T HE response and instability of various types of shell structures are problems that continue to pose formidable difficulties to the analyst and remain of current research interest. Recently, a numerical analytical approach has been developed by Budiansky and Roth1 for the particular case of a shallow spherical cap deforming symmetrically under an arbitrary time-dependent pressure. The nonlinear response of the shell is computed as a function of time for a series of pressure pulse sizes, showing a rather sharp jump in response amplitude at a particular pulse size. This is identified as dynamic buckling. The purpose of the shock-tube experiments reported herein has been to test this analytical method in a situation where the pressure environment is well controlled and reasonably uniform. A detailed pressure calibration is first made using rigid models to determine the pressure pulse shape, which can then be used in the numerical program to obtain a response prediction. This prediction, and in particular the load level at which dynamic buckling occurs, can thus be compared directly to various methods of response measurement in the actual blast tests of flexible models. This comparison provides greater insight into the applicability and limitations of an analysis of this type (which neglects any imperfections of the shell or nonsymmetry of loading or response) in more complex situations and, therefore, more interesting situations that involve this general kind of loading environment.