Abstarct: The internal shock or detonation loading of cylindrical shells involves loads that propagate at high speeds. An internal detonation produces a pressure load that propagates down the tube. Because the speed of the gaseous detonation can be comparable to the flexural wave group speed, excitation of flexural waves in the tube wall must be considered. Flexural waves can result in much higher strains and stresses than static loading with the same loading pressures. Strains were measured in experiment, exceed the equivalent static strain by a factor up to 4. Several analytical models are available to calculate the structural response of shells to this type of loading. These models show that the speed of the load is an important parameter. In fact, for a linear model of a shell of infinite length, the amplitude of the radial deflection becomes unbounded when the speed of the shock or detonation is equal to a critical velocity. The critical velocity is a function of material and geometrical properties of the tube. It is evident that simple (static) design formulas are no longer accurate in this case. The present work deals with numerical models, adopted to obtain the structural response of cylindrical shells with variable geometry to detonation loading. First, we compare numerical models with analytical and experimental Models. Finally, we illustrated the effect of velocity, thickness and length parameters at the baxse of numerical models in some parametric charts.