For thin shells, y can be approximated by unity, and Eq. (2a) adopts the identity of Eq. (1). Figure 1 shows the shell response history computed from Eq. (2) for three different loading rates for the unstable mode (m = 1, n = 30, Ref. 1). Comparison of these curves shows that, with fixed shell geometry, material, and load magnitude, the higher rate initiates a larger oscillation earlier. In otherwords, it causes the shell instability to occur sooner. The governing equations for Fig. 1. are given in the Appendix.