Research Of Frames Collapse Under Blast Load Using Plastic Limit Theory

In industrial production, building collaps caused by blast hurt the people's life and property.Nowadays, the whole world is relatively stable, but local conflicts and terror affairs happens unceasingly, blasts in industrial production also happens occasionally. Thus, many constructions are under the function of blast load. Quite different from other dynamic loads, blast wave shares the characteristics of high initial value, fast decline and short duration. It is thus of great application value to research on the structure collapse under blast wave.From literature review, we found that the calculation method of putting plastic limit theory into architecture constructions blast-resistance is not mature. According to the feature of blast load, this paper puts forward a method of blast-resistance with the basic theory of plastic limit theory. The method aims to search for plastic limit theory, the stress (internal force) distribution and damage construction. Without concentrating on the stress and strain of cross-section calculation, this method is not only easy to calculate, also practical and reliable to use.This paper includes the following subjects:First, it is necessary to get overpressure (â–³P_m) of blast by explosion theory.Second, equivalent load (P_m) of overpressure (â–³P_m) is calculated, and then the dynamic load P_m spreads to frame structure. Analyze the frame by dynamic theory and get the equivalent dead load (P) of dynamic load (P_m).Third, analyze the frame which is under dead load (P) by plastic limit theory, get limit load of plastic and the stress (or internal force) and destroy mechanism.Fourth, the method of this paper is programmed by Fortran90 language. Make some simulated exam and analyze the result between the program of this paper and SAP2000.