Abstract :
Simplified procedures for the analyses of random thermal acoustic responses of aircraft structures are derived using equivalent lineanization and the Fokker–Plank equation. Experimental results are obtained for an aluminum plate with combined radiant heating and base excitation. Base excitation can provide a flat frequency spectrum of uniform pressure excitation whereas loudspeaker devices will give standing wave and coupling effects. The nonlinear dynamic behaviour of the acoustic response of thermally buckled plates from the theoretical results agreed with those from the experimental results. The most important dynamic behaviour is the presence of low frequency dynamic snap-through motion which changed the static equilibrium state of the buckled plate. Also the nonlinear dynamic behaviour changed from the hardening spring type to the softening spring type due to the snap through motion. It is found that the Fokker–Planck equation gives an accurate prediction of the intermittent snapthrough response where as the equivalent linearization give a good prediction for continuous snap-through response.
