Nonlinear dynamic response of elliptical cylindrical shell underHarmonic excitation

The nonlinear dynamic response of elliptical cylindrical shell under transverse harmonic excitation is experimentally investigated. The elliptical cylindrical shell depicts softening nonlinearity for the excitation range considered. The circumferential variation of acceleration at different time instants of a cycle depicts standing, travelling waves over part of the circumference and travelling waves along the full circumference with/without variable amplitude depending upon the forcing frequency. For symmetric excitation, the travelling wave response is observed for the forcing frequency ωF=81, 85-89, 97.5-99.6, 112, 123.2, 149-155, 178-200 Hz. The participation of different modes involving 1:1, 1:2, 1:3 external, 1:1, 1:2, 2:3 internal resonances and the presence of harmonics including multiples of 1/2, 1/3 are reported.