Interior Propagation Of Blast Wave And Overpressure Model For Common Structures

Ever since 9.11 event, the societystability and the economydevelopment of somecountries have been severely affected by a series of terror attack events. In order tostudy the dynamic response of a structure with inner explosion, the distribution ofblast load should be firstly determined. Therefore, for the blast resistance research instructural design and construction, the investigation of overpressure load modelproduced by the explosion inside of structure is of great importance and practicalvalue.According to the complex situation when explosion happens inside of structure,the study on the interior propagation rule of blast wave and the resulting overpressureload on structure are very challenging. This dissertation addresses the veryissue basedon the theory of hydrodynamics and explosion mechanics. The numerical simulationanalysis is accomplished using the AUTODYN software and the Euler method is alsoemployed. The primary works includes three sections:(1) Two identical models are constructed. One is defined as totally enclosed,while, the other is added with a consideration of the cavity effect on blast wavepropagation. Based on the numerical analysis of these two models, the blast wavepropagation and overpressure load distribution are contrastively analyzed. The cavityeffect on blast wave propagation is also expounded.(2) Anumerical simulation model of common structure is built up. By simulatingand analyzing various scenarios that explosion occurs within the structure, a databaseof the resulting overpressure load and transient impulsive moment is obtained.(3) Based on the date in the database obtained from numerical simulation, ageneral comparative analysis is accomplished. Finally, a set of load models is built upfor people to use in structure design and substantive load distribution rules are alsoconcluded.Accordingly, the following conclusions can be achieved. For the enclosedstructure, the inside blast wave will be enhanced due to the reflection of surroundingwalls. Byconducting the two types of analysis that considering and not consideringthe cavityeffect when explosion occurs within the structure, it is found that, a bigdifference between the maximum overpressure load values will be generated from the cavity effect at the opening location. However, for the locations where the blast wavecan straightlyreach without anyreflection or refraction, the cavityeffect on themaximum overpressure load value is verysmall.Around the jointing area of walls, themaximum overpressure load value is about two times of those of other locations,while the transient impulsive moment is about 30% higher than those of otherlocations. In addition, the scaled distance and scaled radius etc. also have importantinfluence on the overpressure load generated bythe blast wave.