This research discusses the exponential function of the explosion load and the pressure decay factor in this function (a). After that, four functions with four different values of the pressure decay factor are studied, and that is for the un-damped S
DOF system, where the equation of motion is formed and solved. Then, using MATLAB software for every function, the relationship between (Yst/Y(t)) and t/T is plotted, and that enables plotting the response spectrum for each one. Moreover, a comparison between the spectra of the last three functions with the first one that describes the triangular explosion load is drawn. This research has concluded that for a certain range of (a), it is possible, and with acceptable approximation, to use the spectra of triangular load, but beyond that it is better to use the spectra of exponential load.
