ABSTRACT
Objective To observe the effect of different explosion impulse on rabbit lung injury and decide the death curve,so as to provide a reference for the prediction of lung injury.Methods Six healthy male New Zealand white rabbits with weight of 2.0-2.5 kg and age of (6 ± 1)months were selected.The rabbits were put 0.5 m,0.6 m,0.7 m,0.9 m,1.0 m,and 1.2 m away from 90 g TNT to carry out the blast injury experiment.The characteristic parameters of blast shock wave and general lung injury were recorded.Based on the experimental results combined with theoretical analysis,the changes of rabbit lung injury depending on the explosion distance as well as the rabbit death curve were determined.Results After the 90 g TNT explosion,the peak overpressure of shock wave and the corresponding specific impulse decreased quickly with the increase of explosion distance.The peak overpressure was 0.79 MPa and the specific impulse was 82 Pa · s at the explosion distance of 0.5 m.The peak overpressure was 0.1 MPa and the specific impulse was 34 Pa · s at the explosion distance of 1.2 m.The rabbits at 0.5 m and 0.6 m died,the rabbit at 0.7 m was severely injured,and the rabbits at 0.9 m,1.0 m,and 1.2 m were slightly injured.The dependence of lung injury degree on the explosion distance under 90 g TNT explosion was established based on dimensional analysis theory.The lung injury degree was exponentially attenuated with the explosion distance:φ =(R/0.6)-5.64(φ represented lung injury degree,and R represented the explosion distance).Considering the combined injury effects of peak overpressure of shock wave and its specific impulse on rabbit lung,the death curve of rabbit was determined:(p-0.1) (I-59) =2.6 (p represented peak overpressure,and I represented specific impulse).The criterion of "overpressure-specific impulse" was used to estimate the death of rabbit,and the death curve of rabbit was determined as (p-0.1)(I-59) =2.6(p represented peak overpressure and I represented specific impulse).The critical overpressure was 0.1 MPa and the critical specific impulse was 59 Pa · s.Conclusions Under the explosion condition of 90 g TNT,the relationship between degree of lung injury in rabbits and explosion distance is established.Death curve of rabbits is determined based on the damage effect of shock wave peak overpressure and specific impulse on the lungs of rabbits,which is significant for predicting the blast injury.