This paper describes the experimental setup of combustion chamber, and the shock loads resultant of gases mixture detonation. The results of experiments performed with fully clamped circular steel plates subjected to detonation of acetylene (C₂H₂)–oxygen (O₂) in various volume ratio and different initial pressure. The energy of deformation of plates is determined by measuring pressure of explosion chamber after detonation and the results presented in terms of central deflection of the plates. Also, in this paper, theoretical modelling is presented to predict the midpoint deflection versus impulsive loading by assuming a zero Bessel function shape of the deformed circular plate. This approach is developed based on energy method for plastic material behaviour, and since the shock wave energy is equal to the deformation energy. The strain energy of the plate can be calculated by using the initial shock load energy imparted to the circular plate. The results of this model have good agreement with the experimental values. Moreover, it has been shown that the obtained model has much less error compared with those previously proposed in the literature.