Uncertainties and regularities coexist in the projection and flight process of explosion fragments.The transient explosion of chemical vessels was viewed as polytropic process.Initial projection velocity of fragments was deduced by combining the polytropic process state equations and the work done by explosive gases pressure.Flight distance and flight velocity equations were obtained by solving acceleration equations and determining boundary conditions.Taking these equations as the objective functions

the uncertainty factors were analyzed and viewed as random variables.Impact probability in different distances could be obtained by random sampling of such random variables and accumulating the frequency in a specific flight distance.Then domino effect impact probability model was proposed by studying the secondary influence and multiple influences caused by fragments.The study reveals the mechanism of fragments generation

projection

flight and impact on target.The results lay a foundation for analysis of domino impact risk caused by explosive fragments in chemical industrial complex.