessel cylinder.Analysis results show that:the special "steel plate-buffer interlayer-steel plate" structure has a certain safer protection effect,which can effectively attenuate explosion shock wave energy.The frequency distribution range of vibration signal at the outer surface was more centralized than inner surface,which was mainly distributed in the 0?200 Hz lower-frequency band.Furthermore,the vibration action time and frequency of the lower-order frequency band were obviously shortened,and the frequency distribution was far away from the natural vibration frequency of the explosion vessel.