| Phenolic cotton fabric material is a kind of fiber reinforced composite materials with impact resistance,abrasion resistance,shock absorption,anti damage performance and moderate density,more and more application in the production of missiles,rockets,artillery and other parts.For the prediction of the phenolic laminated composite structures subjected to blast and impact caused by the dynamic response and internal injury,and launch evaluation of its protective properties,this paper on the impact behavior,explosion shock wave propagation characteristics in the,and its application in the detonator mould were studied.In the first,the strain rate 10-3s-1-103s-1 quasi-static compression test and separate Hopkinson pressure bar?SHPB?experiments were carried out on the phenolic laminated composites,and the corresponding stress-strain curves were obtained.Among them,in SHPB experiment,the pulse shaping technique will be rectangular incident pulse shaping is approximated as a power function of the incident pulse,elongated incident pulse rising edge,add the trapezoidal wave rise time and reduce the dispersion effect caused by high frequency oscillation;analysis in SHPB impact test piece early stress balance of external factors,gives the improved early stress uniformity,more accurately the stress-strain curve are obtained.The results show that the peak value of phenolic laminated composite stress and failure strain strain rate has a strong effect,and quasi static(1.67×10-3s-1)when compared to the dynamic load(7×102 s-1),the material of the peak stress and failure strain have obvious changes,the peak stress increased approximately 10 times,the failure strain is reduced by about half;the material with the loading rate increased,the yield stress increases with the strain rate hardening effect;yield strain decreases with the increase of strain rate,resulting in high speed impact toughness conversion material;dynamic strain rate sensitivity of load conditions is higher than that of quasi-static,obviously correlation of different strain rate,there are two main relaxation time,prove that the material is a kind of nonlinear viscoelastic material.Analysis revealed that the material under quasi static load,with obvious measured along a radial layered failure characteristics;under the dynamic load,with obvious splitting characteristics,characteristics of the material itself cause different failure modes.Introduction has two main relaxation time Zhu Wang Tang?ZWT?nonlinear viscoelastic constitutive relation established phenolic laminated composite nonlinear dynamic constitutive response,without considering the thermal damage and softening under the influence the mechanical properties of materials,utilization of lower strain rate experimental data and two groups obtained from SHPB experiment of high strain rate experimental data fitting constitutive equation of seven parameters.By comparing the experimental results and the constitutive relation curve fitting results.It is found that the fitting data with the experimental curves are in good agreement,indicating that the proposed constitutive model can better in over a wide range of strain rates in the description of the mechanical behavior of phenolic laminated composite.Then,the pressure and velocity of RDX passivation were calculated by formula ?-?,by mapping RDX explosive powder column and phenolic laminated composite separator at the interface of the initial wave parameters are obtained.According to the impact of dense medium wave attenuation,calculated by the passivation of RDX explosion attenuation rule of shock wave in the material in the partition by empirical formula.Using AUTODYN software,the establishment of phenolic laminated composite constitutive model of RDX explosive shock wave in the attenuation of the numerical simulation,clearly observed the propagation path of explosion shock wave,you can see due to the rarefaction wave and clapboard viscous damping effect,shock wave strength with increase of diaphragm thickness gradually decreased.The manganin pressure resistance sensor experiment measured the passivated RDX propellant explosion shock wave peak pressure at the different thickness of phenolic laminated composite plates,and on this basis,calculated in different thickness plate material of shock wave velocity and wave particle velocity and density,and fitting out of shock wave pressure and velocity,wave particle velocity and density in the separator material attenuation law.By comparison with the empirical formula and numerical simulation results,indicating that the manganin pressure resistance sensor can accurately measuring explosion shock wave propagating in a laminated phenolic composite separators,in different thickness of the peak pressure.Finally,the piezoelectric quartz sensor experiment to measure the different number of detonator in phenolic laminated composite mold explosion peak pressure of shock wave,and carton packaging 100 detonator explosion shock wave peak pressure fitted pressure in the air attenuation law.According to the air shock wave overpressure on the exposure of the injuries,there are 50 detonators industrial detonator production line conveying process of mold,to avoid "medium","serious" and "very serious injury when the safety distance.Through the quantitative analysis shows that the mold on the shock wave of detonator explosion has better absorption effect,however,explosion of detonator in the mold,mold itself to form a fragment easily lead to secondary damage.In setting the safety distance should be considered.Using lifting method obtained different kinds of boxed 100 detonator sympathetic detonation safety distance,and analyze the reasons for the different distance,also proposed for production line of the whole box of detonators explosion problem,not only to focus on detonator explosion shock wave,at the same time of detonator explosion of thermal explosion in a gas. |
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